WorldWideScience

Sample records for anticlines

  1. Anticlines in the US Gulf Coast [anticlineg

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This dataset of anticlines is intended primarily for reference; it includes major structures such as those shown on Plate 2, Principal structural features, Gulf of...

  2. Chloroplasts move towards the nearest anticlinal walls under dark condition.

    Science.gov (United States)

    Tsuboi, Hidenori; Wada, Masamitsu

    2012-03-01

    Chloroplasts change their intracellular positions in response to their light environment. Under darkness, chloroplasts assume special positions that are different from those under light conditions. Here, we analyzed chloroplast dark positioning using Adiantum capillus-veneris gametophyte cells. When chloroplasts were transferred into darkness, during the first 1-5 h, they moved towards the anticlinal cell walls bordering the adjacent cells rather rapidly. Then, they slowed down and accumulated at the anticlinal walls gradually over the following 24-36 h. The chloroplast movements could be roughly classified into two different categories: initial rapid straight movement and later, slow staggering movement. When the chloroplast accumulation response was induced in dark-adapted cells by partial cell irradiation with a microbeam targeted to the center of the cells, chloroplasts moved towards the beam spot from the anticlinal walls. However, when the microbeam was switched off, they moved to the nearest anticlinal walls and not to their original positions if they were not the closest, indicating that they know the direction of the nearest anticlinal wall and do not have particular areas that they migrate to during dark positioning.

  3. 75 FR 47626 - Notice of Reestablishment of the Pinedale Anticline Working Group, Wyoming

    Science.gov (United States)

    2010-08-06

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF THE INTERIOR Bureau of Land Management Notice of Reestablishment of the Pinedale Anticline Working Group, Wyoming... Management's (BLM) Pinedale Anticline Working Group (PAWG). FOR FURTHER INFORMATION CONTACT: Allison...

  4. 75 FR 53980 - Notice of Field Tours for the Pinedale Anticline Working Group

    Science.gov (United States)

    2010-09-02

    ... Bureau of Land Management Notice of Field Tours for the Pinedale Anticline Working Group AGENCY: Bureau... Pinedale Anticline Working Group (PAWG) charter, the U.S. Department of the Interior, the Bureau of Land... Advisory Committee Act group which develops recommendations and provides advice to the BLM on...

  5. 76 FR 65209 - Notice of Meetings of the Pinedale Anticline Working Group, Wyoming

    Science.gov (United States)

    2011-10-20

    ... Bureau of Land Management Notice of Meetings of the Pinedale Anticline Working Group, Wyoming AGENCY... Interior, Bureau of Land Management (BLM) Pinedale Anticline Working Group (PAWG) will hold a series of... Advisory Committee Act (FACA) chartered group which develops recommendations and provides advice to the...

  6. 75 FR 38538 - Notice of Intent To Solicit Nominations: Pinedale Anticline Working Group, Wyoming

    Science.gov (United States)

    2010-07-02

    ... Bureau of Land Management Notice of Intent To Solicit Nominations: Pinedale Anticline Working Group...: Nominations are being solicited for two positions on the Pinedale Anticline Working Group (PAWG) that will become open on May 28, 2010. DATES: Individuals or groups wishing to submit a nomination must send...

  7. 75 FR 66789 - Notice of Intent To Solicit Nominations: Pinedale Anticline Working Group, Wyoming

    Science.gov (United States)

    2010-10-29

    ... Bureau of Land Management Notice of Intent To Solicit Nominations: Pinedale Anticline Working Group...: Nominations are being solicited for nine positions on the Pinedale Anticline Working Group (PAWG). DATES: Individuals or groups wishing to submit a nomination must send the required information postmarked within...

  8. 76 FR 22723 - Notice of Meetings of the Pinedale Anticline Working Group, Wyoming

    Science.gov (United States)

    2011-04-22

    ... Bureau of Land Management Notice of Meetings of the Pinedale Anticline Working Group, Wyoming AGENCY... of the Interior, Bureau of Land Management (BLM) announces that the Pinedale Anticline Working Group... September 12, 2008. The PAWG is a FACA-chartered group which develops recommendations and provides advice...

  9. 75 FR 21035 - Notice of Rescheduled Meetings of the Pinedale Anticline Working Group, Wyoming

    Science.gov (United States)

    2010-04-22

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF THE INTERIOR Bureau of Land Management Notice of Rescheduled Meetings of the Pinedale Anticline Working Group, Wyoming...), the U.S. Department of the Interior, Bureau of Land Management (BLM) Pinedale Anticline Working...

  10. 77 FR 58863 - Notice of Meeting of the Pinedale Anticline Working Group

    Science.gov (United States)

    2012-09-24

    ... Bureau of Land Management Notice of Meeting of the Pinedale Anticline Working Group AGENCY: Bureau of... Interior, Bureau of Land Management (BLM) Pinedale Anticline Working Group (PAWG) will meet in Pinedale... INFORMATION: The PAWG is a Federal Advisory Committee Act (1972) chartered group established in...

  11. 75 FR 53980 - Notice of Rescheduled Meetings of the Pinedale Anticline Working Group

    Science.gov (United States)

    2010-09-02

    ... Bureau of Land Management Notice of Rescheduled Meetings of the Pinedale Anticline Working Group AGENCY.... Department of the Interior, Bureau of Land Management (BLM) Pinedale Anticline Working Group (PAWG) will... Committee Act (FACA) group which develops recommendations and provides advice to the BLM on...

  12. Late Quaternary deformation, Saddle Mountains anticline, south-central Washington

    Science.gov (United States)

    West, M. W.; Ashland, F. X.; Busacca, A. J.; Berger, G. W.; Shaffer, M. E.

    1996-12-01

    Grabens and beheaded streams above a subjacent thrust fault illuminate late Quaternary deformation on the north limb of the Saddle Mountains anticline, Yakima fold belt, Washington. Geologic mapping and trenches excavated across a scarp on the north flank of a 13-km-long graben and a ± 5-m-high scarp north of the graben, confirm that deformation is related to coseismic slip on the underlying Saddle Mountains fault. Graben development began ca. 100 ka and continued into the Holocene. At least 6.5 m of vertical displacement in a ca. 20 40 ka paleosol yields minimum normal fault slip rates of 0.16 0.33 mm/yr. Assuming that normal slip in the hanging wall above the daylighting fault tip is related to primary reverse slip on the fault, resolution of throw on the 30°-dipping Saddle Mountains fault yields minimum slip of 13 m and minimum slip rates of 0.33 0.65 mm/yr, 2.3 9.4 times greater than slip rates used in a recent seismic hazard analysis for the Hanford Reservation.

  13. Anticlines and synclines of the Lower White River coal field (lwrclineg)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This shapefile includes anticlines and synclines of the Lower White River coal field. Nominal map scale is 500,000. The original digital source data for this...

  14. Deformation in thrust-ramp anticlines and duplexes: implications for geometry and porosity

    Energy Technology Data Exchange (ETDEWEB)

    Groshong, R.H. Jr.; Usdansky, S.I.

    1986-05-01

    A computerized kinematic model of thrust-ramp anticline geometry allows workers to predict the zones of greatest deformation in ramp anticlines and fault duplexes. The model assumes a constant cross-section area, symmetrical fold hinges, and slip in the hanging wall parallel to the ramp and forelimb. Assuming that the collapse of original porosity or the generation of secondary fracture porosity is proportional to deformation, the model can be used to predict porosity changes. Deformation in a single ramp anticline is greatest in the forelimb and backlimb, and may be absent in the crest. A duplex structure results from comparatively closely spaced thrusts that have a common upper detachment horizon. Relatively wide spacing between the duplex faults yields a bumpy roofed duplex as in the central Appalachians. Forelimbs may be deformed twice and should show greater porosity modification. Relatively close spacing between ramp-and-flat thrusts can produce a listric-fault, snakehead anticline geometry because younger faults deform the preexisting thrust slices. The resulting geometry is here called a snakehead duplex and appears to be fairly common, as in the Jumpingpound field in the Canadian Rockies. Each thrust slice within the duplex is deformed six times or more, providing the maximum opportunity for deformation-related porosity changes. Maximum fracture porosity should occur in thrusts having listric-fan or snakehead duplex geometry. Structures involving duplexes generally should be better than isolated ramp anticlines.

  15. 3D gravity imaging of deep geological structure of Huangling Anticline in Three Gorges area, China

    Science.gov (United States)

    Zhang, Y.; Chen, C.

    2010-12-01

    Three Gorges Dam is the largest hydraulic project in the world. Previous studies showed that Huangling Anticline is one of the main geological units in this area and has great influence on the safety of the dam, so it is important to investigate deep geological structure and evaluate stability of Huangling Anticline. Huangling Anticline locates in northern margin of Yangtze Block. It is surrounded by a few faults, and two of them are Xiannushan Fault and Yuan’an Fault, with NNW direction. There are also two main faults named Xinhua Fault and Yuyangguan-Tumen Fault with NNE and NE direction. These faults are regional faults with different sizes and cutting depth, and take charge of the development of geological structures in Three Gorges area with a long time. Two main arguments about the ability of inducing earthquakes of these faults were presented. One of the arguments suggested that these faults has weak or no enough activity to induce strong earthquakes, their key evidence is the thermoluminescence (TL) dating with some geological characteristics; the other was just opposite, in their opinion, Xiannushan Fault and Yuan’an Fault has deep cutting depth with great activity to induce strong earthquakes. However, they can not provide the evidences of deep geological structures and cutting depth of these faults. In our paper, 3D density structure of upper and middle crust beneath Three Gorges Dam and its adjacent regions is reconstructed by gravity imaging, using the Bouguer gravity anomaly and surface density constraints. Results of gravity imaging indicate that Huangling Anticline is a relatively high density zone. (1) Horizontally, Huangling Anticline is a huge U-shaped crystal rock controlled by Xiannushan Fault and Yuan’an Fault along NNW direction. In the southeast, Yuyangguan-Tumen Fault becomes the boundary of the anticline, and in the west, Xinhua Fault and Xiannushan Fault separate Huangling Anticline from Zigui basin; (2) From vertical profiles of

  16. 77 FR 41201 - Call for Nominations for the Pinedale Anticline Working Group, Wyoming

    Science.gov (United States)

    2012-07-12

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF THE INTERIOR Bureau of Land Management Call for Nominations for the Pinedale Anticline Working Group, Wyoming AGENCY: Bureau of Land Management, Interior. ACTION: Notice. SUMMARY: Nominations are being solicited for...

  17. 76 FR 65534 - Call for Nominations for the Pinedale Anticline Working Group, Wyoming

    Science.gov (United States)

    2011-10-21

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF THE INTERIOR Bureau of Land Management Call for Nominations for the Pinedale Anticline Working Group, Wyoming AGENCY: Bureau of Land Management, Interior. ACTION: Notice. SUMMARY: Nominations are being solicited for...

  18. 77 FR 2315 - Call for Nominations for the Pinedale Anticline Working Group, Wyoming

    Science.gov (United States)

    2012-01-17

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF THE INTERIOR Bureau of Land Management Call for Nominations for the Pinedale Anticline Working Group, Wyoming AGENCY: Bureau of Land Management, Interior. ACTION: Notice. SUMMARY: Nominations are being solicited for...

  19. Active fold-thrust belts in the foreland of eastern Tibet, the Longquan and Xiongpu anticlines in Sichuan, China

    Science.gov (United States)

    Lee, Jian-Cheng; Chan, Yu-Chang; Lu, Chia-Yu; Chen, Chih-Tung; Chu, Hao-Tsu; Liu, Yuiping; Li, Jianzhong

    2016-04-01

    The 2008 M7.9 Wenchuan earthquake ruptured from the Longmenshan fault system, which is the frontal thrust system in eastern Tibet. Further east toward the foreland area in the Sichuan basin, it sits two anticlinal structures, the Longquan and Xiongpu anticlines, which trends sub-parallel to the Longmenshan range with a distance of about 70-100 km to the mountain front. It is widely considered that these two anticlinal features are attributed to propagation of the eastward extrusion of the eastern Tibetan plateau, similar to the stress system the Wenchuan earthquake. In this study, we carried out field investigations on these two active anticlinal structures in order to characterize the bulk deformation of the anticlines. We also conducted fracture analysis and fault-slip data analysis, in an attempt to characterize the fracture developments of the rock and the paleostress states related to the faulting events associated growth of the anticlines. We thus constructed a series of geological cross sections along these two anticlines. Our results show that the Longquan anticline is characterized by pop up structure with a dominant west-vergent thrust (i.e., backthrust) on the western limb. On the other hand to the eastern limb, an east-vergent thrust only well developed in the middle part of the anticline and die out toward the north and the south. For the Xiongpu anticline, it is characterized by a pre-dominant west-vergent backthrust system without developing an east-vergent thrust. A strike-slip fault and a series of N-S-trending pop-up thrusts cut across the Xiongpu anticline indicate a rather complex stress system with two dominant compression directions, NW-SE and E-W, subsequently or alternatively affected the area. Finally, the fracture analysis revealed that 2-3 pre-dominant bedding-perpendicular fracture sets are commonly developed in the massive sandstone layers. Most of them seemingly are of the characteristics of the mode I open joint, without clear

  20. Subsurface temperature as a passkey for exploration of mature basins: Hot anticlines - A key to discovery?

    Science.gov (United States)

    Merriam, D.F.

    2004-01-01

    Temperature anomalies associated with oil-producing structures in the US Midcontinent and similar cratonic areas probably can be used reliably as a passkey for petroleum exploration in mature areas, and thus the concept of hot anticlines could be a key to discovery. Analysis of accumulated data during the past several decades allows a definition of the problem of hot anticlines. A possible solution for migration and entrapment of petroleum can be explained by the Roberts temperature differential model and the Walters fluid-flow paradigm. In fact, if the Roberts model is valid, higher shallow temperatures, temperature gradients, or heat flow could indicate the entrapment of hydrocarbons at depth. The recognition and promotion of shallow "hotspots" as an exploration key is not new and was proposed years ago by Haas and Hoffmann, Kappelmeyer, and as recently as 1986 by Blackwell.

  1. Restoring paleomagnetic data in complex superposed folding settings: The Boltaña anticline (Southern Pyrenees)

    Science.gov (United States)

    Mochales, T.; Pueyo, E. L.; Casas, A. M.; Barnolas, A.

    2016-03-01

    Complex kinematic scenarios in fold-and-thrust belts often produce superposed and non-coaxial folding. Interpretation of primary linear indicators must be based on a careful restoration to the undeformed stage following the reverse order of the deformation events. Therefore, sequential restoration to the ancient coordinate system is of key importance to obtain reliable kinematic interpretations using paleomagnetic data. In this paper, a new paleomagnetic study in the western flank of the Boltaña anticline (Southern Pyrenees) illustrates a case study of a complex tectonic setting having superposed, non-coaxial folds. The first stage of NW-SE folding linked to the oblique Boltaña anticline took place during Lutetian times. The second stage was linked to the vertical axis rotation and placed the Boltaña anticline in its present-day N-S configuration. Our data support a long-lasting Lutetian to Priabonian period with main rotational activity during the Bartonian-Priabonian; other authors support a VAR coeval with anticlinal growth. The third stage resulted in southwards tilting related to the emplacement of the N120E striking Guarga basement thrust (Oligocene-Early Miocene). Based on this deformational history, a sequential restoration was applied and compared with the classic bedding correction. At the site scale, single bedding correction gives errors ranging between 31° and - 31° in the estimation of vertical axis rotations. At the locality scale, in sites grouped in three folds (from W to E Arbella, Planillo and San Felizes), the bedding corrected data display rotation values in accordance with those found in the Ainsa Basin by other authors. Sequential restoration (based on the afore-mentioned evolution in three-steps) improves both some locality-means and the internal consistency of the data. Therefore, reasonably-constrained sequential restoration becomes essential to reconstruct the actual history of superposed folding areas.

  2. THE TECTONOPHYSICAL RESEARCHES OF THE SEMISAMSKAYA ANTICLINE (NORTH-WESTERN CAUCASUS FOLD AND THRUST BELT

    Directory of Open Access Journals (Sweden)

    A. V. Marinin

    2015-09-01

    Full Text Available Structural paragenetic and cataclastic analysis methods were applied to study tectonic fracturing within one of the folds of the southern wing of the North-Western Caucasus fold-and-thrust belt. The object of the study was the Semisamskaya anticline (Fig. 1 and 2 comprising the Upper Cretaceous and Paleogenic layered terrigenic-carbonate sediments that contain various well-developed geological indicators of palaeostresses (Fig. 3, 5, 7, and 9.In the folded structure under study, a paragenesis is revealed which is associated with the effect of sub-horizontal minimum compression (deviator extension stresses of the north-western orientation (NW 320° and traced by detached normal fault systems striking in the north-eastern direction (Fig. 6, 8, 10, 11, and 17. Upthrust-overthrust systems of the north-western strike (NW–SE, which are of importance for the whole folded structure of the North-Western Caucasus, are mainly manifested in the wings of the Semisamskaya anticline (Fig. 6, 12, and 13.The overall field of stresses related to formation of the folded structure is significantly variable as evidenced by the pattern of local parameters of the paleostress field, which are calculated by the cataclastic analysis method (Figure 15, 16, and 17.It is established that the geodynamic regime within the anticline is considerably variable by types (Fig. 18. Areas with horizontal extension in the axial part of the fold are replaced by areas of horizontal compression at its wings (Fig. 19.  

  3. A Fault-Cored Anticline Boundary Element Model Incorporating the Combined Fault Slip and Buckling Mechanisms

    Directory of Open Access Journals (Sweden)

    Wen-Jeng Huang

    2016-02-01

    Full Text Available We develop a folding boundary element model in a medium containing a fault and elastic layers to show that anticlines growing over slipping reverse faults can be significantly amplified by mechanical layering buckling under horizontal shortening. Previous studies suggested that folds over blind reverse faults grow primarily during deformation increments associated with slips on the fault during and immediately after earthquakes. Under this assumption, the potential for earthquakes on blind faults can be determined directly from fold geometry because the amount of slip on the fault can be estimated directly from the fold geometry using the solution for a dislocation in an elastic half-space. Studies that assume folds grown solely by slip on a fault may therefore significantly overestimate fault slip. Our boundary element technique demonstrates that the fold amplitude produced in a medium containing a fault and elastic layers with free slip and subjected to layer-parallel shortening can grow to more than twice the fold amplitude produced in homogeneous media without mechanical layering under the same amount of shortening. In addition, the fold wavelengths produced by the combined fault slip and buckling mechanisms may be narrower than folds produced by fault slip in an elastic half space by a factor of two. We also show that subsurface fold geometry of the Kettleman Hills Anticline in Central California inferred from seismic reflection image is consistent with a model that incorporates layer buckling over a dipping, blind reverse fault and the coseismic uplift pattern produced during a 1985 earthquake centered over the anticline forelimb is predicted by the model.

  4. Northern Wabash Valley Seismic Zone and the La Salle anticline seismicity determined by a short period phased array

    Science.gov (United States)

    Brazitis, Daniel

    The Wabash Valley Seismic Zone (WVSZ) has produced three moderate sized earthquakes greater than or equal to mb 5.0 in the past 50 years. The majority of Wabash Valley faults originate near the junction of the Rough Creek and Cottage Grove faults and extend northeastward along the Wabash River. These faults extend through the Paleozoic and into the Precambrian and are believe to be associated with the Reelfoot Rift. Two of these moderate sized earthquakes have occurred north of the terminus of the Wabash Valley faults that the WVSZ is commonly associated with. This suggests that other sources of seismicity exist. The La Salle anticline, a Precambrian basement feature, is oriented NW to SE just north of the termination of these faults. The La Salle anticline creates up to a 750 meter uplift in the above Paleozoic strata. This uplift creates faults within the Paleozoic strata and within the La Salle anticline. This study uses seismometers arranged in a phased array near the southern terminus of the La Salle anticline to analyze the seismicity of the region. Analyzing the seismicity of the region over a 6-month period found 834 events. The vast majority were determined to be mine blasts or otherwise human induced. Two small earthquakes ( M 1.0) located near the La Salle anticline. These earthquakes likely occur on faults associated with the anticline. The lack of earthquakes suggested the b-value of the La Salle region could be as low as 0.56. This is lower than the typical value of 1, but consistent with other intraplate regions and previous studies of the WVSZ finding values nearer 0.7.

  5. Transverse Zones in the Eastern Cordillera (Colombia): An example in the Zipaquira Anticline

    Science.gov (United States)

    Garcia Delgado, H. S.; Jimenez, G.

    2014-12-01

    Lateral connectors are expressed in map view by along-strike terminations of thrust faults and ramp anticlines; by curves and offsets in strike; and by along-strike changes in angle and direction of plunge, dip of fold limbs, direction of vergence, stratigraphic level of detachment, and structural style. Such lateral connectors could be formed from reactivated transform faults, transverse faults or lateral ramps. The Zipaquira Anticline (ZA) is a salt-cored structure, with a NE-SW axial axis direction, a clear defined map-view curvature. The Neusa Transverse Zone (NTZ) controls the kinematicof faults and folds. The Zipaquirá Transverse Zone (ZTZ) is located to the southern of the ZA. This transverse zone is a key feature in the area, controlling the ZA and allowing the ascend of diapirs and salt sheets to shallow deeps. Our study was focused on Cretaceous marine sediments and Cenozoic transitional to continental sedimentary sequence around the ZA. 224 oriented cores were collected using a gas portable drill. At each site we collected 10 cores, spaced in order to try to average out secular variation. All samples were oriented using a magnetic compass, corrected to account for the local magnetic field declination. Cores were cut into standard cylindrical specimens and magnetic fabric, rock magnetic and paleomagnetic measurements were done in the shielded room of the paleomagnetic laboratory of in the IAG in the Sao Paulo University. We measured the low-field (AMS) in a Kappabridge (MFK1-FA, AGICO). All samples were thermally demagnetized up to 680°C by a shielded oven, and the natural remanent magnetization (NRM) of the specimens was measured. Magnetic mineralogy analyses were carried out to identify and characterize the main magnetic carriers. The ZA is an important example of natural connection between multiple factors controlling deformation and geological evolution. Interaction between salt, transverse zones and folding, the ZA could be considered as a scale

  6. Active faulting in Raghunandan Anticline, NE Bengal Basin, implications for future earthquake hazards

    Science.gov (United States)

    Ahsan, A.; Kali, E.; Coudurier Curveur, A.; van der Woerd, J.; Tapponnier, P.; Alam, A. K.; Ildefonso, S.; Banerjee, P.; Dorbath, C.

    2015-12-01

    The Bengal basin is situated in a complex tectonic zone where the Indian-Eurasian Plates and Indian-Burmese Plates are colliding. This region is known for some of the largest intra-continental seismic events of the last 500 years, the 1548 Bengal earthquake of magnitude M>8?, the 1762 Arakan earthquake of magnitude M>8?, the 1897 Shillong earthquakes of magnitude Ms 8.7, the 1918 Srimangal earthquake of magnitude Ms 7.6 and the 1950 Assam earthquake of magnitude Mw 8.6. The source faults of these events and whether these large earthquakes occurred on faults that reached the surface or reminded blind remain controversial. The Bengal basin still needs to be better understood in terms of active faulting and seismicity. The Eastern boundary of Bengal basin is marked by numerous NS trending folds of the Indo-Burma Ranges. We focused on the Raghunandan Anticline, NE Bengal basin, a broad, asymmetric, growing ramp anticline, steep west-facing front and bounded westwards by a steep tectonic scarp truncating gently east dipping Quaternary sandstone beds. The scarp morphology is suggestive of a still preserved co-seismic free face above a colluvial wedge. We carried out more than 20 topographic profiles to document the precise height and shape of this 12-15 m high scarp (above alluvial surface) and to survey a set of uplifted alluvial terraces located along the Shahapur River behind the scarp. The analysis of the topographic profiles around the Shajibazar area reveals the presence of 5 alluvial terraces hanging 3 m to 19 m above Shahapur River bed. T1 and T2 terraces are the best-preserved terraces on both sides of the Shahapur River. C14 and Be 10 ages allow to date the lowest abandonned terrace and to estimate the uplift rate of this area.

  7. Joint development normal to regional compression during flexural-flow folding: the Lilstock buttress anticline, Somerset, England

    Science.gov (United States)

    Engelder, Terry; Peacock, David C. P.

    2001-02-01

    Alpine inversion in the Bristol Channel Basin includes reverse-reactivated normal faults with hanging wall buttress anticlines. At Lilstock Beach, joint sets in Lower Jurassic limestone beds cluster about the trend of the hinge of the Lilstock buttress anticline. In horizontal and gently north-dipping beds, J3 joints ( 295-285° strike) are rare, while other joint sets indicate an anticlockwise sequence of development. In the steeper south-dipping beds, J3 joints are the most frequent in the vicinity of the reverse-reactivated normal fault responsible for the anticline. The J3 joints strike parallel to the fold hinge, and their poles tilt to the south when bedding is restored to horizontal. This southward tilt aims at the direction of σ 1 for Alpine inversion. Finite-element analysis is used to explain the southward tilt of J3 joints that propagate under a local σ 3 in the direction of σ 1 for Alpine inversion. Tilted principal stresses are characteristic of limestone-shale sequences that are sheared during parallel (flexural-flow) folding. Shear tractions on the dipping beds generate a tensile stress in the stiffer limestone beds even when remote principal stresses are compressive. This situation favors the paradoxical opening of joints in the direction of the regional maximum horizontal stress. We conclude that J3 joints propagated during the Alpine compression caused the growth of the Lilstock buttress anticline.

  8. Structural analysis of the Tabaco anticline, Cerrejón open-cast coal mine, Colombia, South America

    Science.gov (United States)

    Cardozo, Néstor; Montes, Camilo; Marín, Dora; Gutierrez, Iván; Palencia, Alejandro

    2016-06-01

    The Tabaco anticline is a 15 km long, south plunging, east-vergent anticline in northern Colombia, close to the transpressional collisional margin between the Caribbean and South American plates. In the Cerrejón open-cast coal mine, systematic mapping of coal seams in the middle to upper Paleocene Cerrejón Formation has yielded an exceptional dataset consisting of 10 horizontal slices (sea level to 90 m elevation, regularly spaced at 10 m intervals) through the anticline. Coal seams and fault traces in these slices are used to construct a 3D model of the anticline. This 3D model shows tighter folds within lower coal seams, NW-vergent thrusts and related folds on the gentler western limb, and strike-slip faults on the steeper eastern limb. Fault slip-tendency analysis is used to infer that these two faulting styles resulted from two different stress fields: an earlier one consistent with thrusting and uplift of the Perijá range, and a later one consistent with strike-slip faulting (Oca, Ranchería and Samán faults). Our preferred interpretation is that the anticline developed its eastern vergence during the early stages (late Paleocene-early Eocene) of tilting of the Santa Marta massif. Later NW-vergent thrusting on the western limb (early to middle Eocene) was related to western propagation of the Perijá thrust system. These results contribute to the understanding of the structural evolution of the area. They are also a good example of the complex interplay between detachment folding, thrusting, and strike-slip faulting during the growth of a km-size fold in a transpressive setting.

  9. Tectonic origin for polygonal normal faults in pelagic limestones of the Cingoli anticline hinge (Italy)

    Science.gov (United States)

    Petracchini, Lorenzo; Antonellini, Marco; Billi, Andrea; Scrocca, Davide

    2016-04-01

    Polygonal faults are a relatively-recent new class of normal faults which are thought to be formed during early burial and diagenesis as a consequence of heterogeneous lateral volume changes. Polygonal faults are non-systematically oriented and, in map view, they form rhombus-, pentagon-, or hexagon-like pattern, suggesting a non-tectonic origin. Furthermore, polygonal faults are layer bound and they are restricted to particular stratigraphic level. Predicting the pattern of polygonal normal fault results crucial for geofluid exploration and exploitation, but, despite the large number of studies, the origin of these faults remains still largely controversial. One of the main reason for this uncertainty is that they are poorly known in outcrops. Polygonal faults have been identified in few localities within Mesozoic chalk (United Kingdom, France, and Egypt), in Paleogene claystone (Belgium), and in the Cretaceous Khoman Formation (Egypt) where polygonal faults have been observed in an extensive exposure of chalk. In this study, we describe an outcrop in the Cingoli anticline hinge, which is located at external front of the northern Apennines fold-thrust belt (Italy), showing normal faults that we interpreted as syn-tectonically (syn-thrusting) polygonal faults. The outcrop shows three vertical exposures of sub-horizontal fine-grained marly limestones with chert interlayers of Albian-Turonian age. Intraformational short normal faults affect the carbonate and chert beds. These faults are poorly-systematic and they cut through the carbonate beds whereas usually stop against the chert layers. The fault surfaces are often characterized by slickolites, clayey residue, and micro-breccias including clasts of chert and carbonate. Fault displacement is partly or largely accommodated by pressure solution. At the fault tips, the displacement is generally transferred, via a lateral step, to an adjacent similar fault segment. The aim of our study is to understand the nucleation

  10. Great earthquake surface ruptures along backthrust of the Janauri anticline, NW Himalaya

    Science.gov (United States)

    Jayangondaperumal, R.; Kumahara, Y.; Thakur, V. C.; Kumar, Anil; Srivastava, Pradeep; Dubey, Shubhanshu; Joevivek, V.; Dubey, Ashok Kumar

    2017-01-01

    Results of a paleoseismic trenching investigation on a backthrust in the northern margin of Janauri hill, at Mehandpur (31°18‧11.37″N, 76°18‧31.47″E), Sub-Himalayan range of the Himachal Himalaya are presented. The active backthrust revealed the last event took place after 0.8 ± 0.03 ka ago (i.e. post CE 1200). The age of the last earthquake with a minimum fault slip ∼1 m along F1 fault and presence of single colluvium on the back thrust nearly matches with an earthquake event previously documented on the Bhatpur forethrust of the Himalayan frontal thrust system. Uplifted and truncated fluvial terraces due to displacement on the backthrust are preserved along several north flowing river valley sections in the northern limb of Janauri anticline. The long-term vertical uplift rate calculated through dividing difference between current elevation and elevation of current river grade is 1.08 ± 0.08 mm/yr. Field evidence shows fore and backthrusts are active and they form simultaneously, but displacements are episodic suggesting the backthrust develops either due to locking of forethrust or to accommodate a large amount of fault slip due to magnitude of earthquake event along the forethrust. Further, the backthrust may be used as an indirect method of inferring the age of the last event that took place along the forethrust.

  11. Transverse zones controlling the structural evolution of the Zipaquira Anticline (Eastern Cordillera, Colombia): Regional implications

    Science.gov (United States)

    García, Helbert; Jiménez, Giovanny

    2016-08-01

    We report paleomagnetic, magnetic fabric and structural results from 21 sites collected in Cretaceous marine mudstones and Paleogene continental sandstones from the limbs, hinge and transverse zones of the Zipaquira Anticline (ZA). The ZA is an asymmetrical fold with one limb completely overturned by processes like gravity and salt tectonics, and marked by several axis curvatures. The ZA is controlled by at least two (2) transverse zones known as the Neusa and Zipaquira Transverse Zones (NTZ and ZTZ, respectively). Magnetic mineralogy methods were applied at different sites and the main carriers of the magnetic properties are paramagnetic components with some sites being controlled by hematite and magnetite. Magnetic fabric analysis shows rigid-body rotation for the back-limb in the ZA, while the forelimb is subjected to internal deformation. Structural and paleomagnetic data shows the influence of the NTZ and ZTZ in the evolution of the different structures like the ZA and the Zipaquira, Carupa, Rio Guandoque, Las Margaritas and Neusa faults, controlling several factors as vergence, extension, fold axis curvature and stratigraphic detatchment. Clockwise rotations unraveled a block segmentation following a discontinuos model caused by transverse zones and one site reported a counter clockwise rotation associated with a left-lateral strike slip component for transverse faults (e.g. the Neusa Fault). We propose that diverse transverse zones have been active since Paleogene times, playing an important role in the tectonic evolution of the Cundinamarca sub-basin and controlling the structural evolution of folds and faults with block segmentation and rotations.

  12. Syn-thrusting polygonal normal faults exposed in the hinge of the Cingoli anticline, northern Apennines, Italy

    Directory of Open Access Journals (Sweden)

    Lorenzo ePetracchini

    2015-11-01

    Full Text Available The Cingoli arcuate anticline is part of the Apennines fold-thrust belt in Italy. The anticline involves sedimentary carbonate strata generally affected by syn-thrusting contractional structures such as bed-normal pressure solution seams, folds, and reverse faults. An exception is constituted by an outcrop in the anticline hinge, where sub-horizontal carbonate and chert beds are affected by joints and intraformational short normal faults. These faults are poorly-systematic and conceivably polygonal in map view. They cut through the carbonate beds while usually stop against the chert layers that are bent and extended along the faults themselves. At the fault tips, the displacement is generally transferred, via a lateral step, to an adjacent similar fault segment. The fault surfaces are often characterized by slickolites, greenish clayey residue, and micro-breccias including chert and carbonate clasts. Fault displacement is partly or largely accommodated by pressure solution. The faults, in effect, are usually accompanied by bed-parallel pressure solution seams in the two contractional quadrants located at the present or past fault tips. The pressure solution features fade away departing from the faults. This evidence and others are analytically explained with fault tip stress distributions. The faults are interpreted as polygonal normal faults syn-tectonically (syn-thrusting nucleated in response to multi-directional stretching processes occurred at the Cingoli triple-folded anticline extrados. The faults then grew through a four-stage process: (1. stop the faults stopped at the competent chert beds; (2. shrink faulting produced shrinkage (pressure solution of carbonate beds at the fault compressive tips; (3. shrink and step the faults stepped laterally at the competent chert beds; (4. shatter the chert beds were shattered along the fault surfaces. The case presented constitutes the first reported one of syn-thrusting non-diagenetic polygonal

  13. GPS Velocities and Structure Across the Burma Accretionary Prism and Shillong Anticline in Bangladesh

    Science.gov (United States)

    Steckler, M. S.; Akhter, S. H.; Seeber, L.; Bilham, R. G.; Kogan, M. G.; Masson, F.; Maurin, T.; Mondal, D.; Piana Agostinetti, N.; Rangin, C.; Saha, P.

    2012-12-01

    Himalayan front. The surface expression of this boundary is the steep front limb of the south-verging Shillong anticline with secondary folding of the syn-tectonic Quaternary sediment of its foredeep. This suggests that the Dauki Fault is blind and extends well south of the topographic break. In support of this conclusion, receiver function analysis images a NNE-dipping velocity inversion corresponding to basement overthrusting sediment at ~6 km depth just south of the Plateau. Our GPS data, in combination with velocity data from northeast India suggests ~7 mm/y of shortening across the Dauki Fault, with the velocity gradient associated with the fault concentrated within Bangladesh, south of the Shillong anticline.

  14. Ground Penetrating Radar Profiles of Breached Anticlinal Ridges in the Northern Piedmont of the San Bernardino Mountains in Southern California

    Science.gov (United States)

    Bobyarchick, A. R.; Eppes, M. C.; Diemer, J. A.; Cathey, R. B.; Cottingham, M. A.; Eckardt, I. J.; Shiflet, J. E.; Waldron, A. J.

    2006-12-01

    The northern piedmont of the San Bernardino Mountains contains kinematic elements characteristic of the Mojave block dextral plate boundary zone between the North American and Pacific plates and the complex convergent Transverse Ranges partition of that motion here represented by the North Frontal thrust system. Predominantly lateral slip in the central Mojave block is carried by the Helendale fault through Lucerne Valley and southward to intersect the North Frontal thrust system in the San Bernardino Mountains. Active anticlinal flexures and partially emergent north-verging thrust faults have deformed Pleistocene alluvial fans and older rocks into east-trending ridges in the piedmont on both sides of the Helendale fault. The Cougar Buttes anticline underlies such a ridge east of the fault and is breached by contemporaneous orthogonal washes in several places along strike of the anticline. Greater relief occurs where the alluvial fans comprise carbonate- cemented soils and particularly resistant, prominent petrocalcic horizons. It is within these incised valleys that the sequence of Tertiary through Pleistocene deposits show that the asymmetric anticline is cored by a thrust fault. In order to examine more closely the fold-fault association in the Cougar Buttes anticline and suggest possible kinematic models, we conducted several ground penetrating radar (GPR) profiles at different levels across the ridge. Relatively superior relief in some washes allowed us to conduct profiles along the present topographic ridge crests (and thus along the crestal zone of the fold) and also along wash bottoms to provide profiles at the level of the fold's core. We used a GSSI SIR-3000 GPR system equipped with a monostatic 100 MHz antennae set to continuous recording mode; traverses over very irregular ground were done in point data mode. The system was set up with nominal high and low cutoff filters and automatic gain control, but we found that AGC overly amplified multiples or

  15. Geometry, kinematics and dynamic characteristics of a compound transfer zone: the Dongying anticline, Bohai Bay Basin, eastern China

    Directory of Open Access Journals (Sweden)

    Tian Fei

    2016-01-01

    Full Text Available The Dongying anticline is an E-W striking complex fault-bounded block unit which located in the central Dongying Depression, Bohai Bay Basin. The anticline covers an area of approximately 12 km2. The overlying succession, which is mainly composed of Tertiary strata, is cut by normal faults with opposing dips. In terms of the general structure, the study area is located in a compound transfer zone with major bounding faults to the west (Ying 1 fault and east (Ying -8 and -31 faults. Using three-dimensional seismic data, wireline log and checkshot data, the geometries and kinematics of faults in the transfer zone were studied, and fault displacements were calculated. The results show that when activity on the Ying 1 fault diminished, displacement was transferred to the Ying -8, Ying -31 and secondary faults so that total displacement increased. Dynamic analysis shows that the stress fields in the transfer zone were complex: the northern portion was a left-lateral extensional shear zone, and the southern portion was a right-lateral extensional shear zone. A model of potential hydrocarbon traps in the Dongying transfer zone was constructed based on the above data combined with the observed reservoir rock distribution and the sealing characteristics of the faults. The hydrocarbons were mainly expulsed from Minfeng Sag during deposition periods of Neogene Guantao and Minghuazhen Formations, and migrated along major faults from source kitchens to reservoirs. The secondary faults acted as barriers, resulting in the formation of fault-bound compartments. The high points of the anticline and well-sealed traps near secondary faults are potential targets. This paper provides a reservoir formation model of the low-order transfer zone and can be applied to the hydrocarbon exploration in transfer zones, especially the complex fault block oilfields in eastern China.

  16. Fold-related-fracturing at the Livingstone River anticline (AB; Canada) by coupling field surveying and numerical modelling

    Science.gov (United States)

    Humair, Florian; Epard, Jean-Luc; Bauville, Arthur; Jaboyedoff, Michel; Pana, Dinu; Kaus, Boris; Schmalholz, Stefan

    2016-04-01

    The interpretation of fold-related joints and faults is of primary importance in terms of fluids prospection (e.g. water, oil, gas, C02) since anticlines are potential structural trap while fracturing can strongly influence the storage capacity as well as the migration pathways. Located at the front of the Foothills of the Rocky Mountains in Alberta (Canada), the Livingstone Range (LRA) is analogous to hydrocarbon reservoir that occur elsewhere in the Foothills (Cooley et al., 2011). The Livingstone Range fold system is related to the development of the Livingstone thrust that cuts around 1000m up-section from a regional decollement in the Palliser Formation (Devonian) to another in the Fernie Formation (Jurassic). Our study focuses on the detailed structural investigation of the Livingstone River anticline (northern part of the LRA). It aims at characterizing the anticline geometry as well as the fracturing pattern (orientation, mode, infilling, spacing, trace length, density, and cross-cutting relationships) in order to propose a kinematic interpretation of the fold-related fracturing genesis. The study area is investigated at different scales by combining field surveys with remote sensing (HR-Digital Elevation Model, Ground-based LiDAR, Gigapixel photography) and thin-sections analyses. In a second step we performed finite difference 3D numerical simulations in order to compute the evolution of local principal stress orientation during folding. We compared the fracture (or plastic bands) distribution in the field with 1) a dynamic numerical model of detachment folding; and 2) an instantaneous numerical model based on the final fold geometry. Cooley, M.A., Price, R.A., Dixon, J.M., Kyser, T.K. 2011. Along-strike variations and internal details of chevron-style flexural slip thrust-propagation folds within the southern Livingstone Range anticlinorium, a paleo-hydrocarbon reservoir in southern Alberta Foothills, Canada. AAPG bulletin, 95 (11), 1821-1849.

  17. Metallogenetic modeling for uranium exploration in rocks of the Abaira-Jussiape Anticlinal nucleus, Chapada Diamantina, Bahia; Modelagem metalogenetica para prospeccao de uranio nas rochas do nucleo da Anticlinal Abaira-Jussiape, Chapada Diamantina, Bahia

    Energy Technology Data Exchange (ETDEWEB)

    Santana, Jocilene dos Santos; Cruz, Simone Cerqueira Pereira; Barbosa, Johildo Salomao Figueiredo [Universidade Federal da Bahia (PPGG/UFBA), Salvador, BA (Brazil); Abram, Maisa Bastos; Martins, Adriano Alberto Marques, E-mail: jocilenesanttana@yahoo.com.br, E-mail: simonecruzufba@gmail.com, E-mail: johildo@cpgg.ufba.br, E-mail: maisa.abram@cprm.gov.br, E-mail: adriano1952@gmail.com [Companhia de Pesquisas de Recursos Minerais (CPRM), Salvador, BA (Brazil). Superintendencia Regional de Salvador. Servico Geologico do Brasil

    2011-06-15

    The NNW-SSE-trending Abaira-Jussiape Anticlinal is an antiformal culmination of folding and shearing in the Paramirim Corridor of the Western Chapada Diamantina. In its core paleoproterozoic, mylonitized Caraguatai Suite, tonalites-granodiorites, alkali-feldspar granites, syenites to quartz-syenites and Jussiape Suite granites crop out. Compressional and distensional stresses mark the structural geology of the area. The compressional structures are related to two distinct deformation phases, named D1a and D1b. The main compressional phase is ductile D1a, which is related to the nucleation of dextral to dextral-reverse shearing zones. Deformation and syn-D1a recrystallization involving plagioclase and the K-feldspar suggest deformation temperature conditions above 550 deg C. The following phase D2 is of ductilebrittle nature and culminates in reverse shearing zones. The distensional structures correspond to the D3 phase and are represented by frontal shear zones with normal movement. The petrographic study helped identify a pre-D1a hydrothermal alteration process related to albitization and potassification, syn-D1 oxidation process, and hydration and saussuritization related to phases D2 and D3. The integration of lithological, petrographic, structural and geophysical data by means of the logic Fuzzy, plus the existing information regarding structural and lithologic controls of the known uranium mineralization in the Paramirim Corridor, led us to identify two promising areas for radioactive element exploration in the nucleus of Abaira-Jussiape Anticlinal. (author)

  18. Permian magmatism, Permian detachment faulting, and Alpine thrusting in the Orobic Anticline, southern Alps, Italy

    Science.gov (United States)

    Pohl, Florian; Froitzheim, Niko; Geisler-Wierwille, Thorsten; Schlöder, Oliver

    2014-05-01

    Lombardo. It is therefore an Alpine structure. (4) Several south-directed Alpine thrusts duplicate the lithostratigraphy, including the detachment, and are related to the Orobic thrust further north. They also offset the Biandino Fault. U-Pb zircon ages measured with LA-ICP-MS (work in progress) will further clarify the temporal relations between the intrusions, volcanics, and the shear zones. Froitzheim, N., Derks, J.F., Walter, J.M. & Sciunnach, D. 2008. Evolution of an Early Permian extensional detachment fault from synintrusive, mylonitic flow to brittle faulting (Grassi Detachment Fault, Orobic Anticline, southern Alps, Italy) Geological Society, London, Special Publications, 298; 69-82. doi:10.1144/SP298.4 Thöni, M., Mottana, A., Delitala, M. C., De Capitani, L. & Liborio, G. 1992. The Val Biandino composite pluton: A late Hercynian intrusion into the South-Alpine metamorphic basement of the Alps (Italy). Neues Jahrbuch für Mineralogie-Monatshefte, 12, 545-554. Sciunnach, D. 2001. Early Permian palaeofaults at the western boundary of the Collio Basin (Valsassina, Lombardy). Natura Bresciana. Annuario del Museo Civico di Scienze Naturali, Brescia, Monografia, 25, 37-43.

  19. 2-D modelling of the anticlinal structures and structural development of the eastern fold belt of the Bengal Basin, Bangladesh

    Science.gov (United States)

    Sikder, Arif Mohiuddin; Alam, M. Mustafa

    2003-02-01

    Structural architecture of the Bengal Basin has been strongly controlled by the collision pattern of the Indian plate with the Burma and Tibetan plates. The eastern fold belt (EFB) of the basin, comprising a series of north-south-trending curvilinear anticlines and synclines, represents a fold-and-thrust belt that constitutes the westward continuation of Arakan-Chin fold system of the Indo-Burman Ranges. The present study is mainly concerned with the 2-D modelling of the anticlinal structures in order to develop an understanding about the process-response relationships between the structural style and tectonic evolution of the eastern fold belt. The dominant fold-generating mechanism is believed to be the east-west-directed compressional force arising from oblique subduction of the Indian plate beneath the Burma plate that resulted in the growth of fault-propagation folds above a detachment or decollement at depth, giving rise to the Neogene accretionary prism complex development. A prominent feature of the region is the major east-dipping thrusts separating successive accretionary wedges. In seismic sections, evidence for several phases of compressional deformation suggests that multiphase stress conditions were responsible for the structural expression of the fold belt. Deep seismic sections reveal that the base of folding is characterized by a low-interval velocity horizon that represents a detachment separating the upper folded zone from the lower, seismically coherent, nearly unfolded zone. This detachment coincides with the undercompacted pressured shale unit, which is thought to have played an important role in the structural development of the eastern fold belt. Clay mineralogical analysis reveals the presence of a low-density shale horizon within the dense and thick shale sequence that is thought to be an undercompacted pressured shale during the geological past, and was responsible for the initiation of decollement and incipient diapirism involving thin

  20. The use of HVSR measurements for investigating buried tectonic structures: the Mirandola anticline, Northern Italy, as a case study

    Science.gov (United States)

    Tarabusi, G.; Caputo, R.

    2017-01-01

    The Mirandola anticline represents a buried fault-propagation fold which has been growing during Quaternary due to the seismogenic activity of a blind segment belonging to the broader Ferrara Arc. The last reactivation occurred during the May 2012 Emilia sequence. In correspondence with this structure, the thickness of the marine and continental deposits of the Po Plain foredeep is particularly reduced. In order to better define the shallow geometry of this tectonic structure, and hence its recent activity, we investigated in a depth range which is intermediate between the surficial morphological observations and seismic profiles information. In particular, we carried out numerous passive seismic measurements (single-station microtremor) for obtaining the horizontal-to-vertical spectral ratio. The results of a combined analysis of the peak frequency and its amplitude nicely fit the available geological information, suggesting that this low-cost geophysical technique could be successfully applied in other sectors of wide morphologically flat alluvial plains to investigate blind and completely buried potential seismogenic structures.

  1. FINITE ELEMENT NUMERICAL SIMULATION FOR THE HYDRODYNAMIC FIELD EVOLUTION OF GEOTHERMAL WATER IN THE NANWENQUAN ANTICLINE IN CHONGQING IN CHINA

    Institute of Scientific and Technical Information of China (English)

    LUO Yun-ju; LIU Dong-yan; LIU Xin-rong

    2006-01-01

    The Nanwenquan (South Hot Spring) and Xiao quan (Small Hot Spring) in the Nanwenquan anticline are well-known attraction for their geothermal water, but currently, the two natural hot springs have hot flow naturally. In order to protect the geothermal water resource, the evolution of hydrodynamic field must be researched for the causation of the hydrodynamic field destroyed. The finite element numerical simulation was adopted and quantitative study on the geothermal water hydrodynamic field. The finite element model was set up to simulate the research sites, the simulated water level was compared with the actual water level, the feasibility of this model was proved when the simulated water level is approximate to actual one, and an applicable finite element model was obtained. The finite element model was used to simulate the evolution of the hydrodynamic field. This paper supplies a basis to exploit adequately and protect effectively the geothermal water resource, at the same time it is proved feasible in practice to apply finite element numerical simulation to quantitative study of the geothermal water.

  2. Finite Element Modeling of the Effect of Cementation on Mohr Coulomb Failure Criteria for Tensleep Sandstone, Alcova Anticline, Wyoming

    Science.gov (United States)

    Busetti, S.; Hennings, P.; Ramos, R.

    2011-12-01

    We simulated rock mechanics tests to model the effect of cementation on the Mohr Coulomb failure parameters of reservoir rock. Experiments show that lithologic variations affect both elastic and inelastic constitutive behavior. To understand controls on inelastic parameters we combined finite element (FE) modeling, a powerful technique that can solve for complex mechanical processes under realistic in-situ conditions, with observations of mineralogy and rock mechanics experiments on Tensleep sandstone, Alcova anticline, Wyoming. Here we present findings on the effect of cement volume % (Vc) on Mohr Coulomb (MC) parameters of internal angle of friction (φ), cohesion (C0), and unconfined compressive strength (UCS). The FE model is of a 1" diameter by 2" long cylindrical plug loaded in axisymmetric triaxial compression. Heterogeneity is defined by randomly assigning each element in the plug one of two MC constitutive definitions based on typical mechanical properties for Tensleep sandstone. The rock is a subarkose sandstone with Vc ranging from 9.5-15.4% increasing from an undeformed area to the limbs and crest of Alcova anticline. In the FE model different values of either φ (45° or 55°) or C0 (20 MPa or 40 MPa), representing weakly or well cemented rock, are assigned to each element for a range of Vc while all other elastic constants and failure parameters remain constant. Steel platens with frictional contact bound the sample, confining pressure is set at either 10 or 35 MPa, and then axial loading is applied until failure. Axial stress-strain plots are used to derive overall MC parameters. Preliminary FE results generally agree with laboratory data and indicate that MC parameters scale with amount of cementation. The Tensleep data indicates quartz overgrowth cementation correlates positively to strengthening, where φ and C0 increase moderately (33°-52°; 24-39 MPa), and UCS nearly doubles (100-188 MPa). FE results show that overall yield stress scales with

  3. A Palaeoproterozoic Super-Large Synformal Sheath Anticline: an example from the Keivy Terrane, northeastern Baltic Shield

    Science.gov (United States)

    Mudruk, S. V.; Balagansky, V. V.; Gorbunov, I. A.; Raevsky, A. B.

    2012-04-01

    core. Taking into account the thickness of the nonmagnetic Carbonate Sequence, the length of sheath is estimated at 4-5 km. Geometrical analysis of orientation data on Keivy paraschists that immediately surround the Palaeoproterozoic fold core directly indicate its sheath-like morphology. The eastern closure of the fold core displays the NW-plunging hinge line, while the western closure has the NNE-plunging hinge line. A north-plunging lineation subdivides the angle between hinge lines (51°) into two nearly equal parts. From these data, the length of sheath is estimated also at 4-5 km. Sedimentary structures indicative of the polarity of bedding (graded and cross-bedding, erosion surfaces) indicate that the Palaeoproterozoic fold core is a synformal anticline, i.e. its northern, undeformed limb is normal, and its southern, strongly thinned one is overturned. Kinematic indicators (sigma and s-c structures, the asymmetric appearance of the Serpovidny Ridge Fold Core and exposure-scale sheath folds in Keivy paraschists) suggest that these structures resulted from north-directed movements. We conclude that the Palaeoproterozoic Serpovidny Ridge Fold Core is a super-large synformal sheath anticline. This is interpreted as an outlier of a Helvetic-type nappe come from the Palaeoproterozoic Imandra-Varzuga Rift-Belt. This is a contribution to projects RFBR-12-05-00878a and ONZ-6.

  4. Marine uppermost Cretaceous and Garumnian facies in the region of Boixols-Coll de Nargó Anticline (prov. Lérida. Spain

    Directory of Open Access Journals (Sweden)

    Willems, H.

    1985-04-01

    Full Text Available The lithostratigraphic evolution of marine uppermost Campanian-Maestrichtian (Arén Sandstone Formation and of lagoonal and continental Maestrichtian-Paleocene "Garumnian" facies (Tremp Formation on the southern margin of Boixols-Coll de Nargó Antic1ine was studied. Dating, based mainly on orbitoidal forarninifera, indicates that the formations are diachronous and become younger from west to east.
    The transgression of the formations from south, respectively southwest upon Campanian 10 Santonian units, their tapering out northward , and the change in the pebble spectra (from San tonian lo Aptian of the conglomeratic layers reflect the elevation and denudation of the anticline uplift area ("island" at the Cretaceous-Tertiary boundary.

    Se estudia la evolución litoestratigráfica del Campaniense superior-Maestrichtiense marino (Formación Arenisca de Arén y de las facies garumnienses continentales y de lagoon del Maestrichtiense (Formación Tremp del borde sur del anticlinal de Boixols-Coll de Nargó, Las dotaciones, basadas principalmente en foraminíferos (Orbitoididae indican que las formaciones son diacrónicas, disminuyendo en edad de oeste a este.
    La transgresión de estas formaciones desde el sur y suroeste, respectivamente, sobre las unidades del Campaniense-Santoniense, su buzamiento norte, y el cambio del tamaño de los cantos (Santonienses-Aptienses de las capas conglomeráticas, indican una elevación y erosión del área anticlinal emergida (isla en el límite Cretácico-Terciario.

  5. A natural fiber composite in a pelagic limestone-chert sequence. The importance of mechanical stratigraphy for fracture type development in carbonate anticlines.

    Science.gov (United States)

    Petracchini, Lorenzo; Antonellini, Marco; Scrocca, Davide; Billi, Andrea

    2013-04-01

    Thrust fault-related folds in carbonate rocks are characterized by deformation accommodated by different kinds of structures, such as joints, faults, pressure solution seams (PSSs), and deformation bands, which may form at various stages during the folding process. Defining the distribution, orientation, and the type of fold-related structures and understanding the relationships between folding and fracturing is significant both for theoretical and practical purposes. Furthermore, as the deformation related to the folding process influences fluid flow through rocks, identifying the types of structures formed during folding is as important as predicting their geometries. To unravel the relationship between mechanical stratigraphy and folding process, the well-exposed Cingoli anticline (Northern Apennines), has been studied in detail. The Upper Cretaceous-Middle Eocene stratigraphy of the Cingoli anticline is characterized by a pelagic multilayer made up of fine-grained pelagic limestones and, marly limestones, in places alternated with thin continuous chert layers. The presence of several outcrops located in different structural positions of the anticline makes the Cingoli anticline an excellent natural laboratory to investigate relationships between folding, fracturing, and mechanical stratigraphy relative to the structural setting of the fold. The field data collected show that high angle to bedding PSSs, which formed before tilting and during the first stage of folding, are not homogeneously distributed in the pelagic limestones. Generally, high angle to bedding PSSs form in the marly pelagic limestones and they have been observed in several outcrops and in different structural positions except where the marly limestones are inter-bedded with stiffer chert layers. In order to analyse theoretically what observed in the field, we compared the deformation of limestones and chert layers with the deformation acting on fiber composites. In the mechanics of materials

  6. Fluid systems and fracture development during syn-depositional fold growth: An example from the Pico del Aguila anticline, Sierras Exteriores, southern Pyrenees, Spain

    Science.gov (United States)

    Beaudoin, Nicolas; Huyghe, Damien; Bellahsen, Nicolas; Lacombe, Olivier; Emmanuel, Laurent; Mouthereau, Frédéric; Ouanhnon, Laure

    2015-01-01

    This paper reports an integrated, spatio-temporal analysis of the fracture-controlled paleo-fluid system in the Pico del Aguila anticline, a N-S trending fold located in the Sierras Exteriores, the southern front of the Spanish Pyrenees. Eight fracture sets (joints or faults) are recognized throughout the fold and are separated into a fracture sequence that is defined using field relationships and the remarkable temporal constraints offered by the syn-tectonic sedimentary deposits. This fracture sequence records a complex Paleocene to Early Oligocene structural evolution, including map-view, clockwise rotation and tilting of the fold axis. The geochemical analysis of calcite cements from the different mineralized fracture/vein sets reveals a compartmentalized fluid system during most of fold development. This initial paleofluid system was later perturbed when bending-related fractures associated with foreland flexure and outer arc extension triggered small-scale, vertical fluid migration. Fractures developed in shallow strata facilitated downward migration of surficial fluids that controlled the paleo-fluid system in the Late Priabonian/Stampian continental deposits. The study of the Pico del Aguila anticline depicts for the first time the evolution of a fluid system in a shallow, syn-depositional compressional setting, and results further strengthen the statement that fluids migrate vertically across stratigraphic boundaries take place during fold hinge-related deformation.

  7. Degeneracy lifting due to thermal fluctuations around the frustration point between anticlinic antiferroelectric SmC(A)* and synclinic ferroelectric SmC*.

    Science.gov (United States)

    Sandhya, K L; Chandani, A D L; Fukuda, Atsuo; Vij, Jagdish K; Emelyanenko, A V; Ishikawa, Ken

    2013-01-01

    In the binary mixture phase diagram of MC881 and MC452, the borderline between anticlinic antiferroelectric SmC(A)(*) and synclinic ferroelectric SmC(*) becomes apparently parallel to the temperature ordinate axis at the critical concentration r(c). The free energy difference between SmC(A)(*) and SmC^{*} is extremely small in a wide temperature range near r(c). In such circumstances, by observing Bragg reflection spectra due to the director helical structure and electric-field-induced birefringence, we have observed the continuous change from SmC(A)(*) to SmC(*) for r/~r(c). These intriguing phenomena have been explained, successfully at least in the high-temperature region, by a thermal equilibrium between the synclinic and anticlinic orderings and the resulting Boltzmann distribution for the ratio between them; the thermal equilibrium is considered to be attained in a nonuniform defect-assisted way through solitary waves moving around dynamically. We have also discussed qualitatively an important role played by the effective long-range interlayer interactions in the low-temperature region.

  8. Fluid systems and fracture development during syn-depositional fold growth: example from the Pico del Aguilla anticline, Sierras Exteriores, Southern Pyrenees, Spain.

    Science.gov (United States)

    Beaudoin, Nicolas; Huyghe, Damien; Bellahsen, Nicolas; Lacombe, Olivier; Emmanuel, Laurent; Mouthereau, Frédéric; Ouanhon, Laure

    2014-05-01

    This study presents a reconstruction of fold-fracture-fluid evolution at the Pico del Aguila Anticline, located on the southwestern front of the Jaca piggy-back basin, Southern Pyrenees, Spain. The kinematic evolution of the Pico del Aguila anticline is related to the successive development of N-S ramps and reactivation of E-W striking basement thrusts that occurred coevally with sedimentation in the foreland basin. Consequently, this anticline offers an ideal frame to assess the evolution of the fluid system during the syn-depositional deformation at the front of a fold-thrust belt. Eight fracture sets (joints or faults) observed at fold-scale compose the fracture sequence defined by field and micro-scale chronological relationships. This fracture sequence reflects the Middle Eocene to Early Oligocene tectonic events and the progressive rotation of some fracture sets from NE-SW to E-W witnesses the clockwise rotation that occurred during folding. ∂18O and ∂13C values from vein cements suggest a fluid system buffered by host rocks in most cases. Fluid inclusion microthermometry measurements indicate a fluid entrapment temperature <50°C, supporting that the fluid system reflects strata burial during the main part of strata history. Small-scale vertical migrations from reservoir to reservoir are triggered by fractures related to strata-curvature, both during foreland flexure/forebulge and fold development. After folding, fractures developing in shallow sub-continental to continental strata triggered downward migration of surficial fluids, likely of meteoric origin. This phenomenon is poorly developed in early marine deposits but strongly influenced the fluid system recorded in the late continental deposits. The case study of the Pico del Aguila supports recent finding that fold-fluid systems seem to exhibit a common behavior during folding, with development of curvature-related joints triggering vertical migration of fluids from a reservoir to another. It also

  9. The Skælskør structure in eastern Denmark – wrench-related anticline or primary Late Cretaceous sea-floor topography?

    DEFF Research Database (Denmark)

    Surlyk, Finn; Boldreel, Lars Ole; Lykke-Andersen, Holger;

    2010-01-01

    Sorgenfrei (1951) identified a number of NW–SE oriented highs in the Upper Cretaceous – Danian Chalk Group in eastern Denmark, including the Skælskør structure and interpreted them as anticlinal folds formed by wrenching along what today is known as the Ringkøbing-Fyn High. Recent reflection...... seismic studies of the Chalk Group in Øresund and Kattegat have shown that similar highs actually represent topographic highs on the Late Cretaceous – Danian seafloor formed by strong contourparallel bottom currents. Reflection seismic data collected over the Skælskør structure in order to test...... the hypothesis of Sorgenfrei show that the Base Chalk reflection is relatively flat with only very minor changes in inclination and cut by only a few minor faults. The structure is situated along the northern margin of a high with roots in a narrow basement block, projecting towards the northwest from...

  10. Fingerprinting stress: stylolite and calcite twinning paleopiezometry reveal the complexity of stress distribution during the growth of the Monte Nero anticline (Apennines, Italy).

    Science.gov (United States)

    Beaudoin, Nicolas; Koehn, Daniel; Lacombe, Olivier; Lecouty, Alexandre; Billi, Andrea; Aharonov, Einat; Parlangeau, Camille

    2016-04-01

    This contribution presents for the first time how quantitative stress estimates can be derived by combining calcite twinning and stylolite roughness stress fingerprinting techniques in a structure part of a complex fold and thrust belts. We report a high-resolution deformation and stress history that was experienced by Meso-Cenozoic limestone strata in the overturned Monte Nero Anticline during its late Miocene-Pliocene growth in the Umbria-Marche Arcuate Ridge (northern Apennines, Italy). New methodological development enables an easier use for the inversion technique of sedimentary and tectonic stylolite roughness. A stylolite-fracture network developed during layer-parallel shortening (LPS), as well as syn- and post-folding. Stress fingerprinting shows how stress builds up in the sedimentary strata during LPS with variations of differential stress before folding around a value of 50 MPa. The stress regime oscillated between strike-slip and compressional during LPS and became transiently extensional in limbs of developing fold due to a coeval increase of vertical stress related to local burial and decrease of maximum horizontal stress related to hinge development, before ultimately becoming strike-slip again during late stage fold tightening. Our case study shows that stress fingerprinting is possible and that this novel method can be used to unravel complex temporal relationships that relate to local variations within evolving regional orogenic stresses. Beyond regional implication, this study validates our approach as a new exciting toolbox to high-resolution stress fingerprinting in basins and orogens.

  11. Magnetostratigraphy of the late Cenozoic Laojunmiao anticline in the northern Qilian Mountains and its implications for the northern Tibetan Plateau uplift

    Institute of Scientific and Technical Information of China (English)

    FANG; Xiaomin; ZHAO; Zhijun; LI; Jijun; YAN; Maodu; PAN; Ba

    2005-01-01

    Cenozoic sediments in the foreland basin--Jiuquan Basin in west Hexi Corridor recorded tectonic uplift information of the Qilian Mountains. High resolution paleomagnetic dating of the Laojunmiao (LJM) section across the central LJM anticline in the southern Jiuquan Basin reveals ages of the Getanggou Member, Niugetao Member in the Shulehe Formation, the Yumen Conglomerate, Jiuquan Conglomerate and Gobi Formation at >13-8.3 Ma, 8.3-4.9 Ma, 3.66-0.93 Ma, 0.84-0.14 Ma and 0.14-0 Ma, respectively. Sedimentary evolution study suggests that the Qilian Mountains should begin to rise gradually since ~8-6.6 Ma, accompanied by sedimentary environments changing from lacustrine mudstones-sandstones to alluvial conglomerates. Rapid uplift of the Qilian Mountains began at ~3.66 Ma, followed by a series of stepwise or intermittent intensive uplifts at about <1.8-1.23 Ma, 0.93-0.84 Ma and 0.14 Ma, which finally resulted in the present high Qilian Mountains.

  12. Fingerprinting stress: Stylolite and calcite twinning paleopiezometry revealing the complexity of progressive stress patterns during folding—The case of the Monte Nero anticline in the Apennines, Italy

    Science.gov (United States)

    Beaudoin, Nicolas; Koehn, Daniel; Lacombe, Olivier; Lecouty, Alexandre; Billi, Andrea; Aharonov, Einat; Parlangeau, Camille

    2016-07-01

    In this study we show for the first time how quantitative stress estimates can be derived by combining calcite twinning and stylolite roughness stress fingerprinting techniques in a fold-and-thrust belt. First, we present a new method that gives access to stress inversion using tectonic stylolites without access to the stylolite surface and compare results with calcite twin inversion. Second, we use our new approach to present a high-resolution deformation and stress history that affected Meso-Cenozoic limestone strata in the Monte Nero Anticline during its late Miocene-Pliocene growth in the Umbria-Marche Arcuate Ridge (northern Apennines, Italy). In this area an extensive stylolite-joint/vein network developed during layer-parallel shortening (LPS), as well as during and after folding. Stress fingerprinting illustrates how stress in the sedimentary strata did build up prior to folding during LPS. The stress regime oscillated between strike slip and compressional during LPS before ultimately becoming strike slip again during late stage fold tightening. Our case study shows that high-resolution stress fingerprinting is possible and that this novel method can be used to unravel temporal relationships that relate to local variations of regional orogenic stresses. Beyond regional implications, this study validates our approach as a new powerful toolbox to high-resolution stress fingerprinting in basins and orogens combining joint and vein analysis with sedimentary and tectonic stylolite and calcite twin inversion techniques.

  13. Triassic to recent tectonic evolution of a crestal collapse graben above a salt-cored anticline in the Glückstadt Graben/North German Basin

    Science.gov (United States)

    Al Hseinat, M.; Hübscher, C.; Lang, J.; Lüdmann, T.; Ott, I.; Polom, U.

    2016-06-01

    In this study we investigate faulting above a salt wall in the Glückstadt Graben/North German Basin. Two supra-salt faults are mapped from coast to coast over a distance of 6-9 km based on offshore and onshore seismic data. These faults form a ca. 2 km wide crestal collapse graben and pierce the seafloor. Salt wall evolution started in the early Late Triassic to Early Jurassic due to regional extension and resulting sub-salt faulting. The salt wall was eroded following exposure to costal and sub-aerial erosion by the regional Mid-Late Jurassic to Early Cretaceous uplift. Late Cretaceous to Early Paleogene compressional tectonics reactivated the vertical salt movement and shortened the salt wall, creating a salt-cored anticline with the crestal collapse graben above. The supra-salt faults were reactivated between the Late Eocene and Middle Miocene when the principal horizontal stress orientation changed from a NE-SW to a NW-SE, the present-day orientation. Stratigraphic data indicate that these faults moved mainly in the Cenozoic. Several observations strongly suggest that the faults continued developing during the Pleistocene until today: (i) the Pleistocene Unconformity is concave upwards and cut by faults; (ii) growth strata within the marine Holocene deposits above the graben imply recent tectonic movements; (iii) onshore high-resolution P-wave vibroseis data of the south-eastern Eckernförde Bay suggest about 10 m of faulted Holocene strata; and (iv) marine seismic data show the faults piercing the seafloor. We suggest that the recent salt tectonics and upward propagation of supra-salt faults resulted from differential ice-sheet loading. That effect on the salt wall stopped once ice grew over the whole structure, at which time the wall subsided because of ice loading. The salt wall and faults were reactivated again once the ice front retreated so that the ice loaded only one side of the structure.

  14. Miocene extension and extensional folding in an anticlinal segment of the Black Mountains accommodation zone, Colorado River extensional corridor, southwestern United States

    Science.gov (United States)

    Varga, Robert J.; Faulds, James E.; Snee, Lawrence W.; Harlan, Stephen S.; Bettison-Varga, Lori

    2004-02-01

    Recent studies demonstrate that rifts are characterized by linked tilt domains, each containing a consistent polarity of normal faults and stratal tilt directions, and that the transition between domains is typically through formation of accommodation zones and generally not through production of throughgoing transfer faults. The mid-Miocene Black Mountains accommodation zone of southern Nevada and western Arizona is a well-exposed example of an accommodation zone linking two regionally extensive and opposing tilt domains. In the southeastern part of this zone near Kingman, Arizona, east dipping normal faults of the Whipple tilt domain and west dipping normal faults of the Lake Mead domain coalesce across a relatively narrow region characterized by a series of linked, extensional folds. The geometry of these folds in this strike-parallel portion of the accommodation zone is dictated by the geometry of the interdigitating normal faults of opposed polarity. Synclines formed where normal faults of opposite polarity face away from each other whereas anticlines formed where the opposed normal faults face each other. Opposed normal faults with small overlaps produced short folds with axial trends at significant angles to regional strike directions, whereas large fault overlaps produce elongate folds parallel to faults. Analysis of faults shows that the folds are purely extensional and result from east/northeast stretching and fault-related tilting. The structural geometry of this portion of the accommodation zone mirrors that of the Black Mountains accommodation zone more regionally, with both transverse and strike-parallel antithetic segments. Normal faults of both tilt domains lose displacement and terminate within the accommodation zone northwest of Kingman, Arizona. However, isotopic dating of growth sequences and crosscutting relationships show that the initiation of the two fault systems in this area was not entirely synchronous and that west dipping faults of the

  15. El basamento prejurásico medio en el anticlinal Chihuido, Malargüe: evolución magmática y tectónica

    Directory of Open Access Journals (Sweden)

    E.J. Llambías

    2005-09-01

    Full Text Available En el anticlinal de Chihuido al sur de Mendoza aflora el basamento de la cuenca neuquina, el cual consiste en tres unidades volcano-sedimentarias separadas por discordancias angulares. La unidad más antigua corresponde al complejo volcanosedimentario El Fortín, constituido por brechas, coladas y domos andesíticos, conglomerados y areniscas. El último evento de esta unidad corresponde a la intrusión de un potente dique de riolita-monzogranito que fue datado por el método U-Pb convencional en 250 ± 5 Ma. Esta edad permite correlacionar al Complejo El Fortín con el Grupo Choiyoi de la Cordillera Frontal y del bloque de San Rafael. En discordancia angular sobre la unidad anterior se encuentra el Grupo Tronquimalal del Triásico Tardío, con un espesor de 370 metros. Está constituido por sedimentitas ricas en componentes volcánicos con intercalaciones de brechas andesíticas. Los bancos del Grupo Tronquimalal se acuñan lateralmente debido a la transitoriedad de sus depocentros y a la naturaleza catastrófica de la depositación de parte de ellos. La discordancia que separa al Grupo Tronquimalal del Complejo El Fortín es adjudicada a la fase diastrófica huárpica, de extensión regional. Por encima del Grupo Tronquimalal se apoya en discordancia angular un conjunto de conglomerados con intercalaciones de areniscas y pelitas, a los que se ha equiparado con la Formación Remoredo. Los clastos de los conglomerados son mayormente ígneos y están constituidos por volcanitas y granitoides similares a los del Complejo El Fortín, por lo cual no se puede descartar que se hayan formado por la destrucción de volcanes permo-triásicos, favorecidos por los movimientos del Triásico Tardío que causaron la discordancia mencionada. La Formación Remoredo pasa en aparente concordancia a la Formación Bardas Blancas, de edad bajociana. En la región estudiada la actividad volcánica fue continua desde el Pérmico hasta el Triásico Tardío, pero a

  16. Fault spacing in the El Teniente Mine, Central Chile, the fold style inversion method, fold segmentation and fault linkage of the Barrancas/Lunlunta-Carrizal anticlinal complex, Mendoza, Argentina

    Science.gov (United States)

    Brooks, Benjamin Armstead

    1999-11-01

    An interval counting technique and standard cumulative statistics, in concert with residual and differential slope analysis, are employed on multiple parallel scanlines to test the applicability of fractal fault spacing at the El Teniente Mine, Central Chile. A negative exponential distribution best describes fault spatial distribution at the mine, while the interval counting method gives deceptively good fits to a fractal distribution. The results are consistent for the majority of the scanlines over thousands of square meters. These data provide an important counterexample to previously studied fractal spacing distributions and suggest that faulting is not a uniquely self-similar process and/or that faulting is not a consistently self-similar process through time. The "Fold Style Inversion" (FSI) method is developed to place quantitative bounds on balanced cross-sections used in the analysis of blind thrust faults. The method employs a discretized dip isogon construction, in combination with Monte Carlo simulations of seismic reflection depth-conversion errors, to assess a data sets' goodness of fit to bulk hangingwall similar or parallel fold geometry. This enables an objective choice to be made between the Arbitrarily Inclined Simple Shear (AISS) and Constant Bed Length (CBL) fault inversion routines which are specific to similar and parallel fold geometry, respectively. The method performs successfully for a variety of synthetic examples including a synthetic seismic line. The FSI method is applied to seismic reflection lines crossing the Barrancas and Lunlunta-Carrizal anticlines, active fault-bend folds in the Andean foreland of Mendoza Province, Argentina, and the proposed site of the 1985 Mw 5.9 Mendoza earthquake. For the Barrancas anticline, FSI analysis establishes a preference for similar fold style whereas no preference can be established for the Lunlunta-Carrizal anticline. With FSI-constrained cross-sections, it is shown that the earthquake most

  17. El anticlinal y las discordancias de Pareja (Guadalajara: definición de las unidades cenozoicas de la Depresión Intermedia (provs. Cuenca y Guadalajara, España

    Directory of Open Access Journals (Sweden)

    Arribas, I.

    2006-12-01

    Full Text Available This paper deals with the stratigraphic units visible at the Pareja Anticline in the Cenozoic-age Depresión Intermedia. The stratigraphic section allowed us to identify three main stratigraphic units differentiated through angular unconformities and sedimentary breaks. Some subunits are also been defined from sedimentary breaks linked to minor diastrophic processes. These subunits as well as the main ones (Cretaceous-Paleogene Unit, Paleogene Unit and Neogene Unit can be defined as tectosedimentary units being identifiable in all the Depresión Intermedia Basin extent through field sections and borehole logs where large numbers of fossil mammals have been located.Este trabajo contempla las unidades representadas en la sección estratigráfica del Anticlinal la Pareja (Guadalajara, España en la cuenca cenozoica denominada Depresión Intermedia. La columna estratigráfica de la zona permite identificar tres unidades principales separadas por discordancias angulares relacionables con fases tectónicas de la orogenia alpina. También se han diferenciado subunidades que, en su mayor parte, vienen definidas por rupturas sedimentarias ligadas a procesos diastróficos y que, como las tres unidades principales (Unidad Cretácico-Paleógena, Unidad Paleógena y Unidad Neógena, se corresponden con unidades tectosedimentarias, siendo identificables en toda la extensión de la Depresión Intermedia a partir de cortes y sondeos mecánicos de reconocimiento donde abundan los yacimientos de micromamíferos.

  18. El basamento prejurásico medio en el anticlinal Chihuido, Malargüe: evolución magmática y tectónica The pre-mid Jurassic basement in the Chihuido anticline, Malargüe: Magmatic and tectonic evolution

    Directory of Open Access Journals (Sweden)

    E.J. Llambías

    2005-09-01

    Full Text Available En el anticlinal de Chihuido al sur de Mendoza aflora el basamento de la cuenca neuquina, el cual consiste en tres unidades volcano-sedimentarias separadas por discordancias angulares. La unidad más antigua corresponde al complejo volcanosedimentario El Fortín, constituido por brechas, coladas y domos andesíticos, conglomerados y areniscas. El último evento de esta unidad corresponde a la intrusión de un potente dique de riolita-monzogranito que fue datado por el método U-Pb convencional en 250 ± 5 Ma. Esta edad permite correlacionar al Complejo El Fortín con el Grupo Choiyoi de la Cordillera Frontal y del bloque de San Rafael. En discordancia angular sobre la unidad anterior se encuentra el Grupo Tronquimalal del Triásico Tardío, con un espesor de 370 metros. Está constituido por sedimentitas ricas en componentes volcánicos con intercalaciones de brechas andesíticas. Los bancos del Grupo Tronquimalal se acuñan lateralmente debido a la transitoriedad de sus depocentros y a la naturaleza catastrófica de la depositación de parte de ellos. La discordancia que separa al Grupo Tronquimalal del Complejo El Fortín es adjudicada a la fase diastrófica huárpica, de extensión regional. Por encima del Grupo Tronquimalal se apoya en discordancia angular un conjunto de conglomerados con intercalaciones de areniscas y pelitas, a los que se ha equiparado con la Formación Remoredo. Los clastos de los conglomerados son mayormente ígneos y están constituidos por volcanitas y granitoides similares a los del Complejo El Fortín, por lo cual no se puede descartar que se hayan formado por la destrucción de volcanes permo-triásicos, favorecidos por los movimientos del Triásico Tardío que causaron la discordancia mencionada. La Formación Remoredo pasa en aparente concordancia a la Formación Bardas Blancas, de edad bajociana. En la región estudiada la actividad volcánica fue continua desde el Pérmico hasta el Triásico Tardío, pero a

  19. Tectonic features, formation and evolution of Weimake anticline-structure of Kongquehe Slope, Tarim Basin%塔里木盆地孔雀河斜坡维马克背斜构造的构造特征与形成演化

    Institute of Scientific and Technical Information of China (English)

    刘阵; 何登发; 李涤

    2013-01-01

    Weimake anticline-structure zone,whose west part developed NW striking faults and east part developed NEE striking faults,located in the eastern part of Kongquehe Slope,is the structural transferring zone of the two faults system of Kongquehe Slope.The interpretation and analysis of the anticline structure is very important to recognize the formation and evolution of Kongquehe Slope and to reveal the geodynamic settings of the northeastern margin of Tarim Basin since Early Paleozoic.Through the fine interpretation of the seismic profile across Weimake anticline-structural zone,using the theory of fault-related fold,this paper analyzed the tectonic features and the formation and evolution of the anticline structure.Weimake 1st anticline,which is NW-SE direction spreading,is controlled by the NW striking faults Fwi and Fw2,the west part of Weimake anticline-structure zone ; Weimake 2nd anticline,which is NE-SW direction spreading,is controlled by the NEE striking faults Fw3 and Fw4,the east part of Weimake anticline-structure zone; the deformation strata of the anticline whose faults system are the asymmetric positive flower structure having dynamics characteristics of extrusion and wreathe,are the middle-upper Ordovician,the Silurian,the Jurassic and the Cretaceous.The structure evolution of Weimake anticline-structure and its periphery area have five stages.The crustal shortening of the belt between Weimake anticline-structure zone and the Quruqtagh Mountain front is 37.4 km,the crustal shortening of the south slope of Yingjisu Sag is 4.31 km,the shortening rate is 25.32% . This research thinks the positive flower structure of Weimake anticline faults system,is the result of the interaction of NW striking and NEE striking faults system.The structure stress from south and north generate strike-slip effect in Weimake anticline-structure zone,made the Weimake anticline fault system have the characteristics of extrusion and wrench movement.%维马克背斜构造带

  20. Los carbonatos marinos aptienses del anticlinal de Santillana del Mar. Cantabria: Procesos diagenéticos y su relación con los contenidos en Sr. Fe y Mn

    Directory of Open Access Journals (Sweden)

    Fort, R.

    1990-04-01

    Full Text Available Strontium, Fe, and Mn are reported for lower Cretaceous carbonate rocks from Santillana del Mar anticline, Cantabria. The carbonate rocks studied in this work include limestones, dolostones, and dedolomitized dolostones. The limestones are packstones composed of orbitolinid debris. The dolostones consist of geometric hypidiotopic mosaics with crystals ranging from 50 um up to 200 um, diagenesis having obliterated almost all primary textures. Only sorne orbitolinid ghosts are presento Mean values obtained for Sr, Fe, and Mn contents in limestones are 216 ppm, 605 ppm, and 33 ppm, respectively. For dolostones, these values are 48 ppm, 9.740 ppm, and 165 pp, respectively. Finally, mean values for Sr, Fe and Mn in dedolomitized dolostones are 15 ppm, 12.202 ppm, and 202 ppm, respectively. These values are agreed with previous hypothesis about dolomitization by late diagenetic processes and dedolomitization in a meteoric environment. Although Sr contents can be a useful tool in limestones diagenesis, Sr/Fe and Sr/Mn ratios reveal more clearly the different diagenetic processes wich take place in carbonate rocks.En este trabajo se hace un estudio de los contenidos en Sr, Fe y Mn en los carbonatos del Cretácico inferior del anticlinal de Santillana del Mar, Cantabria. Las rocas carbonáticas estudiadas incluyen calizas, dolomías y dolomías dedolomitizadas. Las calizas están constituidas por packstones de orbitolinas. Las dolomías son mosaicos de cristales con tamaños que oscilan entre 50 micras y 200 micras, habienduo destruido la diagénesis casi todas las texturas primarias. Unicamente se observan algunos fantasmas de orbitolinas. Los valores medios obtenidos para el Sr, Fe y Mn en las calizas, son 216 ppm, 605 ppm y 33 ppm, respectivamente. Para las dolomías estos valores son de 48 ppm, 9.740 ppm y 165 ppm, respectivamente y, por último, en las dolomías dedolomitizadas los contenidos medios presentes para el Sr, Fe y Mn son de 15 ppm, 12

  1. Petrophysical examination of CO₂-brine-rock interactions-results of the first stage of long-term experiments in the potential Zaosie Anticline reservoir (central Poland) for CO₂ storage.

    Science.gov (United States)

    Tarkowski, Radosław; Wdowin, Magdalena; Manecki, Maciej

    2015-01-01

    The objective of the study was determination of experiment-induced alterations and changes in the properties of reservoir rocks and sealing rocks sampled from potential reservoir for CO₂. In the experiment, rocks submerged in brine in specially constructed reactors were subjected to CO₂ pressure of 6 MPa for 20 months at room temperature. Samples of Lower Jurassic reservoir rocks and sealing rocks (sandstones, claystones, and mudstones) from the Zaosie Anticline (central Poland) were analysed for their petrophysical properties (specific surface area, porosity, pore size and distribution) before and after the experiment. Comparison of the ionic composition the brines before and after the experiment demonstrated an increase in total dissolved solids as well as the concentration of sulphates and calcium ions. This indicates partial dissolution of the rock matrix and the cements. As a result of the reaction, the properties of reservoir rocks did not changed significantly and should not affect the process of CO₂ storage. In the case of the sealing rocks, however, the porosity, the framework density, as well as the average capillary and threshold diameter increased. Also, the pore distribution in the pore space changed in favour of larger pores. The reasons for these changes could not be explained by petrographic characteristics and should be thoroughly investigated.

  2. PALEOEARTHQUAKE EVENTS AND FORMATION OF RIVER TERRACES IN ACTIVE ANTICLINE REGION,NORTHERN PIEDMONT OF TIANSHAN MOUNTAINS, CHINA%天山北麓活动背斜区河流阶地与古地震事件

    Institute of Scientific and Technical Information of China (English)

    杨晓平; 李安; 黄伟亮; 张玲

    2011-01-01

    Using the aerial remote sensing photos and Google earth satellite images,we find seven terraces at the both sides along the Kuytun River in Dushanzi active anticline area, northern piedmont of Tians-han. Based on the field investigation, we find that all these terraces are pedestal terraces. The rock of pedestal is Pliocene mud rock, and on the top of each terrace pedestal are the stratums of sandy gravel or sandy clay with 2. 5 ~ 15m in thickness. We collected samples from deposits of all terraces for OSL (optically stimulated luminescence) geological dating using the SMAR( single-multiple-aliquot-regeneration) method on fine grains. We also performed dating using the C method to the samples from the deposit of terrace T, of the Kuytun River. The results show that the ages of all these deposits are the later phase of the Late Pleistocene. The accumulation time of the upper stratum for T, , T2, T3 , T5 , T6and T7 terraces is about 1. 7ka, 14. 98ka,20. 7 ~ 27. 3ka,29. 3 ~ 39. 2ka,47 ~ 56ka and 103 ~ 118ka,respectively. Combining with late Quaternary climate change,we believe that the formation age forT1 ~T7 terraces of Kuytun River are 1. 7ka, 14ka,20ka,25ka, 30ka,50ka and lOOkaBP. Paleo-earthquake data reveal that eight paleoearthquake events occurred on the Dushanzi-Anjihai reverse fault since about 25ka BP, respectively at 2ka, 3. 4ka, 4. 3ka, 5. 8ka, 7. 5ka, 12. 8ka, 18ka and 24ka BP. Comparing the ages of paleoearthquakes and terraces,we find that the ages of the latest,the sixth, the seventh and the eighth paleoearthquake are roughly corresponding to the formation times of T1 , T2 ,T3and T4 terraces,respectively. The other four paleoearthquake events occurred during the period after the formation of T2and before the formation of T,. In this time,no terraces developed along the Kuytun River, but the Kuytun River incised rapidly for 40m. We believe that the paleoearthquake e-vents resulted in the fast uplift of Dushanzi active anticline on the hanging wall of

  3. Geochemical surface exploration between Bueckeberge Hills and Rehburg Anticline (Lower Saxony Basin, Germany)

    Energy Technology Data Exchange (ETDEWEB)

    Berner, U. [Bundesanstalt fuer Geowissenschaften und Rohstoffe, Hannover (Germany); Marquardt, D. [Rijksuniversiteit Utrecht (Netherlands)

    2013-01-15

    The Lower Saxony Basin (LSB) of northwestern Germany is since long a target in hydrocarbon-related research in which the organic-rich Wealden sediments, known to contain good to excellent source rocks, play an important role. We demonstrate that cost effective surface exploration and geochemical research provide significant insight into the petroleum geology of an area of interest. Our research concentrates on a sub-basin in the eastern part of the LSB and aims at assessing the petroleum geology, hydrocarbon potential, depositional environment and tectonics of the Stadthagen syncline using surface samples of Wealden outcrops and evaluating these subsequently with geochemical methods (XRF, total sulfur, total organic carbon, Rock-Eval pyrolysis) and physical property data. The depositional environment in the research area varied significantly throughout the Lower Cretaceous (oxic to anoxic) due to paleoclimate changes and tectonically induced marine ingressions. Microbial sulfate reduction related to the marine ingressions reduced organic matter quality in the basin significantly, supporting the strong vertical variability in hydrocarbon potential of the sediments. Thermal maturity data suggests a complex tectonic history for the Stadthagen syncline. Thermal maturities (oil to wet gas window) combined with a multi-heat flow scenario result in estimated burial and subsequent uplift in the region of more than 2500 m. (orig.)

  4. Relation between shell beds and trace fossils of the Albian-Cenomanian Aitamir Formation in Amirabad anticline- northeast Mashhad

    OpenAIRE

    2012-01-01

    Aitamir Formation (Albian-Cenomanian) in the Kopet-Dagh Basin has diverse trace fossils and several shell beds. These trace fossils contain diverse ethological patterns, including domichnia, fodinichnia, grazing, equilibrichnia, navichnia, chemichnia and fugichnia. The types of shell beds distinguished based on differences in sedimentological, palaeoecological and taphonomic features. Shell beds and sandstone layers containing characteristic trace fossils represent a storm-influenced successi...

  5. Use of speleologic data to evaluate Holocene uplifting and tilting: an example from the Frasassi anticline (northeastern Apennines, Italy)

    NARCIS (Netherlands)

    Mariani, S.; Mainiero, M.; Barchi, M.; van der Borg, K.; Vonhof, H.B.; Montanari, A.

    2007-01-01

    Deep inside the Frasassi cave complex in the foreland fold and thrust belt of the northeastern Apennines (central Italy), the remains of hundreds of eels (Anguilla anguilla) are found scattered on the shores of phreatic lakes up to 5 m above the water table. These sub-fossil eels, and the speleothem

  6. Formation of diapiric structure in the deformation zone, central Indian Ocean: A model from gravity and seismic reflection data

    Digital Repository Service at National Institute of Oceanography (India)

    Krishna, K.S.; Rao, D.G.; Neprochnov, Y.P.

    Analyses of bathymetry, gravity and seismic reflection data of the diffusive plate boundary in the central Indian Ocean reveal a new kind of deformed structure besides the well-reported structures of long-wavelength anticlinal basement rises...

  7. The parenchymo-vascular cambium and its derivative tissues in stems and roots of Bougainvillaea glabra Choisy (Nyctaginaceae)

    OpenAIRE

    Z. Puławska

    2015-01-01

    In the shoots and roots of Bougainmllaea, the parenchymo-vascular cambium produces thinwalled secondary parenchyma to one side and the secondary vascular bundles embedded in the "conjunctive tissue" to the other. Periclinal division of a single cambial cell in one radial row brings about periclinal divisions of the adjacent cells of the neighbouring rows. Anticlinal division of a single cambial cell at one level, on the other hand, causes anticlinal. divisions of the adjacent cells of the ove...

  8. Philosophy of Petroleum Exploration Promoting the Petroleum Geoscience and Exploration Technology

    Institute of Scientific and Technical Information of China (English)

    SongJianguo

    2004-01-01

    From the mid-1800s to the present, the philosophy of oil and gas exploration has had three major breakthroughs. The first breakthrough--from oil seepage to the anticlinal theory; The second breakthrough--from the anticlinal theory to the trap theory; The third breakthrough--from the trap theory to the petroleum system. The philosophy of oil finding promotes the petroleum geosciences and exploration technology.

  9. Determination of density pattern of fracture in Asmari Formation in Marun oilfield

    Directory of Open Access Journals (Sweden)

    Kheyrollah Noraeinezhad

    2015-05-01

    Full Text Available Marun oilfield is located in the middle part of Dezful Embayment and is situated along the Aghajari, Ahvaz and Ramin anticline. Given the important role of fracture characteristics for improving production, so the aim of this research is to investigate the density pattern of fracture in Asmari formation in Marun oilfield. For this purpose, results of image log, core data, graphic well log, methods of inscribed circle analysis and curvature changes geometry of anticline were analyzed. Asmari formation is the main reservoir rock in Marun oilfield that divided into five zones. Limestone and dolomite are the main lithology of zones 1, 2 and 3 which has a high density of fractures (especially in zones with 90% dolomite. Also there is less fracture density (micro fracture in the 4 and 5 Asmari zone due to an increase of shale and marl layers and due to less break ablity has a less distribution of fractures. The result show that there are a good conformity existed between the results of inscribed circle analysis, image log, core data, curvature and the presence of fractures in Marun anticline. The data indicate that highest density of fracture density concentrates in the southern limb in the central region of anticline and also in the north limb in the northeast region of the anticline. So, finally using these parameters, it is recommended that further development and production wells be drilled in the north eastern part of the oil filed as well as center part of southern flank of the anticline.

  10. Interference between thick- and thin-skinned tectonics along mountain fronts. Example of the Andean foothill (Neuquén basin, Argentina)

    Science.gov (United States)

    Nivière, B.; Messager, G.; Lacan, P.; Xavier, J.

    2007-12-01

    The Chihuido anticline (37°30'S-38°40'S and 69° W-70° W) in western Argentina underlines the eastern orogenic front of Andes. North-south-oriented, it is a crustal-scale anticline, 120 km long and 80 km wide. It culminates at 1500 m in elevation. It is limited to the west by the Agua Amarga syncline and by the deep-rooted Salado fault system late Cretaceous in age. The main river of the area, the Neuquén river, runs north-south behind the Chihuidos to the west in the Agua Amarga syncline. To the south, it bends to the east across the southern terminaison of the anticline. To the north, the northern end of the Chihuido had been cross cut by the Colorado river that currently flows 60 km farther to the north. Folding of terrace remnants of these rivers attests of a Pleistocene tectonic activity of the anticline. They appear clearly bended over a length of ca 30 km with an amplitude of 350 m at the apex. Behind the anticline above the Agua Amarga syncline, the rio Neuquén is depositing a strong thickness of alluvial deposits. Uplift of the anticline resulted in an increase of dip, to the west and to the east, of a decollement level made of the Huitrin evaporites Aptian in age. This tilt allowed decollement of pelicular shales and sandstones of the Rayoso formation and of the Cenamanian continental redbed clastics of the Neuquén group above it. This slide lead to the opening of valleys at the apex of the anticline, interprated as extrado tension gashes, and to the growth of superficial folds at the eastern toe of the Chihuido. These folds root in the Huitrin evaporites and achieve extension of the apex of the anticline. Farther to the west along the Salado fault system, vertical offset of Pleistocene alluvial fans with surface faulting attest of an on-going reactivation of the former mountain front. This reactivation is interprated as the consequence of the uplift of the Chihuido fold. The increase of dip of the decollement level beneath the former tectonic wedge

  11. Application of Mixture of Gaussian Clustering on Joint Facies Interpretation of Seismic and Magnetotelluric Sections

    Science.gov (United States)

    Shahrabi, Mohammad Ali; Hashemi, Hosein; Hafizi, Mohammad Kazem

    2016-02-01

    Seismic and magnetotelluric (MT) methods are the most applicable geophysical methods in exploration of hydrocarbon resources. In this paper, mixture of Gaussian clustering is used to combine seismic and MT images under the scheme of Expectation/Maximization (EM) algorithm. Pre-Stack Depth Migration (PSDM) velocity, Root Mean Square (RMS) velocity and vertical gradient of RMS velocity of seismic and resistivity model of MT along 19.3 km MUN-21 profile in Munir Block that has been located in Southwest of Iran in Dezful embayment over the Seh-Qanat anticline are applied. The anticline is the most important oil trap of this area. The Expectation/Maximization (EM) method that has been applied includes: (1) creation of data vectors from the seismic and MT images using image processing techniques, (2) normalizing and mapping using Principal Component Analysis (PCA) procedure (3) unsupervised learning of dataset matrix, (4) setting the matrix in Expectation/Maximization (EM) iteration algorithm (5) remapping to physical space. The final model consists fof six classes which could be given to eight formations that belong to Eocene to Neocomian geological age. Pre-Stack Depth Migration (PSDM) velocity model obtained from seismic study on Seh-Qanat anticline only detected 2 horizons of formations, Asmari and Sarvak Formations; however, the current methodology introduces subdivision anticline into six classes by matching it to the log information of Seh-Qanat Deep-1 (SQD-1) borehole where it was excavated over the anticline with total depth of 2876 m.

  12. Quaternary folding in the south piedmont of central segment of Tianshan Mountains

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The Tianshan Mountains are an important active structural belt in the interior of Eurasia. By integrated methods of surface geology survey and interpretation of seismic profiles, we distinguish fold scarps located at the south limb of the Kuqatawu anticline and the north limb of the Dongqiulitag anticline in the Kuqa rejuvenation foreland thrust belt, south piedmont of central segment of the Tianshan Mountains. Fold scarp is a newly found structural phenomenon. Because of the bend of thrust plane and the movement of hanging wall above the thrust plane, the original horizontal deposits of hanging wall and their surface become a monocline structure, resulting from the separating and migration of the active and fixed axial surfaces. Measuring the geometry of fold scarp and using the data of age of the deformed deposits, the crustal shortening rate resulting from the deeply seated subsurface thrust is calculated. The crustal shortening rate reflected by the fold scarp located at the north limb of the Dngqiulitag anticline is (1±0.1) mm/a. The fold scarps of the Dongqiulitag anticline and the Kuqatawu anticline identify that the deformation process of the crustal compressive structures in the Kuqa area extends into the Late Quaternary.

  13. Two conceptual models of displacement transfer and examples

    Institute of Scientific and Technical Information of China (English)

    GUAN; Shuwei; WANG; Xin; YANG; Shufeng; HE; Dengfa; ZHAO; W

    2005-01-01

    This paper presents two conceptual models of displacement transfer, reverse symmetry model and infinitely equal division model, based on the fault-bend folding theory. If the fault shape is held constant in the trend, then the distribution of slip magnitude, geometry of imbricate structures and its axial surface map all display reverse symmetry on the process of displacement transfer, as called reverse symmetry model in this paper. However, if the ramp height of thrust fault decreases gradually along its strike, the displacement is postulated to be equally and infinitely divided to every thrust that is formed subsequently, this kinematic process is described using infinitely equal division model. In both models, displacement transfer is characterized by the regular changes of imbricate thrusting in the trend. Geometric analysis indicates that the displacement transfer grads can be estimated using the tangent of deflective angle of hinterland structures. Displacement transfer is often responsible for the distortion and branching of the surface anticlines, especially in the region where the multi-level detachment structures is developed. We also present some examples from the frontal structures of the Southern Tianshan fold-and-thrust belt, Xinjiang, China. Displacement transfer between deep imbricate thrusts in the middle segment of Qiulitag anticline zone causes the Kuqatawu and Southern Qiulitag deep anticlines left-lateral echelon. The region, where these two deep anticlines overlap, is characterized by duplex structures, and extends about 18 km. The shallow anticline is migrated southward displaying obvious "S" form in this area.

  14. The parenchymo-vascular cambium and its derivative tissues in stems and roots of Bougainvillaea glabra Choisy (Nyctaginaceae

    Directory of Open Access Journals (Sweden)

    Z. Puławska

    2015-01-01

    Full Text Available In the shoots and roots of Bougainmllaea, the parenchymo-vascular cambium produces thinwalled secondary parenchyma to one side and the secondary vascular bundles embedded in the "conjunctive tissue" to the other. Periclinal division of a single cambial cell in one radial row brings about periclinal divisions of the adjacent cells of the neighbouring rows. Anticlinal division of a single cambial cell at one level, on the other hand, causes anticlinal. divisions of the adjacent cells of the overlying and underlying tiers.

  15. Variações químicas e mineralógicas na zona de cisalhamento de Gouveia (Minas Gerais) e suas implicações no processo de reativação tectônica.

    OpenAIRE

    Cruz, Simone Cerqueira Pereira; Evangelista, Hanna Jordt; Alkmim, Fernando Flecha de

    2005-01-01

    A zona de cisalhamento dúctil-rúptil de Gouveia, junto com três outras estruturas similares a ela, se entende por 10 km no embasamento do núcleo do Anticlinório de Gouveia, uma culminação regional nucleada na porção externa do cinturão de dobramentos e cavalgamentos Araçuaí, de idade neoproterozóica. O embasamento do Anticlinório de Gouveia consiste essencialmente de migmatitos arqueanos, granitóides e xistos, enquanto as unidades de coberturas compreendem seqüências de quartzitos e filitos d...

  16. New geological-geophysical data on the structure of the Ninetyeast Ridge

    Digital Repository Service at National Institute of Oceanography (India)

    Levchenko, O.V.; Sager, W.W.; Frey, F.A.; Pringle, M.S.; Krishna, K.S.; Rao, D.G.; Gauntlett, E.; Mervine, E.E.; Marinova, Y.G.; Piotrowski, A.A.; Paul, S.F.; Huang, S.; Eisin, A.E.

    fan. Farther up to 17 degrees N, the Ninetyeast Ridge is traceable in the form of a buried anticlinal uplift of the oceanic basaltic basement. There are many hypotheses proposed for explaining the origin of this enigmatic structure, of which two...

  17. Strontium isotopes as an indicator for groundwater salinity sources in the Kirkuk region, Iraq.

    Science.gov (United States)

    Sahib, Layth Y; Marandi, Andres; Schüth, Christoph

    2016-08-15

    The Kirkuk region in northern Iraq hosts some of the largest oil fields in the Middle East. Several anticline structures enabled vertical migration and entrapment of the oil. Frequently, complex fracture systems and faults cut across the Eocene and middle Oligocene reservoirs and the cap rock, the Fatha Formation of Miocene age. Seepage of crude oil and oil field brines are therefore a common observation in the anticline axes and contamination of shallow groundwater resources is a major concern. In this study, 65 water samples were collected in the Kirkuk region to analyze and distinguish mixing processes between shallow groundwater resources, uprising oil field brines, and dissolution of gypsum and halite from the Fatha Formation. Hydrochemical analyses of the water samples included general hydrochemistry, stable water isotopes, as well as strontium concentrations and for 22 of the samples strontium isotopes ((87)Sr/(86)Sr). Strontium concentrations increased close to the anticline axes with highest concentrations in the oil field brines (300mg/l). Strontium isotopes proved to be a valuable tool to distinguish mixing processes as isotope signatures of the oil field brines and of waters from the Fatha Formation are significantly different. It could be shown, that mixing of shallow groundwater with oil field brines is occurring close to the major fault zones in the anticlines but high concentrations of strontium in the water samples are mainly due to dissolution from the Fatha Formation.

  18. Petroleum resources assessment (II)

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-12-01

    This report consists of 4 subjects. 1) An interactive seismic velocity analysis, 2) AVO analysis for direct hydrocarbon detection, 3) 3D seismic data processing, 4) Study of structural(syncline) effect of the near surface on the resolution of anticline oil trap structure by seismic modeling. (author). 36 refs., 3 tabs., 97 figs.

  19. Pectin degradation by Botrytis cinerea: recognition of endopolygalacturonases by an Arabidopsis receptor and utilization of Dgalacturonic acid

    NARCIS (Netherlands)

    Lisha Zhang, Lisha

    2013-01-01

    The necrotrophic fungal plant pathogenBotrytis cinerea is able to infect over 200 host plants and cause severe damage to crops, both pre- and post-harvest. B. cinerea often penetrates host leaf tissue at the anticlinal cell wall and subsequently grows into and through the middle lamella, which consi

  20. Structural deformation pattern within the NW Qaidam Basin in the Cenozoic era and its tectonic implications

    Science.gov (United States)

    Mao, Liguang; Xiao, Ancheng; Zhang, Hongwei; Wu, Zhankui; Wang, Liqun; Shen, Ya; Wu, Lei

    2016-09-01

    The Qaidam Basin is located in the northeastern Tibetan Plateau and provides an excellent field laboratory in understanding the history and mechanism of the plateau growth. It deformed widely over the northwest during the Cenozoic but with little thrust loading along the margins, where no foreland depression is observed. Based on satellite images, seismic and borehole data, we investigated the structural deformation pattern (including the structural style and timing of deformation) and its formation mechanism within the northwestern Qaidam Basin during the Cenozoic era. Mapping of surface geology shows that the modern Qaidam Basin is characterized by five SE-trending anticlinal belts. Each belt consists of several right-step en echelon anticlines with plenty of normal and strike-slip faults crossing the crests. Those anticlines are generally dominated by double fault systems at different depths: an upper thrust fault system, controlling the anticlines identified on the surface and a lower dextral transpressional fault system characterized by typical flower structures. They are separated by weak layers in the upper Xiaganchaigou or the Shangganchaigou formations. The upper system yields shortening strain 2-5 times larger than that of the lower system and the additional strain is interpreted to be accommodated by hinge-parallel elongation in the upper system. Growth strata indicate that deformation within the Qaidam Basin initiated in the middle Miocene ( 15 Ma) and accelerated in the late Miocene ( 8 Ma). A simple Riedel-P-Shear model is used to explain the deformation mechanism within the northwestern Qaidam Basin.

  1. The development and geometry of shape change in Arabidopsis thaliana cotyledon pavement cells

    Directory of Open Access Journals (Sweden)

    Halsey Leah E

    2011-02-01

    Full Text Available Abstract Background The leaf epidermis is an important architectural control element that influences the growth properties of underlying tissues and the overall form of the organ. In dicots, interdigitated pavement cells are the building blocks of the tissue, and their morphogenesis includes the assembly of specialized cell walls that surround the apical, basal, and lateral (anticlinal cell surfaces. The microtubule and actin cytoskeletons are highly polarized along the cortex of the anticlinal wall; however, the relationships between these arrays and cell morphogenesis are unclear. Results We developed new quantitative tools to compare population-level growth statistics with time-lapse imaging of cotyledon pavement cells in an intact tissue. The analysis revealed alternating waves of lobe initiation and a phase of lateral isotropic expansion that persisted for days. During lateral isotropic diffuse growth, microtubule organization varied greatly between cell surfaces. Parallel microtubule bundles were distributed unevenly along the anticlinal surface, with subsets marking stable cortical domains at cell indentations and others clearly populating the cortex within convex cell protrusions. Conclusions Pavement cell morphogenesis is discontinuous, and includes punctuated phases of lobe initiation and lateral isotropic expansion. In the epidermis, lateral isotropic growth is independent of pavement cell size and shape. Cortical microtubules along the upper cell surface and stable cortical patches of anticlinal microtubules may coordinate the growth behaviors of orthogonal cell walls. This work illustrates the importance of directly linking protein localization data to the growth behavior of leaf epidermal cells.

  2. Inversion of surface subsidence data to quantify reservoir compartmentalization: A field study

    NARCIS (Netherlands)

    Fokker, P.A.; Visser, K.; Peters, E.; Kunakbayeva, G.; Muntendam-Bos, A.G.

    2010-01-01

    The Roswinkel gas field in the northeastern part of the Netherlands has been in production between 1980 and 2005. Located at about 2100 m depth, it is a severely faulted anticlinal structure, constituting up to 30 reservoir compartments. Due to the complicated nature of this field, there are large u

  3. Void space structure in carbonate deposits of the Voronezh Horizon in the Pripyat trough

    Energy Technology Data Exchange (ETDEWEB)

    Kazenkina, G.A.; Demidovich, L.A.

    1977-05-01

    Change characteristics in void space were identified by studying the void space of carbonate rock-collectors on model-counterparts and by petrographic studies. The rock in the anticline sections of local structures have the most complex structure. Mixed types of collectors predominate here. 1 table, 2 figures, 2 references.

  4. Tectonic setting of the Wooded Island earthquake swarm, eastern Washington

    Science.gov (United States)

    Blakely, Richard J.; Sherrod, Brian L.; Weaver, Craig S.; Rohay, Alan C.; Wells, Ray E.

    2012-01-01

    Magnetic anomalies provide insights into the tectonic implications of a swarm of ~1500 shallow (~1 km deep) earthquakes that occurred in 2009 on the Hanford site,Washington. Epicenters were concentrated in a 2 km2 area nearWooded Island in the Columbia River. The largest earthquake (M 3.0) had first motions consistent with slip on a northwest-striking reverse fault. The swarm was accompanied by 35 mm of vertical surface deformation, seen in satellite interferometry (InSAR), interpreted to be caused by ~50 mm of slip on a northwest-striking reverse fault and associated bedding-plane fault in the underlying Columbia River Basalt Group (CRBG). A magnetic anomaly over exposed CRBG at Yakima Ridge 40 km northwest of Wooded Island extends southeastward beyond the ridge to the Columbia River, suggesting that the Yakima Ridge anticline and its associated thrust fault extend southeastward in the subsurface. In map view, the concealed anticline passes through the earthquake swarm and lies parallel to reverse faults determined from first motions and InSAR data. A forward model of the magnetic anomaly near Wooded Island is consistent with uplift of concealed CRBG, with the top surface swarm and the thrust and bedding-plane faults modeled from interferometry all fall within the northeastern limb of the faulted anticline. Although fluids may be responsible for triggering the Wooded Island earthquake swarm, the seismic and aseismic deformation are consistent with regional-scale tectonic compression across the concealed Yakima Ridge anticline.

  5. Structural Evolution of a Fold-And-Thrust Belt in Hsinchu-Miaoli area, Taiwan

    Science.gov (United States)

    Chen, T. W.; Huang, S. T.; Hu, J. C.

    2015-12-01

    Hsinchu-Miaoli area is the major hydrocarbon producing fields in Taiwan. Oil and gas production in the area have been explored and produced since 1861, and the oldest gas field is still producing gas until now. To understand the nature and the geometry of the reservoirs in this area, 82 wells were drilled in the Chinshui Field, which is one of the important gas fields in the Hsinchu-Miaoli area. However, the subsurface structures and fracture distribution of these fields are still unclear, and the reason for the long time producing is also unknown. Fractures in the oil-bearing reservoir might be one of the important factors of the long time gas producing, but the fracture reservoirs attaining hydrocarbons associated with fault-related folding need to be further clarified. First, we represent a new structural interpretation of Chinshui and adjacent Chuhuangkeng anticlines by a geological cross section across from Miaoli offshore to inner foothills. By comparing the total shortening distances among several published cross sections and the profile in this study, we construct the deformation pattern model in Hsinchu-Miaoli area. Furthermore, we then use Discrete Element Method (DEM) to reconstruct the evolution model of the Chinshui anticline based on the cross sections in the study area. This model can provide fracture densities of Chinshui anticline and also the geometry of potential hydrocarbon reservoirs. According to the result of our restoration, the total shortening distance of the geological cross section is about 20.3km and the entire slip of the deep thrust faults in Chinshui anticline is 5.8 km. This result is similar with previous published cross sections around this region. And the structural evolution of Chinshui anticline would further apply in the model of fracture distribution and densities.

  6. Deformation of the Manazuru Knoll in Sagami Bay, central Japan, associated with subduction of the Philippine Sea plate

    Science.gov (United States)

    No, Tetsuo; Takahashi, Narumi; Miura, Seiichi; Yamashita, Mikiya; Kido, Yukari; Kodaira, Shuichi

    2014-12-01

    In January 2010, we conducted a multichannel seismic (MCS) reflection survey in Sagami Bay. As a result of this study, the deformation of the Manazuru Knoll, which is located near the plate boundary, was obtained. The Manazuru Knoll was formed by an asymmetric anticline, and the knoll has a geometry that is bent in a shape similar to that of a crank. The anticlinal axis, which was confirmed by MCS data, lies along the anticlinal axis shown on the bathymetric map, and the axis is bent first to the southeast and then to the east. It is estimated that the easternmost part of Manazuru Knoll has reached the vicinity of Miura Canyon. The offset of the strike of the anticline axis is approximately 7 km. A reverse fault related to the formation of Manazuru Knoll was identified in the southwestern side of the knoll. It is hypothesized that this reverse fault formed as a result of shortening of the structure, which occurred when the relative motion of the Philippine Sea plate was acting in a perpendicular direction close to the Manazuru Knoll. Therefore, it is estimated that the relative motion of the Philippine Sea plate was almost oblique or parallel to the anticlinal axis of Manazuru Knoll and that the eastern end of Manazuru Knoll was bent into a crank shape by strike-slip motion. This suggests that a part of Manazuru Knoll, located to the west of the plate boundary, moved to the northwest. Finally, it is assumed that the sediments of Miura Canyon and Sagami Knoll have been overlapping on the eastern end of Manazuru Knoll.

  7. Evaluation of thrusting and folding of the Deadman Creek Thrust Fault, Sangre de Cristo range, Saguache County, Colorado

    Science.gov (United States)

    Weigel, Jacob F., II

    The Deadman Creek Thrust Fault was mapped in a structural window on the west side of the Sangre de Cristo Range. The study area, located in southern Colorado, is a two square mile area halfway between the town of Crestone and the Great Sand Dunes National Park. The Deadman Creek Thrust Fault is the center of this study because it delineates the fold structure in the structural window. The fault is a northeast-directed low-angle thrust folded by subsequent additional compression. This study was directed at understanding the motion of the Deadman Creek Thrust Fault as affected by subsequent folding, and the driving mechanism behind the folding of the Pole Creek Anticline as part of a broader study of Laramide thrust faulting in the range. This study aids in the interpretation of the geologic structure of the San Luis Valley, which is being studied by staff of the United States Geological Survey (USGS), to understand Rio Grande Rift basin evolution by focusing on rift and pre-rift tectonic activity. It also provides a geologic interpretation for the Saguache County Forest Service, Great Sand Dunes National Park, and its visitors. The Sangre de Cristo Mountain Range has undergone tectonic events in the Proterozoic, Pennsylvanian (Ancestral Rocky Mountains), Cretaceous-Tertiary (Laramide Orogeny) and mid-Tertiary (Rio Grande Rift). During the Laramide Orogeny the Deadman Creek Thrust Fault emplaced Proterozoic gneiss over Paleozoic sedimentary rocks and Proterozoic granodiorite in the area. Continued deformation resulted in folding of the fault to form the Pole Creek Anticline. The direction of motion of both the fault and fold is northeastward. A self-consistent net of cross-sections and stereonet plots generated from existing and new field data show that the anticline is an overturned isoclinal fold in Pole Creek Canyon, which shows an increasing inter-limb angle and a more vertical axial surface northwestward toward Deadman Creek Canyon. Southwest-directed apparent

  8. A case for wind enhanced tectonics: Plio-Quaternary sedimentation, erosion, and structural evolution controlled by wind within the Qaidam Basin, China

    Science.gov (United States)

    Heermance, R. V.; Kapp, P. A.; Pullen, A.; Garzione, C. N.

    2012-12-01

    The interplay between tectonics and localized erosion through fluvial and/or glacial processes has been widely documented. Wind erosion, however, has gone largely un-recognized as a potentially important process in this concept. We document an acceleration in shortening in response to wind deflation above actively deforming fault propagation anticlines since ~3.0 Ma in the Qaidam Basin, China. Evidence for this comes from a 1750 m measured section along the southwestern flank of an intra-basin anticline (38.33°N, 93.46°E) and regional cross-sections. Magnetostratigraphy provides age control for prominent stratigraphic and isotopic changes within the section. A positive shift of ~6‰ in the δ18O values of lake carbonates occurs at 1090 m (3.1 Ma), interpreted to be the result of increased aridity at that time. An intraformational angular unconformity, associated with anticline growth, appears at 1172 m (3.0 Ma) and records the initiation of growth strata deposition. At 1235 m (2.6 Ma), a marked lithofacies change to sub-aerial, evaporitic conditions is observed, and is associated with a 3-fold reduction in sedimentation rate. Paleo-yardangs, which are wind-eroded landforms preserved in the stratigraphic record, appear at 1260 m (2.4 Ma). These observations indicate that regional aridification at 3.1 Ma was followed closely by or coincident with fold growth. Facies changes to more evaporitic strata and erosion of the basin floor (based on paleo-yardangs) trailed initial climate and tectonic changes by 500,000-700,000 years. Although the on-lap relationship of post-growth strata implies that syn-tectonic strata may have pinched-out along the flanks of the anticline, our new analysis indicates that at least 1172 m of pre-growth strata must have been eroded from the core of the anticline since 3.0 Ma at a time-averaged rate of ~0.4 mm/year, comparable to fluvial and glacial erosion rates within active tectonic settings. The lack of an integrated fluvial channel

  9. The geological structure characteristics of Qinshui coalfield Changjiazhuang exploration area%沁水煤田常家庄勘查区地质构造特征

    Institute of Scientific and Technical Information of China (English)

    李重阳

    2015-01-01

    结合沁水煤田常家庄勘查区的地理位置,对该勘查区内构造特征进行了研究,指出该区内构造简单,主要构造有寺头断层、松树凹向斜、小柳沟背斜,地层总体走向为北北东向,倾角3°~25°。%Combining with the geographic position of Qinshui coalfield Changjiazhuang exploration area,this paper researched the interior struc-ture characteristics of this exploration area,pointed out that this area had simple interior structure,the main structure had Sitou fault,pine hollow anticline,little willow ditch anticline,the formation general trend general strike was NNE direction,inclination was 3°~25°.

  10. Genetic-Structural relations in some types of spanish uranium deposits; Relaciones genetico-estructurales de algunos tipos de mienralizaciones uraniferas espanolas

    Energy Technology Data Exchange (ETDEWEB)

    Alia Medina, M.

    1962-07-01

    On the spanish hercynian areas there are different types of uraniferous deposits, which may be classified in the following groups: Group I, high temperature magmatic deposits, Group II, low temperature veins and Group III supergenic deposits, generated by weathering of the former ones or by lixiviation of the intra granitic uranium. The deposits belonging to Group I are founding the hercynian ge anticlinal; those of Groups II and III, chiefly in the eugeosyncline. The explanation suggested for these genetic-structural relationships assumes that, in the ge anticlinal, uranium would migrate from the dioritic magmas to form and high temperature deposits. In the eugeosyncline, a large fraction of the uranium would migrate towards more differentiated granites, in which it might partially remain or from which it might have been finally concentrated in the epithermal veins or by later tectonic actions. The Group III deposits ar more frequent in the eugeosyncline, due to the greater abundance of more differentiated intrusive rocks. (Author) 16 refs.

  11. Locations of nonstructural hydrocarbon traps on the shelf of the northern Barents Sea

    Science.gov (United States)

    Kazanin, G. S.; Pavlov, S. P.; Tarasov, G. A.; Schlykova, V. V.; Matishov, G. G.

    2016-11-01

    This paper considers the results of summarized integrated geophysical investigations that were carried out from 2006 to 2012. The investigations included common depth point (CDP) seismic reflection survey, over water gravity survey, and differential hydromagnetic exploration with a total work scope of 30 000 linear kilometers. The deep structural tectonic plan, the structural and lithofacies features of the sedimentary cover section on the basic reflecting boundaries, and the features of the seismogeological complexes and seismic sections on a depth scale have been studied, and geological oil-and-gas zoning of the Northern Barents shelf has been made. Seventy-nine local anticlinal highs have been revealed, and the zones with potential nonstructural hydrocarbon traps have been determined. Due to the lack of huge anticlinal highs in the northern Barents Sea region, nonstructural traps are of interest in studying and replacing the mineral raw material base of Russia, as well as for arranging marine exploration.

  12. Fluvial response to active extension: evidence from 3D seismic data from the Frio Formation (Oligo-Miocene) of the Texas Gulf of Mexico Coast, USA

    Energy Technology Data Exchange (ETDEWEB)

    J.R. Maynard [ExxonMobil Upstream Research Company, Houston, TX (United States)

    2006-06-15

    Tectonic deformation of the land surface is known to influence the gradient, water and sediment discharge and the grain-size of modern fluvial systems. Any change in these variables alters the equilibrium of a fluvial system, potentially causing a change in channel morphology. 3D seismic data from the Tertiary (Miocene) age, Upper Frio Formation, Kelsey Field, South Texas, in the US are used to examine changing fluvial channel morphology through time during a period of active growth of a rollover anticline in the hanging wall of a normal fault (the Vicksburg Fault). The studied interval varies between 22 and 47 m thick, and spans several hundred thousand years. It consists of an alternation of fluvial sandstones, overbank mudstones and coal. Seismic extractions show the evolution of sinuous fluvial channels during a phase of growth fault activity. Prior to growth, a single sinuous channel is imaged. During growth, the fluvial system became decapitated by a developing rollover anticline, and a highly sinuous drainage network formed, with frequent avulsion events, headward propagation of streams and related stream capture. Increased channel sinuosity was spatially associated with increased avulsion frequency in the area down dip to the east of the rollover anticline, more than 10 km from the active fault. More than 25 m of relative accommodation developed on the flank of the growing rollover anticline compared with on the crest. The increased channel sinuosity is interpreted as reflecting an increase in longitudinal valley slope analogous to observations made in flume experiments and modern river systems. The increase in avulsion frequency is attributed to increased aggradation as the rivers adjusted back to equilibrium grade following the increase in slope.

  13. Thermodynamic studies of induced antiferroelectric phases in chiral and racemic systems

    Science.gov (United States)

    Filipowicz, M.; Kula, P.; Czuprynski, Krzysztof

    2004-09-01

    Bi- and multicomponent mixtures consisted of two groups of synclinic chiral esters: first one with a partially fluorinated terminal chain and the second one with hydrogenated terminal chain have been used for investigations. For some systems the induction of the anticlinic smectic CA* phase was observed. Enthalpies of the phase transitions for the systems with induced smectic CA phase upon compositions and specific heat were measured by DSC method.

  14. Determining the groundwater potential recharge zone and karst springs catchment area: Saldoran region, western Iran

    Science.gov (United States)

    Karami, Gholam Hossein; Bagheri, Rahim; Rahimi, Fahimeh

    2016-08-01

    Assessing the groundwater recharge potential zone and differentiation of the spring catchment area are extremely important to effective management of groundwater systems and protection of water quality. The study area is located in the Saldoran karstic region, western Iran. It is characterized by a high rate of precipitation and recharge via highly permeable fractured karstic formations. Pire-Ghar, Sarabe-Babaheydar and Baghe-rostam are three major karstic springs which drain the Saldoran anticline. The mean discharge rate and electrical conductivity values for these springs were 3, 1.9 and 0.98 m3/s, and 475, 438 and 347 μS/cm, respectively. Geology, hydrogeology and geographical information system (GIS) methods were used to define the catchment areas of the major karstic springs and to map recharge zones in the Saldoran anticline. Seven major influencing factors on groundwater recharge rates (lithology, slope value and aspect, drainage, precipitation, fracture density and karstic domains) were integrated using GIS. Geology maps and field verification were used to determine the weights of factors. The final map was produced to reveal major zones of recharge potential. More than 80 % of the study area is terrain that has a recharge rate of 55-70 % (average 63 %). Evaluating the water budget of Saldoran Mountain showed that the total volume of karst water emerging from the Saldoran karst springs is equal to the total annual recharge on the anticline. Therefore, based on the geological and hydrogeological investigations, the catchment area of the mentioned karst springs includes the whole Saldoran anticline.

  15. Tectonic Setting of the Wooded Island Earthquake Swarm, Eastern Washington

    Energy Technology Data Exchange (ETDEWEB)

    Blakely, R. J.; Sherrod, B. L.; Weaver, C. S.; Rohay, A. C.; Wells, R. E.

    2012-08-01

    Magnetic anomalies provide insights into the tectonic implications of a swarm of ~1500 shallow (~1 km deep) earthquakes that occurred in 2009 on the Hanford site, Washington. Epicenters were concentrated in a 2 km2 area near Wooded Island in the Columbia River. The largest earthquake (M 3.0) had first motions consistent with slip on a northwest-striking reverse fault. The swarm was accompanied by 35 mm of vertical surface deformation, seen in satellite interferometry (InSAR), interpreted to be caused by ~50 mm of slip on a northwest-striking reverse fault and associated bedding-plane fault in the underlying Columbia River Basalt Group (CRBG). A magnetic anomaly over exposed CRBG at Yakima Ridge 40 km northwest of Wooded Island extends southeastward beyond the ridge to the Columbia River, suggesting that the Yakima Ridge anticline and its associated thrust fault extend southeastward in the subsurface. In map view, the concealed anticline passes through the earthquake swarm and lies parallel to reverse faults determined from first motions and InSAR data. A forward model of the magnetic anomaly near Wooded Island is consistent with uplift of concealed CRBG, with the top surface <200 m below the surface. The earthquake swarm and the thrust and bedding-plane faults modeled from interferometry all fall within the northeastern limb of the faulted anticline. Finally, although fluids may be responsible for triggering the Wooded Island earthquake swarm, the seismic and aseismic deformation are consistent with regional-scale tectonic compression across the concealed Yakima Ridge anticline.

  16. 3-Chloromethyl-6,7-dimethyl-1,2-benzoxazole

    Directory of Open Access Journals (Sweden)

    M. Kayalvizhi

    2012-10-01

    Full Text Available In the title compound, C10H10ClNO, the benzoisoxazole ring is almost planar (r.m.s. deviation = 0.0121 Å and the chloro substituent in the side chain is anticlinal relative to the N—C bond of the isoxazole ring. In the crystal, adjacent molecules are linked via a pair of weak C—H...N hydrogen bonds, forming dimers through a cyclic R22(8 association.

  17. Reactivation of a collisional suture by Miocene transpressional domes associated with the Red River and Song Chay detachment faults, northern Vietnam

    Science.gov (United States)

    Osozawa, Soichi; Van Vuong, Nguyen; Van Tich, Vu; Wakabayashi, John

    2015-06-01

    Elongate Miocene gneissose and granitic domes in northern Vietnam formed in a dextral-transpressional ductile shear regime, possibly associated with large-scale restraining step-overs along dextral faults. Initial anticlinal D1 doming involved folding of both basement and hanging wall rocks with D1 secondary folds that verge toward the anticlinal axes. Such folds reflect dome-scale flexural slip folding. With continued shortening, D2 detachment faults developed on the flanks of the anticlines along the hanging wall-basement interface, so that the basement was extruded vertically into the overlying hanging wall rocks. The detachment faults were associated with D2 drag folds that verge away from the anticlinal axes. The hanging wall assemblage lacks a well-ordered stratigraphy, displaying primarily block-in-matrix fabric. We identified bedded cherts, associated with umbers and alkalic basaltic intrusions within these hanging wall rocks, a first report of such rocks from Vietnam. The association of cherts, umbers, and basaltic intrusions and extrusions with block-in-matrix units with clastic rocks strongly suggest that the hanging wall rocks comprise part of a subduction complex. Because the base of a subduction complex is a former subduction megathrust horizon, the hanging wall-basement interface represents a reactivated collisional suture. Such a suture was probably associated with the Indosinian orogeny, and the basement should be the Indochina continental block. This structure may have influenced the position of Miocene dextral faulting in addition to controlling the position of the dome detachments. The well-known Red River fault marks the boundary of one of the domes, but in this region it appears to be a detachment (normal) fault rather than a dextral strike-slip fault. However, the association with the dome evolution with large-scale restraining step-overs suggests that dextral faulting associated with dome development may lie further away from the dome axes

  18. Sedimentación sinectónica asociada a una subida relativa del nivel del mar durante el Cretácico superior (Fm. Tremp, provincia de Lérida

    Directory of Open Access Journals (Sweden)

    Díaz Molina, M.

    1987-12-01

    Full Text Available The Tremp Formation is the continental lateral equivalent of the Arén Sandstone Formation. Both formations are part of regressive depositional sequences, formed during a relative sea level rise. At the top of the Isona anticline and in tbe south flank of the Sant Comeli anticline, four lithostratigraphic units are distinguisbed in the Tremp Formation. The sedimentary evolution of each of these units is related to tectonic reactivation and a slow down of the diastrophism. The successive sedimentary environments inferred for these units are the following: lagoon and/or fluvial plain, fluvial plain, tidal flat and/or lacustrine-palustrine. At the base and/or within sorne of these units there are progressive unconformities. The maximum slow down of the diastrophism would correspond to sedimentation in the tidal flat and/or lacustrine environments.La Fm. Tremp es el equivalente lateral continental de la Fm. Arenisca de Arén. Ambas formaciones forman parte de secuencias deposicionales de carácter regresivo, en régimen de subida relativa del nivel del mar. En el cierre peridinal del anticlinal de Isona y en el flanco S del anticlinal de Sant Comeli, dentro de la Fm. Tremp, se identifican cuatro unidades estratigráficas cuya evolución sedimentaria estuvo ligada a reactivaciones tectónicas y a la desaceleración del diastrofismo. Los sucesivos ambientes de sedimentación que se infieren en sentido vertical para estas unidades son: ambientes de «lagoon» y/o llanura fluvial, llanura fluvial, llanura de marea y/o lacustrepalustre. En la base y/o en el interior de algunas de estas unidades existen discordancias progresivas, la desaceleración máxima del diastrofismo se correspondería con la sedimentación en ambientes de llanura de marea y/o lacustre.

  19. Strontium isotopes as an indicator for groundwater salinity sources in the Kirkuk region, Iraq

    Energy Technology Data Exchange (ETDEWEB)

    Sahib, Layth Y. [Institute for Applied Geosciences, Technische Universität Darmstadt, Schnittspahnstraße 9, 64287 Darmstadt (Germany); Geology Department, College of Science, University of Baghdad, Jadreya, Baghdad (Iraq); Marandi, Andres; Schüth, Christoph [Institute for Applied Geosciences, Technische Universität Darmstadt, Schnittspahnstraße 9, 64287 Darmstadt (Germany)

    2016-08-15

    The Kirkuk region in northern Iraq hosts some of the largest oil fields in the Middle East. Several anticline structures enabled vertical migration and entrapment of the oil. Frequently, complex fracture systems and faults cut across the Eocene and middle Oligocene reservoirs and the cap rock, the Fatha Formation of Miocene age. Seepage of crude oil and oil field brines are therefore a common observation in the anticline axes and contamination of shallow groundwater resources is a major concern. In this study, 65 water samples were collected in the Kirkuk region to analyze and distinguish mixing processes between shallow groundwater resources, uprising oil field brines, and dissolution of gypsum and halite from the Fatha Formation. Hydrochemical analyses of the water samples included general hydrochemistry, stable water isotopes, as well as strontium concentrations and for 22 of the samples strontium isotopes ({sup 87}Sr/{sup 86}Sr). Strontium concentrations increased close to the anticline axes with highest concentrations in the oil field brines (300 mg/l). Strontium isotopes proved to be a valuable tool to distinguish mixing processes as isotope signatures of the oil field brines and of waters from the Fatha Formation are significantly different. It could be shown, that mixing of shallow groundwater with oil field brines is occurring close to the major fault zones in the anticlines but high concentrations of strontium in the water samples are mainly due to dissolution from the Fatha Formation. - Highlights: • This field study evaluates the salinity sources in the groundwater in Kirkuk region. • Salinity is related to evaporates dissolving and/or mixing with oil field brine. • Strontium isotopes proved to be a valuable tool to distinguish mixing processes.

  20. Determining the groundwater potential recharge zone and karst springs catchment area: Saldoran region, western Iran

    Science.gov (United States)

    Karami, Gholam Hossein; Bagheri, Rahim; Rahimi, Fahimeh

    2016-12-01

    Assessing the groundwater recharge potential zone and differentiation of the spring catchment area are extremely important to effective management of groundwater systems and protection of water quality. The study area is located in the Saldoran karstic region, western Iran. It is characterized by a high rate of precipitation and recharge via highly permeable fractured karstic formations. Pire-Ghar, Sarabe-Babaheydar and Baghe-rostam are three major karstic springs which drain the Saldoran anticline. The mean discharge rate and electrical conductivity values for these springs were 3, 1.9 and 0.98 m3/s, and 475, 438 and 347 μS/cm, respectively. Geology, hydrogeology and geographical information system (GIS) methods were used to define the catchment areas of the major karstic springs and to map recharge zones in the Saldoran anticline. Seven major influencing factors on groundwater recharge rates (lithology, slope value and aspect, drainage, precipitation, fracture density and karstic domains) were integrated using GIS. Geology maps and field verification were used to determine the weights of factors. The final map was produced to reveal major zones of recharge potential. More than 80 % of the study area is terrain that has a recharge rate of 55-70 % (average 63 %). Evaluating the water budget of Saldoran Mountain showed that the total volume of karst water emerging from the Saldoran karst springs is equal to the total annual recharge on the anticline. Therefore, based on the geological and hydrogeological investigations, the catchment area of the mentioned karst springs includes the whole Saldoran anticline.

  1. Structural evolution of the Abu Gharadig field area, Northern Western Desert, Egypt

    Science.gov (United States)

    El Gazzar, A. M.; Moustafa, A. R.; Bentham, P.

    2016-12-01

    Discovered in 1969, the Abu Gharadig (AG) Field was the first large hydrocarbon discovery in the Abu Gharadig Basin of the Western Desert of Egypt. Oil production began in 1973, with gas brought into production in 1975. The field produces mainly from upper Cretaceous clastic reservoirs. The AG Basin is an E-W trending intracratonic rift basin, about 330 km long and 50-75 km wide. It was initially formed as a large half graben basin during the Jurassic time in response to Tethyan rifting and continued to subside throughout the Cretaceous time. The half graben was subsequently inverted during the Late Cretaceous as part of the Syrian Arc deformation which affected northern Egypt. The Mid-Basin Arch, the AG Anticline, and the Mubarak High are three NE-SW oriented main inversion anticlines located within the AG Basin and are controlled by inversion of pre-existing Jurassic rift faults. The AG Anticline has an overall NE-SW orientation with a gentle plunge towards the NE and SW. It is locally bounded by two NE-SW-trending inverted faults on the southwest and northeast, accounting for the asymmetry of the anticline. Reverse offset of Cretaceous horizons is obvious at these inverted faults. Fault propagation folding is developed above the tips of the inverted faults at the Late Cretaceous Abu Roash and Khoman Formations. Based on thickness changes and stratigraphic relationships, inversion started during the Santonian time and continued into the Campanian-Maastrichtian. Inversion continued during deposition of the Paleocene-Middle Eocene Apollonia Formation and the Late Eocene-Oligocene Dabaa Formation.

  2. Secretory structures of Ipomoea asarifolia: anatomy and histochemistry

    OpenAIRE

    Martins,Fabiano M.; Lima,Jamile F.; Ana Angélica S. Mascarenhas; Thayane P. Macedo

    2012-01-01

    Ipomoea asarifolia (Desr.) Roem. & Schult., Convolvulaceae, is a weed that infests agricultural areas and is toxic to cattle. In spite of its toxicity, the leaves of this plant are used in traditional remedies in the state of Bahia, Brazil. The present work describes the leaf anatomy of I. asarifolia and characterizes the exudates of its secretory structures. The leaves have a unistratified epidermis composed of ordinary cells with straight to slightly sinuous anticlinal walls and thin cu...

  3. rac-Ethyl 2-amino-3-hydroxy-3-[4-(methylsulfonylphenyl]propanoate

    Directory of Open Access Journals (Sweden)

    Hao Hu

    2011-02-01

    Full Text Available In the title compound, C12H17NO5S, the orientations of the 2-ethyl-2-amino-3-hydroxypropanoate group and the 4-methylsulfonyl moiety towards the aromatic ring are periplanar and (−-anticlinal, respectively. In the crystal packing, the dominant interaction is O—H...N hydrogen bonding, which generates a chain running along [100]. N—H...O and C—H...O interactions are also observed.

  4. From folding to transpressional faulting: the Cenozoic Fusha structural belt in front of the Western Kunlun Orogen, northwestern Tibetan Plateau

    Science.gov (United States)

    Wang, Cong; Cheng, Xiao-Gan; Chen, Han-Lin; Li, Kang; Fan, Xiao-Gen; Wang, Chun-Yang

    2016-07-01

    Fusha structural belt (FSB) is one of the most important tectonic units in front of the Western Kunlun Orogen, northwestern Tibetan Plateau (NW China), in which the Kekeya oil field was discovered in 1971. However, there is no new oil field discovered since then due to the unclarity of the intense and complex Cenozoic deformation in this area. Based on field investigation, seismic interpretation and Continuous Electromagnetic Profile data, we analyze in detail the Cenozoic deformation history, emphasizing on the spatial and temporal variation of the deformation of the FSB in this paper. The result suggests that the FSB was dominated by two deformation events, (1) early (Miocene-early Pliocene) folding event expressed by anticline, with the western segment E-W orienting, while the eastern segment NWW-SEE orienting and (2) later (since late Pliocene) transpressional faulting event that destroyed and divided the earlier anticline into a number of fault blocks. The transpressional faulting caused dextral strike-slip reverse fault, with the dip angles decreasing eastward from ~90° to reserved. Based on the spatial variation of structural characteristics, we propose that the fault block traps and anticline traps in the eastern segment and fault block traps in western segment are favorable for hydrocarbon accumulation.

  5. Petrografía y geoquímica preliminar de los basaltos cretácicos de la sierra de Las Quijadas y cerrillada de Las Cabras, provincia de San Luis, Argentina

    Directory of Open Access Journals (Sweden)

    Martínez Amancay N.

    2011-11-01

    Full Text Available Preliminary petrography and geochemistry of the Cretacic basalts of the Sierra de Las Quijadasand Cerrillada de Las Cabras, San Luis province, Argentina. We present preliminary results of the petrologyand geochemistry of Cretaceous basalts exposed in the anticlines of the sierra of Las Quijadas and cerrillada ofLas Cabras. In the mountainous western of San Luis crop out at least two depositional sequences which togetherexceed the 1500 m thick and consists mainly of clastic sedimentary sequences typical continental red beds belongingto the Giant Group and Lagarcito Formation. Within this group, recognizes two types of basalt events, representedby lava flows and dykes. The lava flows were described in the northeastern sector of the anticline, in a landscapeof gentle hills. The dykes were found on the western flank of the anticline, northern sector of that mountain.Basalt lava flows have porphyritic texture with phenocrystals show idiomorphic olivine with clinopyroxene,amphibole and plagioclase, while the basaltic dykes show olivine in porphyritic texture embedded in a plagioclasepaste without orientation, amphibole and apatite needles. The basalts of the cerrillada de Las Cabras presented asa volcanic breccia associated with basaltic bombs. They have phenocrystals of olivine and clinopyroxene in pastewith plagioclase oriented. The basalts are classified as alkali basalts and related to intraplate basalts. When analyzingrare earth elements chondrite normalized according to Nakamura’s design are observed with a steep negative slopefor the heavy rare earth elements, a design that is similar to that found in alkaline basalts from the Sierra Chica deCórdoba.

  6. Structural features and petroleum geology of the fold-thrust belt in the southern Tarim basin, China

    Institute of Scientific and Technical Information of China (English)

    ZHOU Xinyuan; LUO Jinhai; WANG Qinghua

    2004-01-01

    The west Kunlun fold-thrust belt (WKFTB) and the Altun fold-thrust belt (AFTB) are respectively located in the southern margin of the Tarim basin, NW China. The analyses of typical structures and regional dynamics of the fold-thrust belts reveal their different structural and petroleum features and mechanisms. WKFTB differs from AFTB by abundant fault-related folds and triangles zones, and was formed by northward extrusion of the west Kunlun orogen. AFTB was affected synchronously by northward extrusion of the Altun orogen and the sinistral strike-slipping of the Altun Fault, so it is characterized by the minor scale and the monotonous structural styles. The Aqike anticline and the Aqike fault, of which the strikes are orthogonal to the strike of the fold-thrust belts, are regarded as the adjustive structures between both of the fold-thrust belts. The oil-gas pools of WKFTB develop mainly in the faulted-related anticline traps, but the oil-gas pools of AFTB develop mainly in the low fault-block and anticlines traps related with the paleo-uplifts. There are different exploration countermeasures for both of the fold-thrust belts.

  7. Structural characteristics of an active fold-and-thrust system in the southeastern Atacama Basin, northern Chile

    Science.gov (United States)

    Lin, Yen-Sheng; Chuang, Yi-Rung; Shyu, J. Bruce H.; González, Gabriel; Shen, Chuan-Chou; Lo, Ching-Hua; Liou, Ya-Hsuan

    2016-08-01

    The western South American margin is one of the most active plate boundaries in the world. Using various remote sensing data sets, we mapped the neotectonic characteristics of an area at the southeastern corner of the Atacama Basin, northern Chile, in the Andean forearc. There, one major N-S trending ridge is clearly visible both in the satellite images and in the field. This ridge reaches 250 m above the basin floor in its middle part and is asymmetrical, with a steep eastern slope and a much gentler western slope. The geometry of the ridge indicates that it formed as an asymmetrical anticline. This anticline is likely formed as a shear fault-bend fold, with a major décollement at a depth of about 2.5 km in the Naranja Formation. We suggest that this décollement is a major structure of the Atacama Basin area. From the ages of the ignimbrites and lake deposits that were deformed by this anticline, we obtained a long-term shortening rate of the major underlying structure at about 0.2 mm/yr. This thin-skinned fold-and-thrust system appears to be active since at least about 3 Ma, and could be as long as since middle Miocene. Therefore, crustal structures may play important roles in the Neogene development of the western Andean margin.

  8. Remote sensing and GIS approach for water-well site selection, southwest Iran

    Science.gov (United States)

    Rangzan, K.; Charchi, A.; Abshirini, E.; Dinger, J.

    2008-01-01

    The Pabdeh-Lali Anticline of northern Khuzestan province is located in southwestern Iran and occupies 790 km2. This structure is situated in the Zagros folded belt. As a result of well-developed karst systems in the anticlinal axis, the water supply potential is high and is drained by many peripheral springs. However, there is a scarcity of water for agriculture and population centers on the anticlinal flanks, which imposes a severe problem in terms of area development. This study combines remotely sensed (RS) data and a geographical information system (GIS) into a RSGIS technique to delineate new areas for groundwater development and specific sites for drilling productive water wells. Toward these goals, RS data were used to develop GIS layers for lithology, structural geology, topographic slope, elevation, and drainage density. Field measurements were made to create spring-location and groundwater-quality GIS layers. Subsequently, expert choice and relational methods were used in a GIS environment to conjunctively analyze all layers to delineate preferable regions and 43 individual sites in which to drill water wells. Results indicate that the most preferred areas are, in preferential order, within recent alluvial deposits, the Bakhtiyari Conglomerates, and the Aghajari Sandstone. The Asmari Limestone and other units have much lower potential for groundwater supplies. Potential usefulness of the RSGIS method was indicated when six out of nine producing wells recently drilled by the Khozestan Water and Power Authority (which had no knowledge of this study) were located in areas preferentially selected by this technique.

  9. Structures associated with inversion of the Donbas Foldbelt (Ukraine and Russia)

    Science.gov (United States)

    Saintot, Aline; Stephenson, Randell; Stovba, Sergiy; Maystrenko, Yuriy

    2003-09-01

    The Donbas Foldbelt is part of the Prypiat-Dnieper-Donets intracratonic rift basin (Belarus-Ukraine-southern Russia) that developed in Late Devonian times and was reactivated in Early Carboniferous. To the southeast, the Donbas Foldbelt joins the contiguous, deformed Karpinsky Swell. Basin "inversions" led first to the uplift of the Palaeozoic series (mainly Carboniferous but also syn-rift Devonian strata in the southwesternmost part of the Donbas Foldbelt, which are deeply buried in the other parts of the rift system), and later to the formation of the fold-and-thrust belt. The general structural trend of the Donbas Foldbelt, formed mainly during rifting, is WNW-ESE. This is the strike of the main rift-related fault zones and also of the close to tight "Main Anticline" of the Donbas Foldbelt that developed along the previous rift axis. The Main Anticline is structurally unique in the Donbas Foldbelt and its formation was initiated in Permian times, during a period of (trans) tensional reactivation, during which active salt movements occurred. A relief inversion of the basin also took place at this time with a pronounced uplift of the southern margin of the basin and the adjacent Ukrainian Shield. Subsequently, Cimmerian and Alpine phases of tectonic inversion of the Donbas Foldbelt led to the development of flat and shallow thrusts commonly associated with folds into the basin. A fan-shaped deformation pattern is recognised in the field, with south-to southeast-vergent compressive structures, south of the Main Anticline, and north- to northwest-vergent ones, north of it. These compressive structures are clearly superimposed onto the WNW-ESE structural grain of the initial rift basin. Shortening structures that characterise the tectonic inversion of the basin are (regionally) orientated NW-SE and N-S. Because of the obliquity of the compressive trends relative to the WNW-ESE strike of inherited structures (major preexisting normal faults and the Main Anticline), in

  10. 3D Fault modeling of the active Chittagong-Myanmar fold belt, Bangladesh

    Science.gov (United States)

    Peterson, D. E.; Hubbard, J.; Akhter, S. H.; Shamim, N.

    2013-12-01

    The Chittagong-Myanmar fold belt (CMFB), located in eastern Bangladesh, eastern India and western Myanmar, accommodates east-west shortening at the India-Burma plate boundary. Oblique subduction of the Indian Plate beneath the Burma Plate since the Eocene has led to the development of a large accretionary prism complex, creating a series of north-south trending folds. A continuous sediment record from ~55 Ma to the present has been deposited in the Bengal Basin by the Ganges-Brahmaputra-Meghna rivers, providing an opportunity to learn about the history of tectonic deformation and activity in this fold-and-thrust belt. Surface mapping indicates that the fold-and-thrust belt is characterized by extensive N-S-trending anticlines and synclines in a belt ~150-200 km wide. Seismic reflection profiles from the Chittagong and Chittagong Hill Tracts, Bangladesh, indicate that the anticlines mapped at the surface narrow with depth and extend to ~3.0 seconds TWTT (two-way travel time), or ~6.0 km. The folds of Chittagong and Chittagong Hill Tracts are characterized by doubly plunging box-shaped en-echelon anticlines separated by wide synclines. The seismic data suggest that some of these anticlines are cored by thrust fault ramps that extend to a large-scale décollement that dips gently to the east. Other anticlines may be the result of detachment folding from the same décollement. The décollement likely deepens to the east and intersects with the northerly-trending, oblique-slip Kaladan fault. The CMFB region is bounded to the north by the north-dipping Dauki fault and the Shillong Plateau. The tectonic transition from a wide band of E-W shortening in the south to a narrow zone of N-S shortening along the Dauki fault is poorly understood. We integrate surface and subsurface datasets, including topography, geological maps, seismicity, and industry seismic reflection profiles, into a 3D modeling environment and construct initial 3D surfaces of the major faults in this

  11. Evolución de las cuencas sinorogénicas de la Cordillera Principal entre 35°- 36° S, Malargüe Evolution of the foreland basins in the Cordillera Principal, at 35º - 36º S. Malargüe

    Directory of Open Access Journals (Sweden)

    J. Silvestro

    2005-12-01

    Full Text Available La faja plegada y corrida de Malargüe se encuentra localizada en el extremo sur de la Cordillera Principal a los 35°-36° S. Los estratos de crecimiento preservados en cuencas sintectónicas registraron la cinemática de plegamiento de la faja plegada durante el Cenozoico. La cuenca Pinchera-Ventana, ubicada en el sector oeste del área, está rellena por dos secuencias volcaniclásticas cubiertas por basaltos. En el sector occidental de esta cuenca, las secuencias se adelgazan hacia los anticlinales de La Valenciana y Torrecillas en el oeste y hacia los retrocorrimientos de La Brea en el este, desarrollando discordancias progresivas observadas en el campo. En el sector oriental de la cuenca, el arreglo de facies, la composición de los clastos y la presencia de discordancias sugieren una proveniencia desde el anticlinal Bardas Blancas en el oeste. Dataciones radimétricas de los niveles andesíticos basales (15,1 Ma y de los basaltos al techo (6,7 Ma limitan la edad de esta cuenca al Mioceno medio y superior. La cuenca Malargüe desarrollada en el sector oriental del área de estudio, está rellena por dos secuencias sintectónicas volcaniclásticas, cubiertas por una secuencia postectónica. El análisis sísmico de las secuencias de crecimiento muestra un arreglo divergente relacionado al levantamiento del anticlinal Malargüe en el oeste de la cuenca y un triángulo de crecimiento hacia el este relacionado al levantamiento del anticlinal Chacay. La datación de niveles andesíticos basales en 5,04 Ma y la secuencia postectónica al tope, limitan la edad de la cuenca entre el Mioceno superior y Cuaternario. Estas observaciones indican que los depocentros sedimentarios migraron hacia el antepaís conjuntamente con el avance de la faja plegada en igual sentido.The Andean fold-and-thrust belt of Malargüe is located in the foothills of Cordillera Principal at 35º-36º S. The geometry and age of the growth strata preserved in syntectonic

  12. Exocarp Anatomy of Polygonum and Related Species from Shandong Province%山东蓼属及近缘植物(蓼科)果实外果皮解剖学研究

    Institute of Scientific and Technical Information of China (English)

    张晓霞; 熊先华; 徐芳; 邓丽娜; 王康满; 侯元同

    2011-01-01

    利用光学显微镜对山东产蓼属(Polygonum)及近缘植物20种2变种的果实外果皮解剖学特征进行了观察研究.结果表明,其果实外果皮细胞在横切面上为方形、短矩形或狭长矩形,排列为栅栏状,细胞腔形状多样,大小取决于细胞壁增厚程度,具树状分枝或二叉分枝,垂周壁平直或波纹状.根据细胞垂周壁式样及细胞腔形状划分为3种类型,即:A.细胞腔近狭三角形,具树状分支,垂周壁强烈折曲,壁内多褶皱和空隙,如萹蓄.B.细胞腔近狭长、具树状分支,该类型又分为两个亚型:B1细胞腔形状无规则,垂周壁强烈折曲或波纹状,如春蓼;B2细胞腔形状规则,垂周壁平直,如拳参.C.细胞腔狭小,二叉至四叉分支,垂周壁平直,如篱蓼.果实外果皮解剖学特征对蓼族各属的范围界定及某些存疑种的系统学位置的处理具有重要意义.%The anatomical characters of the fruit exocarps of 20 species and 2 varieties of Polygonum and related species from Shandong Province were observed under light microscope. The results showed that the exocarp cells (in cross section) were square (isodia-metric), shortly rectangular, or elongated-rectangular, and aligned in parallel, resembling a palisade;the cell lumens were variable in shape and their sizes depending on cell wall thickening, and may show branches or canals dichotomously or trichotomously or as dendritic ramifications at the outer limit anticlinal branching ;the anticlinal walls were undulate or straight. Fruit exocarps were devided into three types based on the anticlinal wall patterns and cell lumen shapes,and they are, A. Nearly narrow triangular cell lumen with dendritic ramifications and strongly flexuose anticlinal walls with numerous folds and gaps internally, e. G. Polygonum aviculare-, B. Nearly long and narrow cell lumen with dendritic ramifications,and were divided into two subtypes, B, the cell lumens irregular,and anticlinal walls strongly

  13. Geomorphic assessment of the tectonic activity of Qiulitagh fold-belt, Kuqa foreland basin, Xinjiang, China

    Science.gov (United States)

    Saint Carlier, Dimitri; Graveleau, Fabien; Delcaillau, Bernard; Hurtrez, Jean-Emmanuel; Vendeville, Bruno

    2014-05-01

    The Qiulitagh fold belt is an anticline structure located in the Kuqa fold-and-thrust belt (southern Tian Shan, China), whose active folding is well documented by structural and palaeomagnetic studies (Chen et al., 2007; Hubert-Ferrari et al., 2007; Li et al., 2012; Wang et al., 2011). The topography of Quilitagh fold belt can be divided into two SW-NE parallel ridges: 1) a 90 km long northern ridge, composed of the Northern Qiulitagh anticline and the Yakelike anticline, and 2) a 165km long southern ridge, composed of the Southern Qiulitagh anticline and the Mishikantage anticline. Due to the current absence of vegetation and relative homogeneity of outcropping lithologies (mainly Neogene detrital sandstone and silstone), these anticlines provide exceptional field cases for investigating the dynamic relationships between fold growth mechanisms, the subsurface structures, the geomorphic entities and the drainage network evolution. We used free topographic and satellite image datasets to carry out a morphometric study of the Quilitagh fold-belt and investigate the kinematics of active folding. Topographic datasets include Digital Elevation Models (DEM) from the NASA SRTM V.4.0 and ASTER programs, whereas satellite images are extracted from Landsat 7 shots and Google Earth. These datasets were incorporated in GIS software where three scales of observation were investigated: 1) a global fold scale, 2) a drainage basin scale and 3) a valley scale. At the drainage basin scale, we selected about 250 items and quantified several geomorphic indices of relative active tectonic growth. These are the basin mean slope, hypsometric integral, basin asymmetry and local relief. We also used published seismic profiles to link the 3D subsurface geometry of the salt-related Qiulitagh fold belt with the geomorphic signal. Results indicate that the morphometry of Quilitagh drainage basins (hypsometry, drainage basin asymmetry, local relief, valley incision, steepness index) change

  14. Evolución estructural de la zona de transición entre las fajas plegadas y corridas de Aconcagua y Malargüe Provincia de Mendoza Structural evolution of the transition zone between the Aconcagua and Malargûe fold and thrust belts, province of Mendoza

    Directory of Open Access Journals (Sweden)

    S. Broens

    2005-12-01

    Full Text Available En el presente trabajo se describe brevemente la estratigrafía y la estructura de los Andes en la zona de transición entre las fajas plegadas y corridas del Aconcagua y Malargüe. Las rocas aflorantes corresponden a un basamento volcánico acido permotriásico, sedimentitas mesozoicas de la cuenca neuquina y efusiones volcánicas y depósitos continentales neógenos. Estructuralmente se reconocen de oeste a este, cuatro segmentos denominados: zona de inversión tectónica, zona de pliegues apretados, zona central o de imbricación y anticlinal del Carrizalito. Se construyeron dos secciones estructurales que se ajustan a los datos de campo recogidos en las zonas de imbricación, de pliegues apretados y del flanco dorsal del anticlinal del Carrizalito, que permitieron describir las estructuras presentes en el área. Lineamientos regionales de orientación noroeste-sureste podrían estar actuando como zonas de transferencia de rechazos. Pueden reconocerse dos o tres pulsos deformacionales según se considere la edad relativa de las estructuras respecto al levantamiento de la Cordillera Frontal. Para el caso en que el cordón del Carrizalito haya actuado como un alto de basamento se proponen dos pulsos, uno de piel fina y otro posterior que levanta a la Cordillera Frontal basculando la secuencia previamente deformada. Si en cambio la estructuración del anticlinal del Carrizalito hizo que este se comporte como punto de fijación (sticking point podria sumarse un tercer episodio deformacional con corrimientos fuera de secuencia.In this work we describe briefly the stratigraphy and the structure of the Andes in the transition zone between the Aconcagua and Malargüe fold and thrust belts. The outcrops are a Permotriasic volcanic acid basement, Mesozoic sediments of the Cuenca Neuquina and Neogene volcanic rocks and continental deposits. Structuraly we distinguish from west to east four segments: a tectonic inversion zone, a tight folds zone, a

  15. Long-wavelength Folding on Mercury: Lithospheric Boudinage in the Caloris Basin?

    Science.gov (United States)

    Klimczak, C.; Byrne, P. K.; Solomon, S. C.; Ernst, C. M.; Watters, T. R.; Murchie, S. L.; Preusker, F.; Oberst, J.

    2012-12-01

    Both laser altimetric and stereo photogrammetric datasets returned by the MESSENGER spacecraft in orbit about Mercury reveal impact craters whose floors show systematic tilts away from topographically high regions. Such tilted craters indicate that Mercury's lithosphere has been affected by large-scale folding that, when mapped, is manifest as several long-wavelength and low-amplitude rises and troughs, interpreted as anticlines and synclines, that cross the planet. Topographic profiles across the syn- and anticlines show that folding can be described as more or less harmonic with wavelengths of 800 to 1300 km and amplitudes of 1.5 to 3 km. These dimensions show that folding accommodated shortening strains of only ~0.002%. Several syn- and anticlines are found in the region in and around the Caloris basin, the largest recognized impact basin on the planet. The topography within the basin is characterized by two anticlines, each trending approximately east-west and having crests that rise more than 2 km above a low-lying region near the basin center. Fault displacement analysis of several radial graben and circumferential ridges, together with crater excavation depths of spectrally distinct materials, yields stratigraphic information on the uppermost smooth volcanic plains in the basin's interior, revealing a pinch-and-swell structure to these units. Specifically, the plains are thicker in the vicinity of the topographic highs and thinner at the topographic low. We used numerical simulations with the two-dimensional module of the finite-element modeling code ADELI to explore how folding of the lithosphere on Mercury and the pinching and swelling might have been accommodated for a range of assumed boundary conditions and properties of the lithosphere and mantle, informed by recent geophysical data returned by MESSENGER. We find that continuing lithospheric folding with periodic emplacement of volcanic plains units can account for the observed topography and

  16. Down-hole geophysical characterization of middle-upper Quaternary sequences in the Apennine Foredeep, Mirabello, Italy

    Directory of Open Access Journals (Sweden)

    Luca Minarelli

    2016-11-01

    Full Text Available The 2012 earthquakes sequence stroke a wide area of the alluvial plain in the Emilia-Romagna Region and triggered a new research interest on the role of the subsurface stratigraphic architecture and petrophysical property distribution in the modulation of the local seismic effects. Few direct shear wave velocity V_S data were however available below the depth of 50m. The only available V_S measurements were obtained from an anticline area, characterized by a reduced stratigraphic thickness and peculiar sedimentary facies, hardly representative of the majority of the alluvial plain subsurface. The study provides the first V_S profile available from middle-upper Quaternary successions deposited into a fast subsiding syncline area of the Apennine Foredeep Basin. The P-wave velocity V_P and the S-wave velocity V_S logs fill in the previous data gap on the geophysical parameters needed for the estimation of the local seismic response. Both V_P and V_S logs were continuously acquired to the depth of 265 m. The log records a velocity increase with depth, punctuated by sharp increases at some stratigraphic discordance surfaces. The value of 800 m/s that characterizes the “seismic bedrock”, as defined by the Italian building code [NTC 2008] was never reached at any depth. The investigated succession records a depositional evolution from deltaic-marine to alluvial plain conditions, punctuated by six glacio-eustatic depositional cycles, developed in Middle-Upper Quaternary times. The stratigraphic units described in the syncline log were correlated at a regional scale, with the thinner anticline succession of Mirandola. Correlatable units deposited into syncline and anticline areas reveal similar shear wave velocity values, supporting the regional extrapolation of the measured values.

  17. Evolución estructural de la zona de transición entre las fajas plegadas y corridas de Aconcagua y Malargüe Provincia de Mendoza

    Directory of Open Access Journals (Sweden)

    S. Broens

    2005-12-01

    Full Text Available En el presente trabajo se describe brevemente la estratigrafía y la estructura de los Andes en la zona de transición entre las fajas plegadas y corridas del Aconcagua y Malargüe. Las rocas aflorantes corresponden a un basamento volcánico acido permotriásico, sedimentitas mesozoicas de la cuenca neuquina y efusiones volcánicas y depósitos continentales neógenos. Estructuralmente se reconocen de oeste a este, cuatro segmentos denominados: zona de inversión tectónica, zona de pliegues apretados, zona central o de imbricación y anticlinal del Carrizalito. Se construyeron dos secciones estructurales que se ajustan a los datos de campo recogidos en las zonas de imbricación, de pliegues apretados y del flanco dorsal del anticlinal del Carrizalito, que permitieron describir las estructuras presentes en el área. Lineamientos regionales de orientación noroeste-sureste podrían estar actuando como zonas de transferencia de rechazos. Pueden reconocerse dos o tres pulsos deformacionales según se considere la edad relativa de las estructuras respecto al levantamiento de la Cordillera Frontal. Para el caso en que el cordón del Carrizalito haya actuado como un alto de basamento se proponen dos pulsos, uno de piel fina y otro posterior que levanta a la Cordillera Frontal basculando la secuencia previamente deformada. Si en cambio la estructuración del anticlinal del Carrizalito hizo que este se comporte como punto de fijación (sticking point podria sumarse un tercer episodio deformacional con corrimientos fuera de secuencia.

  18. Three-dimensional patterns of cell division and expansion throughout the development of Arabidopsis thaliana leaves.

    Science.gov (United States)

    Kalve, Shweta; Fotschki, Joanna; Beeckman, Tom; Vissenberg, Kris; Beemster, Gerrit T S

    2014-12-01

    Variations in size and shape of multicellular organs depend on spatio-temporal regulation of cell division and expansion. Here, cell division and expansion rates were quantified relative to the three spatial axes in the first leaf pair of Arabidopsis thaliana. The results show striking differences in expansion rates: the expansion rate in the petiole is higher than in the leaf blade; expansion rates in the lateral direction are higher than longitudinal rates between 5 and 10 days after stratification, but become equal at later stages of leaf blade development; and anticlinal expansion co-occurs with, but is an order of magnitude slower than periclinal expansion. Anticlinal expansion rates also differed greatly between tissues: the highest rates occurred in the spongy mesophyll and the lowest in the epidermis. Cell division rates were higher and continued for longer in the epidermis compared with the palisade mesophyll, causing a larger increase of palisade than epidermal cell area over the course of leaf development. The cellular dynamics underlying the effect of shading on petiole length and leaf thickness were then investigated. Low light reduced leaf expansion rates, which was partly compensated by increased duration of the growth phase. Inversely, shading enhanced expansion rates in the petiole, so that the blade to petiole ratio was reduced by 50%. Low light reduced leaf thickness by inhibiting anticlinal cell expansion rates. This effect on cell expansion was preceded by an effect on cell division, leading to one less layer of palisade cells. The two effects could be uncoupled by shifting plants to contrasting light conditions immediately after germination. This extended kinematic analysis maps the spatial and temporal heterogeneity of cell division and expansion, providing a framework for further research to understand the molecular regulatory mechanisms involved.

  19. Use of integrated analogue and numerical modelling to predict tridimensional fracture intensity in fault-related-folds.

    Science.gov (United States)

    Pizzati, Mattia; Cavozzi, Cristian; Magistroni, Corrado; Storti, Fabrizio

    2016-04-01

    Fracture density pattern predictions with low uncertainty is a fundamental issue for constraining fluid flow pathways in thrust-related anticlines in the frontal parts of thrust-and-fold belts and accretionary prisms, which can also provide plays for hydrocarbon exploration and development. Among the drivers that concur to determine the distribution of fractures in fold-and-thrust-belts, the complex kinematic pathways of folded structures play a key role. In areas with scarce and not reliable underground information, analogue modelling can provide effective support for developing and validating reliable hypotheses on structural architectures and their evolution. In this contribution, we propose a working method that combines analogue and numerical modelling. We deformed a sand-silicone multilayer to eventually produce a non-cylindrical thrust-related anticline at the wedge toe, which was our test geological structure at the reservoir scale. We cut 60 serial cross-sections through the central part of the deformed model to analyze faults and folds geometry using dedicated software (3D Move). The cross-sections were also used to reconstruct the 3D geometry of reference surfaces that compose the mechanical stratigraphy thanks to the use of the software GoCad. From the 3D model of the experimental anticline, by using 3D Move it was possible to calculate the cumulative stress and strain underwent by the deformed reference layers at the end of the deformation and also in incremental steps of fold growth. Based on these model outputs it was also possible to predict the orientation of three main fractures sets (joints and conjugate shear fractures) and their occurrence and density on model surfaces. The next step was the upscaling of the fracture network to the entire digital model volume, to create DFNs.

  20. Differential uplift and incision of the Yakima River terraces, central Washington State

    Science.gov (United States)

    Bender, Adrian M; Amos, Colin B.; Bierman, Paul R.; Rood, Dylan; Staisch, Lydia; Kelsey, Harvey M.; Sherrod, Brian

    2016-01-01

    The fault-related Yakima folds deform Miocene basalts and younger deposits of the Columbia Plateau in central Washington State. Geodesy implies ~2 mm/yr of NNE directed shortening across the folds, but until now the distribution and rates of Quaternary deformation among individual structures has been unclear. South of Ellensburg, Washington, the Yakima River cuts a ~600 m deep canyon across several Yakima folds, preserving gravel-mantled strath terraces that record progressive bedrock incision and related rock uplift. Here we integrate cosmogenic isochron burial dating of the strath terrace gravels with lidar analysis and field mapping to quantify rates of Quaternary differential incision and rock uplift across two folds transected by the Yakima River: Manastash and Umtanum Ridge. Isochron burial ages from in situ produced 26Al and 10Be at seven sites across the folds date episodes of strath terrace formation over the past ~2.9 Ma. Average bedrock incision rates across the Manastash (~88 m/Myr) and Umtanum Ridge (~46 m/Myr) anticlines are roughly 4 to 8 times higher than rates in the intervening syncline (~14 m/Myr) and outside the canyon (~10 m/Myr). These contrasting rates demonstrate differential bedrock incision driven by ongoing Quaternary rock uplift across the folds at rates corresponding to ~0.13 and ~0.06 mm/yr shortening across postulated master faults dipping 30 ± 10°S beneath the Manastash and Umtanum Ridge anticlines, respectively. The reported Quaternary shortening across the anticlines accounts for ~10% of the ~2 mm/yr geodetic budget, suggesting that other Yakima structures actively accommodate the remaining contemporary deformation.

  1. Superimposed folding and thrusting by two phases of mutually orthogonal or oblique shortening in analogue models

    Science.gov (United States)

    Deng, Hongling; Koyi, Hemin A.; Nilfouroushan, Faramarz

    2016-02-01

    Orogens may suffer more than one phase shortening resulting in superposition of structures of different generations. Superimposition of orthogonal or oblique shortening is studied using sandbox and centrifuge modelling. Results of sand models show that in orthogonal superimposition, the two resulting structural trends are approximately orthogonal to each other. In oblique superimposition, structures trend obliquely to each other in the relatively thin areas of the model (foreland), and mutually orthogonal in areas where the model is thickened during the first phase of shortening (i.e. the hinterland). Thrusts formed during the first shortening phase may be reactivated during the later shortening phase. Spacing of the later phase structures is not as wide as expected, considering they across the pre-existing thickened wedge. Superposition of structures results in formation of type 1 fold interference pattern. Bedding is curved outwards both in the dome and basin structures. Folded layers are dipping and plunging outwards in a dome, while they are dipping and plunging inwards in a basin. In the areas between two adjacent domes or basins (i.e. where an anticline is superimposed by a syncline or a syncline is superimposed by an anticline), bedding is curved inwards, and the anticlines plunge inwards and the synclines outwards. The latter feature could be helpful to determine the age relationship for type 2 fold interference pattern. In tectonic regions where multiple phases of shortening have occurred, the orogenic-scale dome-and-basin and arrowhead-shaped interference patterns are commonly formed, as in the models. However, in some areas, the fold interference pattern might be modified by a later phase of thrusting. Similar to models results, superimposition of two and/or even more deformation phases may not be recorded by structures all over the tectonic area.

  2. Occurrence of pockmarks and gas seepages along the central western continental margin of India

    Digital Repository Service at National Institute of Oceanography (India)

    Karisiddaiah, S.M.; Veerayya, M.

    ). T hese depressions are 100 ? 200 m wide and 2 ? 3 m deep. Sonographs along a parallel line confirm their presence (Figure 4 c ). These v - shaped notches on the seafloor appear to be isolated pockmarks and are circular enclosed depressions... sub - bottom reflector and the seafloor, while some formed 2 ? 12 m deep (?) depressions on the seafloor; a few others lie on the anticline. On the other hand, buried pockmarks lie 2 ? 8 mbsf (Figure 5). The pockmarks in general are 80 ? 130...

  3. Mineralización de Cu (V-U) en la formación Huincul, prospecto Tordillos, cuenca Neuquina

    OpenAIRE

    2014-01-01

    Tordillos es uno de los numerosos depósitos de cobre (V-U) estratiformes de la Cuenca Neuquina y está ubicado en el sector norte de la dorsal de Huincul, al SO del anticlinal Sauzal Bonito. Presenta recursos de 9,5 Mt y una ley media de Cu de 0,42 % con anomalías de U (135-251 ppm) y V (250-980 ppm). La mineralización es epigenética y rellena la porosidad secundaria de las areniscas permeables, alteradas y decoloradas correspondientes a la Formación Huincul. Consiste en calcosina con calcopir...

  4. Using the stratigraphic record to document tectonic-geomorphologic interactions in a foreland basin setting: outcrop study of the Ainsa Basin, Spain

    Science.gov (United States)

    Pyles, D. R.; Moody, J.; Gordon, G.; Hoffman, M.; Moss-Russell, A.; Silalahi, H.; Setiawan, P.; Clark, J.; Bracken, B.; Guzofski, C.

    2013-12-01

    Eocene strata of the Ainsa Basin (Spain) contain clastic and carbonate strata deposited in a relatively small (100 km^2), structurally active piggyback foreland basin. The basin is bounded by the Mediano Anticline to the east and the Boltana Anticline to the west. Clastic strata were sourced by an eastern fluvial-deltaic system whereas carbonate strata were sourced from shallow-water carbonate systems that rimmed the southern and western margins of the basin. Four time-stratigraphic units, which form an upward transect through the basin-fill succession, were studied in detail: Ainsa, Morillo, Guaso, Sobrarbe-Escanilla. The study uses the stratigraphic record to document linkages between progressive uplift of the basin-bounding structures, spatial-temporal changes in the amount and location of subsidence, and temporal changes in the landscape. The Ainsa unit contains submarine channels that entered the basin from the east and exited the basin to the northwest, although some channels locally transfer to lobes near the northwest end of the basin. The Morillo unit contains submarine channels that entered the basin from the east, dispersed onto the basin floor, then converged at the western end of the basin where they continued onto the longitudinally adjacent Jaca Basin. The Guaso unit contains submarine channels that entered the basin from the east and transfer to a ponded distributive submarine fan at the center of the basin. The Escanilla-Sobrarbe unit contains a linked shelf-to-basin system that prograded from south to north and records the final filling of the basin. Four lines of evidence collectively support the basin-fill succession was deposited during structural growth. First, the depocenter, which is interpreted to reflect the position of maximum subsidence during deposition, of the systems systematically shifted westward as the basin filled. Second, the axial part of the clastic sediment systematically shifted southward as the basin filled. Third, the

  5. Application of teleseismic tomography to the study of shallow structure beneath Shizigou in the western Qaidam basin

    Institute of Scientific and Technical Information of China (English)

    Xiaoming Xu; Yinsheng Ma; Danian Shi; Xiaofeng Wang; Chengming Yin

    2009-01-01

    Teleseismic body wave traveltime tomography is used to inverse the three-dimensional seismic velocity structure beneath Shizigou in the western Qaidam basin. The travel time are picked from the continuous observation data on a small seismic array of stations deployed during 2004-2007. The tomographic results obtained indicate that a NW-trending low velocity anomaly just beneath the target region insert northeastwards with a high dip angle, to the north, northeast and east of the low velocity anomaly, some high-velocity anomalies distribute with the same strike and coverage as those of Shizigou anticline.

  6. Development of High Viscous Oil in Sandstone Reserviors During the High Water Cut Stage, Gudao Oilfield

    Institute of Scientific and Technical Information of China (English)

    Bi Yanpeng; Li Yang; Lu Xianliang

    1994-01-01

    @@ Geological Characteristics and Production History The oil-bearing area of Gudao Oilfield covers 80. 9 square kilometers, with 373 million tons of oil in place. It is a large drape anticlinal. Neogene Gudao Formation is main oil-beraing reservoir developed with dip gentle from 30′ to 1°30′in general.The main oil-bearing sequences can be divided into 6sand groups and 34 layers in detail, in which the Ng3-Ng6 sand groups are the main payzones in which oil in place accounts for 97.2% of the total.

  7. Los Fósiles Humanos de Atapuerca (Burgos: Nota Preliminar

    Directory of Open Access Journals (Sweden)

    Emiliano AGUIRRE

    2009-10-01

    Full Text Available Los restos cuyo estudio nos ocupa, han sido extraídos en la denominada «Sima de los Huesos» en la Cueva Mayor, situada en la Sierra de Atapuerca, en las cercanías del pueblo de Ibeas de Juarros, a 14 km. de Burgos, en la margen derecha del río Arlanzón. La Sierra de Atapuerca puede definirse geológicamente como un anticlinal de calizas y margas del cretácico superior, rodeado por terrenos neógenos que se apoyan con una fuerte discordancia angular.

  8. Exploration of Subtle Trap in Jiyang Depression

    Institute of Scientific and Technical Information of China (English)

    LiPilong; ZhangShanwen; XiaoHuanqin; WangYongshi; QiuGuiqiang

    2004-01-01

    This article analyses the procedure of exploration of the Tertiary subtle trap in Jiyang depression and divides the Tertiary subtle trap into 3 types (lithologic reservoir, stratigraphic reservoir and fractured reservoir) and 8 groups, then summarizes the common feature and founding discipline of the subtle trap and finds 4 accumulating modes including steep slope mode, depression mode, center anticline mode and gentle slope mode. Its main exploration methods are explicated from the viewpoint of reservoir geological modeling, description of recognizing traps and comprehensive evaluation of reservoir and so on.

  9. Research on Techniques for Rolling Exploration and Development and Application to Dongying Oilfield

    Institute of Scientific and Technical Information of China (English)

    Du Xiangyue; Sun Longde

    1995-01-01

    @@ The central anticlinal zone of Dongying Basin and Tong-Wang tectonic zone, subordinate to the Xianhe Oil Mine of Shengli Oilfield, are a composite tectonic belt, very complex in geology and diverse in oil pool types, with high oil and gas productivity, and also a very complex geologic body consisting of different strata and oil pools of different types and origins (Fig. 1). This situation made us to work out a complex and step-by-step continuous process of oil and gas exploration and exploitation,i.e. ,the rolling oil exploration and exploitation process.

  10. Deformation in the Bolivian Subandes: a reconstruction of geologic structures along two transects across the Andean Front in Southern Bolivia

    Science.gov (United States)

    Hadeen, Xennephone; Zeilinger, Gerold

    2016-04-01

    The Southern Bolivian Subandes is a highly tectonically active region in the Andes since deformation began approx. 10 Ma ago. The study area is located in the Southern Bolivian Subandes southwest of Santa Cruz. Observations were taken along two transects with each being around 100 km long. They stretch from the Subandes-Interandean boundary into the Chaco Plain. The northern transect extends from Abapó in the Chaco Plain and it continues west near Vallegrande and ends just west of Pucara near La Higuera. The southern transect initiates near Charagua in the Chaco Plain. Then it continues west through Villa Vaca Guzmán and ends around 25 km west of Monteagudo. Structural and stratigraphic data were collected along the two transects. The locations of major geologic structures such as thrust faults, anticlines and synclines were mapped. The map along with the data from the two cross sections was then used to generate a 3D model of the Subandean fold and thrust belt between Abapó and Monteagudo. The cross sections were than restored to quantify the amount of shortening that had occurred over the past 10 million years. The southern transect has undergone 65 km of shortening while 50 to 80 km of shortening have transpired along the less constrain northern transect. The estimated rate of deformation averages at 8 mm/yr. The timing of deformation may differ between the two transects. Deformation may have initiated earlier or undergone at a faster rate in the northern transect than in the southern transect. It is also possible that the decollement is shallower in the western portion of the northern transect. We observe that the east propagating anticlines verge to the west. This may be due to the anticlines being cut by exposed or blind thrust faults and then rotated counterclockwise. They rotate while piggybacking on younger thrust faults that developed and propagate to the east of the anticlines. We postulate deformation continues to propagate eastward into the Chaco

  11. Evidence for a tsunami generated by the 1762 Great Arakan earthquake, Southeastern Bangladesh

    Science.gov (United States)

    Gurung, D.; McHugh, C. M.; Mondal, D. R.; Seeber, L.; Steckler, M. S.; Bastas-Hernandez, A.; Akhter, S. H.; Mustaque, S.; Goodbred, S. L., Jr.

    2014-12-01

    The devastating 2004 Sumatra earthquake and tsunami brought to the world's attention the possibility of large megathrust ruptures occurring along the heavily populated coast of Bangladesh. The Sunda-Andaman subduction arc continues into Bangladesh where oblique convergence of the Indian plate with the Burma segment of the arc was measured at GPS rates of 14 mm/yr. A long section of the megathurst ruptured during the 1762 Great Arakan earthquake along the Myanmar coast. A 1762 tsunami was reported from historic accounts and predicted from modelling, but geologic evidence for it was not previously reported. St Martin's Island and the Teknaf peninsula in SE Bangladesh are expressions of anticlines in the outer part of the accretionary prism of the Arakan subduction boundary. Our lithology, biostratigraphy and C-14 ages in this region provide evidence for a possible tsunami associated with the 1762 earthquake and validate the continuity of the rupture zone for as much as 700 km, from the Myanmar coast, Bay of Bengal shelf to the Sitakund anticline inland. In St. Martin's, ≈70 km north of the shelf break, U-Th ages from ~2 m uplifted dead corals provide evidence for the 1762 rupture. The associated tsunami was dated from benthic foraminifers and marine molluscs obtained from a shell bed in a trench, and from the top of marine terraces possibly uplifted during 1762 or prior earthquakes. In Teknaf a chaotic bed containing benthic foraminifers, marine shells and cobble size rocks, extends for 100's of meters on top of the 2 m uplifted terrace. The marine molluscs were dated at 1695-1791 AD. The large ≈2m uplift found in the region is likely to be deformation associated with the 1762 rupture and could also be partly related to anelastic growth of the accretion wedge and anticlines. It is likely now slowly subsiding due to continuing elastic loading of the megathrust. To produce that large coastal, presumably coseismic, uplift, the megathrust rupture must have reached at

  12. Crystal structure of 1,1'-[imidazolidine-1,3-diylbis(methyl-ene)]bis-(naphthalen-2-ol).

    Science.gov (United States)

    Rivera, Augusto; Rojas, Jicli José; Ríos-Motta, Jaime; Bolte, Michael

    2015-03-01

    The crystal structure of the title compound, C25H24N2O2, at 173 K has monoclinic (C2/c) symmetry. The mol-ecule is located on a crystallographic twofold rotation axis with only half a mol-ecule in the asymmetric unit. The imidazolidine ring adopts a twist conformation, with a twist about the ring C-C bond. The crystal structure shows the anti-clinal disposition of the two (2-hy-droxy-naphthalen-1-yl)methyl substituents of the imidazolidine ring. The structure displays two intra-molecular O-H⋯N hydrogen bonds, each forming an S(6) ring motif.

  13. Late-stage sinking of plutons

    Science.gov (United States)

    Glazner, A.F.; Miller, D.M.

    1997-01-01

    Many granodiorite to diorite plutons in the Great Basin of western North America are surrounded by rim monoclines or anticlines that suggest relative downward movement of the plutons while wall rocks were hot and ductile. We propose that such plutons rise to a level of approximately neutral buoyancy and then founder as their densities increase ??? 40% during crystallization. Late-stage sinking of intermediate to mafic plutons should be common when wall rocks are rich in weak, low-density minerals such as quartz and calcite. Structures related to sinking will overprint those related to initial pluton emplacement and may be mistaken for regional tectonic structures.

  14. Non-cylindrical fold growth in the Zagros fold and thrust belt (Kurdistan, NE-Iraq)

    Science.gov (United States)

    Bartl, Nikolaus; Bretis, Bernhard; Grasemann, Bernhard; Lockhart, Duncan

    2010-05-01

    The Zagros mountains extends over 1800 km from Kurdistan in N-Iraq to the Strait of Hormuz in Iran and is one of the world most promising regions for the future hydrocarbon exploration. The Zagros Mountains started to form as a result of the collision between the Eurasian and Arabian Plates, whose convergence began in the Late Cretaceous as part of the Alpine-Himalayan orogenic system. Geodetic and seismological data document that both plates are still converging and that the fold and thrust belt of the Zagros is actively growing. Extensive hydrocarbon exploration mainly focuses on the antiforms of this fold and thrust belt and therefore the growth history of the folds is of great importance. This work investigates by means of structural field work and quantitative geomorphological techniques the progressive fold growth of the Permam, Bana Bawi- and Safeen- Anticlines located in the NE of the city of Erbil in the Kurdistan region of Northern Iraq. This part of the Zagros fold and thrust belt belongs to the so-called Simply Folded Belt, which is dominated by gentle to open folding. Faults or fault related folds have only minor importance. The mechanical anisotropy of the formations consisting of a succession of relatively competent (massive dolomite and limestone) and incompetent (claystone and siltstone) sediments essentially controls the deformation pattern with open to gentle parallel folding of the competent layers and flexural flow folding of the incompetent layers. The characteristic wavelength of the fold trains is around 10 km. Due to faster erosion of the softer rock layers in the folded sequence, the more competent lithologies form sharp ridges with steeply sloping sides along the eroded flanks of the anticlines. Using an ASTER digital elevation model in combination with geological field data we quantified 250 drainage basins along the different limbs of the subcylindrical Permam, Bana Bawi- and Safeen- Anticlines. Geomorphological indices of the drainage

  15. Deformation Analysis of Curved Folds in the Southern Upper Magdalena Valley. Colombia

    Science.gov (United States)

    Jimenez, G.; Bayona, G. A.; Silva, C.; Rapalini, A.; Trindade, R.

    2008-12-01

    In the Upper Magdalena Valley of Colombia there are folds with changes in the strike of their axes (e.g La Hocha Anticline), the origin of which was studied by integrating field, paleomagnetic and magnetic anisotropy data. Two structural domains were defined: the northern is a symmetrical fold and has a strike N10W, whereas the southern is an asymmetrical fold and has a N30E strike. The principal fault is the San Jacinto Fault, which is a reverse fault with slikensides indicating also a horizontal component of displacement. In the hanging wall of the San Jacinto Fault Mesozoic rocks crops out forming an anticline, whereas in the footwall Cenozoic rocks with vertical and locally overturned beds are exposed. Four magnetic components were isolated, being the low coercivity/temperature component similar to the present field. A characteristic component isolated in Cretaceous and Cenozoic rocks is a pre-fold but post-Oligocene component (n=5, D=0.8, I=2.4, K=62.33, a95=9.8). Two characteristic components were isolated in Jurassic rocks. The directions of the first are similar between domains (north domain: n=10 D=20.7 I=35.6 K=13 a95=12.5; south domain: n=6 D=12 I=28.9 K=16 a95=9.5), suggesting no relationship between strike changes and declination variation. The other component has negative inclination (n=2 D=13.8 I=-27.1 K=61.42 a95=11.8) indicating a mean paleolatitude of 14.4S in Jurassic time. Paleomagnetic data suggest that the curved fold is controlled by the geometry of the paleobasin and support the northward translation of accreted terranes along the Western margin of South America during the Jurassic. Anisotropy of magnetic susceptibility analysis in Jurassic and Cretaceous rocks document three magnetic fabrics: (1) Undeformed fabrics are located in the back limb of La Hocha Anticline; (2) tectonics fabrics are associated to reverse fault planes in the north and south domains and indicated a relationship between the anisotropy ellipsoid with the local stress

  16. Analysis of curved folds and fault/fold terminations in the southern Upper Magdalena Valley of Colombia

    Science.gov (United States)

    Jiménez, Giovanny; Rico, John; Bayona, German; Montes, Camilo; Rosero, Alexis; Sierra, Daniel

    2012-11-01

    We use surface and subsurface fold and fault geometries to document curved geometry of folds, along-strike termination of faults/folds and the change of dip of regional faults in four structural areas in the southern part of the Upper Magdalena Valley Basin. In La Cañada area, strike-slip deformation is dominant and cuts former compressional structures; faults and folds of this area end northward abruptly near Rio Paez. To the north of Paez River is the La Hocha area that includes the Tesalia Syncline and La Hocha Anticline, two curved folds that plunge at the same latitude. The southern domain of La Hocha Anticline is asymmetric and bounded by faults in both flanks, whereas the symmetry of the northern domain is related to subsurface fault bending. Paleomagnetic components uncovered in Jurassic rocks suggest a clockwise rotation of 15.2 ± 11.4 in the southern domain, and 31.7 ± 14.4 in the northern domain. The Iquira Area, North of La Hocha, the internal structure is controlled by east-verging faults that end abruptly to the north of this area. The northernmost area is the Upar area that includes fault systems with opposite vergence; west-verging faults at the east of this area decapitate east-verging faults and folds. Paleomagnetic data, geologic mapping and regional structural cross-sections suggest that: (1) pre-existing basement structure controls the curved geometry of La Hocha Anticline; (2) along-strike changes in structural style between adjacent areas and along-strike termination of faults and folds are related to the location of northwest-striking transverse structures in the subsurface; and (3) at least two deformation phases are documented: an Eocene-Oligocene phase associated with the growth of folds along detachment levels within Mesozoic rocks; and a late Miocene phase associated with transpressive faulting along the Chusma and San Jacinto faults. The latter event drove clockwise rotation of the La Hocha Anticline.

  17. A NEW METHOD FOR IMPROVING WATER DRIVE RESULT AND LEASE TEST

    Institute of Scientific and Technical Information of China (English)

    Li Xianhong; Fan Yuping; Cheng Jincai

    1996-01-01

    @@ Oilfield Outline The Ma No.20 fault block, located in the middle of sugging Xinglongtai ruptured anticlinal belt in the west of Liaohe rift-subsidence basin, is a structure of 4.5 km2 in area, the oil-bearing area of Xinglongtai oil reservoir being4.1 km2, the effective thickness of the oil reservoir being32.2m on average, the buried depth of the oil reserves ranging 2150 to 2300 m, and the geological reserves of crude oil, 1 153×104t.

  18. Trajectories of principal directions of growth, natural coordinate system in growing plant organ

    Directory of Open Access Journals (Sweden)

    Zygmunt Hejnowicz

    2014-02-01

    Full Text Available In symplasticly growing organs the principal directions of growth, which are indicated by the eigenvectors of the symmetric part of the growth tensor, can be associated with each positional point and joined up to form a network of orthogonal trajectories, unless the growth is isotropic. The trajectories represent a natural coordinate system suitable for description of growing organs. These trajectories often can be recognized in patterns of nonrandom alignments in the cell wall network: these alignments are normal to anticlinal and periclinal walls. Coordinate systems that fit the trajectories in different types of growing organ are listed.

  19. Chanco formation, a potential Cretaceous reservoir, central Chile

    Energy Technology Data Exchange (ETDEWEB)

    Cecione, G.

    1983-07-01

    The Chanco embayment lies 300 km SSW of Santiago, Chile. The sequence within this basin above the metamorphic basement is: Chanco Formation (very clean sandstone), Quiriquina Formation (glauconitic sandstone, rich in organic matter), and Navidad Group (a very good caprock). This section thus contains reservoir, source and caprocks, and is therefore very promising for petroleum investigations. The offshore C-1 well yielded salt-water with gas shows, and two wells drilled onshore yielded shows of gas. The C-1 well lies on a gently-dipping EW-striking anticlinal structure, the presence of which makes the area very prospective.

  20. Total petroleum systems of the Pelagian Province, Tunisia, Libya, Italy, and Malta; the Bou Dabbous, Tertiary and Jurassic-Cretaceous composite

    Science.gov (United States)

    Klett, T.R.

    2001-01-01

    Undiscovered conventional oil and gas resources were assessed within total petroleum systems of the Pelagian Province (2048) as part of the U.S. Geological Survey World Petroleum Assessment 2000. The Pelagian Province is located mainly in eastern Tunisia and northwestern Libya. Small portions of the province extend into Malta and offshore Italy. Although several petroleum systems may exist, only two ?composite? total petroleum systems were identified. Each total petroleum system comprises a single assessment unit. These total petroleum systems are called the Bou Dabbous?Tertiary and Jurassic-Cretaceous Composite, named after the source-rock intervals and reservoir-rock ages. The main source rocks include mudstone of the Eocene Bou Dabbous Formation; Cretaceous Bahloul, Lower Fahdene, and M?Cherga Formations; and Jurassic Nara Formation. Known reservoirs are in carbonate rocks and sandstone intervals throughout the Upper Jurassic, Cretaceous, and Tertiary sections. Traps for known accumulations include fault blocks, low-amplitude anticlines, high-amplitude anticlines associated with reverse faults, wrench fault structures, and stratigraphic traps. The estimated means of the undiscovered conventional petroleum volumes in total petroleum systems of the Pelagian Province are as follows: [MMBO, million barrels of oil; BCFG, billion cubic feet of gas; MMBNGL, million barrels of natural gas liquids] Total Petroleum System MMBO BCFG MMBNGL Bou Dabbous?Tertiary 667 2,746 64 Jurassic-Cretaceous Composite 403 2,280 27

  1. Using Vertical Electrical Soundings for Characterizing Hydrogeological and Tectonic Settings in Deir El-Adas Area, Yarmouk Basin, Syria

    Science.gov (United States)

    Al-Fares, Walid

    2016-06-01

    The present study is aimed at characterizing the subsurface geological and tectonic structure in Deir El-Adas area, by using Vertical Electrical Sounding survey (VES) and hydrogeological investigations, in order to determine the causes of the failure for the majority of the wells drilled in the area. The survey data was treated in three different approaches including direct VES inversion, pseudo-2D method and horizontal profiling, in order to maximize the reliability of the data interpretation. The results revealed the presence of a local faulted anticline structure at the top of the Paleogene formation, underneath the basaltic outcrops where Deir El-Adas village is situated. The appearance of this subsurface anticline structure has complicated the local hydro-geological situation, and most likely led to limitation of the groundwater recharge in the area. Moreover, the performed piezometric and discharge maps indicated the presence of a notable groundwater watershed, in addition to feeble water productivity of the wells drilled adjacent to Deir El-Adas, mostly related to the subsurface geological and tectonic settings in the area.

  2. Geological study of the northern part of Chicontepec Basin, state of San Luis Potosi

    Energy Technology Data Exchange (ETDEWEB)

    Martinez, J.M.

    The stratigraphic subdivisions, supported by paleontological evidence, comprise Triassic to Paleocene formations. The permo-Triassic basement complex is transgressed by continental clastics of upper Triassic and lower Jurassic age, which are succeeded by marine upper Jurassic that rests unconformably on the basement complex in the northern or Tamalihuale area, on Triassic clastics in the central or Palmira-San Pedro area, and on lower Jurassic clastics in the sourthern or Maguey area. The lower Cretaceous is composed of deep-water deposits, which change into the shallow water and reefoid El Abra formation in the Tamalihuale area. The upper Cretaceous changes upward from fine clastics into argillaceous limestone, while the Paleocene is characterized by arenaceous clays. Anticlines in the basin have been unsuccessfully tested with the exception of one well in the Maguey anticline that encountered distillate and gas in fractured Agua Nueve formation (Cretaceous). Electric logs indicate very irregular and poor porosity and permeability. Potential petroleum source rocks are present in the basin, but absence of reservoir rocks accounts for lack of commercial production.

  3. Characteristics of fracture in the Takinoue (Kakkonda) goethermal area, iwate prefecture

    Energy Technology Data Exchange (ETDEWEB)

    Nakamura, H.; Sato, K.; Miyazaki, S.; Chiba, Y.

    1984-09-01

    Structural contour maps in the Takinoue geothermal area have been made by using data on net slips of faults and fixed-points of bedding planes as well as on strikes and dips of bedding planes. From the relation between the contour maps and distribution of fractures, characteristics of fractures in this area can be pointed out as follows: (1) fractures oblique to the bedding planes caused by flexural bedding are located at the east flank of anticlinal structure; (2) extension of fractures occurred during the period of buildup operation of production wells has been detected by acceleration-sense long-distance AE measurement equipment. Location of determined AE sources coincide fairly well with fractured layers in the Tertiary formations. The result of AE measurements showed that the newly-made fractures extended along the pre-existing faults planes and horizontal fractures; (3) the result of x-ray analysis of samples collected from 11 production wells showed that aureole of rock alteration can be divided into three subzones: chlorite subzone, laumontite subzone and gypsum subzone. Among them, the gypsum subzone is distributed along faults, then, iron-poor chlorite subzone seems to be formed in the formation with high permeability in the process of hydrothermal activity; and (4) well KD-5 drilled into deeper portion of asymmetric anticline produced much amount of geothermal steam which is supplied through vertical fracture zone with fluid temperature higher than formation temperature.

  4. Preliminary geology of eastern Umtanum Ridge, South-Central Washington

    Energy Technology Data Exchange (ETDEWEB)

    Goff, F.E.

    1981-01-01

    The basalt stratigraphy and geologic structures of eastern Umtanum Ridge have been mapped and studied in detail to help assess the feasibility of nuclear waste terminal storage on the Hanford Site in southeastern Washington State. Eastern Umtanum Ridge is an asymmetric east-west-trending anticline of Columbia River basalt that plunges 5 degrees eastward into the Pasco Basin. Geologic mapping and determination of natural remanent magnetic polarity and chemical composition reveal that flows of the Pomona and Umatilla Members (Saddle Mountains Basalt), Priest Rapids and Frenchman Springs Members (Wanapum Basalt), and Grande Ronde Basalt were erupted as fairly uniform sheets. The Wahluke and Huntzinger flows (Saddle Mountains Basalt) fill a paleovalley cut into Wanapum Basalt. No evidence was found to indicate Quaternary-age movement on any structures in the map area. The basalt strata on the south limb of the Umtanum anticline display relatively little tectonic deformation since Miocene-Pliocene time. Thus, the buried south flank of Umtanum Ridge may provide an excellent location for a nuclear waste repository beneath the Hanford Site.

  5. Active basement uplift of Sierra Pie de Palo (Northwestern Argentina): Rates and inception from10Be cosmogenic nuclide concentrations

    Science.gov (United States)

    Siame, Lionel L.; Sébrier, Michel; Bellier, Olivier; Bourlès, Didier; Costa, Carlos; Ahumada, Emilio A.; Gardini, Carlos E.; Cisneros, Hector

    2015-06-01

    Quaternary tectonic and denudation rates are investigated for an actively growing basement anticline: the Sierra Pie de Palo range, which belongs to the Andean foreland of Northwestern Argentina (28°S-33°S). In this study, a detailed morphometric analysis of the topography is combined with in situ-produced cosmogenic10Be concentrations measured in (1) surface boulders abandoned on alluvial terraces affected by fault activity (along the north bounding fault) and growth of the basement fold (along the southeastern border), (2) bedrock outcrops corresponding to an exhumed and folded, regional erosion surface, and (3) fluvial sediments sampled at the outlets of several watersheds. Along the eastern and northern borders of the range, incision and uplift rates have been estimated at approximately 0.5 and 1 mm/yr when integrated on Holocene and Pleistocene time scales, in close agreement with both long-term (structural and basin evolution data) and short-term (GPS-derived velocity field) analyses. Cosmogenic-derived denudation and uplift rates combined with geomorphic characteristics of watersheds and river channels allows estimating the onset of the uplift at 4-6 Ma, followed by a more recent period of topographic rejuvenation at roughly 1-2 Ma, probably synchronous with steepening of the eastern and northern flanks of the anticline.

  6. Natural fracturing of rocks: application to the Ahnet basin (Algeria); Fracturation naturelle des roches: application au bassin de l`Ahnet (Algerie)

    Energy Technology Data Exchange (ETDEWEB)

    Badsi, M.

    1998-07-06

    In the Ahnet basin, the production seems to be unrelated to lithological variations in the reservoirs. In these large anticline structures, located in the central Ahnet basin, the presence of gas has been proven, but only a few production wells have been moderately successful. This inconsistency is probably related to the spatial distribution of fracturing throughout the reservoir. In order to investigate several hypothesis, we used several approach to solve problems posed by the interpreter: namely understanding the deformation process, predicting the fractured zones and building the discrete model of fracture network. This approach combines several methods, including sand box modelling, numerical modelling and Statistics rules, often related with fractal behaviour of faults families, have been used for extrapolating observations from seismic or from wells. The numerical tools and sand box analysis have allowed us to answer to the questions related to the formation of this large anticlines in the Ahnet basin and suggest a probable origin of the variation in the spatial distribution of natural fractures. The deterministic predictions of small-scale faults use probabilistic approaches for spatial interpolation assuming implicitly relationship between detected large faults and unresolved small faults. The statistical modelling is used to carry out analysis of the spatial variation of mean fracture attributes at the global scale (a few kilometers) and a 3D stochastic modelling of the fracture system at the local scale (a few ten of meters). (author) 139 refs.

  7. Use of Remote Sensing Data and GIS Tools for Seismic Hazard Assessment for Shallow Oilfields and its Impact on the Settlements at Masjed-i-Soleiman Area, Zagros Mountains, Iran

    Directory of Open Access Journals (Sweden)

    Hojjat Ollah Safari

    2010-05-01

    Full Text Available Masjed-i-Soleiman (MIS is situated in the northern part of the Dezful embayment, which is in the Zagros fold–thrust belt with high seismic activities. MIS faces a shallow buried anticline, formed by the shallowest oilfield with a thick gas cap. The cap rocks of this oilfield are highly fractured, which has resulted in leakages from the gas cap. In this paper, we have used remote sensing techniques and image interpretation for the identification of the Niayesh, Lahbari, Andika and MIS fault zones in the studied area. Further, the study exploited seismic potential mapping using the remote sensing techniques. The relationships between the structural controls and localized gas leakage are assessed within the GIS environment. Additionally, field observation data corroborated that the leakages (and seepages are smashed within the intersection of Niayesh and MIS fault zone, which belongs to the high fractured hinge zone of the MIS anticline. As a result, the reactivation of these active faults may cause large earthquakes with a maximum magnitude of between 6.23 < Ms < 7.05 (Richter scale and maximum horizontal acceleration 0.26 < a < 0.55 g. Finally, the authors concluded that this anticipated earthquake may cause large scale fracturing of cap rocks, releasing a large volume of H2S gas from the uppermost layer of the reservoir.

  8. Migration and accumulation of natural gas in Kela-2 gas field

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    With the guidance of petroleum system theory, the dynamic filling history of natural gas in the Kela-2 gas field is analyzed by using a large suite of oil and gas geochemistry evidence in combination with the tectonic evolution history and reservoir evolution history. It concludes that the Kela-2 gas field was formed by capturing the gas generated during the main gas generation period, while the late kerogen cracking gas contributed a little to the gas field. It suggests that the gas generated during the main gas generation accumulated in the early-formed wide-gentle anticline, which is the necessary condition for natural gas to re-migrate and enrich late to form the large-scale gas reservoir. The newest research shows that the filling history of gas in the Dabei-1, Yinan-2, Tuziluoke and Dina-2 gas fields was related with the natural gas accumulation in the early wide- gentle anticline as well as late re-migration and enrichment of natural gas.

  9. Plastid movement impaired 2, a new gene involved in normal blue-light-induced chloroplast movements in Arabidopsis.

    Science.gov (United States)

    Luesse, Darron R; DeBlasio, Stacy L; Hangarter, Roger P

    2006-08-01

    Chloroplasts move in a light-dependent manner that can modulate the photosynthetic potential of plant cells. Identification of genes required for light-induced chloroplast movement is beginning to define the molecular machinery that controls these movements. In this work, we describe plastid movement impaired 2 (pmi2), a mutant in Arabidopsis (Arabidopsis thaliana) that displays attenuated chloroplast movements under intermediate and high light intensities while maintaining a normal movement response under low light intensities. In wild-type plants, fluence rates below 20 micromol m(-2) s(-1) of blue light lead to chloroplast accumulation on the periclinal cell walls, whereas light intensities over 20 micromol m(-2) s(-1) caused chloroplasts to move toward the anticlinal cell walls (avoidance response). However, at light intensities below 75 micromol m(-2) s(-1), chloroplasts in pmi2 leaves move to the periclinal walls; 100 micromol m(-2) s(-1) of blue light is required for chloroplasts in pmi2 to move to the anticlinal cell walls, indicating a shift in the light threshold for the avoidance response in the mutant. The pmi2 mutation has been mapped to a gene that encodes a protein of unknown function with a large coiled-coil domain in the N terminus and a putative P loop. PMI2 shares sequence and structural similarity with PMI15, another unknown protein in Arabidopsis that, when mutated, causes a defect in chloroplast avoidance under high-light intensities.

  10. Actin-dependence of the chloroplast cold positioning response in the liverwort Marchantia polymorpha L.

    Directory of Open Access Journals (Sweden)

    Shun Kimura

    2016-09-01

    Full Text Available The subcellular positioning of chloroplasts can be changed by alterations in the environment such as light and temperature. For example, in leaf mesophyll cells, chloroplasts localize along anticlinal cell walls under high-intensity light, and along periclinal cell walls under low-intensity light. These types of positioning responses are involved in photosynthetic optimization. In light-mediated chloroplast positioning responses, chloroplasts move to the appropriate positions in an actin-dependent manner, although some exceptions also depend on microtubule. Even under low-intensity light, at low temperature (e.g., 5°C, chloroplasts localize along anticlinal cell walls; this phenomenon is termed chloroplast cold positioning. In this study, we analyzed whether chloroplast cold positioning is dependent on actin filaments and/or microtubules in the liverwort Marchantia polymorpha L. When liverwort cells were treated with drugs for the de-polymerization of actin filaments, chloroplast cold positioning was completely inhibited. In contrast, chloroplast cold positioning was not affected by treatment with a drug for the de-polymerization of microtubules. These observations indicate the actin-dependence of chloroplast cold positioning in M. polymorpha. Actin filaments during the chloroplast cold positioning response were visualized by using fluorescent probes based on fluorescent proteins in living liverwort cells, and thus, their behavior during the chloroplast cold positioning response was documented.

  11. Numerical Modeling of Geomechanical Processes Related to CO{sub 2} Injection within Generic Reservoirs

    Energy Technology Data Exchange (ETDEWEB)

    Eckert, Andreas

    2013-05-31

    In this project generic anticline structures have been used for numerical modeling analyses to study the influence of geometrical parameters, fluid flow boundary conditions, in situ stress regime and inter-bedding friction coefficient on geomechanical risks such as fracture reactivation and fracture generation. The resulting stress states for these structures are also used to determine safe drilling directions and a methodology for wellbore trajection optimization is developed that is applicable for non-Andersonian stress states. The results of the fluid flow simulation show that the type of fluid flow boundary condition is of utmost importance and has significant impact on all injection related parameters. It is recommended that further research is conducted to establish a method to quantify the fluid flow boundary conditions for injection applications. The results of the geomechanical simulation show that in situ stress regime is a crucial, if not the most important, factor determining geomechanical risks. For extension and strike slip stress regimes anticline structures should be favored over horizontally layered basin as they feature higher ΔP{sub c} magnitudes. If sedimentary basins are tectonically relaxed and their state of stress is characterized by the uni-axial strain model the basin is in exact frictional equilibrium and fluids should not be injected. The results also show that low inter bedding friction coefficients effectively decouple layers resulting in lower ΔP{sub c} magnitudes, especially for the compressional stress regime.

  12. Major Oil Plays In Utah And Vicinity

    Energy Technology Data Exchange (ETDEWEB)

    Thomas Chidsey

    2007-12-31

    Utah oil fields have produced over 1.33 billion barrels (211 million m{sup 3}) of oil and hold 256 million barrels (40.7 million m{sup 3}) of proved reserves. The 13.7 million barrels (2.2 million m3) of production in 2002 was the lowest level in over 40 years and continued the steady decline that began in the mid-1980s. However, in late 2005 oil production increased, due, in part, to the discovery of Covenant field in the central Utah Navajo Sandstone thrust belt ('Hingeline') play, and to increased development drilling in the central Uinta Basin, reversing the decline that began in the mid-1980s. The Utah Geological Survey believes providing play portfolios for the major oil-producing provinces (Paradox Basin, Uinta Basin, and thrust belt) in Utah and adjacent areas in Colorado and Wyoming can continue this new upward production trend. Oil plays are geographic areas with petroleum potential caused by favorable combinations of source rock, migration paths, reservoir rock characteristics, and other factors. The play portfolios include descriptions and maps of the major oil plays by reservoir; production and reservoir data; case-study field evaluations; locations of major oil pipelines; identification and discussion of land-use constraints; descriptions of reservoir outcrop analogs; and summaries of the state-of-the-art drilling, completion, and secondary/tertiary recovery techniques for each play. The most prolific oil reservoir in the Utah/Wyoming thrust belt province is the eolian, Jurassic Nugget Sandstone, having produced over 288 million barrels (46 million m{sup 3}) of oil and 5.1 trillion cubic feet (145 billion m{sup 3}) of gas. Traps form on discrete subsidiary closures along major ramp anticlines where the depositionally heterogeneous Nugget is also extensively fractured. Hydrocarbons in Nugget reservoirs were generated from subthrust Cretaceous source rocks. The seals for the producing horizons are overlying argillaceous and gypsiferous beds in

  13. Playa Del Rey oil field, Los Angeles County, California-- natural gas storage

    Energy Technology Data Exchange (ETDEWEB)

    Barnds, R.M.

    1968-01-01

    The Playa del Rey oil field is on Santa Monica Bay, about 15 miles SW. of Los Angeles. The sedimentary rocks of the field were deposited on the flanks and over the ridge of an erosional surface of Franciscan schist. A NW.-trending anticline resulted from deposition and compaction over the ridge. An apron of schistose clastic material was deposited in the littoral zone at the base of the ridge and in embayments formed by the lateral channels. Conformably overlying the basal conglomerate (productive lower zone) and unconformably overlying the schist is a dark brown, compact shale with abundant small lenticular streaks and nodules of calcium phosphate. The rest of the Miocene rock column is composed of about 500 ft of hard, compact black shale and sandy shale, which is conformably overlain by the typical Los Angeles-basin Pliocene and Pleistocene rocks. The upper oil zone is in the lower Pliocene. The Playa del Rey Field is productive from both the lower zone and from sedimentary rocks of the anticline. There are widely varied porosity and permeability values throughout the Del Rey Hills area. That part chosen for the gas-storage project is where the basal conglomerate overlying the Franciscan schist is overlain by the nodular shale.

  14. 峰峰矿区地质特征及煤层气赋存%The geological characteristics and the coalbed methane accumulation in Fengfeng mine district

    Institute of Scientific and Technical Information of China (English)

    许建平; 袁莉

    2001-01-01

    鼓山背斜是峰峰矿区的主控构造。鼓山背斜以西,断层发育,煤层埋藏较浅,地下水补、径、排条件良好,造成煤层气的逸散,煤层含气量低;鼓山背斜以东,地形相对较低,煤层呈单斜构造向深部倾伏,地下水补、径、排条件较差,煤层气得以保存和富集。%Gushan anticline is the main controlling structure in Fengfeng mine district. In the western part of Gushan anticline, faults develops, coal seams bury in small depth, ground water is in good conditions of supply, flow and drainage. As a result, the coalbed methane scattered and the gas content in coal seams is very low. But in the eastern part, the topography is lower, coal seams are in singe inclination and incline toward depths, ground water is in worse conditions of supply, flow and drainage, the coalbed methane is well preserved and the gas content is high.

  15. Formation of orogen-perpendicular thrusts due to mechanical contrasts in the basal décollement in the Central External Sierras (Southern Pyrenees, Spain)

    Science.gov (United States)

    Vidal-Royo, Oskar; Koyi, Hemin A.; Muñoz, Josep Anton

    2009-05-01

    Two series of analogue models are used to explore the effect of ductile-frictional contrasts of the basal décollement on the development of oblique and transverse structures during thin-skinned shortening. These models simulate the evolution of the Central External Sierras (CES; Southern Pyrenees, Spain), which constitute the frontal emerging part of the southernmost Pyrenean thrust. The CES are characterised by the presence of N-S to NW-SE anticlines, perpendicular to the Pyrenean structural trend and developed in the hanging-wall of the thrust system. They detach on unevenly distributed Triassic materials (evaporitic-dolomitic interfingering). The models simulated the effect of adjacent ductile versus frictional décollements during shortening. Model Series A tests the thickness ratio between overburden and the ductile layer, whereas model Series B tests the width (perpendicular to the shortening direction) of frictional décollement. Model results confirms that deformation reaches further in areas detached on a ductile layer whereas above frictional décollement areas, shortening is accommodated by additional uplift and penetrative strain. This replicates the structural style of the CES: higher structural relief of N-S anticlines with regard to orogen-parallel structures, absence of a representative ductile décollement in the core, plunging towards the hinterland and foreland-side closure not thrusted by the South Pyrenean thrust.

  16. Reevaluation of the Reservoir Gas Sands of Rashidpur Gas Field: A Case Study

    Science.gov (United States)

    Eahsanul Haque, Akm; Ahmed, Nur

    2010-05-01

    Rashidpur Gas Field is located in the west of Srimongal in East Central Bangladesh. The accumulation associated with the Miocene Bhuban-Boka Bil Sandstone Reservoirs in a structural trap. The structure is about 35 km long and 7 km wide with amplitude of some 4900 ft. Rashidpur anticline is a sub-meriodinal axis, elongated, asymmetrical doubly plunging anticline which has two pay sands namely Upper Gas Sand (UGS) and Lower Gas Sand (LGS) indicated in all four wells drilled in the structure. After penetrating the shalebsection beneath LGS, drilling plan was rescheduled to a depth of 9200 ft in order to investigate the deeper sands of potential hydrocarbon accumulation. On reaching a depth of 10073 ft a sudden kick occurred, which halted the drilling operation and forced to kill the well. An immediate sidetrack well (4521 ft) was drilled at Well-4 and an existence of a sealing fault was drawn on the final report. But mud logs of Well-3 and Well-4 based on the hydrocarbon component of UGS and LGS clearly indicate the absence of any fault between Well-3 and Well-4. Recent geological investigation in the study area reveals the updated facts on the two wells of Rashidpur Gas Field. The paper analyses mud logs and other geological data and reevaluates the reservoir gas sands of Rashidpur Gas Field.

  17. Geochemical Characteristics and Sources of Natural Gas from the South Margin of Junggar Basin%准噶尔盆地南缘天然气地球化学特征及来源

    Institute of Scientific and Technical Information of China (English)

    吴小奇; 黄士鹏; 廖凤蓉; 李振生

    2011-01-01

    准噶尔盆地南缘天然气分布较为广泛,在3排背斜带均有分布.该区天然气在组分上以烃类为主,其中甲烷占主导;普遍含有氮气和二氧化碳.准噶尔盆地南缘天然气均为典型热成因气,主要为源自中、下侏罗统成熟-过成熟煤系烃源岩的煤成气,其中第一排背斜带和第二排背斜带天然气均为典型高-过成熟阶段煤成气,第三排背斜带独山子背斜下古近统和呼图壁背斜所有气样也是该类型,第三排背斜带其余煤成气样为典型成熟阶段煤成气.准噶尔盆地南缘煤成气普遍具有碳同位素部分倒转的特征,其主要由于同型不同源(侏罗系不同层位)气的混合,也有部分由于细菌氧化作用(古牧地背斜)或油型气和煤成气的混合(齐古和安集海).该区油型气样品较少,目前发现的2个油型气样品位于卡因迪克油田白垩系和独山子油气田古近系,分别为成熟和高-过成熟阶段油型气,来自白垩系和二叠系腐泥型烃源岩.齐古背斜二叠系和三叠系中煤成气主要是由断裂下盘埋深较大的下侏罗统八道湾组煤系烃源岩所生成,而侏罗系中煤成气则主要来自中侏罗统西山窑组和下侏罗统三工河组烃源岩,其埋深相对较浅,成熟度相对较低,因此生成的天然气碳同位素值和甲烷含量均相对较小.%Natural gas distributes widely in all the three anticline belts in the south margin of Junggar basin.It is mainly composed of hydrocarbons, in which methane is dominated, often with nitrogen and carbon dioxide. The gas is typically thermogenic, and mainly coal-derived from Middle-Lower Jurassic mature-over mature coal-measure source rocks. The natural gas in the first and second anticline belts, and part of the third anticline belt (Dushanzi anticline of Lower Paleogene and Hutubi anticline) is typical high-over mature coal-derived, while that in the other part of the third anticline belt is typical mature coal

  18. Structural, conformational and vibrational properties of 1,1,1-Trifluoro-N-(1,1,2,2,2-pentafluoroethyl) methanesulfinimidoyl chloride, CF₃CF₂-N=S(Cl)CF₃.

    Science.gov (United States)

    Robles, Norma L; Chemes, Doly M; Oberhammer, Heinz; Cutin, Edgardo H

    2015-06-15

    The structural, conformational, and configurational properties of 1,1,1-Trifluoro-N-(1,1,2,2,2-pentafluoroethyl) methanesulfinimidoyl chloride, CF3CF2NS(Cl)CF3 have been studied by vibrational spectroscopy [IR (vapor) and Raman (liquid)] and quantum chemical calculations [B3LYP, MP2 and B3PW91 levels of theory using the 6-311+G(d), 6-311+G(df) and 6-311+G(2df) basis sets]. According to these theoretical approximations, CF₃CF₂-N=S(Cl)CF₃ exists in the gas phase as a mixture of a favored anticlinal form (CN bond anticlinal with respect to the CSCl bisector) with C1 symmetry and a less abundant syn conformer showing C1 symmetry as well (ΔG° ≈ 1.20 kcal mol(-1)). Due to the small contribution only a few corresponding vibrational modes of the syn conformer could be assigned confidently in the experimental spectra. Compared to CF₃CF₂-N=S(F)CF₃, the replacement of F by Cl produces a clear change in NS bond length and the corresponding stretching frequency, without affecting the conformational properties.

  19. CF₃CF₂N=S(F)CF₃: vibrational spectra and conformational properties.

    Science.gov (United States)

    Robles, Norma L; Oberhammer, Heinz; Mews, Rüdiger; Cutin, Edgardo H

    2014-05-05

    The structural, conformational, and configurational properties of 1,1,1-trifluoro-N-(1,1,2,2,2-pentafluoroethyl) methanesulfinimidoyl fluoride, CF3CF2N=S(F)CF3 have been studied by vibrational spectroscopy [IR (vapor) and Raman (liquid)] and quantum chemical calculations [B3LYP, MP2 and B3PW91 levels of theory (using the 6-311+G(d) and 6-311+G(2df) basis sets). According to these theoretical approximations, CF3CF2N=S(F)CF3 might be found in the gas phase as a mixture of a favoured anticlinal form (C-N bond anticlinal with respect to the C-S-F bisector angle) and a less abundant syn conformer showing C1 symmetry as well (ΔG°≈1.5 kcal mol(-1)). However, corresponding vibrational modes for these conformers show only small shifts which would not allow confidently detecting the rather small contribution of this second form in the experimental spectra.

  20. Strike-slip fault network of the Huangshi structure, SW Qaidam Basin: Insights from surface fractures and seismic data

    Science.gov (United States)

    Cheng, Xiang; Zhang, Qiquan; Yu, Xiangjiang; Du, Wei; Liu, Runchao; Bian, Qing; Wang, Zhendong; Zhang, Tuo; Guo, Zhaojie

    2017-01-01

    The Huangshi structure, as one of the NWW-trending S-shaped structures in the southwestern Qaidam Basin, holds important implications for unraveling the regional structural pattern. There are four dominant sets of surface strike-slip fractures at the core of the Huangshi structure. The fractures with orientations of N28°E, N47°E and N65°E correlate well with conjugate Riedel shears (R‧), tension fractures (T) and Riedel shears (R) in the Riedel shear model, respectively. Two conjugate strike-slip fracture sets occur at the surface of the Hongpan structure (secondary to the Huangshi structure) and the southwestern part of the Huangshi structure. In seismic sections, the Huangshi structure is present as a positive flower or Y-shaped structure governed by steeply dipping faults, whereas Hongpan and Xiaoshaping structures, located symmetrically to the Huangshi structure, are thrust-controlled anticlines. The Riedel shear pattern of surface strike-slip fractures, the positive flower or Y-shaped structure in seismic sections and the NW-trending secondary compressional anticlines consistently demonstrate that the Huangshi structure is dominated by left-lateral strike-slip faults which comprise a strike-slip fault network. Considering the similar S-shaped configuration and NWW trend of structures across the southwestern Qaidam Basin, it can be further speculated that these structures are also predominantly of left-lateral strike-slip types.

  1. The Qartaba Structure: An Active Backthrust In Central Mt-Lebanon.

    Science.gov (United States)

    Elias, Ata Richard

    2016-04-01

    The Qartaba structure in central Mt-Lebanon is a 15x5km box fold running parallel to the restraining bend of the sinsitral Yammouneh Fault, the main fault of the central segment of the Dead Sea Transform. The Qartaba structure has long been described as a "horst" and associated with Mesozoic normal faulting. However, the Qartaba anticline is suitably oriented with the direction of maximum compression along the restraining bend. Jurassic carbonate rocks form the core of this anticline culminating at ~1953m asl to the east, of the highest structural elevation of the Mt-Lebanon range indicating important tectonic uplift rate. The fold is asymmetric. The western limb is steep and bordered by the Lebanese Flexure, a prominent continuous monocline of Upper Jurassic to Mid Cretaceous rocks, running along the western flank of Mt-Lebanon. The eastern limb of the anticline has a very steep dip, and forms a 200m high cliff well marked in the topography. Its Jurassic layers are almost vertical and end up overhanging Lower Cretaceous beds. Our study suggest that the Qartaba structure is a growing anticline, built by active thrusting over a west dipping thrust fault that cuts the surface at the base of the eastern limb of the anticline. The fault plane can be seen dipping 30-35 degrees to the west. At depth, this thrust is likely to connect with the blind thrust ramp of the Mt-Lebanon Flexure. The Qartaba backthrust with a dip to the west, is opposite to the general vergence of similar structures in the area. On some of the segments of the steep cliff forming the faulted eastern limb, a fresh scarp with smooth and polished surfaces bearing vertical slickensides can be followed over ~700m along the base of the cliff. It corresponds with the location of the thrust fault tip. Talus accumulation over the steep eastern limb covers most of the cliff base, and may be masking further extent of this scarp. We interpret this scarp as the freeface of a co-seismic rupture on the underlying

  2. 构造运动和气候变化对天山北麓奎屯河阶地发育的影响作用%TECTONIC AND CLIMATIC CONTROLS ON THE DEVELOPMENT OF THE KUITUN RIVER TERRACES IN THE NORTHERN PIEDMONT OF TIANSHAN MOUNTAINS

    Institute of Scientific and Technical Information of China (English)

    李有利; 司苏沛; 吕胜华; 王怡然

    2012-01-01

    The Kuitun River down-cut about 300m and left several river terraces in the northern piedmont of Tianshan Mountains. Based on remote sensing image interpretation and field measurement, the terraces were mapped and a longitudinal profile of river terraces was obtained. According to planar and longitudinal characteristics, the river terraces were divided into five groups. 10Be dating indicated the T4 was deposited in MIS 2, and down-cut around 13kaB. P. The age of the T3 , estimated to be 10. 6kaB. P. With average down-cutting rate , is coincident with the Younger Dryas cold event. The T2 terrace,with 14C age of 3100±40kaB. P., was probable to be correlated with the cooler climate in Sub-Boreal period. In the area of Dushanzi anticline, the uplift between T4 and T3 was 12m with an uplift rate of 5mm/a, the uplift of T3 related to river profile was 13m with an average rate of 1. 2mm/a, indicating that the uplift rates of Dushanzi anticline were greater at earlier stage and became smaller at later stage after the ending of the Last Glacial Stage. The Dushanzi fault has vertically dislocated T2 by 3. 7m with a rate of 1. 09 ~ 1. 14mm/a,similar to the rate of anticline uplift, showing the anticline uplift mainly originated from the movements of Dushanzi fault rather than the arching of Dushanzi anticline. The development of three terraces of T5 suggested southward expansion of Dushanzi anticline, making the boundary between aggradation and degradation migrated southward. On the west bank of Kuntun River,5 pinnate terrace risers which developed on the surface of T4 showed five aggradation and degradation boundary migration events,which were possible to be influenced by uplift of Dushanzi anticline in the north, but were more likely to be the effect of tectonic uplift of Tuositai anticline in the southwest. There were four northward migration events of meander channels in the south limb of Dushanzi anticline since T3 formed. They had good correlation with Holocene paleo

  3. Leaf epidermal micro-morphology characteristics of five plants in Rosaceae%蔷薇科5种植物叶表皮微形态特征研究

    Institute of Scientific and Technical Information of China (English)

    张雪梅; 范曾丽

    2012-01-01

    As seen under an optical microscope, the experiment conducted an observation and a study on micro-morphological char- acters of leaf epidermis of five species in three genera, namely Malus halliana, Rosa banksiae Ait, Rosa multiflora Thunb, Rosa xan- thina, Rose maximowicziana. And some quantity indices were measured by analysis system of microphotograph. The results revealed that the epidermal structure of the five Rosaceae speeies is the same type: almost adaxial epidermis are polygonal shapes and their anticlinal walls are mainly fiat or shallow wavy. Abaxial epidermises are irregular and their anticlinal wails are mainly fiat or shallow wavy. Stomatal apparatus distribute around the outer epidermis, being random. But the types of anticlinal wall , the proportionment of length to width of stomatal aperture and the index of stomatal apparatus eet. are different among species. Therefore, leaf epidermal morphology may verify the systematic relationships and classification of Rosaceae.%在光学显微镜下,对蔷薇科3属5种植物,即垂丝海棠、七里香、多花蔷薇、黄刺玫、伞花蔷薇的叶表皮微形态特征进行观察和研究,并测定相应的数量指标。结果表明,5种蔷薇科植物叶表皮形态较为一致:上表皮几乎全为多边形,垂周壁平直或浅波状;下表皮多为无规则型,垂周壁平直或浅波状;气孔器均分布在下表皮,均为无规则型。但表皮细胞垂周壁式样、气孔长短轴之比及气孔器指数等细微特征在种间存在差异,可以区分种类。因此,叶表皮特征对于蔷薇科种类的划分和亲缘关系的确定具有一定的分类学意义。

  4. 辽宁红阳煤田控煤构造与深部煤炭资源潜力%Structures controlling coal and deep coal resource potential in Hongyang coal field, Liaoning

    Institute of Scientific and Technical Information of China (English)

    钟和清; 朱炎铭; 陈尚斌; 邹明俊; 张建胜

    2011-01-01

    Aimed at exhaustion of shallow coal resources of local mining district in Hongyang coal field in Liaon-ing Province, through study of development regularities of structure and evolution history in the coal field, interpretation of oil and gas seismic exploration data, recovery of balanced section and other techniques and methods, the paper predicted the occurrence of coal resources in great depth and peripheral areas of the coal field, prospective areas for exploration and development as well as amount of coal resources. The second district of the coal field is a normal anticline, a structure controlling coal, the coal reserves at depth less than -1 500 m are 83 148 x 104t. In the south of the coal field, Yuejiabao anticline is developed southward. In the east of Xuwangzi exploration area, there are anticline and syncline of lower order, which can be considered as a prospective exploration area, the estimated coal resources at depth less than -1 500 m are 18 500 x 104t.%针对辽宁红阳煤田局部采区浅部煤炭资源逐渐枯竭的问题,通过煤田构造发育规律和演化史研究、油气地震勘探资料解译、平衡剖面恢复等技术和方法,预测了该煤田深部及外围煤炭资源的赋存状况、远景勘探开发区及煤炭资源量.结果显示:煤田二区为正常背斜的控煤构造,-1 500 m以浅的煤炭资源储量为83 148万t;煤田南部岳家堡背斜往南发育,徐往子勘探区东部存在一个低次序含煤向、背斜构造,可作为远景勘探区,估算-1 500 m以浅的煤炭资源量为1.85亿t.

  5. Central Zagros fold-thrust belt (Iran): New insights from seismic data, field observation, and sandbox modeling

    Science.gov (United States)

    Sherkati, S.; Letouzey, J.; Frizon de Lamotte, D.

    2006-08-01

    We present five generalized cross sections across the central Zagros fold-and-thrust belt (Iran). These sections show that the fold geometry varies significantly both horizontally and vertically. The style is closely related to the changes in the mechanical behavior of the lithostratigraphic horizons and, in particular, to the presence of intermediate décollements within the sedimentary pile. Restoration of the sections shows amounts of shortening of the same order from one section to the other. However, it appears to be unequally distributed, suggesting variations in basal décollement shear strength. Analogue modeling has been performed to systematically investigate the effect of an intermediate décollement level at different depths on the style of folding. The models demonstrate that the position of intermediate décollements is an important factor controlling both structural style and fold wavelength. Models with shallow intermediate décollement show regularly and widely spaced anticlines. In these models, the fold wavelength depends directly on the thickness of the dominant competent layer and short-wavelength superficial structures mask broad anticlines at depth. Models with deep intermediate décollement are characterized by the rapid propagation of deformation (with small rate of shortening) along this décollement influencing localization of forthcoming anticlines in the upper levels. Such propagation favors the development of duplexes and multiwavelength folds. On this basis, fold kinematics in central Zagros is discussed using the variation of structural style along different folds as an indicator of the sequence of deformation. Detachment folding is the main folding style at least for the initial stages of deformation and thrust faults developed only at later stages. Some of these faults, branched on décollement levels, express the progression of folding, whereas others are linked to late basement faults cutting through early structures. In general

  6. Resistivity imaging of strata and faults in Bangladesh

    Science.gov (United States)

    Hosain, A.; Steckler, M. S.; Akhter, S. H.

    2015-12-01

    The Ganges-Brahmaputra-Meghna Delta, the largest in the world, is subject to deformation by active tectonics and dynamic river systems. It lies near the juncture of the Indian, Eurasian and Burmese plates and is being overthrust by both the Shillong Massif and the Indo-Burman Ranges. There are multiple major and minor active faults in Bangladesh, many of which are buried by the sedimentation. For example, the Madhupur tract is a Pleistocene upland in the middle part of Bengal Basin. Whether it is a passive interfluve of the river system or a tilted and tectonically uplifted block has been debated for decades. The Tippera Surface, in Comilla at the eastern part of the basin, is composed of uplifted and oxidized Holocene strata and overlies buried anticlines of the Indo-Burman fold belt. Furthermore, the rivers are subject to migrations, avulsions and other changes in course. The last major avulsion of the Brahmaputra River was only ~200 years ago. During the sea level fall in the last glaciation the major rivers created large incised valleys. In much of the exposed uplands there was the development of a weathered clay surface. This now forms a clay layer separating the Pleistocene and Holocene strata in large parts of Bangladesh. We use electrical resistivity surveying and hand-drilled borehole lithological data to better understand the subsurface discontinuities and structures. The resistivity system consists of an 84 electrode array powered by 2 car batteries and is capable of imaging lithologies to ~100m depth, similar to the depths of the boreholes used to calibrate the data. We extend our previous work on the western margin of the Madhupur Tract with additional lines on the eastern flank of Madhupur. Resistivity lines along the exposed Lalmai anticline in Comilla image the now tilted Holocene-Pleistocene clay layer. Additional lines along the subsurface continuation of the anticline provide additional information on the subsurface lithologies associated with

  7. Identifying tectonic and climatic drivers for deep-marine siliciclastic systems: Middle Eocene, Spanish Pyrenees

    Science.gov (United States)

    Pickering, K. T.; Scotchman, J. I.; Robinson, S. A.

    2009-12-01

    Analysis of the sedimentary record in deep time requires the deconvolution of tectonic and climatic drivers. The deep-marine siliciclastic systems in the Middle Eocene Ainsa-Jaca basin, Spanish Pyrenees, with their excellent outcrops and good temporal resolution, provide an opportunity to identify the relative importance of tectonic and climatic drivers on deposition over ~10 Myr at a time when the Earth’s climate was shifting from a greenhouse to icehouse conditions. The cumulative ~4 km of stratigraphy contains 8 sandy systems with a total of ~25 discrete channelized sandbodies that accumulated in water depths of ~400-800 m, and that were controlled by the ~400-kyr Milkankovitch frequency with modes, at ~100 kyr and ~41 kyr (possibly stacked ~23-kyr) influencing bottom-water conditions, causing periodic stratification in the water column across a submarine sill within the eastern, more proximal depositional systems in the Ainsa basin. We also identify a range of sub-Milankovitch millennial-scale cycles (Scotchman et al. 2009). In the Ainsa basin, the interplay of basin-bounding growth anticlines defined and controlled the position and stacking patterns of the sandy systems and their constituent channelized sandbodies, in a process of seesaw tectonics by: (i) Westward lateral offset-stacking of channelized sandbodies due to growth of the eastern anticline (Mediano), and (ii) Eastward (orogenwards) back-stepping of the depositional axis of each sandy system, due to phases of relative uplift of the opposing Boltaña growth anticline. The first-order control on accommodation, and the flow paths, for deep-marine sedimentation were tectonic, with the pacing of the supply of coarse siliciclastics being driven by global climatic processes, particularly Milankovitch-type frequencies. The dominance of eccentricity and obliquity is similar to results from the continental lacustrine Eocene Green River Formation, and the observations from ODP Site 1258 that the early to

  8. Mesozoic inverted structure analysis of the southern margin of the Junggar Basin%准噶尔盆地南缘中生代正反转构造分析

    Institute of Scientific and Technical Information of China (English)

    王天宝; 贾东; 魏东涛; 王彦君; 李一泉; 张寒

    2013-01-01

    本文以地质露头、钻井和测井资料为约束,运用断层相关褶皱理论解释了新处理的准噶尔盆地南缘94条工业地震反射剖面,并通过数值模拟实验以及平衡剖面恢复技术,合理地再现了准噶尔盆地南缘第一排褶皱冲断带中生代构造演化的运动学过程.研究结果表明准噶尔盆地南缘中三叠世一中侏罗世为拉张环境,喀拉扎正断层、昌吉正断层发育,并控制中-上三叠统—中-下侏罗统沉积;中-晚侏罗世转变为挤压环境,早期正断裂发生反转,同时控制第一排背斜带的齐古逆断裂开始发育,齐古背斜、昌吉背斜雏形形成;上新世(N2)再次发生强烈挤压,齐古背斜、昌吉背斜和喀拉扎背斜最终定型.%The dynamic of the first-order fold-thrust belts were modeled by the combination of the numerical modeling and balanced cross-section techniques, with the constraints from the outcrop,well drilling and logging data. Moreover, 94 seismic sections collected from southern margin of the Junggar Basin were analyzed with the fault-related fold theory. The results indicate that the Junggar Basin showing extensional conditions with the development of the Kalazha and Changji normal faults from the Middle Triassic to Middle Jurassic. This tectonic frame was in charge of the sedimentary characteristics; the switch of the stress field from the extension to compression occurred in the Middle-Late Jurassic. As a result of this switch, normal faults developed earlier reversed to reverse fault ( Qigu fault) and controlled the initial development of the first-order anticlines. Meanwhile, the initial from of the Qigu and Changji anticlines developed; The Qigu, Changji and Kalazha anticlines finally shaped with the strong compression.

  9. Tectonic Controls on Gas Hydrate Distribution off SW Taiwan

    Science.gov (United States)

    Berndt, C.; Chi, W. C.; Jegen, M. D.; Muff, S.; Hölz, S.; Lebas, E.; Sommer, M.; Lin, S.; Liu, C. S.; Lin, A. T.; Klaucke, I.; Klaeschen, D.; Chen, L.; Kunath, P.; McIntosh, K. D.; Feseker, T.

    2015-12-01

    The northern part of the South China Sea is characterized by wide-spread occurrence of bottom simulating reflectors (BSR), indicating the presence of marine gas hydrates. Because the area covers both the tectonically inactive passive margin and the northern termination of the Manila Trench subduction zone while sediment input is broadly similar, this area provides an excellent opportunity to study the influence of tectonic processes on the dynamics of gas hydrate systems. Long-offset multi-channel seismic data show that movement along thrust faults and blind thrust faults caused anticlinal ridges on the active margin, while faults are absent on the passive margin. This coincides with high-hydrate saturations derived from ocean bottom seismometer data and controlled source electromagnetic data, and conspicuous high-amplitude reflections in P-Cable 3D seismic data above the BSR in the anticlinal ridges of the active margin. On the contrary, all geophysical evidence for the passive margin points to normal- to low-hydrate saturations. Geochemical analysis of gas samples collected at seep sites on the active margin show methane with heavy δ13C isotope composition, while gas collected on the passive margin shows highly depleted (light) carbon isotope composition. Thus, we interpret the passive margin as a typical gas hydrate province fuelled by biogenic production of methane and the active margin gas hydrate system as a system that is fuelled not only by biogenic gas production but also by additional advection of thermogenic methane from the subduction system. The location of the highest gas hydrate saturations in the hanging wall next to the thrust faults suggests that the thrust faults represent pathways for the migration of methane. Our findings suggest that the most promising gas hydrate occurrences for exploitation of gas hydrate as an energy source may be found in the core of the active margin roll over anticlines immediately above the BSR and that high

  10. Characterising the nature, evolution and origin of detachment fault in central depression belt, Qiongdongnan Basin of South China Sea:evidence from seismic reflection data

    Institute of Scientific and Technical Information of China (English)

    REN Jianye; YANG Linlong; ZHANG Daojun; TONG Dianjun; HUANG Anmin; WANG Yahui; LEI Chao; ZUO Qianmei; ZHAO Yanghui; HE Weijun

    2014-01-01

    Using regional geological, newly acquired 2D and 3D seismic, drilling and well log data, especially 2D long cable seismic profiles, the structure and stratigraphy in the deep-water area of Qiongdongnan Basin are interpreted. The geometry of No.2 fault system is also re-defined, which is an important fault in the central depression belt of the deep-water area in the Qiongdongnan Basin by employing the quantitative analysis techniques of fault activity and backstripping. Furthermore, the dynamical evolution of the No.2 fault sys-tem and its controls on the central depression belt are analyzed. This study indicates that the Qiongdongnan Basin was strongly influenced by the NW-trending tensile stress field during the Late Eocene. At this time, No.2 fault system initiated and was characterized by several discontinuous fault segments, which controlled a series small NE-trending fault basins. During the Oligocene, the regional extensional stress field changed from NW-SE to SN with the oceanic spreading of South China Sea, the early small faults started to grow along their strikes, eventually connected and merged as the listric shape of the No.2 fault system as ob-served today. No.2 fault detaches along the crustal Moho surface in the deep domain of the seismic profiles as a large-scale detachment fault. A large-scale rollover anticline formed in hanging wall of the detachment fault. There are a series of small fault basins in both limbs of the rollover anticline, showing that the early small basins were involved into fold deformation of the rollover anticline. Structurally, from west to east, the central depression belt is characterized by alternatively arranged graben and half-graben. The central depression belt of the Qiongdongnan Basin lies at the extension zone of the tip of the V-shaped northwest-ern ocean sub-basin of the South China Sea, its activity period is the same as the development period of the northwestern ocean sub-basin, furthermore the emplacement and

  11. Active shortening and intermontane basin formation in the central Puna Plateau: Salar de Pocitos, NW Argentina (24°37'S, 67°03'W)

    Science.gov (United States)

    Strecker, Manfred; Bookhagen, Bodo; Freymark, Jessica; Pingel, Heiko; Alonso, Ricardo N.

    2015-04-01

    Similar to other Cenozoic orogenic plateaus, extensional tectonics associated with mafic volcanism typifies the Altiplano-Puna of the southern Central Andes, while the flanks of the plateau and adjacent foreland areas experience shortening. Extensional tectonism in the plateau region since the late Miocene has been explained with delamination of lithospheric mantle. However, new evidence for protracted basin-wide shortening in the Salar de Pocitos region in the south-central Puna documents that the kinematic changeover from shortening to extension is highly diachronous. In this study we assess the deformation and geomorphic history of the Salar de Pocitos region using DGPS surveys, CRN dating of deformed pediment surfaces, and U/Pb dating of volcanic ash horizons in deformed strata. With average elevations of about 3.7 km the Altiplano-Puna is a first-order morphotectonic province of the southern central Andes and constitutes the world's second largest orogenic plateau. With few exceptions the Andean plateau consists of internally drained, partly coalesced sedimentary basins that are mainly bordered by reverse-fault bounded ranges, 5 to 6 km high. While there are many unifying plateau characteristics in the Altiplano (north) and Puna (south), including internal drainage, semi-arid to arid climate and associated deposition of evaporites, there are notable differences between both plateau sectors. In contrast to the vast Altiplano basin of Bolivia, the Argentine Puna comprises numerous, smaller and partly coalesced basins that reflect continued comparmentalization by the combined effects of tectonism and volcanic activity. The N-S oriented Salar de Pocitos basin is the vestige of a formerly contiguous sedimentary basin within the Puna interior. Unlike many other basins in this region it is bordered by the limb of an anticline developed in Tertiary sedimentary rocks on the west, while the eastern border is a reverse-faulted range front. To the north and south the

  12. Coseismic Deformation of the Great 1762 Arakan Subduction Earthquake Along South-Eastern Coast of Bangladesh

    Science.gov (United States)

    Mondal, D. R.; McHugh, C. M.; Steckler, M. S.; Seeber, L.; Goodbred, S. L.; Akhter, S. H.; Mortlock, R. A.

    2013-12-01

    Large subduction earthquakes and tsunamis along the India-Burma (Sunda) plate boundary were brought to the world's attention after the catastrophic 2004 Sumatra earthquake. Subduction and thus possible megathrust earthquakes are thought to continue north of the Bay of Bengal into the Ganges-Brahmaputra Delta. Here the delta is being subducted resulting in ongoing accretion that is manifested by a wide active fold belt. Bangladesh, with a population of ~160 million is crossed by this plate boundary. Yet, little is known about the hazard there from megathrust earthquakes. The one in 1762 ruptured the >600 km long Arakan segment of the northern Sunda megathrust, well into the shelf area of the delta, including SE Bangladesh. The event was estimated as Mw8.8 by Cummins (2007) based on observed uplift and subsidence. To begin documenting coseismic uplift and the consequences of the 1762 earthquake in southern Bangladesh, we conducted paleoseismological studies on Saint Martin's Island and the Teknaf coast, along the outer portion of the fold belt in southeastern Bangladesh. Our structural and age data indicate that the island of Saint Martin overlies an active anticline, thus uplift can be caused by both anticline growth and the megathrust. Present water depths on the shelf near Saint Martin are ~30 m, but the island was marine during mid- to late-Holocene, and during Oxygen Isotope Stage 5. Shoreline erosion along the southern tip of the island has uncovered the tilted limbs of the anticline. Evidence for the 1762 earthquake is manifested in uplifted coquina terraces dated through detailed radiocarbon studies at 1590-1680 cal yrs AD. Similar ages were obtained for uplifted terraces along the Teknaf coast. Dead corals of the massive species "porites" are exposed along the eastern and western parts of Saint Martin. Coastal emergence was measured by a Fast Static GPS relative to mean sea level using EGM96 geoid model to be 6.6 m for the coquina terraces and 2 m for the

  13. Laramide structure of the central Sangre de Cristo Mountains and adjacent Raton Basin, southern Colorado

    Science.gov (United States)

    Lindsey, D.A.

    1998-01-01

    Laramide structure of the central Sangre de Cristo Mountains (Culebra Range) is interpreted as a system of west-dipping, basement-involved thrusts and reverse faults. The Culebra thrust is the dominant structure in the central part of the range; it dips 30 -55?? west and brings Precambrian metamorphic base-ment rocks over unmetamorphosed Paleozoic rocks. East of the Culebra thrust, thrusts and reverse faults break the basement and overlying cover rocks into north-trending fault blocks; these boundary faults probably dip 40-60?? westward. The orientation of fault slickensides indicates oblique (northeast) slip on the Culebra thrust and dip-slip (ranging from eastward to northward) movement on adjacent faults. In sedimentary cover rocks, east-vergent anticlines overlie and merge with thrusts and reverse faults; these anticlines are interpreted as fault-propagation folds. Minor east-dipping thrusts and reverse faults (backthrusts) occur in both the hanging walls and footwalls of thrusts. The easternmost faults and folds of the Culebra Range form a continuous structural boundary between the Laramide Sangre de Cristo highland and the Raton Basin. Boundary structures consist of west-dipping frontal thrusts flanked on the basinward side by poorly exposed, east-dipping backthrusts. The backthrusts are interpreted to overlie structural wedges that have been emplaced above blind thrusts in the basin margin. West-dipping frontal thrusts and blind thrusts are interpreted to involve basement, but backthrusts are rooted in basin-margin cover rocks. At shallow structural levels where erosion has not exposed a frontal thrust, the structural boundary of the basin is represented by an anticline or monocline. Based on both regional and local stratigraphic evidence, Laramide deformation in the Culebra Range and accompanying synorogenic sedimentation in the western Raton Basin probably took place from latest Cretaceous through early Eocene time. The earliest evidence of uplift and

  14. Evolución de las cuencas sinorogénicas de la Cordillera Principal entre 35°- 36° S, Malargüe

    Directory of Open Access Journals (Sweden)

    J. Silvestro

    2005-12-01

    Full Text Available La faja plegada y corrida de Malargüe se encuentra localizada en el extremo sur de la Cordillera Principal a los 35°-36° S. Los estratos de crecimiento preservados en cuencas sintectónicas registraron la cinemática de plegamiento de la faja plegada durante el Cenozoico. La cuenca Pinchera-Ventana, ubicada en el sector oeste del área, está rellena por dos secuencias volcaniclásticas cubiertas por basaltos. En el sector occidental de esta cuenca, las secuencias se adelgazan hacia los anticlinales de La Valenciana y Torrecillas en el oeste y hacia los retrocorrimientos de La Brea en el este, desarrollando discordancias progresivas observadas en el campo. En el sector oriental de la cuenca, el arreglo de facies, la composición de los clastos y la presencia de discordancias sugieren una proveniencia desde el anticlinal Bardas Blancas en el oeste. Dataciones radimétricas de los niveles andesíticos basales (15,1 Ma y de los basaltos al techo (6,7 Ma limitan la edad de esta cuenca al Mioceno medio y superior. La cuenca Malargüe desarrollada en el sector oriental del área de estudio, está rellena por dos secuencias sintectónicas volcaniclásticas, cubiertas por una secuencia postectónica. El análisis sísmico de las secuencias de crecimiento muestra un arreglo divergente relacionado al levantamiento del anticlinal Malargüe en el oeste de la cuenca y un triángulo de crecimiento hacia el este relacionado al levantamiento del anticlinal Chacay. La datación de niveles andesíticos basales en 5,04 Ma y la secuencia postectónica al tope, limitan la edad de la cuenca entre el Mioceno superior y Cuaternario. Estas observaciones indican que los depocentros sedimentarios migraron hacia el antepaís conjuntamente con el avance de la faja plegada en igual sentido.

  15. Structure of the central Terror Rift, western Ross Sea, Antarctica

    Science.gov (United States)

    Hall, Jerome; Wilson, Terry; Henrys, Stuart

    2007-01-01

    The Terror Rift is a zone of post-middle Miocene faulting and volcanism along the western margin of the West Antarctic Rift System. A new seismic data set from NSF geophysical cruise NBP04-01, integrated with the previous dataset to provide higher spatial resolution, has been interpreted in this study in order to improve understanding of the architecture and history of the Terror Rift. The Terror Rift contains two components, a structurally-controlled rollover anticlinal arch intruded by younger volcanic bodies and an associated synclinal basin. Offsets and trend changes in fault patterns have been identified, coincident with shifts in the location of depocenters that define rift sub-basins, indicating that the Terror Rift is segmented by transverse structures. Multiple phases of faulting all post-date 17 Ma, including faults cutting the seafloor surface, indicating Neogene rifting and possible modern activity.

  16. CENTENNIAL MOUNTAINS WILDERNESS STUDY AREA, MONTANA AND IDAHO.

    Science.gov (United States)

    Witkind, Irving J.; Ridenour, James

    1984-01-01

    A mineral survey conducted within the Centennial Mountains Wilderness study area in Montana and Idaho showed large areas of probable and substantiated resource potential for phosphate. Byproducts that may be derived from processing the phosphate include vanadium, chromium, uranium, silver, fluorine, and the rare earths, lanthanum and yttrium. Results of a geochemical sampling program suggest that there is little promise for the occurrence of base and precious metals in the area. Although the area contains other nonmetallic deposits, such as coal, building stone, and pumiceous ash they are not considered as mineral resources. There is a probable resource potential for oil and gas and significant amounts may underlie the area around the Peet Creek and Odell Creek anticlines.

  17. STACKING ON COMMON REFLECTION SURFACE WITH MULTIPARAMETER TRAVELTIME

    Directory of Open Access Journals (Sweden)

    Montes V. Luis A.

    2006-12-01

    Full Text Available Commonly seismic images are displayed in time domain because the model in depth can be known only in well logs. To produce seismic sections, pre and post stack processing approaches use time or depth velocity models whereas the common reflection method does not, instead it requires a set of parameters established for the first layer. A set of synthetic data of an anticline model, with sources and receivers placed on a flat topography, was used to observe the performance of this method. As result, a better reflector recovering compared against conventional processing sequence was observed.
    The procedure was extended to real data, using a dataset acquired on a zone characterized by mild topography and quiet environment reflectors in the Eastern Colombia planes, observing an enhanced and a better continuity of the reflectors in the CRS stacked section.

  18. Hanston-Oppy field

    Energy Technology Data Exchange (ETDEWEB)

    Ingold, B.L.

    1965-01-01

    In the Hanston-Oppy Field, Hodgeman Co., Kan., the Osagian production is controlled by structure as well as stratigraphy, whereas the structure is primarily anticlinal with a series of local highs and saddles, the overlying Spergen-Warsaw becoming a thin mantle near the subcrop. The Spergen and Warsaw seem to be conformable to each other, but not to the Osage. The long period of erosion near the end of Osagian time has resulted in leaching to great depths within the formation. The Marmaton production is controlled by both structure and porosity and permeability. The Mississippian Osage is composed largely of white, gray, tan, and sometimes varicolored chert within a limy-dolomitic matrix. The Marmaton here defined is that section between the true base of the Kansas City and Cherokee shale. It consists of a cream, tan, or light brown to light gray, dense to oolitic and fossiliferous limestone with slight inter-oolitic vulgar fractured porosity.

  19. Deep crustal structure between the Selkirk Crest, Idaho and the Whitefish Range, Montana from magnetotelluric imaging

    Science.gov (United States)

    Bedrosian, P. A.; Box, S. E.; Pellerin, L.

    2006-12-01

    The Middle Proterozoic Belt Basin, spanning parts of Montana, Idaho, Washington, and British Columbia, is one of the deepest basins in North America. More than 18 km of fine-grained sedimentary strata were deposited rapidly between 1.5-1.4 Ga and split by rifting during late Proterozoic development of the North American passive margin. Basin strata were relatively undeformed until Mesozoic Cordilleran thrusting and early Eocene extension. Many outstanding questions require an understanding of deep basin structure, including the flexural load of the Basin, its role during Cordilleran deformation, and controls on ore-forming fluids that produced stratabound Cu-Ag deposits within the Basin. Long-period (deep-crustal) and broadband (shallow-crustal) magnetotelluric (MT) data were collected in 2005 along a 140 km transect within the central Belt Basin, with an average site spacing of 4 km. A portion of the transect is coincident with two deep-crustal seismic reflection profiles (COCORP lines MT-2 and ID-2). The data generally confirm the NW strike of the Sylvanite anticline and Purcell anticlinorium and the more northerly strike of the Libby Thrust Belt. A best-fit, two-dimensional (2D) resistivity model was generated from the MT data down to 50 km. The model is characterized by two subhorizontal, highly conductive horizons. A shallow horizon at 10-15 km depth begins 10 km west of the Whitefish Range front and continues to the west for 60 km to an abrupt end beneath the Sylvanite anticline. A deeper highly-conductive, concave-up layer occurs at 25-35 km depth from just west of southern Lake Koocanusa to an abrupt end about 20 km east of the Purcell trench. From that point west to the Selkirk Crest, the entire crust is very resistive. A crude resistivity stratigraphy is delineated: highly resistive (>104 Ømega m) middle and upper Belt Supergroup (above the Prichard Fm.), moderately conductive (30-1000 Ømega m) Prichard Fm. (to the present depth of exposure), a highly

  20. The Trobriand Subduction System in the Western Solomon Sea

    Science.gov (United States)

    Lock, J.; Davies, H. L.; Tiffin, D. L.; Murakami, F.; Kisimoto, K.

    1987-09-01

    A south-dipping Subduction system which underlies the Trobriand Trough and 149° Embayment, on the southern margin of the Solomon Sea, is active or was recently active. Oceanic basement is overlain by 2.5 s, two-way travel time (TWTT), of sediment that shows at least two stages of deformation: early thrusts (inner wall) and normal faults (outer wall), and later normal faults that have elevated the outer trench margin. Thrust anticlines and slope basins are developed on the inner wall. The floor of the Solomon Sea Basin arches upward between the Trobriand Trough and the New Britain Trench to form isolated peaks and ridges in the east (152° Peaks) and an east-west Central Ridge in the west. Structures in the subduction system, and in the Solomon Sea Basin, plunge westward towards the point of collision with the New Britain Trench.

  1. Petal anatomy of four Justicia (Acanthaceae) species

    Science.gov (United States)

    Amirul-Aiman, A. J.; Noraini, T.; Nurul-Aini, C. A. C.; Ruzi, A. R.

    2013-11-01

    Comparative anatomical study on flower petals was studied in four selected Justicia species from Peninsular Malaysia, i.e. J. comata (L.) Lam., J. carnea Lindl. J. betonica Linn. and J. procumbens L with the objective to provide useful data for species identification and differentiation within the genus of Justicia. Methods used in this study are mechanical scrapping on the leaf surfaces and observation under light microscope. Finding in this study has shown that all species are sharing similar type of anticlinal walls pattern, which is sinuous pattern. Two or more type of trichomes is present in all species studied and this character can be used to differentiate Justicia species. Simple multicellular trichomes are found to be present in all species studied. Justicia betonica can be isolated from other species by the existence of cyclo-paracytic stomata on the petal surfaces.

  2. Allyl 4-hydroxyphenyl carbonate

    Directory of Open Access Journals (Sweden)

    Víctor Hugo Flores Ahuactzin

    2009-07-01

    Full Text Available The title molecule, C10H10O4, is a functionalized carbonate used in the synthetic route to organic glasses. The central CH fragment of the allyl group is disordered over two positions, with occupancies in a 0.758 (10:0.242 (10ratio. This disorder reflects the torsional flexibility of the oxygen–allyl group, although both disordered parts present the expected anticlinal conformation, with O—CH2—CH=CH2 torsion angles of −111 (2 and 119.1 (4°. The crystal structure is based on chains parallel to [010], formed by O...H—O hydrogen bonds involving hydroxyl and carbonyl groups as donors and acceptors, respectively. The molecular packing is further stabilized by two weak C—H...π contacts from the benzene ring of the asymmetric unit with two benzene rings of neighboring molecules.

  3. NEW DATA ON THE STRUCTURE OF THE OFFSHORE MARGIN OF THE NORTHERN SAKHALIN

    Directory of Open Access Journals (Sweden)

    Vladimir L. Lomtev

    2015-09-01

    Full Text Available This publication presents new data obtained with CDP, gravimetry and magnetometry methods, showing the structure of the offshore margin of the Northern Sakhalin further from the Okhinsky bridge and the Schmidt peninsula, and results of geological interpretation of these data. The study coves: 1 The Trekhbratskaya anticline zone and the mega­dyke with the same name; 2 The East­Sakhalin trough filled in with the Late Cenozoic, mainly the Pomyrskie and Deryuginskie sediments, debris from the Amur river and products of abrasion which occurs at offshore folded structures / bench; 3 The near­bottom gas hydrates and indicators of gas saturation of the Pomyrskie and Deryuginskie sediments. New problems were identified concerning tectonic, magmatic and sedimentation history of the offshore margin and the adjacent structures of the Sakhalin cordillera and the bathyal Deryugin basin.

  4. Surveying of the deformed terraces and crust shortening rate in the northwestern Tarim Basin: Comment

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    @@ The paper of Shen et al., entitled "Surveying of the deformed terraces and crust shortening rate in the northwest Tarim Basin", was published in Chinese Science Bulletin (Vol. 46, No. 12)[1]. Shen et al. found the deformation of Late Pleistocene to Holocene terraces of the Boguzi River across the Artushi Anticline in the northwest Tarim Basin close to the Pamir, and made level survey and differential GPS measurement, which is of great importance to geodynamics for research on the coupling of Tianshan Mountains uplifting and Tarim Basin depression. But their understanding to the deformation mechanics of terraces and the calculation methods of crustal shortening are open to discussion. Therefore, we discuss it with Shen Jun et al.

  5. Depth imaging system for seismic reflection data. Part 1. Outline of system; Hanshaho jishin tansa data no tame no shindo imaging system. 1. System no gaiyo

    Energy Technology Data Exchange (ETDEWEB)

    Shimizu, N. [Japex Jeoscience Institute, Tokyo (Japan); Matsuoka, T. [Japan Petroleum Exploration Corp., Tokyo (Japan); Tsuru, T. [Japan National Oil Corp., Tokyo (Japan)

    1996-10-01

    Structures of oil and gas fields to be recently explored have changed from simple structures represented by anticline into more complicated and more delicate structures in the deeper underground. In order to discover and develop prospective oil and gas fields among such geological structures, it is indispensable to construct a system which can treat seismic exploration date collectively before stacking and can easily perform imaging of underground structures accurately. Based on the advancement of hardware, Japan National Oil Corporation and Japan Petroleum Exploration Co., Ltd. have developed a depth imaging system as an interactive tool for constructing underground structures accurately through a cooperation of highly accurate imaging technology. Using this system, two-dimensional underground structure models can be easily given and modified by interactively referring to results of depth migration velocity analysis and stacking velocity analysis, well data, cross sections after depth transform, etc. 1 fig.

  6. The enhanced callose deposition in barley with ml-o powdery mildew resistance genes

    DEFF Research Database (Denmark)

    Skou, Jens-Peder

    1985-01-01

    Carborundum treatment of barley leaves induced a callose deposition which was detected as diffuse blotches in the epidermal cells of susceptible barleys and as deeply stained tracks along the scratches in barleys with the ml-o powdery mildew resistance gene. Subsequent inoculation with powdery...... mildew resulted in appositions that enlarged inversely to their size in the respective varieties when inoculated without carborundum treatment. Aphids sucking the leaves resulted in rows of callose containing spots along the anticlinal cell walls. The spots were larger in the ml-o mutant than...... in the mother variety. Callose was deposited in connection with the pleiotropic necrotic spotting in barleys with the ml-o gene. Modification of the necrotic spotting by crossing the ml-o gene into other gene backgrounds did not result in any change in the size of appositions upon inoculation with powdery...

  7. Potentiometric-surface map of water in the Fox Hills-Lower Hell Creek aquifer in the Northern Great Plains area of Montana

    Science.gov (United States)

    Levings, Gary W.

    1982-01-01

    The potentiometric surface of water in the Upper Cretaceous Fox Hills-lower Hell Creek aquifer is shown on a base map at a scale of 1:1,000,000. The map is one of a series produced as part of regional study of aquifers of Cenozoic and Mesozoic age in the northern Great Plains of Montana. The contour interval is 100 feet. The map shows that the direction of regional ground-water movement is toward the northeast. Recharge occurs on the flanks of the Black Hills uplift, the Cedar Creek anticline, the southwest part of the Bull Mountains basin, and on the out-crop areas. Discharge from the aquifer occurs along a short reach of the Yellowstone River. The average discharge from 335 wells is about 16 gallons per minute and the specific capacity of 185 wells averages 0.49 gallon per minute per foot of drawdown. (USGS)

  8. (4-Methylpiperazin-1-yl(2,3,4-trimethoxybenzylideneamine

    Directory of Open Access Journals (Sweden)

    Channappa N. Kavitha

    2014-04-01

    Full Text Available In the title compound, C15H23N3O3, the piperazine ring is in a slightly distorted chair conformation and is twisted from the mean plane of the benzene ring making a dihedral angle of 14.94 (6°. The 4-methoxy substituent is almost co-planar with the benzene ring [C—C—O—C torsion angle = 5.4 (1°], while the methoxy groups at positions 2 and 3 [C—C—O—C torsion angles of 122.6 (4 and −66.1 (4°, respectively] are twisted away from the mean plane of the benzene ring in anticlinical and synclinical conformations, respectively. No classical hydrogen bonds or any weak intermolecular interactions are observed in the crystal structure.

  9. Late Quaternary activity along the Ferrara thrust inferred from stratigraphic architecture and geophysical surveys

    Science.gov (United States)

    Stefani, Marco; Bignardi, Samuel; Caputo, Riccardo; Minarelli, Luca; Abu-Zeid, Nasser; Santarato, Giovanni

    2010-05-01

    Since Late Miocene, the Emilia-Romagna portion of the Po Plain-Adriatic foredeep basin was progressively affected by compressional deformation, due to the northward propagation of the Apennines fold-and-thrust belt. The major tectonic structures within the basin have been recognised and are relatively well known, thanks to the widespread, even if outdated, seismic survey, performed after WW II, for hydrocarbon exploration. More recently, a large amount of surface and shallow-subsurface information has been provided by the CARG geological mapping project. The region therefore provides a valuable opportunity to discuss the genetic relationship between tectonic deformation, eustatic-paleoclimatic fluctuations, and depositional architecture. The activity of blind thrusts and fault-propagation folds induced repeated angular unconformities and impressive lateral variations in the Pliocene-Quaternary stratigraphy, causing thickness changes, from a few metres, close to the Apennines piedmont line, to more than 9 km, in fast subsiding depocenters (e.g. Lido di Savio). In the Ferrara region, the post-Miocene succession ranges from about 4 km, west of Sant'Agostino, to less than 200 m, on the Casaglia anticline, where Late Quaternary fluvial strata rest on Miocene marine marls, with an angular unconformity relationship. In this sector of the Po Plain, the tip-line of the northernmost thrust has been reconstructed north of the Po River (Occhiobello) and is associated with the growth of a large fold (Ferrara-Casaglia anticline), cross-cut by a complex splay of minor backthrusts and reverse faults. The thrust-anticline structure hosts an energy producing geothermal field, whose hydrogeological behaviour is largely influenced by the fracture pattern. The Apennines frontal thrust probably provided the seismic source for the earthquakes that severely damaged Ferrara, during the 1570 a.D. fall season, as documented by the structural damage still visible in many historic buildings (e

  10. Sediment—Hosted Gold Deposits in China_geochemistry and Prospecting

    Institute of Scientific and Technical Information of China (English)

    杨蔚华; 刘友梅

    1997-01-01

    Sediment-hosted gold deposits are the major type of gold resources in china,Concen trated mostly in the two"Triangle Regios",they are generally hosted in fine-clastic turbidite,hydrothermal chet and marl ranging from cambrian to Triassic in age,structurally controlled by domes,anticlines and second-ordered faults.They are similar to the Carlin-type gold deposits in mineral assemblage and geochemical marks,with an element association closely comparable to those of modern springs and submarine hydrothermal sediments.Organic matter may have played an important role in mineralization .The ore solution may be hydrothermally altered meteoric water developed i areas of local geothermal anomaly.

  11. Actin-based mechanisms for light-dependent intracellular positioning of nuclei and chloroplasts in Arabidopsis.

    Science.gov (United States)

    Iwabuchi, Kosei; Takagi, Shingo

    2010-08-01

    The plant organelles, chloroplast and nucleus, change their position in response to light. In Arabidopsis thaliana leaf cells, chloroplasts and nuclei are distributed along the inner periclinal wall in darkness. In strong blue light, they become positioned along the anticlinal wall, while in weak blue light, only chloroplasts are accumulated along the inner and outer periclinal walls. Blue-light dependent positioning of both organelles is mediated by the blue-light receptor phototropin and controlled by the actin cytoskeleton. Interestingly, however, it seems that chloroplast movement requires short, fine actin filaments organized at the chloroplast edge, whereas nuclear movement does cytoplasmic, thick actin bundles intimately associated with the nucleus. Although there are many similarities between photo-relocation movements of chloroplasts and nuclei, plant cells appear to have evolved distinct mechanisms to regulate actin organization required for driving the movements of these organelles.

  12. Biostratigraphy of the Garau Formation in Naft well subsurface stratigraphic section, South Kermanshah

    Directory of Open Access Journals (Sweden)

    Y., Ezampanah,

    2012-01-01

    Full Text Available In order to biostratigraphy of the Garau Formation in the centeral Lurestan, one subsurface section (Naft well in Naft anticline, south Kermanshah was selected and studied. The drilled thickness of the Garau Formation in this section is up to 485 meters and lithologically composed of argillaceous limestones and dark gray marls. In this research 1150 thin sections of subsurface Naft well section were studied. In biostratigraphic studies of the Garau Formation in study section 61 species belong to 17 genera of planktonic foraminifera were recognized and 9 biozones were identified. Based on distribution of fossils and biozones identificated, the age of the Garau Formation in drilled part of the subsurface Naft well section is Early Aptian to Early Cenomanian.

  13. InSAR Observations Of Crustal Deformation Mechanics In The Interior Of The Puna Plateau Of The Southern Central Andes

    Science.gov (United States)

    Eckelmann, Felix; Motagh, Mahdi; Bokhagen, Bodo; Strecker, Manfred

    2013-12-01

    Crustal deformation evidences in the orogenic interior of the Southern Central Andes at different time scales are observed by applying ENVISAT InSAR time series from 2005 - 2009 and differential GPS data taken in the study area of the palaeo-lake Salar de Pocitos (24.5°S, 67°W, 3650 m asl). Ongoing shortening in the region from the Tertiary to the present-day is indicated by an uplift of Quaternary palaeo-lake terraces of about 4 to 5m within the last 44ka as well as by the growth of an anticline in Tertiary sediments and the reactivation of the reverse-fault bounded Sierra de Macón, both with uplift rates of 2 - 5mm/a. In summary, this study emphasizes the diachronous and spatially disparate character of the tectonic regime at the Puna Plateau.

  14. Structural interpretation of seismic data of Abu Rudeis-Sidri area, Northern Central Gulf of Suez, Egypt

    Science.gov (United States)

    Zahra, Hesham Shaker; Nakhla, Adel Mokhles

    2016-12-01

    The 2D and 3D seismic data are interpreted to evaluate the subsurface geologic structures in the Abu Rudeis-Sidri area that occupy the northern central part of the Gulf of Suez. The 2D seismic data are used for determination of the structural configurations and the tectonic features which is analyzed through the study of interpretation with the available geologic data, in which the geo-seismic depth maps for the main interesting tops (Kareem, Nukhul, Matulla, Raha and Nubia Formations) are represented. Such maps reflect that, the Miocene structure of Abu Rudeis-Sidri area is an asymmetrical NW-SE trending anticlinal feature dissected by a set of NW-SE fault system (clysmic). Added, the Pre-Miocene structure of the studied area is very complex, where the area is of NE dip and affected by severe faulting through varying stratigraphic levels.

  15. Monitoring a large volume CO2 injection: Year two results from SECARB project at Denbury’s Cranfield, Mississippi, USA

    Science.gov (United States)

    Hovorka, Susan D.; Meckel, Timothy A.; Trevino, Ramon H.; Lu, Jiemin; Nicot, Jean-Philippe; Choi, Jong-Won; Freeman, David; Cook, Paul; Daley, Thomas M.; Ajo-Franklin, Jonathan B.; Freifeild, Barry M.; Doughty, Christine; Carrigan, Charles R.; La Brecque, Doug; Kharaka, Yousif K.; Thordsen, James J.; Phelps, Tommy J.; Yang, Changbing; Romanak, Katherine D.; Zhang, Tongwei; Holt, Robert M.; Lindler, Jeffery S.; Butsch, Robert J.

    2011-01-01

    The Southeast Regional Carbon Sequestration Partnership (SECARB) early project in western Mississippi has been testing monitoring tools and approaches to document storage efficiency and storage permanence under conditions of CO2 EOR as well as downdip injection into brine. Denbury Onshore LLC is host for the study and has brought a depleted oil and gas reservoir, Cranfield Field, under CO2 flood. Injection was started in July 2008 and has now achieved injection rates greater than 1.2 million tons/year though 23 wells, with cumulative mass injected as of August, 2010 of 2.2 million metric tons. Injection is into coarse grained fluvial deposits of the Cretaceous lower Tuscaloosa Formation in a gentle anticline at depths of 3300 m. A team of researchers from 10 institutions has collected data from five study areas, each with a different goal and different spatial and temporal scale.

  16. Shallow structure and its formation process of an active flexure in the forearc basin of the central Nankai subduction zone

    Science.gov (United States)

    Ashi, J.; Ikehara, K.; Omura, A.; Ojima, T.; Murayama, M.

    2013-12-01

    ENE-WSW trending active faults, named Enshu fault system, are developed in the forearc basins of the eastern and central Nankai subduction zone. Three parallel faults developed in the Enshu forearc basin of the eastern Nankai have right lateral slip on the basis of dextral displacement of the canyon axis. Moreover, bathymetry data and side-scan sonar imageries indicate relative uplift of the northern region and the multichannel seismic (MCS) reflection profiles show northward dipping fault planes. In the central Nankai subuduction zone, an ENE-WSW trending step is distributed at the northern part of the Kumano forearc basin and is regarded as the western extension of the Enshu fault system. Although MCS records show deformations including an anticlinal fold beneath the bathymetric step, they have less resolution to identify deformation of basin sequence just below the seafloor. In contrast, deformation seems to reach to the seafloor on a profile by SBP mounted on a mother ship. Investigation of shallow deformation structures is significant for understanding of recent tectonic activity. We carried out deep towed SBP survey by ROV NSS (Navigable Sampling System) during Hakuho-maru KH-11-9 cruise. High resolution mapping of shallow structures was successfully conducted by a chirp SBP system of EdgeTech DW-106. ROV NSS also has capability to take a long core with a pinpoint accuracy around complex topographic region. The Kumano forearc basin is topographically divided into the northern part at a water depth of 2038 m and the other major region at a depth of 2042 m by the ENE-WSW linear step. Three deep towed SBP lines intersected this topographical step and revealed the following structures. This step is composed of 100 m wide gentle slope with an inclination of about 8 degrees. An anticlinal axis is located beneath the upper edge of this slope. Sedimentary layers continue at this slope region without any abut/termination and rapidly increase their thickness toward the

  17. The ultrastructure of the seeds surface of the subgenus Xyridion (Tausch of genus Iris L. (Iridaceae of the Flora of Ukraine

    Directory of Open Access Journals (Sweden)

    S.L. Zhygalova

    2016-06-01

    Full Text Available The surface ultrastructure of seeds coat of the subgenus Xyridion of the genus Iris L. from Ukrainian flora was examined. The studied seeds are characterized by both common and distinct features. The common features are: the shape and position of hilum (roundish, small, by position – basal; the shape and limits of cells of the test (polygonal, their boundaries are almost not visible; the character of thickening and tortuosity degree of anticlinal cell walls (uniformly thickened, straight. These features, as we suggest, could be additional diagnostic at the genera level. The distinct characteristics are: the type of cuticle; the type of seeds shape, the shape and the size of seeds. We suppose these characteristics as additional diagnostic at the species level. The seeds ultrastructure of I. pontica and I. sintenisii subsp. brandzae has been studied for the first time.

  18. Late Cenozoic magnetic polarity stratigraphy in the Jiudong Basin, northern Qilian Mountain

    Institute of Scientific and Technical Information of China (English)

    赵志军; 方小敏; 李吉均

    2001-01-01

    Late Cenozoic sediments in the Hexi Corridor, foreland depression of the Qilian Mountain preserved reliable records on the evolution of the Northern Tibetan Plateau. Detailed magnetic polarity dating on a 1150 m section at Wenshushan anticline in the Jiudong Basin, west of Hexi Corridor finds that the ages of the Getanggou Formation, Niugetao Formation and Yumen Conglomerate are>11-8.6 Ma, 8.6-4.5 Ma and 4.5-0.9 Ma respectively. Accompanying sedimentary analysis on the same section suggests that the northern Tibetan Plateau might begin gradual uplift since 8.6-7.6 Ma, earlier than the northeastern Tibetan Plateau but does not suppose that the plateau has reached its maximum elevation at that time. The commencement of the Yumen Conglomerate indicates the intensive tectonic uplift since about 4.5 Ma.

  19. Occurrence characteristics and prospective evaluation of coal-bed methane of physicochemical prospecting area in Dafang County of Guizhou Province%贵州省大方县理化勘查区煤层气赋存特征及远景评价

    Institute of Scientific and Technical Information of China (English)

    冯玉勇

    2014-01-01

    Physicochemical exploration area in Dafang County of Guizhou Province containing coal seam of Upper Permian Longtan Formation is mainly anticline-syncline coal-accumulating basin,and is rich in coal-bed methane resources.This article evaluates the prospective of coal-bed methane in this region comprehensively by analyzing and concluding the geological character and coal-formation condition of this region.%贵州大方理化勘查区主要含煤层为上二叠统龙潭组,为一些背向斜构造聚煤盆地,区内蕴藏着丰富的煤层气资源。文章通过对该区地质特征及成气条件的分析和总结,对煤层气资源进行综合远景评价。

  20. Structural interpretation of seismic reflection data from eastern Salt Range and Potwar Plateau, Pakistan

    Energy Technology Data Exchange (ETDEWEB)

    Pennock, E.S.; Lillie, R.J.; Zaman, A.S.H.; Yousaf, M.

    1989-07-01

    Approximately 1600 km of seismic reflection profiles from the eastern Salt Range and Potwar Plateau (SR/PP) of Pakistan is integrated with available magnetostratigraphic, surface geologic, and well data to classify structural styles, determine the timing of deformation, and estimate the amount of telescoping of the sedimentary cover. The eastern SR/PP are similar to other fold-and-thrust belts underlain by evaporites in that (1) it is part of a zone of overthrusting that extends considerably farther over the Himalayan foreland than adjacent areas not underlain by evaporites, (2) the overall thrust wedge has a narrow cross-sectional taper, (3) structures verge toward the hinterland as well as toward the foreland, and (4) fold trends are long and continuous, consisting of tight salt-cored anticlines separated by broad synclines. 11 figures, 1 table.

  1. Geophysical Contribution in the Characterization of Deep Water Tables Geometry (Sidi Bouzid, Central Tunisia

    Directory of Open Access Journals (Sweden)

    D. Khazri

    2015-01-01

    Full Text Available Geophysical data combined with geological and hydrogeological data were analyzed to characterize the geometry of Oued El Hajel and Ouled Asker deep water tables (Sidi Bouzid. The obtained results allowed refining the geostructural schema by highlighting the individualization of the NE-SW underground convexity of Ouled Asker and the anticline of axis Es Souda-Hmaeima and Ezaouia on either sides of two hydrogeological thresholds. The geometrical analysis determined the spatial extension of Ouled Asker and Oued El Hajel subbasins. The seismic cartography of semideep and deep reservoirs (Oligo-Miocene; Eocene and upper Cretaceous associated with the main subbasins contributed to proposing hydrogeological prospect zones for a rationalized groundwater exploitation.

  2. Shallow seismic imaging of folds above the Puente Hills blind-thrust fault, Los Angeles, California

    Science.gov (United States)

    Pratt, Thomas L.; Shaw, John H.; Dolan, James F.; Christofferson, Shari A.; Williams, Robert A.; Odum, Jack K.; Plesch, Andreas

    2002-05-01

    High-resolution seismic reflection profiles image discrete folds in the shallow subsurface (Puente Hills blind-thrust fault system, Los Angeles basin, California. The profiles demonstrate late Quaternary activity at the fault tip, precisely locate the axial surfaces of folds within the upper 100 m, and constrain the geometry and kinematics of recent folding. The Santa Fe Springs segment of the Puente Hills fault zone shows an upward-narrowing kink band with an active anticlinal axial surface, consistent with fault-bend folding above an active thrust ramp. The Coyote Hills segment shows an active synclinal axial surface that coincides with the base of a 9-m-high scarp, consistent with tip-line folding or the presence of a backthrust. The seismic profiles pinpoint targets for future geologic work to constrain slip rates and ages of past events on this important fault system.

  3. Attempt to approach geological interpretation using integrate well-logging curve analysis method

    Energy Technology Data Exchange (ETDEWEB)

    Yalin, F.

    1988-01-01

    In recent years, people widely use various well-logging curves to determine geological horizon, lithology, hydrocarbon content, etc. and have reaped some effects. The integrate well-logging curve analysis method described here adopts five types of well-logging curves: microlog curve, resistivity-logging curve, induced-current-log curve, spontaneous-potential curve and sonic-logging curve, which are used to form ''ladder diagram'' and ''spider diagram'' for the analysis. Logging curves taken from some wells in west Baxian depression are used to discuss how they analyse lithology and hydrocarbon content of formation. This method favors the comprehensive interpretation of anticline and lithology.

  4. U-Pb zircon age from the base of the Ediacaran Doushantuo Formation in the Yangtze Gorges,South China: constraint on the age of Marinoan glaciation

    Institute of Scientific and Technical Information of China (English)

    ChongyuYin; FengTang; YongqingLiu; LinzhiGao; PengjuLiu; YushengXing; ZhiqingYang; YushengWan; ZiqiangWang

    2005-01-01

    The reported new U-Pb age by sensitive high-resolution ion microprobe (SHRIMP Ⅱ) on zircon was obtained from a tuff sample at the basal Doushantuo Formation in the Jiuqunao section, which situated at the western limb of the Huangling anticline in the Yangtze Gorges in Zigui, Hubei, South China. Eighteen spots of zircons were analyzed and they form two clusters: one includes three spots, with an inherited age of 784+ 15 Ma (MSWD=0.05); the other consists of 15 spots and gives a weighted mean 206pb/238U age of 628.3±5.8 Ma (MSWD=0.86). It is the first SHRIMP U-Pb zircon age obtained nearly the base of the Doushantuo Formation of Ediacaran and represents a maximum age of the Doushantuo Formation It also forms an age constraint on the upper limit age of the Nantuo (Marinoantype) glaciation.

  5. Shortening rates across the foothills of the Western Kunlun (Xinjiang, China) inferred from geomorphic measurements and cosmogenic 10Be dating.

    Science.gov (United States)

    Coudroy, T.; van der Woerd, J.; Li, H.; Barrier, L.; Tapponnier, P.; Simoes, M.; Thuizat, R.; Pan, J.; Si, J.; Xu, T.

    2009-04-01

    The Western Kunlun, which bounds north-western Tibetan Plateau, is one of the largest mountain range of Asia, with altitudes peaking at 6500-7500 m asl, and crustal thicknesses of up to ~70 km. North of the plateau, in the foreland of the range, an active fold-and-thrust belt extends 200 km into the Tarim basin, but remains poorly documented regarding amounts of shortening or deformation rates. We discuss the distribution of deformation on the basis of a study of specific foreland folds and faults using high resolution satellite imagery, digital elevation models, seismic reflection data, on-site topographic measurements and cosmogenic isotope dating. South of Hotan city, the 250 km-long Tekelike Fault - the mountain-front thrust that dips beneath the 45 km-wide, 5400m-high Tekelike Range, a basement ramp-anticline - cuts and offsets terraces abandoned by the Karakash River. 10Be concentrations of surface and sub-surface samples from these terraces upper-most deposits yield an exposure age of about 100 kyr for the upper terrace that lies 140 m above the present river bed, implying an incision rate of 1.4 mm/yr. Assuming a dip of 45 +/-15° and neglecting changes in river dynamics over this time period, this age would imply a minimum, average shortening rate of 1.4 +/- 0.7 mm/yr across the thrust. Farther North, 100 to 200 km-long WNW-ESE trending anticlines deform the thick Tertiary and Quaternary sedimentary series lying in the foreland of the range. The 150 km-long, 35 km-wide Yecheng-Pishan anticline folds Plio-Quaternary molasses. Drainages crossing this growing anticline have abandoned flights of inset terraces on the sides of wind-gaps. The maximum elevation of the highest terrace above local drainage is about 350m. Near Pishan city, flat, well-preserved terrace surfaces are covered by thin loess, in turn capped by loose gravel pavement. On the uppermost two terraces of this valley, 70 and 120 meters-high, cosmogenic 10Be concentrations in surface and sub

  6. Geologic map of the Fittstown 7.5΄ quadrangle, Pontotoc and Johnston Counties, Oklahoma

    Science.gov (United States)

    Lidke, David J.; Blome, Charles D.

    2017-01-09

    This 1:24,000-scale geologic map includes new geologic mapping as well as compilation and revision of previous geologic maps in the area. Field investigations were carried out during 2009–2011 that included mapping and investigations of the geology and hydrology of the Chickasaw National Recreation Area, Oklahoma, west of the map area.The Fittstown quadrangle is in Pontotoc and Johnston Counties in south-central Oklahoma, which is in the northeastern part of the Arbuckle Mountains. The Arbuckle Mountains are composed of a thick sequence of Paleozoic sedimentary rocks that overlie Lower Cambrian and Precambrian igneous rocks; these latter rocks are not exposed in the quadrangle. From Middle to Late Pennsylvanian time, the Arbuckle Mountains region was folded, faulted, and uplifted. Periods of erosion followed these Pennsylvanian mountain-building events, beveling this region and ultimately developing the current subtle topography that includes hills and incised uplands. The southern and northwestern parts of the Fittstown quadrangle are directly underlain by Lower Ordovician dolomite of the Arbuckle Group that has eroded to form an extensive, stream-incised upland containing the broad, gently southeast-plunging, Pennsylvanian-age Hunton anticline. The northeastern part of the map area is underlain by Middle Ordovician to Pennsylvanian limestone, shale, and sandstone units that predominantly dip northeast and form the northeastern limb of the Hunton anticline; this limb is cut by steeply dipping, northwest-southeast striking faults of the Franks fault zone. This limb and the Franks fault zone define the southwestern margin of the Franks graben, which is underlain by Pennsylvanian rocks in the northeast part of the map area.

  7. Cap rock efficiency of geothermal systems in fold-and-thrust belts: Evidence from paleo-thermal and structural analyses in Rosario de La Frontera geothermal area (NW Argentina)

    Science.gov (United States)

    Maffucci, R.; Corrado, S.; Aldega, L.; Bigi, S.; Chiodi, A.; Di Paolo, L.; Giordano, G.; Invernizzi, C.

    2016-12-01

    Cap rock characterization of geothermal systems is often neglected despite fracturing may reduce its efficiency and favours fluid migration. We investigated the siliciclastic cap rock of Rosario de La Frontera geothermal system (NW Argentina) in order to assess its quality as a function of fracture patterns and related thermal alteration. Paleothermal investigations (XRD on fine-grained fraction of sediments, organic matter optical analysis and fluid inclusions on veins) and 1D thermal modelling allowed us to distinguish the thermal fingerprint associated to sedimentary burial from that related to fluid migration. The geothermal system is hosted in a Neogene N-S anticline dissected by high angle NNW- and ENE-striking faults. Its cap rock can be grouped into two quality categories: rocks acting as good insulators, deformed by NNW-SSE and E-W shear fractures, NNE-SSW gypsum- and N-S-striking calcite-filled veins that developed during the initial stage of anticline growth. Maximum paleo-temperatures (< 60 °C) were experienced during deposition to folding phases. rocks acting as bad insulators, deformed by NNW-SSE fault planes and NNW- and WNW-striking sets of fractures associated to late transpressive kinematics. Maximum paleo-temperatures higher than about 115 °C are linked to fluid migration from the reservoir to surface (with a reservoir top at maximum depths of 2.5 km) along fault damage zones. This multi-method approach turned out to be particularly useful to trace the main pathways of hot fluids and can be applied in blind geothermal systems where either subsurface data are scarce or surface thermal anomalies are lacking.

  8. Deposit Types and Geological Characteristics of the Copper Deposits in Zambia%赞比亚铜矿床类型及地质特征

    Institute of Scientific and Technical Information of China (English)

    张道俊; 冷莹莹

    2013-01-01

    Zambia is one of the most famous copper production places in the world.The copper ore deposits in Zambia include stratabound,sedimentary,metamorphosed-deformation and hydrothermal types,and are dominated by the sedimentary type.Statistics indicate that the sedimentary copper ore resources account for 79% of the whole resources in Zambia.All kinds of the copper ore deposits are controlled by the Luflian arc.The stratabound copper deposits are mainly discovered in the perifornical region,and the ore-bearing rock serious are the Muva megagroup biotite schist and around the anticlines and two-mica quartz schist.The sedimentary copper deposits are mainly distributed around anticlines and the peripheral dome,and the ore-bearing rock series are the lower Katanga megagroup sandstone-shale beds.%赞比亚是世界著名的铜产地之一,其铜矿类型可分为层控型、沉积型、变质改造型及热液型,以沉积型为主.据现有大中型矿床铜资源量统计,沉积型矿产铜资源量占赞比亚铜总资源量的79%.各类型铜矿床总体受卢弗里安(Luflian)弧控制,层控型铜矿主要分布在穹窿核部边缘,含矿岩系为莫瓦(Muva)超群的黑云母片岩、二云石英片岩;沉积型铜矿主要分布在背斜或穹窿外缘周围,含矿岩系主要是加丹加(Katanga)超群下部的砂页岩层.

  9. Neogene sinistral transtension along the Hickman fault zone, southeastern Colorado Plateau, New Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Chamberlin, R.M. (New Mexico Bureau of Mines and Mineral Resources, Socorro, NM (United States))

    1993-04-01

    A north-northeast-trending crustal flaw known as the Hickman fault zone (HFZ) transects the southeastern margin of the Colorado Plateau from Mangas to Grants, New Mexico, a distance of 140 km. Recent reconnaissance mapping of the eastern half of the Quemado 1:100,000 sheet by the author indicates that the southern half of the HFZ is a Neogene oblique-slip zone that displays a normal-sinistral sense of shear. The vertical slip component is 150--200 m and the apparent horizontal component is as much as 120 m. Basaltic debris flows and fluvial deposits of the Miocene Fence Lake Formation are preferentially preserved on the downthrown western side of the HFZ. West of Pietown, Fence Lake strata define an asymmetric synclinal basin. Older northwest-striking Late Oligocene basaltic dikes are locally concealed where they pass under the shallow (200 m) northeast--trending basin. Within the 5-km-wide HFZ, north-trending segments appear to form releasing bends and east-northeast-trending segments appear to form weakly constraining bends, a pattern that implies distributed sinistral shear. Small alluvial basins (incipient half grabens) in the Mangas Mountains are associated with north-striking bends. An east-northeast-trending bend near Pietown is locally defined by an asymmetric anticline; also the Late Oligocene dike trend here bends westerly (counterclockwise) where it crosses the anticlinal axis. Near Hickman (a.k.a. Lehew), the HFZ shows two sinistral offsets of another Late Oligocene dike; cumulative offset is about 120 m.

  10. The epidermal cell structure of the secondary pollen presenter in Vangueria infausta (Rubiaceae: Vanguerieae) suggests a functional association with protruding onci in pollen grains.

    Science.gov (United States)

    Tilney, Patricia M; van Wyk, Abraham E; van der Merwe, Chris F

    2014-01-01

    Secondary pollen presentation is a well-known phenomenon in the Rubiaceae with particularly conspicuous pollen presenters occurring in the tribe Vanguerieae. These knob-like structures are formed by a modification of the upper portion of the style and stigma, together known as the stylar head complex. In the flower bud and shortly before anthesis, the anthers surrounding the stylar head complex dehisce and release pollen grains which adhere to the pollen presenter. The epidermal cells of the pollen presenter facing the anthers are radially elongated with a characteristic wall thickening encircling the anticlinal walls of each cell towards the distal end. These cells were studied in the pollen presenter of Vangueria infausta using electron and light microscopy in conjunction with histochemical tests and immunohistochemical methods. Other prominent thickenings of the cell wall were also observed on the distal and proximal walls. All these thickenings were found to be rich in pectin and possibly xyloglucan. The terms "thickenings of Igersheim" and "bands of Igersheim" are proposed to refer, respectively, to these wall structures in general and those encircling the anticlinal walls of each cell near the distal end. The epidermal cells have an intricate ultrastructure with an abundance of organelles, including smooth and rough endoplasmic reticulum, Golgi apparatus, mitochondria and secretory vesicles. This indicates that these cells are likely to have an active physiological role. The pollen grains possess prominent protruding onci and observations were made on their structure and development. Walls of the protruding onci are also rich in pectin. Pectins are hydrophilic and known to be involved in the dehydration and rehydration of pollen grains. We hypothesise that the thickenings of Igersheim, as well as the protruding onci of the pollen grains, are functionally associated and part of the adaptive syndrome of secondary pollen presentation, at least in the Vanguerieae.

  11. Which Yakima folds are most likely to sustain an earthquake? (Invited)

    Science.gov (United States)

    Yeats, R. S.

    2009-12-01

    An important question for seismic hazard evaluation of critical facilities in the Yakima Fold Belt (YFB) is this: are some folds more likely to sustain an earthquake than others? Some agencies consider the Toppenish Ridge and Saddle Mountains anticlines to be more likely than other folds in the YFB to be underlain by a blind reverse fault capable of a large earthquake. Other folds close to the Hanford waste treatment plant and to large dams on the Columbia River are, by the same reasoning, less likely to experience a large earthquake. Toppenish Ridge and probably Saddle Mountains underwent earthquakes during the Holocene with surface expression, whereas other YFB folds have not revealed such evidence. GPS-based strain rates across the YFB are probably no greater than 1 mm/yr, so that earthquake recurrence intervals on individual structures are measured in 10-30 kyr. Some folds would not have been the site of a large earthquake since the emplacement of the Missoula floods 12-14 ka. These floods are so massive that they would have removed all surficial evidence for any reverse-fault earthquakes, thick-skinned or thin-skinned, that predated the most recent floods. Source faults generating Yakima folds are largely blind, and exposed faults are commonly reverse faults low on the flanks, like the Mill Creek thrust on the north side of Toppenish Ridge, or bending-moment normal faults on the crests of anticlines. The 2009 Wooded Island earthquake swarm at Hanford indicates simply that these structures are still active. Hazard evaluation should include densification of the geodetic network to determine shortening across individual folds, which cannot be done at present.

  12. Detachment folds versus thrust-folds: numerical modelling and applications to the Swiss Jura Mountains and the Canadian Foothills

    Science.gov (United States)

    Humair, Florian; Bauville, Arthur; Epard, Jean-Luc; Schmalholz, Stefan

    2016-04-01

    The Jura Mountains and the Foothills of the Canadian Rockies fold-and-thrust belts are classical examples of thin-skinned belts where folds develop over weak detachment horizons. They offer the possibility to observe and measure strain in folds. In these two belts, a large spectrum of fold geometries is expressed, from symmetric box-fold or pop-up structures to asymmetric thrust-related folds. In this study, we focus on the quantification and prediction of the brittle strain distribution in folds as a function of the fold geometry. Fold geometry is considered as a continuum between two end-member structural styles: symmetric detachment folds and asymmetric foreland-vergent thrust-folds. We performed two-dimensional numerical simulations of visco-plastic detachment folding. The models are used (1) to systematically examine the influence of different initial parameters on the resulting geometry and style of folding and (2) to quantify the local strain pattern through time. The different parameters tested are the following: presence and size of initial geometrical perturbation at the detachment-sediment interface, rheology of the detachment (frictional vs. viscous), additional detachment layer within the series and overbunden thickness. Results of single detachment layer models show that the asymmetry of folds is primarily controlled by the height of the initial geometrical perturbation, regardless to the rheology of the detachment (frictional vs. viscous). Additional detachment interlayer within the series decreases the brittle strain within the stiff layers and favours more rounded anticlines geometry. The models were then adapted to the Swiss Jura and the Canadian Foothills settings. Compared to field observations and cross-sections of existing fault-related anticlines, the proposed simulations agree with the first order geometry and the development of associated localized zones of brittle deformation.

  13. The paleohydrology of Lower Cretaceous seasonal wetlands, Isle of Wight, southern England

    Energy Technology Data Exchange (ETDEWEB)

    Wright, V.P.; Taylor, K.G.; Beck, V.H.

    2000-05-01

    The floodplain deposits of the Wealden Group (Lower Cretaceous) of the Isle of Wight, southern England, were formed in a seasonal wetland setting, a type of environment widespread today along higher-order tropical and subtropical river systems but rarely identified in the geological record. The unit consists of four main lithofacies: sheet sandstones with dinosaur footprint casts; green-gray mudstones with vertebrate remains, abundant lignite, pyrite, and siderite; spectacularly color-mottled mudstones with goethite and locally pseudo-anticlines; and red mudstones with pseudo-anticlines, hematite, and carbonate nodules. The sheet sandstones are interpreted as crevasse deposits; the green-gray mudstones were deposited in shallow ponds on the floodplain, which acted as sinks for debris released by local floods following wildfires; the mottled mudstones represent surface-water gley soils formed in seasonally waterlogged areas; and the red mudstones resemble present-day Vertisols that formed on topographically elevated areas only intermittently flooded. These mudstones show vertical transitions from one to another, and although they could be interpreted as components of simple catenas, the absence of associated facies changes implies that topographic differences were not the only control. It is proposed that these three mudstone types formed as seasonal wetland catenas, in which differences in soil drainage conditions resulted from variations in the flooding hydroperiod affecting areas with minor relief differences, rather than drainage variability simply reflecting static topographic differences. Such seasonal wetland systems are rarely documented in the stratigraphic record despite being a widespread environment in present-day tropical regions, and the Wealden deposits are used to identify criteria for the recognition of this important environment in the rock record. These southern English wetlands are compared with other Lower Cretaceous wetlands from northern Spain

  14. Incremental Folding Rates Determined With 104-5 Year Time Resolutions Along The Pyrenean Thrust Front, Spain

    Science.gov (United States)

    Anastasio, D. J.; Kodama, K. P.; Hinnov, L.; Pares, J. M.

    2015-12-01

    High-resolution rock magnetic cyclostratigraphy in growth strata are used to reconstruct unsteady fault-related folding rates at the regional Pico del Aguila anticline. Published and new magnetobiostratigraphy was used to determine absolute time and to calibrate a cyclostratigraphy based on anhysteretic remanent magnetization (ARM) intensity variations. The ARM data series was tuned to the orbital eccentricity model to remove the effects of sedimentary rate changes between late Lutetian-middle Priabonian chron boundaries (C19-C15) during syntectonic deposition. Sediment accumulation rates increased up section to 1.15 m/kyr during delta progradation with large oscillations in sedimentation rate in phase with eccentricity cyclicity. The ARM data was a proxy for climate change by recording Milankovitch cyclicity in the detrital magnetite concentration of deposits resulting from runoff variability in the wedge-top basin. Incremental tilting rates were calculated between selected growth horizons over 5 myrs of fold growth. The Eocene age limb tilt began rapidly then decreased more slowly at variable rates that were punctuated by periods of tectonic quiescence. Calculated folding rates varied between 0˚ and 100 ˚/myrs and averaged 14 ˚/myr over 100 kyr time increments. Accuracy and precision in the rate calculations include spatial errors associated with outcrop reconstruction and down plunge projection (<10 m and 104 yrs), bedding attitude (few ˚), absolute chron ages (105 yrs), sample spacing (103 yrs), sample size (102 yrs), and orbital tuning (104 yrs). The absolute age resolution on deformation is a few 100 kyrs while the uncertainties in the relative time between growth horizons is less and estimated at ~20 kyrs. Variation in folding rates of the Pico del Aguila anticline is attributed to unsteady thrusting in the fold's core.

  15. Interferencia de pliegues en el valle del río Juramento - Cordillera Oriental (provincia de Salta

    Directory of Open Access Journals (Sweden)

    Mon Ricardo

    2004-06-01

    Full Text Available La estructura del área del curso superior del río Juramento difiere de la de los terrenos situados a lo largo del rumbo regional tanto hacia el norte como hacia el sur. Las estructuras de orientación N-S están afectadas por una significativa componente de acortamiento en esa misma dirección, responsable de una figura de interferencia del plegamiento de escala kilométrica. Esta estructura está asociada a una falla oblicua con desplazamiento de rumbo, interpretada como una rampa lateral de magnitud regional. El desplazamiento a lo largo de esta rampa lateral oblicua genera las componentes de acortamiento de dirección N-S, responsables de la compleja deformación de la lámina colgante. Las capas de calizas cretácicas de la Formación Yacoraite forman un manto continuo que permite definir con precisión la geometría de los pliegues. Los dos juegos de pliegues ortogonales muestran un diseño de interferencia de domos y cuencas. El curso superior del Juramento está situado en la pronunciada depresión estructural entre el anticlinal del Crestón cuyo eje buza hacia el norte y el anticlinal de Castillejo-El Presidio que buza hacia el sur. Ambos son pliegues mayores fuertemente curvados, con su lado cóncavo hacia el oeste, que involucran al basamento. Aquí se postula que la figura de interferencia mencionada más arriba está formada por pliegues propagados por fallas, relacionados a la reactivación de antiguas fallas directas cretácicas de rumbo E-O que interactuaron con otras más jóvenes de rumbo N-S (pliocenas.

  16. Generation and Migration of Natural Gas in Miocene Strata, Offshore Southeastern Korea

    Science.gov (United States)

    Son, Byeong-Kook

    2016-04-01

    Natural gas and condensate are produced from Miocene strata of the Tertiary marine basin, called Ulleung Basin, which is located offshore southeastern Korea. Petroleum system in the basin has not been fully understood, because effective source rocks have not been identified in the area. However, 1-D petroleum system modelling and isotope data indicate that the source rock of the natural gas and condensate might be present at deeper strata than 5,000 m in the basin. In addition, the analysis of diamondoids in the condensate shows that the gas was transformed from type II kerogen. Based on this source rock information and other geological data, 2-D petroleum system modelling was conducted on two cross sections in the southwestern margin of the basin. The 2-D models show two phase generation and migration, which are caused by the geometry of source bed and the maturity level of each pod of the bed. In addition, the accumulation of hydrocarbon is constrained greatly by the timing of development of the regional seal. The first generation and migration of oil and gas begins with a high rate of sedimentation at a deeply and early buried pod of the source bed at 15 Ma. The hydrocarbon, however, migrates upward and diffuses toward the surface. The second generation and migration occurs at around 11 Ma from the other pod of the source bed. This hydrocarbon migrates updip toward anticlines and accumulates into the traps of anticlines. On the other hand, the model shows that the generation and migration is dominated by gas, rather than oil. This model indicates that the accumulation of hydrocarbon can be completed only by the proper and sophisticated combination of the geological elements and the timing of hydrocarbon migration in time and space. This 2-D feature of generation and migration is supported by additional 1-D models of two pseudo-wells drilled on the 2-D section.

  17. GEOTECHNICAL MODELS OF THE ARCH FOUNDATIONS OF THE MASLENICA BRIDGE

    Directory of Open Access Journals (Sweden)

    Tomislav Novosel

    1998-12-01

    Full Text Available On the site of Maslenica bridge structural tectonic, geophysical and engineering geological investigations, geotechnical drilling and laboratory sample testings were performed. Maslenica anticline is characteristic for the investigated area. It is built from the limestone of Cretaceous age. The anticline has an asymmetrical form with the vergence of the axial plane towards the north. Reverse faults with recent activities are present. The recent activity was proved by the discovery of the broken stalactite with the displacement of 11 cm, whose age is 36000 years. On quite young stalactites (stalagmites in the cave on the west side, no displacements were noticed. For the next period of 500 years the maximal possible displacement of 2.0 cm is foreseen. Smaller caves with the dimensions of 1 m3, were formed on the intersections of the reverse faults and greater joints. The canyon Novsko ždrilo was formed in the fault shear zone with tectonic transport to the right. According to the range of fracture, three characteristic types of rock masses were separated by engineering geological investigations. According to »Geomechanical classification« (RMR the first type corresponds to II to III class, while the second type corresponds to IV class, and the third type corresponds to V class (mylonite. Because of the complexity of the terrain structure, original engineering geological bases of design have not enabled the direct application of the analysis of stress-strain behaviour. Because of that the simplified geotechnical models were done. They enabled the projecting of foundation in the rock mass and renewal of poor quality rock mass.

  18. Investigating fault propagation and segment linkage using throw distribution analysis within the Agbada formation of Ewan and Oloye fields, northwestern Niger delta

    Science.gov (United States)

    Durogbitan, Abimbola Adewole

    2016-08-01

    Throw distribution analysis of the key stratigraphic surfaces (sequence boundaries and maximum flooding surfaces) across faults has allowed detailed investigation of the tectonic history within the Ewan and Oloye fields, northwestern Niger delta. The structure in the studied area is dominated by growth fault systems which are listric in cross section and concave to the basin in plan-view. Generally, the faults are active down to 2000 m depth before they die out or sole into the underlying shale. The hanging-wall blocks of growth faults are deformed into broad rollover anticlines, with some synthetic and antithetic faults initiated from the anticline crests, and fault splays off major faults, further complicating these structures. Stratigraphic key surfaces within the syn-faulting succession range in age from 16.7 to 10.35 Ma. Periods of maximum and minimum throw are established from 2-Dimensional throw distribution on the growth fault plane. Throw distribution allows analysis of growth fault nucleation, propagation and linkage. Each fault nucleated at different and a distinct interval within the stratigraphic section, as a result of the paleo-stress distribution between the interacting faults. Nucleation and linkage positions can be identified at points of maximum and minimum throw respectively. Following nucleation, faults propagated radially and linked to form the present geometry. Within the study area, fault propagation and segment linkage (lateral and vertical) are important features of the fault system. Understanding of growth fault evolution and linkage has greatly improved prediction of seal potential, trap geometry and migration. The accurate timing of the segment linkage has helped to evaluate the seal risk.

  19. A Preliminary Analysis of Relations Between Tectonic Deformation of Sedimentary Cover and Basement in Kuqa Depression

    Institute of Scientific and Technical Information of China (English)

    Liu Jie; Qu Guosheng; Tong Xiaoguang; Song Huizhen; Zhou Qing; Zhang Ning

    2004-01-01

    Study of seismic activity in the Kuqa area enables us to infer some possible active faults in basement from the ePicentral distribution on different profiles. The relations between active faults in the basement and surface structures are analyzed and the difference between sedimentary cover and basement in their deformation characteristics and the genesis are discussed. The following conclusions have been drawn: (1) the epicentral distribution indicates that, the east Qiulitag and south and north Qiulitag deep faults in the basement correspond to the east and west Qiulitag anticlines, respectively. Moreover, deep faults also exist beneath the Yiqiklik and Yaken anticlines. It indicates that the formation of surface structures is controlled by deep structures; (2) A NE-trending strike-slip fault develops along the line from the western termination of Yiqiklik structure to Dongqiu Well 5 and a NW-trending active fault on the western side of Baicheng. The two active faults across the tectonic strike are the main causes for tectonic segmentation of the Kuqa depression and possibly the cause for the middle segment (Kuqa-Baicheng) of the depression to be more shortened than both its eastern and western terminations; (3) The difference between the sedimentary cover and basement in their deformation characteristics depends mainly on the different properties of media between them.The lithospheric strength of the basement in the basin is fairly high, which determines the basement deformation to be mainly of brittle fracture seismic activity. While the strength of sedimentary cover is low, where there exist weak thin layers, such as coal and gyps. Under the effect of strong tectonic compression, the sedimentary rocks may undergo strong viscous or plastic flow deformation; meanwhile, an aseismic detachment may take place along the weak layers.

  20. Geological constraints of giant and medium-sized gas fields in Kuqa Depression

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    There is a gas-rich and well-charged petroleum system in the Kuqa Depression where Triassic and Jurassic source rocks play important roles. Distributed in an area of more than 10000 km2 and with a thickness of up to 1000 m, they are composed of dark mudstones, carbonaceous mudstones and coal seams containing 6%, 40% and 90% of TOC, respectively, and are mainly the humic organic matter. As high-quality regional cap rocks, the Neogene and Eogene gypsum rocks and gypseous mudstones matched well with the underlying Neogene and Cretaceous-Eogene sandstones. They have formed the most favorable reservoir-seal assemblages in the Kuqa Depression. Also the Jurassic sandstones and mudstones formed another favorable reservoir-seal assemblage. The traps are shaped late in the fold-thrust belt, mainly fixed in the Tertiary-Quaternary, where ten structure styles have been distinguished. These traps spread as a zone in N-S, are scattered like a segmental line in W-E and show tier-styled vertically. The best traps are gypsum-salt covered fault-bend anticlines related to the passive roof duplex. This petroleum system is characterized by late accumulation. In the early Himalayan Movement, mainly gas condensate and oil accumulated and were distributed in the outer circular region of the kitchen; whereas in the middle and late Himalayan the gas accumulations mainly formed and were distributed in the inner circular region near the kitchen. The overpressure of gas pools is common and is formed by seal capacity of thick gypsum layers, extensive tectonic compression and large uplift. The well-preserved anticline traps underlying the high-quality regional cap rocks of the Tertiary gypsum rocks and gypseous mudstones are the main targets for the discovery of giant and medium-sized gas fields. Above conclusions are important for the petroleum geology theory and the exploration of the fold-thrust belt in foreland basins in central and western China.

  1. Geological and geochemical characteristics of high arsenic coals from endemic arsenosis areas in southwestern Guizhou Province, China

    Science.gov (United States)

    Ding, Z.; Zheng, B.; Long, J.; Belkin, H.E.; Finkelman, R.B.; Chen, C.; Zhou, D.; Zhou, Y.

    2001-01-01

    Southwest Guizhou Province is one of the most important areas of disseminated, sediment-hosted-type Au deposits in China and is an important area of coal production. The chemistry of most of the coals in SW Guizhou is similar to those in other parts of China. Their As content is near the Chinese coal average, but some local, small coal mines contain high As coals. The highest As content is up to 3.5 wt.% in the coal. The use of high As coals has caused in excess of 3000 cases of As poisoning in several villages. The high As coals are in the Longtan formation, which is an alternating marine facies and terrestrial facies. The coals are distributed on both sides of faults that parallel the regional anticlinal axis. The As content of coal is higher closer to the fault plane. The As content of coal changes greatly in different coal beds and different locations of the same bed. Geological structures such as anticlines, faults and sedimentary strata control the distribution of high As coals. Small Au deposits as well as Sb, Hg, and Th mineralization, are found near the high As coals. Although some As-bearing minerals such as pyrite, arsenopyrite, realgar (?), As-bearing sulfate, As-bearing clays, and phosphate are found in the high As coals, their contents cannot account for the abundance of As in some coals. Analysis of the coal indicates that As mainly exists in the form of As5+ and As3+, perhaps, combined with organic compounds. The occurrence of such exceptionally high As contents in coal and the fact that the As is dominantly organically associated are unique observations. ?? 201 Elsevier Science Ltd.

  2. Use of microbes for paraffin cleanup at Naval Petroleum Reserve No. 3

    Energy Technology Data Exchange (ETDEWEB)

    Giangiacomo, L.; Khatib, A.

    1995-12-31

    Naval Petroleum Reserve No. 3 (NPR-3), also known as Teapot Dome, is a government-owned oil field in Natrona County, Wyoming. It is an asymmetrical anticline located on the western edge of the Powder River Basin, just south of the Salt Creek Anticline. Production started in 1922, and today the field is a marginally economic stripper field with average production of less than 3 BOPD (0.5 m{sup 3}/D) per well. Total field production is about 1,800 BOPD (286 m{sup 3}/D). The Second Wall Creek Formation was waterflooded from 1979 until June 1992 with poor results due to the extensive natural fracture system in this sandstone unit. Since water injection ceased, reservoir pressure has declined to very low levels. Liquids extraction and reinjection of the gas produced from high-GOR wells along the gas-oil contact continues, but the average gas cap pressure has fallen to approximately 150 psi (1.03 MPa) from an original pressure of 1,120 psi (7.72 MPa). Since the oil is highly paraffinic, wax deposition in the hydraulic fractures and the perforations has become a serious production problem. Microbial treatment was considered as a possible low-cost solution. Four wells were selected in the Second Wall Creek Reservoir with severe paraffin problems and production rates high enough to economically justify the treatment. Problems were experienced with the production of thick oil after approximately three months. This was interpreted to be a result of previously immobile paraffin being cleaned up. A slight decrease in the decline rate was seen in the wells, although some external factors cloud the interpretation. Microbial treatments were discontinued because of marginal economics. Three of the four wells produced additional oil and had a positive incremental cash flow. Oil viscosity tests did indicate that some positive microbial thinning was occurring, and changes to the treatment procedure may potentially yield more economic results in the future.

  3. Seismic studies of coal bed methane content in the west coal mining area of Qinshui Basin

    Institute of Scientific and Technical Information of China (English)

    Zou Guangui⇑; Peng Suping; Yin Caiyun; Xu Yanyong; Chen Fengying; Liu Jinkai

    2013-01-01

    The coal bed methane content (CBMC) in the west mining area of Jincheng coalfield, southeastern Qinshui Basin, is studied based on seismic data and well-logs together with laboratory measurements. The results show that the Shuey approximation has better adaptability according to the Zoeppritz equation result;the designed fold number for an ordinary seismic data is sufficient for post-stack data but insufficient for pre-stack data regarding the signal to noise ratio (SNR). Therefore a larger grid analysis was created in order to improve the SNR. The velocity field created by logging is better than that created by stack velocity in both accuracy and effectiveness. A reasonable distribution of the amplitude versus offset (AVO) attributes can be facilitated by taking the AVO response from logging as a standard for calibrating the amplitude distribution. Some AVO attributes have a close relationship with CBMC. The worst attri-bute is polarization magnitude, for which the correlation coefficient is 0.308; and the best attribute is the polarization product from intercept, of which the correlation coefficient is ?0.8136. CBMC predicted by AVO attributes is better overall than that predicted by direct interpolation of CBMC; the validation error of the former is 14.47%, which is lower than that of the latter 23.30%. CBMC of this area ranges from 2.5 m3/t to 22 m3/t. Most CBMC in the syncline is over 10 m3/t, but it is below 10 m3/t in the anticline;on the whole, CBMC in the syncline is higher than that in anticline.

  4. Fracture patterns in synclinal folds, Miaofengshan, Beijing

    Science.gov (United States)

    Liu, X. Z.; Liao, Z.; Reches, Z.

    2014-12-01

    The anticlinal bends are of interest for the oil/gas exploration and drilling designs as they are structural traps associated with high intensity of natural fractures due to bending curvature extension. However, some petroliferous areas with proven oil reserves were identified in synclinal structures, e.g. Songliao, Ordos and Bohai Bay Basins, northeast China, Bonaparte Basin, Australia, and Santa Maria Valley field, California. We analyze the fractures in synclines that are expected to carry curvature related fractures similarly to anticlines. The analysis is conducted on a 500m long and ~300 tall exposure of a folded sequence of dolomite and limestone layers at Miaofengshan, Beijing. Two general fracture groups are recognized: (1) layer crossing joints that are sub-parallel to the syncline axial surface; and (2) a distinct system of extension veins, which are joints filled with secondary calcite, that was found only in two layers of 0.8 and 2.2 m thick. These veins are layer-bound, they are up to 5 cm wide, and their width tapers toward the top and bottom of the host layers. Most of them are oriented normal to the bedding surfaces and radially with respect to the syncline shape. We recognized two phases of secondary mineralization that indicate layer-parallel extension of 5% or more. Apparently, these veins developed by bending extension of the most brittle layers whereas the more ductile layers above and below extended quasi-continuously. The analysis suggests that synclinal fracturing should be considered as possible mechanism for exploration of unconventional.

  5. Constraints on bed scale fracture chronology with a FEM mechanical model of folding: The case of Split Mountain (Utah, USA)

    Science.gov (United States)

    Sassi, W.; Guiton, M. L. E.; Leroy, Y. M.; Daniel, J.-M.; Callot, J.-P.

    2012-11-01

    A technique is presented for improving the structural analysis of natural fractures development in large scale fold structures. A 3D restoration of a fold provides the external displacement loading conditions to solve, by the finite element method, the forward mechanical problem of an idealized rock material with a stress-strain relationship based on the activation of pervasive fracture sets. In this elasto-plasticity constitutive law, any activated fracture set contributes to the total plastic strain by either an opening or a sliding mode of rock failure. Inherited versus syn-folding fracture sets development can be studied using this mechanical model. The workflow of this methodology was applied to the Weber sandstone formation deformed by forced folding at Split Mountain Anticline, Utah for which the different fracture sets were created and developed successively during the Sevier and the syn-folding Laramide orogenic phases. The field observations at the top stratigraphic surface of the Weber sandstone lead to classify the fracture sets into a pre-fold WNW-ESE fracture set, and a NE-SW fracture set post-dating the former. The development and relative chronology of the fracture sets are discussed based on the geomechanical modeling results. Starting with a 3D restoration of the Split Mountain Anticline, three fold-fracture development models were generated, alternately assuming that the WNW-ESE fracture set is either present or absent prior to folding process. Depending on the initial fracture configuration, the calculated fracture patterns are markedly different, showing that assuming a WNW-ESE joint set to predate the fold best correlates with field observations. This study is a first step addressing the complex problem of identification of fold-related fracturing events using an elementary concept of rock mechanics. When tight to complementary field observations, including petrography, diagenesis and burial history, the approach can be used to better

  6. Reservoir leakage along concentric faults in the Southern North Sea: Implications for the deployment of CCS and EOR techniques

    Science.gov (United States)

    Ward, Nicholas I. P.; Alves, Tiago M.; Blenkinsop, Tom G.

    2016-10-01

    High-quality 3D seismic and borehole data in the Broad Fourteens Basin, Southern North Sea, is used to investigate newly recognised concentric faults formed in salt-withdrawal basins flanking reactivated salt structures. Throw-depth and throw-distance plots were used to understand the growth histories of individual faults. As a result, three families of concentric faults are identified: a) intra-seal faults within a salt-withdrawal basin, b) faults connecting the seal and the reservoir on the crest of an inverted anticline, c) raft-bounding faults propagating into reservoir units. They have moved obliquely and show normal throws, even though they formed during a period of regional compression. Faults in the salt-withdrawal basin and on the inverted anticline are highly segmented, increasing the chances of compartmentalisation or localised fluid flow through fault linkages. Slip tendency analysis was carried out on the distinct fault families to compare the likelihood of slip along a fault at different pore fluid pressures and within different lithologies. Our results show that sections of the faults are optimally oriented with regards to maximum horizontal stresses (σHmax), increasing the slip tendency. The identified faults cut through a variety of lithologies, allowing different values of pore fluid pressures to build up before faults reactivate. Within the Vlieland Sandstones, pore fluid pressures of 30 MPa are not sufficient to reactivate pre-existing faults, whereas in the deeper Posidonia Shales faults might reactivate at pore fluid pressures of 25 MPa. Fluid flow features preferentially occur near fault segments close to failure. Heterogeneity in slip tendency along concentric faults, and high degrees of fault segmentation, present serious hazards when injecting CO2 into the subsurface. This study stresses the importance of high-quality 3D seismic data and the need to evaluate individual fault systems when investigating potential reservoirs for carbon

  7. La cuenca cenozoica del río Grande y Palauco: edad, evolución y control estructural, faja plegada de Malargüe The Río Grande and Palauco Cenozoic basin: Age, evolution and structural control, Malargue fold-belt (36°S

    Directory of Open Access Journals (Sweden)

    José Silvestro

    2009-10-01

    Full Text Available La región del valle del Río Grande y Palauco a los 36° de latitud sur, forma parte de la faja plegada y corrida de Malargüe, en la Cordillera Principal. La evolución tectónica de este sector durante el Cenozoico quedó registrada en los depósitos volcaniclásticos preservados en las cuencas sinorogénicas. La configuración de estas cuencas estuvo controlada por las estructuras de basamento, que a esta latitud definen un sector interno ocupado por la subcuenca Río Grande y un sector frontal ocupado por la subcuenca Palauco. El relleno de estas cuencas muestra una etapa preorogénica que se extendió por lo menos hasta los 23 Ma dominada por secuencias basálticos. Desde los 18 Ma las principales estructuras comenzaron a levantarse provocando que en una primera etapa cada subcuenca evolucione de forma independiente. De esta forma, la subcuenca Río Grande recibió el aporte de sedimentos clásticos gruesos desde el oeste, producto de la erosión de la sierra Azul, que gradan a depósitos finos y evaporíticos distales en la parte oriental de la subcuenca, para finalmente acuñarse contra el borde occidental del anticlinal Pampa Palauco-Ranquil Co. Esta estructura ya constituía una barrera interna, posibilitando que en la subcuenca Palauco queden retenidos los depósitos basálticos alimentados desde centros efusivos activos presentes en este sector. Esta etapa finalizó aproximadamente a los 11 Ma, edad a partir de la cual ambas subcuencas presentan nuevamente un relleno similar dominado por depósitos volcánicos presentes en toda el área. En esta nueva etapa diferentes eventos de reactivación del anticlinal Pampa Palauco-Ranquil Co quedaron registrados en discordancias angulares observadas en el campo, que a partir de dataciones en niveles guía pudieron ser acotadas a los 11 Ma y 8 Ma. Estos eventos generaron también el desarrollo de un nuevo frente de deformación hacia el este, con el levantamiento de los anticlinales Cerro

  8. 西昆仑山前和田-柯克亚挤压构造带新生代变形时序及其地质意义%Cenozoic Deformation Sequence of Hetian-Kekeya Structural Belt in the Piedmont of West Kunlun Mountains

    Institute of Scientific and Technical Information of China (English)

    梁瀚; 汪新; 陈伟; 王宇

    2014-01-01

    The uplift of the West Kunlun Mountains led to the development of the Cenozoic fold and thrust belt in eastern section of the piedmont of West Kunlun ranges. This paper focuses on the growth strata and sedimentary pattern of the fold and thrust belt to constrain the uplift time of the West Kunlun Mountains. There are three set of growth strata along the Keliyang-Fusha structural belt in the piedmont of West Kunlun Mountains. The first set of growth strata which deposited in the front limb of Kedong structure started at Middle Miocene, the second one deposited in the back limb of Kekeya anticline since Early Pliocene, and the third one deposited in the front limb of Kekeya anticline in Late Pliocene. It is evident that the Kekeya anticline began tectonic deformation since Pliocene, and the second growth strata were related to this anticline. It displayed“anti-fanning”shape, which is characterized by the break-forward sequence. On the other hand, geological age of growth strata in the Hetian’nan anticline (south Hetian anticline) is the Middle Miocene. Therefore, the Hetian-Kekeya structural belt began deformation since Middle Miocene too. Combined with the wedge shape sediment of the Cenozoic fold and thrust belt in eastern section of the piedmont of West Kunlun, we infer that the Western Kunlun Mountains uplift from Miocene, while the intensive uplift stage of Western Kunlun Mountains began at Pliocene.%受西昆仑山抬升挤压的影响,西昆仑山前东段发育褶皱冲断带,最新反射地震资料显示该地区发育了多套新生代的生长地层。本文利用这些生长地层数据分析了和田-柯克亚挤压构造带的变形时序,并且结合新生界的沉积形态探讨了西昆仑山的挤压隆升时间。研究结果表明,西昆仑山前和田-柯克亚挤压构造带西段的克里阳-甫沙构造发育三期前列式的生长地层:第一期在甫东构造东端始于中新世中期安居安期;第二期从上新世

  9. Major Oil Plays In Utah And Vicinity

    Energy Technology Data Exchange (ETDEWEB)

    Thomas Chidsey

    2007-12-31

    Utah oil fields have produced over 1.33 billion barrels (211 million m{sup 3}) of oil and hold 256 million barrels (40.7 million m{sup 3}) of proved reserves. The 13.7 million barrels (2.2 million m3) of production in 2002 was the lowest level in over 40 years and continued the steady decline that began in the mid-1980s. However, in late 2005 oil production increased, due, in part, to the discovery of Covenant field in the central Utah Navajo Sandstone thrust belt ('Hingeline') play, and to increased development drilling in the central Uinta Basin, reversing the decline that began in the mid-1980s. The Utah Geological Survey believes providing play portfolios for the major oil-producing provinces (Paradox Basin, Uinta Basin, and thrust belt) in Utah and adjacent areas in Colorado and Wyoming can continue this new upward production trend. Oil plays are geographic areas with petroleum potential caused by favorable combinations of source rock, migration paths, reservoir rock characteristics, and other factors. The play portfolios include descriptions and maps of the major oil plays by reservoir; production and reservoir data; case-study field evaluations; locations of major oil pipelines; identification and discussion of land-use constraints; descriptions of reservoir outcrop analogs; and summaries of the state-of-the-art drilling, completion, and secondary/tertiary recovery techniques for each play. The most prolific oil reservoir in the Utah/Wyoming thrust belt province is the eolian, Jurassic Nugget Sandstone, having produced over 288 million barrels (46 million m{sup 3}) of oil and 5.1 trillion cubic feet (145 billion m{sup 3}) of gas. Traps form on discrete subsidiary closures along major ramp anticlines where the depositionally heterogeneous Nugget is also extensively fractured. Hydrocarbons in Nugget reservoirs were generated from subthrust Cretaceous source rocks. The seals for the producing horizons are overlying argillaceous and gypsiferous beds in

  10. 安徽省滁州市储郢地区金矿找矿远景%Prospecting Prospective of the Gold Deposit in Chuzhou City,Anhui Province

    Institute of Scientific and Technical Information of China (English)

    李永杰; 闫李军; 杨艳

    2016-01-01

    安徽省滁州市储郢地区金矿点位于郯庐断裂带东侧、扬子陆块北缘滁州褶断带内,处于杨梅山背斜 NE 向延伸部位,在唐家洼—储郢地区称为百米山背斜,该矿点位于马厂—花山 NE向金铜成矿带上。区内出露的地层主要为震旦系灯影组和皮园村组、寒武系黄栗树组及侏罗系黄石坝组,主要为一套碳酸盐岩及硅质岩建造,构造部位主要处于杨梅山复式背斜北东端,该背斜为区内重要的赋矿构造。区内的主干构造———黄马断裂带具有主导的控岩控矿作用。在分析区域地质背景、地球化学特征的基础上,对区内控矿条件和找矿远景进行了分析。结果表明:①区内东部为黄石坝中生代火山岩盆地,1∶50000区域航磁资料显示,在火山岩下存在隐伏中—酸性侵入岩,为成矿作用提供了物质来源和热源;②区内震旦系灯影组中段 Au 丰度值(42×10-9)远高于区域Au 背景值(7×10-9),表明 Au 在赋矿层位内已有较强的集中,成矿物质基础较雄厚。%The gold occurrence of Chuying area,Anhui province is located in the Chuzhou plait bro-ken belt that is located in the east side of Tanlu fault zone and the north rim of Yangtze massif.The gold occurrence of Chuying area,Anhui province is located in the northeast extension area of Yangmeishan an-ticline,the Yangmeishan anticline is named as Baimishan anticline in Tangjiawa-Chuying area.The gold occurrence of Chuying area is located in Machang-Huashan northeast gold and copper metallogenic belt. The strata exposed in the area are mainly include Denying formation and Piyuancun formation of Sinian system,Huanglishu formation of Cambrian system and Huangshiba formation of Jurassic system,the main formation of the strata is a set of carbonate rocks and siliceous rocks.The tectonic position is located in the northeast compound anticline of Yangmeishan duplex anticline

  11. 塔里木盆地巴楚隆起北缘阿恰基底卷入构造%Basement-Involved wedge-shaped Structure of Aqia Fault in Northern Magin of Bachu Uplift in Northwestern Tarim Basin, Northwest China

    Institute of Scientific and Technical Information of China (English)

    杨庚; 李本亮; 杨海军; 陈竹新; 王晓波; 张朝军; 雷永良

    2012-01-01

    The Tarim Basin records the history of deposition and deformation affected by the Indian-Eurasia collision during the Cenozoic. The seismic data shows that the faulted rigid Bachu uplift, central Tarim, is a paleo-uplift covered by Quaternary deposits. NW-striking Aqia fault, Qiaolaitnaiti fault and Salambulake syncline and anticline between them were developed on the north margin of the Bachu uplift, northward adjacent to Awati depression. Many seismic lines and well data show that the Aqia fault is a deep basement-involved, south-dipping thrust fault, and the shallow structures are both Qiaolaimaiti north-dipping thrust fault and Salambulake fold. The Aqia fault cuts through the Precambrian basement to the Middle Cambrian evaporates and its displacements decrease from west to east. Salambulake anticline is a fault-propagation fold controlled by the Qiaolaimaiti fault which develops from the main decollement layer of the Cambrian evaporates. The south-dipping basement-involved fault, north-dipping cover-detached fault and Salambulake anticline forms a typical wedge-shaped structure in profile and a triangular structural belt in map view. The Aqia fault and the Salambulake fold extend northwestwardly into the Kelpin thrust belt and forms the NW-striking surface structures superimposed by northeastern-striking deformation. The growth strata indicates that NW-striking wedge-shaped structure formed during Eocene to Miocene, which extends northwestwards into the Kelping thrust zone formed in the Quaternary.%塔里木盆地巴楚隆起为第四系不整合覆盖的古隆起,在其西北缘发育NW走向的阿恰断裂、萨拉姆布拉克背斜、向斜和隐伏的乔来麦提断裂.地震剖面和钻井资料显示,阿恰断裂为倾向南的基底卷入逆冲断裂,向北逆冲,错断层位从前寒武系基底一直到中寒武统膏岩,从西向东逆冲断距减少.乔来麦提断裂则以中寒武统膏岩为滑动面,向南逆冲,并在断层端部发育萨拉

  12. A reassessment of earthquake depths in the Zagros with observations from InSAR and local seismic data

    Science.gov (United States)

    Nissen, Edwin; Jackson, James; Tatar, Mohammad; Yamini-Fard, Farzam

    2010-05-01

    The Zagros mountains of Iran are one of the most seismically active fold-and-thrust belts in the world, with frequent reverse faulting earthquakes of Mw 5 - 6 and rare larger events of up to Mw ~6.7. Earthquakes in the Zagros rarely rupture the surface, and there is a long-standing debate over whether faulting is restricted to the basement or also occurs within the thick (~10 km) sedimentary cover. In addition, there is little consensus on whether the buried reverse faults control the growth of ‘whaleback' anticlines that dominate the topography of the range, or whether faulting and folding are detached along weak layers in the sedimentary cover. To address these problems we investigated some recent earthquakes in the south-eastern Zagros, at Qeshm Island (27 November 2005 and 10 September 2008) and Fin (25 March 2006). We used radar interferometry (InSAR) to map coseismic ground displacements for each earthquake, and modelled these data using elastic dislocation theory to determine the source parameters, including the geometry and the top and bottom depths of the causative faulting. In each case, we found rupture was concentrated between a bottom depth of 8 - 10 km and a top depth of 3 - 5 km. These results confirm that Mw ~6 earthquakes do occur within the folded sediments, probably within the thick ‘competent group' of Paleozoic and Mesozoic conglomerates and platform carbonates that make up the lower part of the cover. Furthermore, patterns of coseismic uplift showed little correlation with the location of surface anticlines, implying that locally the two are decoupled. We also measured the distribution of smaller aftershocks using data from local seismic networks. Most of these occurred within the crystalline basement, at depths of ~10 km to ~20 km, substantially and resolvably deeper than the main-shock faulting. This vertical separation indicates that the main earthquakes failed to rupture the full thickness of the seismogenic layer, and probably

  13. Earthquake deformation in the Zagros Simply Folded Belt (Iran) from radar interferometry and local seismic data

    Science.gov (United States)

    Nissen, E.; Jackson, J. A.; Yamini-Fard, F.; Tatar, M.; Roustaei, M.; Gholamzadeh, A.; Parsons, B.

    2009-12-01

    The Zagros mountains of Iran accommodate almost half of the total Arabia-Eurasia continental convergence and are one of the most seismically active fold-and-thrust belts in the world. The range contains a ~10 km-thick sedimentary cover which is folded into parallel trains of ‘whaleback’ anticlinal mountains and synclinal valleys. Seismicity is dominated by buried reverse faulting earthquakes, which very rarely rupture the surface. However, there is no consensus on whether faulting is restricted to the crystalline basement, the sedimentary cover, or occurs within both. It is also unclear whether there is a one-to-one correlation between surface anticlines and underlying faults, or whether the two are detached along weak layers in the sedimentary cover. We addressed these problems by establishing the depth and geometry of faulting in some recent earthquakes in the Zagros, and investigating the connection between this faulting and surface folding. A better understanding of these processes here, where they are ongoing, may help inform us about fold-and-thrust belts globally, including those that are no longer active. We focused on three, Mw ~6 earthquakes in the SE Zagros, at Qeshm Island (27 November 2005 and 10 September 2008) and Fin (25 March 2006). In each case, coseismic ground displacements were mapped with radar interferometry (InSAR) and modeled using elastic dislocation theory to determine the source parameters. All three earthquakes ruptured between depths of ~9±1 km and ~4±1 km, with slip probably concentrated within the thick ‘competent group’ of Paleozoic and Mesozoic conglomerates and platform carbonates that make up the lower part of the sedimentary cover. The lower and upper limits of rupture may have been governed by the presence of mechanically-weak Precambrian Hormuz salt and Cretaceous marls at these levels. In none of the cases was there a clear correlation between the pattern of coseismic uplift and surface folding; indeed, faulting in

  14. First quantification of severe wind erosion in yardang fields using cosmogenic 10Be within the western Qaidam Basin, China

    Science.gov (United States)

    Rohrmann, A.; Heermance, R.; Kapp, P. A.; Mc-Callister, A.

    2010-12-01

    Desert environments are a major source of global loess and may undergo substantial wind-erosion as evidenced by yardangs, which are streamlined bedrock ridges sculpted from uni-directional winds. However, there are few quantitative estimates of wind erosion rates in deflationary deserts, globally. Here, we report the first quantitative rates of bedrock wind erosion determined using cosmogenic 10Be in the western Qaidam basin, China, where roughly one-third of the modern basin floor (~3.88 × 104 km2) exposes yardangs. Eleven Neogene bedrock sandstone samples and one pre-Cenozoic granite sample were analyzed for 10Be concentrations. The Neogene samples were collected from crests and limbs of broad and actively growing anticlines, where in most places strata have been wind-sculpted into yardangs. Sedimentary bedrock erosion rates vary from 0.04-0.34 mm/yr, although 60 percent (n=7) of all samples cluster tightly at 0.1 ± 0.03 mm/yr. Erosion rates assume steady-state erosion over ~10,000 years. The lowest rate of 0.0025 mm/yr was obtained from a granite bedrock sample along the Altyn-Tagh range bounding the northwestern margin of the Qaidam basin and is consistent with other 10Be bedrock erosion rates collected from granitic bedrock elsewhere on the Tibetan Plateau. These results demonstrate the importance of lithology in controlling bedrock erodibility by wind. The highest erosion rates of 0.17, 0.25, and 0.34 mm/yr were determined along a transect across an active anticline. The lowest of the three rates was obtained from the top of the structure, suggesting that wind erosion and thus wind speeds are highest on the limbs of an anticline as wind is forced around the obstacle (Bernoulli-effect), rather than flowing over it. The determined sedimentary bedrock erosion rates of 0.04-0.34 mm/yr are in good agreement with previous analysis of basin wide-average erosion rates from geological cross-sections (0.29 mm/yr) and simple erosion calculations using previous lake

  15. Annual Hanford Seismic Report for Fiscal Year 2010

    Energy Technology Data Exchange (ETDEWEB)

    Rohay, Alan C.; Clayton, Ray E.; Sweeney, Mark D.; Devary, Joseph L.; Hartshorn, Donald C.

    2010-12-27

    area swarm has largely subsided. Pacific Northwest National Laboratory will continue to monitor for activity at this location. The highest-magnitude events (3.0Mc) were recorded on February 4, 2010 within the Wooded Island swarm (depth 2.4 km) and May 8, 2010 on or near the Saddle Mountain anticline (depth 3.0 km). This latter event is not considered unusual in that earthquakes have been previously recorded at this location, for example, in October 2006 (Rohay et al. 2007). With regard to the depth distribution, 173 earthquakes were located at shallow depths (less than 4 km, most likely in the Columbia River basalts), 18 earthquakes were located at intermediate depths (between 4 and 9 km, most likely in the pre-basalt sediments), and 19 earthquakes were located at depths greater than 9 km, within the crystalline basement. Geographically, 178 earthquakes were located in known swarm areas, 4 earthquakes occurred on or near a geologic structure (Saddle Mountain anticline), and 28 earthquakes were classified as random events. The Hanford Strong Motion Accelerometer (SMA) network was triggered several times by the Wooded Island swarm events and the events located on or near the Saddle Mountain anticline. The maximum acceleration value recorded by the SMA network during fiscal year 2010 occurred February 4, 2010 (Wooded Island swarm event), approximately 2 times lower than the reportable action level for Hanford facilities (2% g) with no action required.

  16. Interpretación qeodinámica de la vertiente centro-occidental surpirenaica (cuencas de Jaca-Tremp

    Directory of Open Access Journals (Sweden)

    Cámara, P.

    1985-12-01

    Full Text Available A system of imbricated thrusts (piggy-back sequence, coeval with the sedimentary filling of the Jaca and Tremp basins, was generated during Eocene and Oligocene. The Eocene sedimentation was conditioned by ramp anticlines, thus creating syntectonic slope facies _on the smooth or rear slope of each thrust (Burgui marls and limes tones. Separating these ramp anticlines are several troughs containing different turbiditic systems. Within these systems and channelized along the troughs, assembla,ges of carbonate megabeds are intercalated. These assemblages migrated southwards, while each individual megabed within every assemblage shifted eastwards. This arrangement reflects the general thrust sheets movements as they were emplaced earlier at the western pan of the Jaca basin, being progressively displaced towards South and East. The carbonate material that compose the megabeds would source from a northern Eocene platform, located on the active basin margin, as well as from erosion on the ramp anticlines simultaneously created.
    The imbricated thrust system affecting the cover is genetically related to and overlain a big duplex system developed on the basement. The latter dips NW, being of "hinterland dipping" type and has its root or "branch line" located on an intrapaleozoic fault within the axial zone. The tectonic configuration was generated by an NNW-SSE compression, probably due to the dextral relative movement between the Iberian and European plates.

    Durante el Eoceno y Oligoceno en las cuencas de Jaca y Tremp se produce un sistema de cabalgamientos imbricados ("piggy-back sequence" contemporáneos con el relleno sedimentario de las mismas. Toda la sedimentación eocena está condicionada por las rampas anticlinales formadas, originándose una facies de talud sintectónica en los flancos suaves o traseros de cada cabalgamiento (calizas y margas de Burgui, Entre estas rampas anticlinales se crean una serie de surcos en los cuales se

  17. Petroleum geologic characteristis and exploration potential of Block D in Burma%缅甸D区块石油地质特征及勘探潜力

    Institute of Scientific and Technical Information of China (English)

    李红; 曹永斌; 王新云

    2011-01-01

    Block D located in the western-central of Irrawaddy basin in Burma, has two major Eocene deltaic sedimentary systems with one in the east and the other in the west. The main sedimentary facies include delta plain-prodelta and shallow marine facies. Block D experienced three main tectonic evolution phases including the Eocene united subsidence, the Oligocene-Miocene differential subsidence and the post-Pliocene overthrus-ting. The tectonic framework of Block D is characterized by NS-trending and EW-zoning "four uplifts, two depressions and one slope". The quality source rocks in Block D are dominated by the Tabyin Formation gray mudstone and coal-seam mudstone, and the Laungshe Formation dark shale. They feature in high organic abundance and high hydrocarbon-generation potential. Moreover, three reservoir-seal combinations in the Pengdang, Kabaw and Tabyin formations provide favorable conditions for effective hydrocarbon accumulation and preservation. There are two trap styles in Block D, including anticline trap controlled by faults and sand lens trap. Study of thermal evolution of source rocks indicates that the timing of hydrocarbon generation, migration, trap formation and reservoir-seal combination is rational. The potential plays of Block D mainly occur in three structural belts including Patolon anticline belt, Mahudaung anticline belt and Thingadon synclinorial belt.%缅甸D区块位于伊洛瓦底盆地中西部,主要勘探层系始新统发育东、西两大三角洲沉积体系,沉积相以三角洲平原-前三角洲亚相以及浅海相为主,构造演化主要经历了始新世的统一沉降期、渐新世-中新世的差异沉降期和上新世以后的逆冲推覆期3个阶段,形成了南北走向、东西分带的“四隆二凹一斜坡”的构造格局.烃源岩以塔本组的灰色泥岩和煤系泥岩以及朗欣组的暗色泥岩为主,有机质丰度高,具有非常好的生烃能力.蓬当组、塔本组和提林组3套储-盖组合保

  18. Stratigraphic controls on saltwater intrusion in the Dominguez Gap area of coastal Los Angeles

    Science.gov (United States)

    Edwards, B.D.; Ehman, K.D.; Ponti, D.J.; Reichard, E.G.; Tinsley, J.C.; Rosenbauer, R.J.; Land, M.

    2009-01-01

    a broad anticlinal fold that occurs parallel to, but ??2 km north of, the axis of the Pliocene Wilmington anticline. The Dominguez sequence breaches the crest of the young anticline, cuts through the upper Pleistocene Mesa and Pacific sequences, and into the middle Pleistocene Harbor sequence. Saltwater migrates along channels within the Dominguez sequence and into the underlying sequences (composed mostly of shallow marine and tidal sands, silts, and clays) that contain the classically defined Gage and Lynwood aquifers. The newly recognized Pacific Coast Highway fault cuts through the core of this young fold and is downthrown on the northern side, thereby creating accommodation space for a thick succession of middle Pleistocene sediments that constitute the Upper Wilmington sequence. North of the Pacific Coast Highway fault, the Upper Wilmington sequence contains the classic Silverado aquifer (composed of fluviodeltaic deposits); the Silverado is the primary freshwater aquifer for the West Coast and Central Los Angeles Groundwater Basins. Pore fluid and electric log analyses show the upper part of this aquifer to be saline-intruded near the crest of the young fold. This relationship implies that some saltwater is migrating into deeper aquifers from above, across the regional unconformity that marks the base of the Harbor sequence (ca. 240-270 ka). This sequence-stratigraphic model provides new insight into the potential flow paths for saltwater intrusion, and as such, should allow improved characterization of fluidflow that will aid in transport model studies and in managing groundwater resources. ?? 2009 Geological Society of America.

  19. Altering Reservoir Wettability to Improve Production from Single Wells

    Energy Technology Data Exchange (ETDEWEB)

    W. W. Weiss

    2006-09-30

    Many carbonate reservoirs are naturally fractured and typically produce less than 10% original oil in place during primary recovery. Spontaneous imbibition has proven an important mechanism for oil recovery from fractured reservoirs, which are usually weak waterflood candidates. In some situations, chemical stimulation can promote imbibition of water to alter the reservoir wettability toward water-wetness such that oil is produced at an economic rate from the rock matrix into fractures. In this project, cores and fluids from five reservoirs were used in laboratory tests: the San Andres formation (Fuhrman Masho and Eagle Creek fields) in the Permian Basin of Texas and New Mexico; and the Interlake, Stony Mountain, and Red River formations from the Cedar Creek Anticline in Montana and South Dakota. Solutions of nonionic, anionic, and amphoteric surfactants with formation water were used to promote waterwetness. Some Fuhrman Masho cores soaked in surfactant solution had improved oil recovery up to 38%. Most Eagle Creek cores did not respond to any of the tested surfactants. Some Cedar Creek anticline cores had good response to two anionic surfactants (CD 128 and A246L). The results indicate that cores with higher permeability responded better to the surfactants. The increased recovery is mainly ascribed to increased water-wetness. It is suspected that rock mineralogy is also an important factor. The laboratory work generated three field tests of the surfactant soak process in the West Fuhrman Masho San Andres Unit. The flawlessly designed tests included mechanical well clean out, installation of new pumps, and daily well tests before and after the treatments. Treatments were designed using artificial intelligence (AI) correlations developed from 23 previous surfactant soak treatments. The treatments were conducted during the last quarter of 2006. One of the wells produced a marginal volume of incremental oil through October. It is interesting to note that the field

  20. The Response of Petroleum Trap Types to the Structural-Depositional Pattern in Shenxian Depression,Jizhong Sub-Basin%冀中坳陷深县凹陷构造沉积格局与圈闭类型响应关系

    Institute of Scientific and Technical Information of China (English)

    张锐锋; 李先平; 于兴河; 田建章; 孙相灿; 李伟茹; 郭文峰

    2011-01-01

    Shenxian depression is located in the center part of Jizhong Sub-basin, North China, with extremely complicated structures and diverse sedimentation systems.There are many different recognizations of the classification of hydrocarbon traps ( particularly stratigraphic trap) and their distribution in the past years, which has restriced the accurate hydrocarbon exploration in such kind of complicated faulted depressions.Five structure zones can be defined in Shenxian depression and each has its particular sedimentary pattern that results in different trap types.Four major types and 8 subdivided trap types of petroleum trap, such as structural trap, lithologic trap, stratigraphic trap and buried hill trap etc., were summarized in this paper, which had responses to the structural-sedimentary patterns in this area.Structural trap mainly composed of fault block and fault nose had a wider distribution scale and concentrated in bulges of the secondary structural zones, mainly in Shennan anticline and Yuke anticline.Buried hill trap mainly occured in Hezhuang-Shenxi buried hill zone and ShenzeLiucun low bulge of the northern gentle slope belt.Lithologic and stratigraphic traps mainly existed in two flanks of buried hill zone and Shennan anticline and Baisongzhuang trough in the south, which responded to lenticular sandy conglomerate, updip sand body and tectonic setting in these areas.Therefore, it can be concluded that structural-stratigraphic composite petroleum reservoirs should be more important in the future hydrocarbon exploration in Shenxian depression.%深县凹陷位于冀中坳陷中部,其构造复杂,沉积类型多样,而多年来人们对凹陷内的油气圈闭(尤其是岩性地层圈闭)类型与分布规律缺乏统一认识,不利于在这类复杂断陷盆地内开展精细油气勘探.深县凹陷可划分为5个构造区带,各构造区带具有不同的沉积格局,这是各区带内油气圈闭类型存在差异的关键因素.总结出该凹陷主

  1. Geological Characteristics and Prospecting Direction of Taishanmiao Copper Deposits in Fengxian County,Shaanxi Province%陕西凤县太山庙铜矿地质特征及找矿方向

    Institute of Scientific and Technical Information of China (English)

    李永勤; 王瑞廷; 孟德明; 代军治; 黄长青

    2015-01-01

    凤县太山庙铜矿点位于凤(县)太(白)矿集区南部铅硐山苇子坪铜牌沟铜铅锌多金属成矿带之铁炉湾九子沟矿化区,区内从西到东矿化分带明显,成矿条件十分有利。太山庙铜矿赋存于中泥盆统古道岭组灰岩与星红铺组千枚岩接触界面及其附近,属沉积改造型矿床;背斜构造、中泥盆统古道岭组灰岩与上泥盆统星红铺千枚岩接触带和硅化、黄铁矿化等蚀变是其主要找矿标志。目前,在太山庙铜矿区已发现 K1、K2两条铜矿体,矿石类型以硅化灰岩型为主,其次为硅化千枚岩型、含铜石英方解石脉型及硅质岩型。通过与东部凤县九子沟铜矿床对比研究,认为二者处于同一含矿层位,区内找矿应关注背斜构造转折端及其翼部的古道岭组灰岩和星红铺组千枚岩接触界面这2个主要找矿标志,注意背斜南翼铁碳酸岩脉及平行背斜构造,结合化探异常和物探异常,进而优选靶位开展深部工程验证,按照这一指导思想和工作方法,在区内及太山庙铜矿点有望取得新的找矿突破。%The Taishanmiao copper deposit of Fengxian County is located in Tieluwan-Jiuzigou mineralized district of Qiandongshan-Weiziping-Tongpaigou Cu-Pb-Zn polymetallic mineraliza-tionbelt,south of Fengxian-Taibai ore-concentrated area.Mineralization zoning is clear from east to west of this area and metallogenetic conditions are favorable.Ore body occurs at the contact zone or nearby of Middle Devonian Gudaoling formation limestone and Upper Devonian Xinghong-pu formation phyllite,belonging to sedimentary-reformation deposit.Anticline,contact zone of limestone and phyllite,silication and pyritization are the main indicators for prospecting.Ore bodies including K1 and K2 are found in this deposit,in which silicified limestone is the main ore type,followed by silicified phyllite type,copper-bearing quartz-calcite vein type and siliceous rock type

  2. 地质构造对煤层气井产能的控制机理与规律%Control Mechanism and Law of Geological Structure Affected to Production Capacity of Coal Bed Methane Well

    Institute of Scientific and Technical Information of China (English)

    赵少磊; 朱炎铭; 曹新款; 王怀勐; 周友

    2012-01-01

    The paper discussed the control mechanism of the structure evolution and structural shape affected to the production capacity of the coal bed methane well. In combination with the practices in Fenzhuang Mining Area of Qinnan Area, the paper analyzed the control law of the geological structure to the distribution of the coal bed methane wells with different production capacity. The study showed that the structure evolution would control the full accumulation process of coal bed methane. The later structure shape would be critical impor- tant to the migration and storage of the coal bed methane. The two wings of the fold and the syncline core would have high methane content and the anticline core and the open fault nearby would have low methane content. The study on the Fanzhuang Mining Area showed that the production capacity of coal bed methane well would have a close relationship to the structure location. The high production wells main- ly distributed at the wings of the fold structure, the subordinate anticline core of synclinorium and the subordinate syncline core of anticli-norium and the average daily gas production could reach to 1 000-5 000 m^3. The low production coal bed methane well and the water production well mainly distributed at the subordinate anticline core of anticlinorium and around the normal faults and the average daily gas production would reach to less than 500 m^3.%探讨了构造演化与构造形态对煤层气井产能的控制机理,并结合沁南地区樊庄矿区实践,分析了构造对不同产能煤层气井分布的控制规律。研究表明:构造演化控制煤层气的整个成藏过程;后期构造形态对煤层气的运移和保存至关重要,褶曲两翼及向斜核部含气量高,背斜核部及开放性断层附近含气量低。同时对樊庄矿区研究表明:煤层气井产能与所处构造部位密切相关,高产井主要分布于褶曲构造翼部、复向斜的次级背斜核部及复背斜的次级向

  3. The promotion of geomorphosites on salt from Sovata - Praid and Turda using cultural and scientific tourism

    Science.gov (United States)

    Toma, B.; Irimus, I.; Petrea, D.

    2012-04-01

    The paper highlights the role of geomorphosites on salt, in experts and specialists training, in geography of tourism and planning, namely, the involvement of educational factor in defining managerial and marketing skills of future specialists in training. Geographical area of investigation belongs to the Transylvanian tectonic basin, overlapped to saliferous tectonic area from eastern Transylvania, represented by Praid - Sovata - Corund anticline and Sic -Cojocna - Turda anticline, analysis is focused on the Praid - Sovata and Turda diapirs. Saliferous area Praid - Sovata - Corund is situated on the contact area of the Transylvanian Basin with neo-eruptiv mountain chain of Eastern Carpathians, Calimani - Gurghiu - Harghita, and at the contact of Târnavelor Plateau with the orogen alignment of Gurghiu - Harghita Mountains. The salt body, in the horizontal plane, has a quasi-circular shape, slightly ellipsoidal, with diameters of 1.2 and 1.4 km, and is estimated to have a burial depth of 2.6 to 2.8 km. The salt massif from Praid, pierce the Mio-Pliocene blanket around and appears at the surface as diapir, flanked by sedimentary rocks that are partially covered by extrusive post-Pliocene volcanic formations and Quaternary deposits. Evaporitic deposits presents a varied lithology represented by gypsum, anhydrite, salt rock, potassium salt and celestine. The salt massif from Turda develops on the anticline Sic -Cojocna - Turda, oriented NE - SW, 2 km NE of Turda's downtown. It has an elongated shape, about 4 km, with widths ranging from 700 m to 200 m and also with a thickness ranging from 750 m to over 1000 m. In terms of stratigraphy, the salt massif is surrounded by deposits belonging to Badenian, Sarmatian and Quaternary. Due to salt dissolution by meteoric waters, carsto-saline lakes were formed, and due to ceiling collapse, because of an intensive exploitation, and infiltrations of rainwater and rivers, antropo-salted lakes were formed. The water and mud of

  4. Relationship Between Fold-thrust Belt Tectonic Deformation and Transverse River%山前断褶带构造变形与横向河道作用研究

    Institute of Scientific and Technical Information of China (English)

    杨甫; 陈刚; 丁超; 毛小妮; 李楠; 李岩

    2011-01-01

    构造变形与地表过程之间关系是近年来的研究热点,并取得了一些进展,特别是在较小空间尺度上的山前褶皱冲断带变形与地表过程耦合关系研究方面,提出了横向河流的切割作用影响背斜构造变形的新认识,改变了构造变形对地表作用单向控制的传统认识.背斜变形样式受地表过程和构造变形共同影响,背斜变形与横向河流切割之间存在双向耦合关系.山前带背斜构造变形区的地表河流是通过改变上覆物质的分布影响褶皱变形.在山前带背斜构造变形和河流作用关系时,不仅应考虑构造变形对河流的影响,而且要考虑河流的侵蚀下切作用以及相应时间内气候因素的影响,这为盆山耦合动力学研究提供了新思路.%The relation between tectonic deformation and surface process is a research front in recent years. European geologists study on the relationship between tectonic deformation and surface process and make some new progress, especially a coupling relationship between fold thrust belt deformation and surface processes at the smaller length scale. It has altered the traditional concept that tectonic deformation effects on surface processes with one-way control, and the new idea that the transverse river cutting could influence anticline deformation style is put forward. Deformation is influenced by surface processes and terrain slope (tectonic deformation), and there is a two-way coupling between the transverse river cutting and anticline deformation. The research with a numerical model shows that surface processes (mainly fluvial) effect deformation folding through the distribution change of the overlying material weight. Anticline deformation styles are not strongly influenced by lateral erosion of river incision. In order to study the interplay between structure deformation and transverse river at the piedmont region, it should not only consider the influence of tectonic deformation on

  5. Remobilisation features and structural control on ore grade distribution at the Konkola stratiform Cu-Co ore deposit, Zambia

    Science.gov (United States)

    Torremans, K.; Gauquie, J.; Boyce, A. J.; Barrie, C. D.; Dewaele, S.; Sikazwe, O.; Muchez, Ph.

    2013-03-01

    The Konkola deposit is a high grade stratiform Cu-Co ore deposit in the Central African Copperbelt in Zambia. Economic mineralisation is confined to the Ore Shale formation, part of the Neoproterozoic metasedimentary rocks of the Katanga Supergroup. Petrographic study reveals that the copper-cobalt ore minerals are disseminated within the host rock, sometimes concentrated along bedding planes, often associated with dolomitic bands or clustered in cemented lenses and in layer-parallel and irregular veins. The hypogene sulphide mineralogy consists predominantly of chalcopyrite, bornite and chalcocite. Based upon relationships with metamorphic biotite, vein sulphides and most of the sulphides in cemented lenses were precipitated during or after biotite zone greenschist facies metamorphism. New δ34S values of sulphides from the Konkola deposit are presented. The sulphur isotope values range from -8.7‰ to +1.4‰ V-CDT for chalcopyrite from all mineralising phases and from -4.4‰ to +2.0‰ V-CDT for secondary chalcocite. Similarities in δ34S for sulphides from different vein generations, earlier sulphides and secondary chalcocite can be explained by (re)mobilisation of S from earlier formed sulphide phases, an interpretation strongly supported by the petrographic evidence. Deep supergene enrichment and leaching occurs up to a km in depth, predominantly in the form of secondary chalcocite, goethite and malachite and is often associated with zones of high permeability. Detailed distribution maps of total copper and total cobalt contents of the Ore Shale formation show a close relationship between structural features and higher copper and lower cobalt contents, relative to other areas of the mine. Structural features include the Kirilabombwe anticline and fault zones along the axial plane and two fault zones in the southern limb of the anticline. Cobalt and copper behave differently in relation to these structural features. These structures are interpreted to have

  6. A study of seed micromorphology in the genus Ophrys (Orchidaceae

    Directory of Open Access Journals (Sweden)

    Galán Cela, Pablo

    2014-12-01

    Full Text Available Seed micromorphology of 19 taxa of the genus Ophrys have been studied using SEM and light microscope. Quantitative data (length and width of seed and embryo, number of testa cells along the longitudinal axis, volume of seed and embryo, and percentage of free air space, as well as qualitative characters (seed shape, features of the anticlinal and periclinal walls, ornamentation and colour were analysed. All the seeds are fusiform, with an asymmetrical basal pole, the periclinal walls of the medial cells have parallel and transverse to slanting ridges, and raised anticlinal walls. Statistical analyses show two large clusters according to the volumes of seed and embryo. Our results support the monophyly of the genus and their recent diversification, however, seed features are not congruent with the recognition of sections and groups within Ophrys.Se ha estudiado la micromorfología de semillas de 19 taxones del género Ophrys mediante el empleo de microscopio óptico y electrónico de barrido. Se han analizado datos cuantitativos (longitud y anchura de la semilla y del embrión, número de células en la testa a lo largo del eje longitudinal, volumen de la semilla y del embrión, y porcentaje de espacio aéreo libre y cualitativos (morfología de la semilla, características de sus paredes anticlinales y periclinales, ornamentación y color. Todas las semillas analizadas son fusiformes, con polo basal asimétrico, ornamentación de las paredes periclinales formada por costillas paralelas y transversales a oblicuas, y paredes anticlinales prominentes. Los análisis estadísticos revelan dos grandes cluster según los valores de los volúmenes de la semilla y el embrión. Nuestros resultados apoyan la monofilia del género y su reciente diversificación, sin embargo, los caracteres micromorfológicos de las semillas no son congruentes con el reconocimiento de secciones y grupos dentro del género Ophrys.

  7. New ages and chemical analysis on Lower Jurassic volcanism close to the dorsal de Huincul, Neuquén Nuevas edades del volcanismo Jurásico Inferior de la cuenca Neuquina en la dorsal de Huincul

    Directory of Open Access Journals (Sweden)

    Mario SCHIUMA

    2008-12-01

    Full Text Available New single zircon ages from hydrocarbon well cores in the A-1 Norte de la Dorsal and Anticlinal Campamento area of the Neuquén basin indicate that 199.0 ± 1.5 Ma andesite lava flow and 203.75 ± 0.26 Ma dacite breccia overlie a 286.5 ± 2.3 Ma granodiorite and 284.0 ± 1.3 Ma andesite dike. The Lower Jurassic volcanics were deposited on a regional erosion surface affecting the Permian rocks. In the studied area there is no record of Middle to Upper Triassic volcanics as in other areas of the basin. Exotic zircon crystals gave ages of Mesoproterozoic, Middle Cambian, Early Devonian and Early Carboniferous, suggesting a poliphasic basement. Chemical analyses of three selected samples show a calc-alkaline signature, supporting the existence of a volcanic arc at the Early Jurassic as it has been proposed for the center of the basin.Se dan nuevas edades U/Pb en cristales únicos de circón de muestras de corona de pozos exploratorios en el área petrolera A-1 Norte de la Dorsal y Anticlinal Campamento de la cuenca Neuquina. Estas edades permiten acotar un volcanismo Jurásico Inferior apoyado directamente sobre un basamento ígneo del Pérmico Inferior. Una muestra de andesita arrojó una edad de 199,0 ± 1,5 Ma y una de dacita 203,75 ± 0,26 Ma. El basamento está constituido por una granodiorita de 286,5 ± 2,3 Ma intruida por diques de andesita con 284,0 ± 1,3 Ma, ambas rocas están cortadas por una superficie de erosión de carácter regional labrada durante el Triásico, posiblemente Medio. En las perforaciones estudiadas no se han encontrado rocas triásicas. Los circones exóticos hallados indican la existencia de un complejo basamento con edades del Mesoproterozoico, Cámbrico Medio, Devónico Temprano y Carbonífero Temprano. Los análisis químicos muestras una filiación calco-alcalina que apoya la hipótesis de la existencia de un arco volcánico Jurásico Temprano en el centro de la cuenca Neuquina.

  8. Analysis of tectonic structures and excavation induced fractures in the Opalinus Clay, Mont Terri underground rock laboratory (Switzerland)

    Energy Technology Data Exchange (ETDEWEB)

    Nussbaum, Ch.; Bossart, P. [Federal Office of Topography swisstopo, Wabern (Switzerland); Amann, F. [Swiss Federal Institute of Technology Zuerich, Zuerich (Switzerland); Aubourg, Ch. [Laboratoire des fluides complexes et leurs reservoirs, Centre National de la Recherche Scientitfique CNRS, Universite de Pau, Pau (France)

    2011-09-15

    Excavated in the Opalinus Clay formation, the Mont Terri underground rock laboratory in the Jura Mountains of NW Switzerland is an important international test site for researching argillaceous formations, particularly in the context of deep geological disposal of radioactive waste. The rock laboratory is intersected by naturally formed tectonic structures, as well as artificial fractures primarily formed as a consequence of tunnel excavation and the associated stress redistribution. The description and characterisation of tectonic and artificial structures is, in many cases, of key importance for interpreting the results of the various in situ experiments conducted in the rock laboratory. Systematic small-scale mapping of the tunnel walls and floor, and adjacent niches, provides basic information about the geometry and the kinematics of the geological fractures intersecting the underground laboratory. A compilation of all tectonic structures identified is presented in this paper. The underground laboratory is located in the backlimb of the Mont Terri anticline, a NNW-vergent imbricate fault-bend fold, which is characterised by a pronounced along-strike asymmetry resulting from variously oriented inherited faults. The total shortening accommodated by this structure was estimated by mass (area) balancing to be approximately 2.1 km. The Mont Terri area is significantly affected by N- to NNE-striking normal faults of the Eo-Oligocene Rhine-Bresse transfer zone and by ENE-striking faults of Late Variscan age. Depending on their orientation with respect to the transport direction towards the NNW, these faults served as oblique and frontal ramps during the subsequent Jura thrusting in the Late Miocene. The various fault systems identified in the underground rock laboratory clearly correlate with the regional-scale structures. In addition to classical structural analysis, the anisotropy of magnetic susceptibility was measured to determine the magnetic fabric and strain

  9. Cenozoic intracontinental deformation of the Kopeh Dagh Belt, Northeastern Iran

    Science.gov (United States)

    Chu, Yang; Wan, Bo; Chen, Ling; Talebian, Morteza

    2016-04-01

    Compressional intracontinental orogens represent large tectonic zones far from plate boundaries. Since intracontinental mountain belts cannot be framed in the conventional plate tectonics theory, several hypotheses have been proposed to account for the formations of these mountain belts. The far-field effect of collision/subduction at plate margins is now well accepted for the origin and evolution of the intracontinental crust thickening, as exemplified by the Miocene tectonics of central Asia. In northern Iran, the Binalud-Alborz mountain belt witnessed the Triassic tectonothermal events (Cimmerian orogeny), which are interpreted as the result of the Paleotethys Ocean closure between the Eurasia and Central Iran blocks. The Kopeh Dagh Belt, located to the north of the Binalud-Alborz Belt, has experienced two significant tectonic phases: (1) Jurassic to Eocene rifting with more than 7 km of sediments; and (2) Late Eocene-Early Oligocene to Quaternary continuous compression. Due to the high seismicity, deformation associated with earthquakes has received more and more attention; however, the deformation pattern and architecture of this range remain poorly understood. Detailed field observations on the Cenozoic deformation indicate that the Kopeh Dagh Belt can be divided into a western zone and an eastern zone, separated by a series of dextral strike-slip faults, i.e. the Bakharden-Quchan Fault System. The eastern zone characterized by km-scale box-fold structures, associated with southwest-dipping reverse faults and top-to-the NE kinematics. In contrast, the western zone shows top-to-the SW kinematics, and the deformation intensifies from NE to SW. In the northern part of this zone, large-scale asymmetrical anticlines exhibit SW-directed vergence with subordinate thrusts and folds, whereas symmetrical anticlines are observed in the southern part. In regard to its tectonic feature, the Kopeh Dagh Belt is a typical Cenozoic intracontinental belt without ophiolites or

  10. The role of salt tectonics in the evolution of the northeastern Pyrenees

    Science.gov (United States)

    Ford, Mary; Christophoul, Frédéric; Menzer, Lionel; Simonis, Jules; Saura, Eduard; Vergés, Jaume

    2016-04-01

    unconformities and pinched salt-cored anticlines. Several of these structures have generated considerable controversy in the past (Pinède de Durban, Boutenac anticline, Ripaud syncline). In the light of new advances in understanding salt-related stratal and fault geometries we propose a new interpretation of these foreland structures integrating halokinesis, which leads to a new coherent regional tectonic history.

  11. Evolution of the heterogeneous structure of 1999 Mw 7.6 Chi-Chi earthquake thrust in Chushan excavation site, central Taiwan, based on distinct element models

    Science.gov (United States)

    Hsu, Chia-Hsiang; Huang, Wen-Jeng; Chang, Yu-Yi; Nien, Wei-Tung; Huang, Wen-Chao

    2016-04-01

    Exposures in the Chushan trench, 40 m long and 10 m deep, excavated across a 1999 earthquake-induced escarpment of 2 m high, show a steep, monocline-like fold with significantly different limb-truncated structures on either side of the 14 m wide trench. On southern exposure the fold is truncated through along the axial trace of its anticline by a fault branch with a dip angle of 32° and a maximum separation of ~4.2 m while on the northern exposure the steep limb of the fold is displaced up to ~3.0 m along the axial trace of its syncline by another fault branch with a dip angle of 24°. This study intends to explore how this heterogeneous structure might form using distinct element simulation of blind reverse faulting. All our models in this study consist of two mechanical layers, including an upper clayey layer of 7 meters thickness and a lower gravelly layer of 8 meters thickness at maximum, as revealed by the excavation, a borehole nearby and soil tests. Our results show that the steep, monocline-like fold can be simulated by a low-angle reverse faulting similar to a subsurface dominant fault with a dip angle of 24° derived from the trench site at the ground surface and in a borehole in the hanging wall. Furthermore, the different structures on the two exposures were mainly controlled by the dip-angle variation of the upper part of the subsurface dominant fault. The simulation of reverse faulting with a dip angle of 24°shows a monocline forms in the clayey layer, and then a gravelly wedge starts to protrude into the clayey layer and displace it along the axial trace of the anticline similar to the structure on the southern exposure, and the simulation of reverse faulting with a dip angle of 32°shows a monocline forms in the clayey layer, and then this monoclonal clayey layer starts to be displaced along the axial trace of the synclinal by a newly fault similar to the structure on the northern exposure. We also find the strength of clayey layer and the

  12. Results from SCS Profiling of the Sumatra accretionary prism: insights into tsnamigenesis

    Science.gov (United States)

    Fisher, D.; Mosher, D.; Austin, J.; Gulick, S.; Moran, K.; Masterlark, T.

    2007-12-01

    The SEATOS high resolution single-channel seismic reflection survey of the Sumatran accretionary prism depicts a landward-vergent thrust front, with active folding characterizing part of the December 2004 Mw9.2 earthquake rupture zone. Structure and bathymetry co-vary at distinct wavelengths along a 220-km-long profile crossing the prism and the Aceh (forearc) Basin. At the largest wavelength (tens of kms), the prism surface is defined by a steep (8-12 degrees), 55-km-wide outer slope, a 110-km-wide upper slope forming a broad depression between two forearc highs, and a 25 km-wide, steep inner slope between the landward high and the forearc basin. Anticlinal ridges spaced ~13 km apart display landward- and seaward-vergent folds along the inner and outer slopes, respectively; symmetric folding occurs across the upper slope. We suggest that the long-wavelength variations are consistent with the existence of a strong inner wedge beneath the upper slope. The ~13 km anticline spacing implies deformation of a slope apron deforming independently of this stronger wedge interior. Seismic profiles crossing the toe of the prism image a series of landward vergent, fault-related folds, suggesting that the shallow fill of the Sunda Trench is delaminated from the predominantly seaward-vergent plate boundary system and is uptilted along a triangle zone. Profiles crossing the seaward flank of the Aceh Basin reveal a near- vertical, undulatory deformation front that appears to mark the location of the West Andaman-Mentawai right- lateral strike-slip fault zone. Our model for prism architecture based on these geophysical results involves advance of the strong inner wedge during great earthquakes like the 2004 event, which then peels up shallower and less competent trench fill, deforming the toe and the upper slope of the forearc, producing massive uplift that is likely tsunamigenic. Seismic rupture was limited to the megathrust westward of the West Andaman fault and ROV observations

  13. Neotectonics and structure of the Himalayan deformation front in the Kashmir Himalaya, India: Implication in defining what controls a blind thrust front in an active fold-thrust belt

    Science.gov (United States)

    Gavillot, Y. G.; Meigs, A.; Yule, J. D.; Rittenour, T. M.; Malik, M. O. A.

    2014-12-01

    Active tectonics of a deformation front constrains the kinematic evolution and structural interaction between the fold-thrust belt and most-recently accreted foreland basin. In Kashmir, the Himalayan Frontal thrust (HFT) is blind, characterized by a broad fold, the Suruin-Mastargh anticline (SMA), and displays no emergent faults cutting either limb. A lack of knowledge of the rate of shortening and structural framework of the SMA hampers quantifying the earthquake potential for the deformation front. Our study utilized the geomorphic expression of dated deformed terraces on the Ujh River in Kashmir. Six terraces are recognized, and three yield OSL ages of 53 ka, 33 ka, and 0.4 ka. Vector fold restoration of long terrace profiles indicates a deformation pattern characterized by regional uplift across the anticlinal axis and back-limb, and by fold limb rotation on the forelimb. Differential uplift across the fold trace suggests localized deformation. Dip data and stratigraphic thicknesses suggest that a duplex structure is emplaced at depth along the basal décollement, folding the overlying roof thrust and Siwalik-Muree strata into a detachment-like fold. Localized faulting at the fold axis explains the asymmetrical fold geometry. Folding of the oldest dated terrace, suggest that rock uplift rates across the SMA range between 2.0-1.8 mm/yr. Assuming a 25° dipping ramp for the blind structure on the basis of dip data constraints, the shortening rate across the SMA ranges between 4.4-3.8 mm/yr since ~53 ka. Of that rate, ~1 mm/yr is likely absorbed by minor faulting in the near field of the fold axis. Given that Himalaya-India convergence is ~18.8-11 mm/yr, internal faults north of the deformation front, such as the Riasi thrust absorbs more of the Himalayan shortening than does the HFT in Kashmir. We attribute a non-emergent thrust at the deformation front to reflect deformation controlled by pre-existing basin architecture in Kashmir, in which the thick succession

  14. Tectonics and sedimentology of post-rift anomalous vertical movements: the rifted margin of Morocco

    Science.gov (United States)

    Bertotti, Giovanni; Charton, Remi; Luber, Tim; Arantegui, Angel; Redfern, Jonathan

    2016-04-01

    Roughly 15 years ago it was discovered that substantial parts of the Morocco passive continental margin experienced km-scale, post-rift exhumation. It was predicted that the sands resulting from the associated erosion would be present in the offshore and potentially form hydrocarbon reservoirs. At the same time, anomalous post-rift vertical movements have been documented in various localities of the world and rifted continental margins are at present exciting objects of research. Following intense research efforts the knowledge of the kinematics of vertical movements and their implications for sedimentary systems is increasing. The low-T geochronology initially limited to the classical Meseta-Massif Ancien de Marrakech transect has been expanded reaching the Reguibate Massif to the S and covering, possibly more importantly, one transect in E-W direction along the Anti Atlas. Exhumation occurred along two dominant trends. In N-S direction a several hundred-kilometers long exhuming domain developed roughly parallel to the Atlantic margin. Changes in magnitude and timing of exhumation are observed along this elevated domain associated with E-W trending undulations. The timing of main stage of upward movement of E-W trending highs seems to be Late Jurassic-Early Cretaceous in the Meseta and High Atlas and somewhat older, Early to Middle Jurassic, in the Anti-Atlas and Reguibate. The discovery of E-W trending highs and lows has major implication for sediment distribution and dispersal. At the large scale, it means that the drainage basins were smaller than initially predicted. This seems to be compatible with the paucity of sands encountered by recent exploration wells drilled offshore Morocco. At the scale of several kilometers, W-E trending anticlines and synclines developed in a generally subsiding coastal environment. These folds often had an expression at the sea floor documented by ravinement surfaces and (Jurassic) reef build-ups on top of the anticlines

  15. A 3-Dimensional Model of Water-Bearing Sequences in the Dominguez Gap Region, Long Beach, California

    Science.gov (United States)

    Ponti, Daniel J.; Ehman, Kenneth D.; Edwards, Brian D.; Tinsley, John C.; Hildenbrand, Thomas; Hillhouse, John W.; Hanson, Randall T.; McDougall, Kristen; Powell, Charles L.; Wan, Elmira; Land, Michael; Mahan, Shannon; Sarna-Wojcicki, Andrei M.

    2007-01-01

    A 3-dimensional computer model of the Quaternary sequence stratigraphy in the Dominguez gap region of Long Beach, California has been developed to provide a robust chronostratigraphic framework for hydrologic and tectonic studies. The model consists of 13 layers within a 16.5 by 16.1 km (10.25 by 10 mile) square area and extends downward to an altitude of -900 meters (-2952.76 feet). Ten sequences of late Pliocene to Holocene age are identified and correlated within the model. Primary data to build the model comes from five reference core holes, extensive high-resolution seismic data obtained in San Pedro Bay, and logs from several hundred water and oil wells drilled in the region. The model is best constrained in the vicinity of the Dominguez gap seawater intrusion barrier where a dense network of subsurface data exist. The resultant stratigraphic framework and geologic structure differs significantly from what has been proposed in earlier studies. An important new discovery from this approach is the recognition of ongoing tectonic deformation throughout nearly all of Quaternary time that has impacted the geometry and character of the sequences. Anticlinal folding along a NW-SE trend, probably associated with Quaternary reactivation of the Wilmington anticline, has uplifted and thinned deposits along the fold crest, which intersects the Dominguez gap seawater barrier near Pacific Coast Highway. A W-NW trending fault system that approximately parallels the fold crest has also been identified. This fault progressively displaces all but the youngest sequences down to the north and serves as the southern termination of the classic Silverado aquifer. Uplift and erosion of fining-upward paralic sequences along the crest of the young fold has removed or thinned many of the fine-grained beds that serve to protect the underlying Silverado aquifer from seawater contaminated shallow groundwater. As a result of this process, the potential exists for vertical migration of

  16. Beaufort Sea deep-water gas hydrate recovery from a seafloor mound in a region of widespread BSR occurrence

    Science.gov (United States)

    Hart, Patrick E.; Pohlman, John W.; Lorenson, T.D.; Edwards, Brian D.

    2011-01-01

    Gas hydrate was recovered from the Alaskan Beaufort Sea slope north of Camden Bay in August 2010 during a U.S. Coast Guard Cutter Healy expedition (USCG cruise ID HLY1002) under the direction of the U.S. Geological Survey (USGS). Interpretation of multichannel seismic (MCS) reflection data collected in 1977 by the USGS across the Beaufort Sea continental margin identified a regional bottom simulating reflection (BSR), indicating that a large segment of the Beaufort Sea slope is underlain by gas hydrate. During HLY1002, gas hydrate was sampled by serendipity with a piston core targeting a steep-sided bathymetric high originally thought to be an outcrop of older, exposed strata. The feature cored is an approximately 1100m diameter, 130 m high conical mound, referred to here as the Canning Seafloor Mound (CSM), which overlies the crest of a buried anticline in a region of sub-parallel compressional folds beneath the eastern Beaufort outer slope. An MCS profile shows a prominent BSR upslope and downslope from the mound. The absence of a BSR beneath the CSM and occurrence of gas hydrate near the summit indicates that free gas has migrated via deep-rooted thrust faults or by structural focusing up the flanks of the anticline to the seafloor. Gas hydrate recovered from near the CSM summit at a subbottom depth of about 5.7 meters in a water depth of 2538 m was of nodular and vein-filling morphology. Although the hydrate was not preserved, residual gas from the core liner contained >95% methane by volume when corrected for atmospheric contamination. The presence of trace C4+hydrocarbons (inflation of the seafloor caused by formation and accumulation of shallow hydrate lenses is also a likely factor in CSM growth. Pore water analysis shows the sulfate-methane transition to be very shallow (0-1 mbsf), also supporting an active high-flux interpretation. Pore water with chloride concentrations as low as 160 mM suggest fluid migration pathways may extend to the mound from buried

  17. Characterization of the Qishn sandstone reservoir, Masila Basin-Yemen, using an integrated petrophysical and seismic structural approach

    Science.gov (United States)

    Lashin, Aref; Marta, Ebrahim Bin; Khamis, Mohamed

    2016-03-01

    This study presents an integrated petrophysical and seismic structural analysis that is carried out to evaluate the reservoir properties of Qishn sandstone as well as the entrapment style of the hydrocarbons at Sharyoof field, Sayun-Masila Basin that is located at the east central of Yemen. The reservoir rocks are dominated by clean porous and permeable sandstones zones usually intercalated with some clay stone interbeds. As identified from well logs, Qishn sandstone is classified into subunits (S1A, S1B, S1C and S2) with different reservoir characteristics and hydrocarbon potentiality. A number of qualitative and quantitative well logging analyses are used to characterize the different subunits of the Qishn reservoir and identify its hydrocarbon potentiality. Dia-porosity, M-N, Pickett, Buckles plots, petrophysical analogs and lateral distribution maps are used in the analysis. Shale volume, lithology, porosity, and fluid saturation are among the most important deduced parameters. The analysis revealed that S1A and S1C are the main hydrocarbon-bearing units. More specifically, S1A unit is the best, as it attains the most prolific hydrocarbon saturations (oil saturation "SH″ up to 65) and reservoir characteristics. An average petrophysical ranges of 4-21%, 16-23%, 11-19%, 0-65%, are detected for S1A unit, regarding shale volume, total and effective porosity, and hydrocarbon saturation, respectively. Meanwhile, S1B unit exhibits less reservoir characteristics (Vsh>30%, ϕEff<15% and SH< 15%). The lateral distribution maps revealed that most of the hydrocarbons (for S1A and S1C units) are indicated at the middle of the study area as NE-SW oriented closures. The analysis and interpretation of seismic data had clarified that the structure of study area is represented by a big middle horst bounded by a group of step-like normal faults at the extreme boundaries (faulted anticlinal-structure). In conclusion, the entrapment of the encountered hydrocarbon at Sharyoof oil

  18. Geometría y cinemática de las estructuras que involucran al basamento en la zona del arroyo Tordillo, faja corrida y plegada de Malargüe, Mendoza Geometry and kinematic of the basement-involved structures at the Arroyo Tordillo zone, Malargüe fold-thrust belt, Mendoza

    Directory of Open Access Journals (Sweden)

    M.M. Turienzo

    2005-12-01

    Full Text Available El estudio detallado realizado en la zona de los arroyos Tordillo y Blanco, en la faja corrida y plegada de Malargüe, permitió reconocer una gran variedad de estructuras tectónicas que afectan tanto al basamento como a la cubierta sedimentaria. Con los datos estructurales relevados e información de subsuelo, confeccionamos una sección estructural retrodeformable de las estructuras aflorantes y su continuidad en profundidad, e interpretamos su evolución cinemática. Dos pares anticlinal-sinclinal, que posiblemente involucran al basamento, tienen lugar en el sector más occidental del área de estudio. Estos son transportados sobre una cuña de basamento, la cual en su avance hacia el antepaís genera un pliegue por propagación de falla en la cubierta sedimentaria. Cuando el desplazamiento hacia el este de la cuña es obstaculizado, en su extremo se generan dos retrocorrimientos. En este intrincado marco estructural, el corrimiento que dio origen a la cuña es reactivado como una falla fuera de secuencia. Finalmente un nuevo corrimiento desarrollado más al este genera otra escama de basamento que eleva a las estructuras previas. La interpretación cinemática permitió calcular los acortamientos tectónicos para cada estadio de la estructuración así como visualizar la estrecha relación existente entre las estructuras.Detailed studies made at the Tordillo and Blanco streams, in the Malargüe fold-thrust belt, allowed us to recognize a broad variety of tectonic structures affecting both, basement and cover rocks. Using surface structural data together with sub-surface information we made a retrodeformable structural cross-section of the outcropping structures and its continuity in deep, and interpreted the kinematic evolution. Two pairs anticline-syncline, possibly involving basement rocks, occur at the westernmost area. These structures are carried by an eastward vergent basement wedge that in its movement toward the east produces a

  19. Third Quarter Hanford Seismic Report for Fiscal Year 2010

    Energy Technology Data Exchange (ETDEWEB)

    Rohay, Alan C.; Sweeney, Mark D.; Hartshorn, Donald C.; Clayton, Ray E.; Devary, Joseph L.

    2010-09-29

    The Hanford Seismic Assessment Program (HSAP) provides an uninterrupted collection of high-quality raw and processed seismic data from the Hanford Seismic Network for the U.S. Department of Energy and its contractors. The HSAP is responsible for locating and identifying sources of seismic activity and monitoring changes in the historical pattern of seismic activity at the Hanford Site. The data are compiled, archived, and published for use by the Hanford Site for waste management, natural phenomena hazards assessments, and engineering design and construction. In addition, the HSAP works with the Hanford Site Emergency Services Organization to provide assistance in the event of a significant earthquake on the Hanford Site. The Hanford Seismic Network and the Eastern Washington Regional Network consist of 44 individual sensor sites and 15 radio relay sites maintained by the Hanford Seismic Assessment Team. The Hanford Seismic Network recorded 23 local earthquakes during the third quarter of FY 2010. Sixteen earthquakes were located at shallow depths (less than 4 km), five earthquakes at intermediate depths (between 4 and 9 km), most likely in the pre-basalt sediments, and two earthquakes were located at depths greater than 9 km, within the basement. Geographically, twelve earthquakes were located in known swarm areas, 3 earthquakes occurred near a geologic structure (Saddle Mountain anticline), and eight earthquakes were classified as random events. The highest magnitude event (3.0 Mc) was recorded on May 8, 2010 at depth 3.0 km with epicenter located near the Saddle Mountain anticline. Later in the quarter (May 24 and June 28) two additional earthquakes were also recorded nearly at the same location. These events are not considered unusual in that earthquakes have been previously recorded at this location, for example, in October 2006 (Rohay et al; 2007). Six earthquakes were detected in the vicinity of Wooded Island, located about eight miles north of Richland just

  20. Synchronous unroofing and faulting in the Precordillera of Argentina: thermochronometric constraints on fault-propagation in a thin- to thick-skinned orogenic system

    Science.gov (United States)

    Fosdick, J. C.; Carrapa, B.

    2013-12-01

    Mass removal via erosion is an important process that interacts with deformation in convergent mountain belts such as the Andes, and improved quantification of denudation is critical for elucidating spatio-temporal patterns of deformation. We report new apatite and zircon (U-Th)/He (AHe, ZHe) and apatite fission track (AFT) results from the Precordillera of Argentina that record Neogene fault-related unroofing during growth of the Andean retroarc fold-and-thrust belt. The Precordillera fold-and-thrust belt of Argentina is located west of the thick-skinned Sierras Pampeanas and evolved concurrently with the Bermejo retroarc foreland basin since at least the early Miocene. At the Rio Jáchal latitude (30°S), most crustal shortening associated with the Andean orogen is accommodated across the Precordillera, however, its unroofing record remains poorly constrained. Here we test the relationships between thrust faulting and exhumation and quantify the erosional input of sediments to the foreland basin. ZHe samples from Silurian-Carboniferous metasedimentary rocks collected across the Rio Jáchal transect yield entirely Permo-Triassic cooling ages, indicating that the present-day erosional depth of the Precordillera has resided above the ZHe partial retention zone (PRZ) throughout Mesozoic-Cenozoic time. Preliminary AFT data of the Precordillera also indicate mixed pre-Cenozoic ages. ZHe and AFT ages provide a nominal Iglesia piggy-back basin and the Las Salinas anticline at the eastern boundary between the Precordillera and Pampean craton. Apatite AHe and AFT data from the western Sierras Pampeanas indicate cooling through both AHe and AFT PRZs between ~5-4 Ma and suggest rapid exhumation during faulting of the Sierra de Valle Fértil. These data suggest a higher magnitude of Miocene exhumation of the Sierras Pampeanas compared to the Precordillera. Miocene exhumation rates across the Precordillera range from 0.16 to 1.11 mm/yr, with highest rates concentrated along

  1. An ongoing large submarine landslide at the Japan trench

    Science.gov (United States)

    Nitta, S.; Kasaya, T.; Miura, S.; Kawamura, K.

    2013-12-01

    This paper deals with an active submarine landslide on a landward trench slope in the Japan trench. Studied area is located on the upper terrace ranging from 400 to 1200 m in water depth, off Sendai, northeast Japan. We have surveyed in detail the seabed topography using a multi narrow beam (hereafter MBES) and a subbottom profiler (hereafter SBP) during the cruise MR12-E02 of R/V Mirai. The survey lines were 12 lines in N-S, and 3 lines in E-W, and situated in the region from 141°45'E, 37°40'N to 142°33'E, 38°32'N. Moreover, we used multi-channel seismic profile by the cruise KR04-10 of R/V Kairei in the interpretation of the SBP results. In general, horseshoe-shaped depressions of about 100 km wide along the trench slope are arrayed along the Japan trench. It has thought that they were formed by large submarine landslides, but we could not understand critically the relationship between the depressions and the submarine landslides. Based on the survey results, we found signals of an active submarine landslide in the depression as follows. 1) We observed arcuate-shaped lineaments, which are sub-parallel to a horseshoe-shaped depression. The lineaments concentrate in the south region from 38°N at about 20 km wide. These lineaments are formed by deformation structures as anticlines, synclines and normal fault sense displacements. 2) Most of the synclines and anticlines are not buried to form the lineaments. 3) Normal faults cutting about 1 km deep are observed in a multi-channel seismic profile. The normal faults are located just below the arcuate-shaped lineaments, and are tilted eastward being the downslope direction. It indicates a large submarine landslide. We concluded that the arcuate-shaped lineaments were generated by surface sediment movement with the submarine landsliding. We think that the submarine landslide of about 20 km wide and about 1 km thick move continuously down the landward trench slope. This would be the formation process of the horseshoe

  2. Neotectonics of the Surma Basin, Bangladesh from GPS analysis

    Science.gov (United States)

    Bulbul, M. A. U.

    2015-12-01

    The Surma Basin is a sub-basin of the Bengal Basin situated at the northeastern corner of Bangladesh. The tectonically-active basin lies at the junction of three tectonic plates: the Indian plate, the Eurasian plate and the Burma platelet. The Surma Basin is bounded on the north by the Shillong Massif, east and southeast by CTFB of the Indo-Burman Ranges, west by the Indian Shield and to the south and southeast it is open to the main part of Bengal Basin. The Surma basin is subsiding at a high rate, which is controlled by flexure loading along the southern margin of the 2-km high Shillong Massif because of Dauki thrust fault system. The objective of this study is to explore and reconstruct the present scenario of the tectonically active zone of the northeastern Bangladesh, identify the active faults, identify the relation between the neotectonic activities and seismicity, relation between neotectonic activities and natural hazards and describe the nature of the possible future earthquakes. The present effort to establish the tectonics of the Surma basin mainly utilizes the horizontal and vertical movements of the area using GPS geodetic data and other constraints on the structure of the region. We also make use historical seismologic data, field geology, and satellite image data. The GPS data has been processed using GAMIT-GLOBK. The analysis of 5 continuous GPS geodetic stations installed in the Surma Basin are combined with published data from the adjacent parts of India. While the area is moving northeast at a rate of 50-52 mm/year relative to ITRF2008 reference frame, it is moving south in an Indian reference frame. The velocities reflect that the Surma Basin being overthrust by both Shillong Plateau from the north and Burmese microplate from the east, respectively. The combined GPS velocity data indicates shortening across Dauki Fault and Indo Burman Ranges at a rate of 7 mm/yr and 18 mm/yr, respectively. The complex anticlinal structures in and around the

  3. Submergence and Uplift Associated to Paleoearthquakes in the Northern Sunda Subduction System: Implications for Future Earthquakes.

    Science.gov (United States)

    Mondal, D. R.; McHugh, C. M.; Mortlock, R. A.; Steckler, M. S.; Seeber, L.; Goodbred, S. L., Jr.; Akhter, S. H.; Mustaque, S.

    2015-12-01

    Recent studies documented that the northern part of the Sunda subduction zone ruptured several times in the past 1500 years including one in 1762. To better understand megathrust surface ruptures and the hazards associated to them, we surveyed the SE coast of Bangladesh along the Teknaf peninsula and the Saint Martin anticline by dating coral microatolls of Porites lutea species by the U-Th dating method. Porites luteagrows a few centimeters below the low tide level creating a 5-12 mm thick skeletal band per year, which makes them a good indicator of relative sea level change that might be caused during tectonic submergence and uplift. U-Th ages were obtained from coral slabs and their growth bands interpreted from x-rays. The corals and marine terraces uplift were measured with high precision RTK GPS and modeled with high resolution DEM. The coral microatolls along the St. Martin anticline were dated to be ~ 250, 800 and 1300 years old. Since storm and other climatic phenomenon cannot cause uplift, we interpret that 2.5 m uplift was caused by 1762 earthquake that killed the coral microatolls. The coral slabs show three growth interruptions, where skeletal growth bands continued to grow onlapping the older growth bands. These growth onlaps could be the result of smaller uplift events after 1762 that did not result in coral mortality. The subsidence history extracted from vertical growth of the slabs suggests that the island is submerging at a rate of 11 mm/year. Corals growing 250 m from the dead coral colony post date the 1762 earthquake. Today living Porites lutea can be found 2.5 m below the dead coral heads and 9 cm above the spring low tide. The elevation of marine terraces (T1, T2 and T3) along the Teknaf coast is 2.5 m, 5-7 m and 11-13 m above sea level, respectively. A shell bed on top of T1 was dated at 1763 (dated by C14). This and the other two terraces could have been uplifted during the three earthquakes dated from coral microatolls. Considering the

  4. Numerical Modeling of an Active Salt System in Canyonlands, Utah: The Role of Topography in Driving Plastic Flow and Brittle Extension

    Science.gov (United States)

    Kravitz, K.; Upton, P.; Mueller, K. J.

    2014-12-01

    The Needles District of Canyonlands, Utah contains a coupled array of extensional faults, salt diapirs and an elongate anticline produced by gravitational stresses associated with erosion and canyon cutting along the Colorado River and its tributaries. Three-dimensional numerical models using high-resolution topography have been produced using FLAC3D to test how plastic flow of evaporites and brittle extension of overburden are coupled during deformation and how they combine to form salt structures in the region. High resolution (50 m DEM) topographic models were built of the Needles District and of the region to the southwest of the Needles containing the Imperial Valley fault. The overburden in these models was described by a strain-softening Mohr-Coulomb rheology and is 400 m thick from the surface to the base of the Colorado River canyon. It overlays a flat, 340 m thick, viscous layer representing the salt, which outcrops in the Colorado river downstream of the grabens. The Needles District is dominated by horst and graben structures which extend updip from the Colorado River to the southeast. In models of the Needles, lateral displacement is dominantly to the northwest, toward the river canyon with the most displacement occurring in regions containing side canyons. In the canyon, salt flows upward to form an anticline that follows the sinuosity of the river, and diapirs appear adjacent to side canyons or where the canyon widens, which is observed in the field and the models. Without a salt layer, models show much smaller displacement rates that vary from northwest to southeast demonstrating the importance of a flat lying salt layer in propagating deformation toward the river. The region to the southwest is an area of broader subsidence bounded by a major fault (Imperial Valley fault) with fewer developed extensional faults near the river canyon. The Imperial Valley fault model shows similar patterns in which deformation is driven perpendicular to the river

  5. Depth and Morphology of Wrinkle Ridge Detachments at Solis Planum, Mars

    Science.gov (United States)

    Colton, S. L.; Ferrill, D. A.; Smart, K. J.

    2005-12-01

    Wrinkle ridges -- long, linear to sinuous anticlines separated by relatively broad, flat synclinal valleys -- are a fundamental component of Martian geomorphology. The anticlinal crests show variable morphologies, but are often characterized by weak to strong asymmetry with variable vergence directions between adjacent ridges and along strike for any given ridge. Although wrinkle ridges are typically interpreted as contractional features, there is ongoing debate about their underlying structure and whether thrust faults penetrate to tens of kilometers of depth ("thick-skinned shortening") or sole into a detachment in the upper few kilometers of the Martian crust ("thin-skinned shortening"). Previous workers have estimated depth to the detachment horizon using a variety of methods including gravity inversion, geometry of crater-ridge intersections, mechanical modeling, and geometric modeling. Here we use a well-established terrestrial technique to calculate depth to the detachment horizon for wrinkle ridges in the Solis Planum region of Mars. We interpolate topographic profiles perpendicular to the regional trend of wrinkle ridges from Mars Orbiter Laser Altimeter (MOLA) Mission Experiment Gridded Data Record (MEGDR) altimetry data, set vertical reference lines on both sides of the ridge that define the limits of our measurement range, estimate the topographic surface prior to wrinkle ridge formation, and calculate the area uplifted above the original topographic surface. Dividing this excess area by the amount of shortening (the topographic profile length minus the length prior to deformation), provides depth to detachment. We calibrate the results with profiles from the less spatially-extensive but greater along-track density MOLA Precision Experiment Data Record (PEDR). Additional topographic and structural interpretation and analysis of wrinkle ridge morphology are conducted with Mars Orbiter Camera (MOC), Thermal Emission Imaging System (THEMIS), and High

  6. Quantification of fold growth of frontal antiforms in the Zagros fold and thrust belt (Kurdistan, NE Iraq)

    Science.gov (United States)

    Bretis, Bernhard; Bartl, Nikolaus; Graseman, Bernhard; Lockhart, Duncan

    2010-05-01

    The Zagros fold and thrust belt is a seismically active orogen, where actual kinematic models based on GPS networks suggest a north-south shortening between Arabian and Eurasian in the order of 1.5-2.5 cm/yr. Most of this deformation is partitioned in south-southwest oriented folding and thrusting with northwest-southeast to north-south trending dextral strike slip faults. The Zagros fold and thrust belt is of great economic interest because it has been estimated that this area contains about 15% of the global recoverable hydrocarbons. Whereas the SE parts of the Zagros have been investigated by detailed geological studies, the NW extent being part of the Republic of Iraq have experienced considerably less attention. In this study we combine field work and remote sensing techniques in order to investigate the interaction of erosion and fold growth in the area NE of Erbil (Kurdistan, Iraq). In particular we focus on the interaction of the transient development of drainage patterns along growing antiforms, which directly reflects the kinematics of progressive fold growth. Detailed geomorphological studies of the Bana Bawi-, Permam- and Safeen fold trains show that these anticlines have not developed from subcylindrical embryonic folds but they have merged from different fold segments that joined laterally during fold amplification. This fold segments with length between 5 and 25 km have been detected by mapping ancient and modern river courses that initially cut the nose of growing folds and eventually got defeated leaving behind a wind gap. Fold segments, propagating in different directions force rivers to join resulting in steep gorges, which dissect the merging fold noses. Along rapidly lateral growing folds (e.g. at the SE end of the Bana Bawi Anticline) we observed "curved wind gaps", a new type of abandoned river course, where form of the wind gap mimics a formed nose of a growing antiform. The inherited curved segments of uplifted curved river courses strongly

  7. Evaporite deposits of Bogota area, Cordillera Oriental, Colombia

    Science.gov (United States)

    McLaughlin, Donald H.

    1972-01-01

    Four evaporite-bearing stratigraphic zones are known in Cretaceous strata of the Cordillera Oriental of Colombia north and east of Bogota. The easternmost and oldest zone is probably of Berriasian to Valanginian age. The next oldest is probably late Barremian to early Aptian in age. The third appears to be Aptian. The westernmost and best known sequence in the Sabana de Bogota is Turonian to early Coniacian in age. This youngest sequence contains the thickest salt deposits known in Colombia and is probably the most widespread geographically. Most of the rock salt exposed in the three accessible mines (at Zipaquira, Nemocon, and Upin) has a characteristic lamination of alternating slightly argillaceous and highly argillaceous salt layers of varied but moderate thickness. Black, calcareous claystone, commonly very pyritic, is interbedded conformably with the laminated salt in many places throughout the deposits. Fragments of black claystone derived from the thinner interbeds are ubiquitous in all deposits, both as concordant breccia zones and as isolated clasts. Anhydrite is scarce at Zipaquira and apparently even rarer at Nemocon and Upin. Gypsum is produced at three small deposits in the oldest evaporite zone where it probably was concentrated by leaching of salt initially associated with it. The two intervening evaporite zones are not exposed, but their existence and distribution are indicated by brine springs and locally by "rute," a distinctive black, calcareous mud formed by the leaching of salt beds. Fossils show that the youngest salt-claystone zone, in the Sabana de Bogota, is contemporary with associated hematitic sandstone and siltstone, and with carbonaceous and locally coaly claystone. Although evidence is poor, this same facies relation probably exists within the other three evaporite zones. All salt deposits in this study probably are associated with anticlines, a relation best exemplified by the deposits on the Sabana de Bogota. Within these

  8. La cuenca cenozoica del río Grande y Palauco: edad, evolución y control estructural, faja plegada de Malargüe

    Directory of Open Access Journals (Sweden)

    José Silvestro

    2009-10-01

    Full Text Available La región del valle del Río Grande y Palauco a los 36° de latitud sur, forma parte de la faja plegada y corrida de Malargüe, en la Cordillera Principal. La evolución tectónica de este sector durante el Cenozoico quedó registrada en los depósitos volcaniclásticos preservados en las cuencas sinorogénicas. La configuración de estas cuencas estuvo controlada por las estructuras de basamento, que a esta latitud definen un sector interno ocupado por la subcuenca Río Grande y un sector frontal ocupado por la subcuenca Palauco. El relleno de estas cuencas muestra una etapa preorogénica que se extendió por lo menos hasta los 23 Ma dominada por secuencias basálticos. Desde los 18 Ma las principales estructuras comenzaron a levantarse provocando que en una primera etapa cada subcuenca evolucione de forma independiente. De esta forma, la subcuenca Río Grande recibió el aporte de sedimentos clásticos gruesos desde el oeste, producto de la erosión de la sierra Azul, que gradan a depósitos finos y evaporíticos distales en la parte oriental de la subcuenca, para finalmente acuñarse contra el borde occidental del anticlinal Pampa Palauco-Ranquil Co. Esta estructura ya constituía una barrera interna, posibilitando que en la subcuenca Palauco queden retenidos los depósitos basálticos alimentados desde centros efusivos activos presentes en este sector. Esta etapa finalizó aproximadamente a los 11 Ma, edad a partir de la cual ambas subcuencas presentan nuevamente un relleno similar dominado por depósitos volcánicos presentes en toda el área. En esta nueva etapa diferentes eventos de reactivación del anticlinal Pampa Palauco-Ranquil Co quedaron registrados en discordancias angulares observadas en el campo, que a partir de dataciones en niveles guía pudieron ser acotadas a los 11 Ma y 8 Ma. Estos eventos generaron también el desarrollo de un nuevo frente de deformación hacia el este, con el levantamiento de los anticlinales Cerro

  9. Major temporal variations in shortening rate absorbed along a large active fold of the southeastern Tianshan piedmont (China)

    Science.gov (United States)

    Saint-Carlier, Dimitri; Charreau, Julien; Lavé, Jérôme; Blard, Pierre-Henri; Dominguez, Stéphane; Avouac, Jean-Philippe; Wang, Shengli

    2016-01-01

    The investigation of deformation rates on a mountain piedmont can provide key information for improving our understanding of the overall dynamics of a mountain range. Here, we estimate the shortening rate absorbed by a Quaternary emergent detachment fold on the southeastern piedmont of the Tianshan (China). Our work is primarily based on new 10Be cosmogenic exposure dating of deformed alluvial surfaces. The method we have developed combines depth profiling with sampling of surface cobbles, thereby allowing exposure time, erosion rate and inheritance to be simultaneously constrained. The exposure ages of the uppermost uplifted alluvial surfaces are around 140 ± 17 ka, 130 ± 9 ka and 47 ± 9 ka, from west to east. A terrace lying below the 140 ka surface is dated at 65 ± 5 ka. The ages of the uplifted and folded alluvial surfaces were then combined with estimates of shortening obtained using two distinct methods: (1) the excess area method, where sedimentation rates, extracted from magnetostratigraphic studies, are used to determine the amount of sedimentation after the abandonment of the river; and (2) a folding model derived from sandbox experiments. The late Pleistocene shortening rates are shown to be between 0.4 ± 0.1 mm /yr and 0.8 ± 0.5 mm /yr on the western part of the fold and 2.1 ± 0.4 mm /yr along its central part. The central part of the frontal Yakeng anticline therefore accommodates up to 25% of the total shortening currently absorbed across the whole Eastern Tianshan range (8 mm/yr). However, this situation seems to have prevailed for only the last 150 ka, as the shortening rate absorbed by this nascent fold was previously ten times slower. While the initiation of folding of the Yakeng anticline can be traced back to 5.5 Ma ago, the basinward migration of the active deformation front onto the Yakeng fold is a relatively recent phenomenon and appears to be diachronous from west to east, probably in relation to the tectonic activity of the folds in

  10. Mound Spring Complexes in Central Australia: An Analog for Martian Groundwater Fed Outflow Channels?

    Science.gov (United States)

    Clarke, J. D. A.; Stoker, C.

    2003-01-01

    discharged artesian waters are of low to moderate salinity (700 - 9400 ppm), near neutral pH (6.8-7.3) and warm (20-46 C). The elevated temperatures are due to passage of the groundwater through deeply buried (up to 3 km) aquifers in an region of high heat flow, rather than magmatic heating. The waters also contain high levels of dissolved iron and H2S and less than 1 ppm dissolved oxygen. The water is carried in the Late Jurassic Algebuckina Sandstone beneath the aquaclude of the Bulldog Shale. It is brought near the surface by the mid-Cenozoic Dalhousie anticline and the ground water flow focused along a series of faults that breach the anticline's crest.

  11. Interplay of tectonism and carbonate sedimentation in the Bahamas foreland basin

    Science.gov (United States)

    Masaferro, Jose Luis

    of the structure. Because of the in-situ production of sediments independent of local tectonics, the platform was able to shed sediments continuously into the basin producing a complete record of growth strata. Seismically imaged syntectonic strata in the Santaren Anticline revealed the influence of sedimentation and local tectonics in defining growth stratal geometries. A detailed analysis of the growth strata deposited on the the northern limb of the Santaren Anticline indicates that growth stratal geometries are a result of a close competition between sedimentation and local tectonics. Neither sedimentation nor tectonic uplift dictates the final overlap-onlap/offlap geometries observed within the growth strata. The prevalence of one over the other defines the final geometry of the stratal patterns.

  12. Spatial analysis of temperature (BHT/DST) data and consequences for heat-flow determination in sedimentary basins

    Science.gov (United States)

    Forster, A.; Merriam, D.F.; Davis, J.C.

    1997-01-01

    Large numbers of bottom-hole temperatures (BHTs) and temperatures measured during drill-stem tests (DSTs) are available in areas explored for hydrocarbons, but their usefulness for estimating geothermal gradients and heat-flow density is limited. We investigated a large data set of BHT and DST measurements taken in boreholes in the American Midcontinent, a geologically uniform stable cratonic area, and propose an empirical correction for BHTs based on relationships between BHTs, DSTs, and thermal logs. This empirical correction is compared with similar approaches determined for other areas. The data were analyzed by multivariate statistics prior to the BHT correction to identify anomalous measurements and quantify external influences. Spatial patterns in temperature measurements for major stratigraphic units outline relations to regional structure. Comparision of temperature and structure trend-surface residuals reveals a relationship between temperature highs and local structure highs. The anticlines, developed by continuous but intermittent movement of basement fault blocks in the Late Paleozoic, are subtle features having closures of 10-30 m and contain relatively small hydrocarbon reservoirs. The temperature anomalies of the order of 5-7 ??C may reflect fluids moving upward along fractures and faults, rather than changes in thermal conductivity resulting from different pore fluids. ?? Springer-Verlag 1997.

  13. The investigation of fault-controlled groundwater recharge within a suburban area of Damascus, Syria

    Science.gov (United States)

    Wannous, M.; Siebert, C.; Tröger, Uwe

    2016-08-01

    Al-Mazraa is a heavily populated suburb of Damascus (Syria) with agricultural activity. It is adjacent to the Cretaceous Qassioun Mountain Range, from which it is structurally separated by the Damascus fault. Al-Mazraa waterworks abstracts from a shallow Quaternary aquifer, whose recharge processes are unidentified. The functions of Qassioun Mountain, the Damascus fault, the agricultural activities, the ascending deeper groundwater, and the through-flowing Tora River are not well understood and they are, hence, subject to study. The application of hydrochemical parameters and ratios in combination with signatures of δD and δ18O revealed that recharge predominantly occurs in the outcropping Cretaceous rocks through subsurface passages rather than through influent conditions of the Tora River or through direct rainfall. Interestingly, high Na/Cl ratios indicate contact with volcanic rocks which exist within the Cretaceous anticline and also in the subsurface of the studied Quaternary aquifer. Evidence for deeper circulating groundwater is given, since replenishing waters are up to 4 °C warmer and have much lower nitrate concentrations than the groundwater in the study area. From these points, it is indicated that the Damascus fault is conductive in respect to groundwater, rather than being impermeable, as it is elsewhere.

  14. Oulituozi Europe 601 Oil Well Sha Three Sections--Study Trachyte Reservoir Structural Characteristics%欧利坨子油田欧601井区沙三段--粗面岩油藏构造特征研究

    Institute of Scientific and Technical Information of China (English)

    鄢菲

    2016-01-01

    Euro 601 well area located in Central East Depression,Liaohe Basin,east to the construction of the Three Realms bubble hill,south Rehetai anticline fracture adjacent to the west,Dong Gang slope,north-dipping at home not in the house sag. Through research the area well Shahejie structural characteristics,find out its tectonic evolution,distribution of the overall shape and fracture systems.%欧601井区位于辽河盆地东部凹陷中段,构造上东到三界泡潜山、南与热河台断裂背斜相邻、西接董家岗斜坡、北倾没于于家房子洼陷。通过开展该井区沙三段构造特征研究,搞清了其构造演化规律、整体形态和断裂系统的分布特征。

  15. Morphological characteristics of leaf epidermis and size variation of leaf, flower and fruit in different ploidy levels in Buddleja macrostachya (Buddlejaceae)

    Institute of Scientific and Technical Information of China (English)

    Gao CHEN; Wei-Bang SUN; Hang SUN

    2009-01-01

    Buddleja macrostachya (Buddlejaceae) is a widespread shrub native to the Sino-Himalayan mountains and beyond. It has been found to occur at two ploidy levels, hexaploid, 2n=6x=114 and dodecaploid, 2n=12x=228. To determine if morphological characters might be used as indicators of ploidy levels, we measured floral and fruit length, relative and absolute leaf size, trichome density on both leaf surfaces, and stomatal density and length in different populations of B. macrostachya. In general, flower and fruit length, absolute leaf size, and stomatal length increased with an increase at ploidy level (P0.05) in different populations. Other characters studied such as trichome type, cuticular membrane and ornamentation of stomata, cell and stomatal shape, and anticlinal wall pattern were quite constant in this species. Thus it appears that flower and fruit length, absolute leaf size, and stomatal frequency and length can be used to distinguish hexaploid from dodecaploid cytotypes either in the field or in herbarium specimens.

  16. Technical and other experience at Embalut coal mine; Embalut tanko deno gijutsu kaizen

    Energy Technology Data Exchange (ETDEWEB)

    Kakizaki, A. [Mitsui Mining Co. Ltd., Tokyo (Japan)

    1997-10-25

    This paper describes technology development at Embalut Coal Mine in Indonesia. This coal mine opened in 1983. There is an anticlinal axis in the east and a synclinal axis at the west end. The coal seam inclines towards west. Coal seams in Miocene Epoch, Tertiary Period compose of 23 seams from lower No. 1 Seam to upper No. 23 Seam. Calorific values are between 6700 and 5800 kcal/kg, and sulfur contents are between 0.2 and 2%. At initial stages, logs with diameter between 10 and 15 cm were used as supports, and coal seams were dug by picks (air hoses). Coals were flown by themselves through vinyl trough, and were loaded in coal tubs in the lower gallery. They were carried by hand pushing to the lifting slope. Driving could not be progressed due to the frequent roof fall within 10 m, which resulted in the very low recovery. Steel props were employed at five faces and air supply to picks was increased, to enhance the production. The production was further enhanced using blasting. Coal tubs using 22 kW motors were introduced in stead of hand-pushing transportation. Since spontaneous firing often happened due to random mining and incomplete closing, upcast shaft with a depth 30 m and an internal diameter 3 m was excavated in the rock gallery. 3 figs., 1 tab.

  17. Formation of diapiric structure in the deformation zone, central Indian Ocean: A model from gravity and seismic reflection data

    Indian Academy of Sciences (India)

    K S Krishna; D Gopala Rao; Yu P Neprochnov

    2002-03-01

    Analyses of bathymetry, gravity and seismic reflection data of the diffusive plate boundary in the central Indian Ocean reveal a new kind of deformed structure besides the well-reported structures of long-wavelength anticlinal basement rises and high-angle reverse faults. The structure (basement trough) has a length of about 150 km and deepens by up to 1 km from its regional trend (northward dipping). The basement trough includes a rise at its center with a height of about 1.5 km. The rise is about 10 km wide with rounded upper surface and bounded by vertical faults. A broad free-air gravity low of about 20 mGal and a local high of 8 mGal in its center are associated with the identified basement trough and rise structure respectively. Seismic results reveal that the horizontal crustal compression prevailing in the diffusive plate boundary might have formed the basement trough possibly in early Pliocene time. Differential loading stresses have been generated from unequal crust/sediment thickness on lower crustal and upper mantle rocks. A thin semi-ductile serpentinite layer existing near the base of the crust that is interpreted to have been formed at mid-ocean ridge and become part of the lithosphere, may have responded to the downward loading stresses generated by the sediments and crustal rocks to inject the serpentinites into the overlying strata to form a classic diapiric structure.

  18. Structural feature and tectonic evolution of Awati——Bachu area in Tarim Basin

    Institute of Scientific and Technical Information of China (English)

    Zhihong LIU; Defeng ZHU; Junyi GAO; Xiangmei WU; Dongcheng LIN; Liguo ZHANG

    2008-01-01

    The research area is situated in the western part of Tarim basin,which includes Awati depression and Bachu uplifted block. It underwent three times processes of compression in a large scale and a near term extension since Cambrian. The first compression occurred during Middle Cambrian to Devonian, which formed fault band folds in NW axial direction. They were "under-water uplift"and distributed all over the research area. The second compression occurred in Late Permian and formed fault band folds and a few fault propagation folds in NS axial direction. They are developed near Tumuxiuke fault belt and the northern research area. The western anticline is bigger than the eastern one in extent and size. The third compression occurred during Palaeogene to Quaternary and formed tumuxiuke fault belt and fault propagation folds in NW direction. They are distributed over the south part of the research area. Tumuxiuke fault belt is a big scale dextral reversed strike-slip fault belt; it transformed or destroyed the fold structure of the research area. A short-term extension occurred during Early Permian. Tarim Basin is in the rift forming stage of craton, and there exist widespread basic volcanic rocks, basic intrusive bodies and dikes.

  19. Neotectonic morphotructures in the junction zone of the Cape Verde Rise and Cape Verde Abyssal Plain, Central Atlantic

    Science.gov (United States)

    Skolotnev, S. G.; Kolodyazhny, S. Yu.; Tsukanov, N. V.; Chamov, N. P.; Sokolov, S. Yu.

    2009-01-01

    Acoustic profiling carried out with an Edgetech 3300 prophilograph in the junction zone of the Cape Verde Rise, Cape Verde Abyssal Plain, and Grimaldi and Bathymetrists seamounts in the Central Atlantic during Cruise 23 of the R/V Akademik Nikolaj Strakhov allowed us to obtain new data on neotectonic deformations in the ocean and to propose their interpretation. It has been established that neotectonic movements occurred in the discrete manner: blocks of undeformed rocks alternate with linear zones of intense deformation spatially related to paleotransform fracture zones, where anticlines, horsts, diapir-like morphostructures, and grabens were formed. The Cape Verde Ridge is a large horst. Its sedimentary cover is disturbed by thrust (?), reverse, and normal faults, steeply dipping fracture zones, and folds. Three stages of tectonic movements—Oligocene-early Miocene, pre-Quaternary, and Holocene—are recognized. The tectonic deformations occurred largely under near-meridional compression. Extension setting was characteristic of the Cape Verde Ridge and the Carter Rise in the Holocene.

  20. Fi Investigations On Hp-Rocks From The Lower Engadine Window New Insights On Its Late Tectono-Metamorphic Evolution

    Science.gov (United States)

    Bertle, R. J.; Götzinger, M. A.; Koller, F.

    2003-04-01

    Fluid inclusions studies in metamorphic rocks allow to reconstruct not only the chemistry of the fluids enabling and/or supporting metamorphic reactions but also the late metamorphic evolution of orogenesis. Therefore late, discordant quarz-calcite veins were investigated using FI-techniques. The Engadine Window which is exposed at the Swiss-Austrian-border exposes the penninic units of the Western Alps as a tectonic window within the Austroalpine nappes of the Eastern Alps. The nappes of the Engadine window underwent metamorphism and deformation during Tertiary times (THÖNI 1981, BERTLE 2000). The highest unit (Fimber unit) and the core of the window (= Zone of Pfunds) suffered HP-LT-metamorphism. P-T-conditions for parts of the Zone of Pfunds at the region of Piz Mundin are at 13-15 kbar at 380^oC (BOUSQUET et al. 2002) indicated by the occurrence of carpholite and glaucophane. The late metamorphic history is not very well constrained. There exist only a few FI-data published in an abstract by STÖCKHERT et al. 1990 and some unpublished data in RING 1989. During the ongoing mapping campaign of the first author samples from the Fimber unit and the Zone of Pfunds were collected and investigated using a LINKHAM freezing-cooling-stage. The investigated veins are discordant in respect to the main-foliation of the rocks and show nice cristalls of quarz, calcite and sometimes feldspar (adularia). Structural data implie that the investigated veins correspond to a set of ac-joints that correlate to the late updoming of the large "Engadiner Gewölbe" (Engadin anticlinal structure, MATTMÜLLER 1996). All investigated veins (from all tectonic units) show the same relationship to the anticlinal structure. FI-investigations show, that a large amount of the primary FI are decrepitated, however it was possible to find enough to provide a serious statistical data set. FI from Piz Mundin in the core of the Engadine window exhibit at the base of the vein quarz at the contact to

  1. Results of geological prospecting operations for oil and gas in Hrvatia in 1969-1979

    Energy Technology Data Exchange (ETDEWEB)

    Vladimir, T.; Branimir, M.

    1980-01-01

    In 1969-1979, exploratory and prospecting operations in Hrvatia were conducted at 34 districts which showed promise in terms of the likelihood of oil and gas. Definite advances were achieved both in the area of prospecting and in exploration. Prospecting techniques for non-anticlinal deposits and for testing fissured reservoirs were improved. A significant saving was attained by applying controlled-directional drilling. Discoveries which were made markedly increased the oil and gas reserves in categories A, B, and C. Over the 11-year period, 832 prospecting boreholes were drilled, of which 461 were vertical, 189 inclined, and 182 controlled-directional. The overall length (in meters) of these boreholes amounted to 1,318,272 m; 27.5% of the drilled boreholes were unsuccessful (in the United States, by comparison, in 1969 26.9% of all boreholes did not show positive results). This indicator may be considered acceptable, since Hrvatia deposits are small in size, irregular in shape, and have complicated geological structures. Through the use of controlled-directional drilling, it was possible to retain a large number of already drilled vertical boreholes for subsequent exploitation of producing levels; only 7.24% of the total number of boreholes were eliminated. During this period, a noticeable growth in oil and gas reserves was achieved; within the Pannonnsk basin of Hrvatian, these deposits, increased 51% (oil) and 26% (gas).

  2. Organic geochemistry of oils and condensates in the Kekeya field, southwest depression of the Tarim Basin (China)

    Energy Technology Data Exchange (ETDEWEB)

    Maowen Li; Snowdon, L.R. [Geological Survey of Canada, Calgary (Canada); Renzi Lin; Peirong Wang [Jianghan Petroleum Institute, Hubei (China); Yongsheng Liao; Peilong Li [Shengli Petroleum Administrative Bureau, Shandong (China)

    1999-07-01

    This study shows that the oils and condensates in the Kekeya Field in the Tarim Basin, NW China, belong to a single family, most likely derived from marine shale source rocks deposited under oxic-suboxic conditions with mixed terrigenous and algal-bacterial organic inputs. The maturity data clearly indicate that the paraffinic condensates were not formed by thermal cracking of oil during late catagenesis (R{sub o} > 1.2%). Both the oils and condensates were generated within the normal oil window, whereas addition of gaseous hydrocarbons from a separate source resulted in migration fractionation and hence spuriously high heptane indices. Age specific biomarkers show that the oils and condensates were not generated from the Mesozoic-Cenozoic strata, but from the Carboniferous-Permian sections. 1D basin modelling results are consistent with this interpretation, suggesting that the Mesozoic-Eocene strata are currently immature with respect to hydrocarbon generation and expulsion. Deep-seated faults may have provided routes for upward fluid migration at the time of active deformation during several pulses of the Himalayan orogeny. The favoured targets for further petroleum exploration in front of the Kunlun Mountains include the deep structures within the Carboniferous-Permian strata for indigenous petroleum accumulations and anticlines and stratigraphic traps within the Mesozoic-Cenozoic sections that are cut by deep-seated thrust faults where secondary petroleum accumulations most likely occurred. (author)

  3. 3D high resolution stratigraphy of early rift deltaic deposits in the Sergipe-Alagoas basin: impact on the reservoir compartmentalization; Estratigrafia de alta resolucao 3D em depositos deltaicos do inicio do rifte da bacia de Sergipe-Alagoas: impacto na compartimentacao de reservatorios

    Energy Technology Data Exchange (ETDEWEB)

    Borba, Claudio [Petroleo Brasileiro S. A. (PETROBRAS/UO-SEAL), Aracaju, SE (Brazil). Unidade de Operacoes de Exploracao e Producao de Sergipe e Alagoas], E-mail: cborba@petrobras.com; Paim, Paulo Sergio Gomes [Universidade do Vale do Rio dos Sinos (UNISINOS), Sao Leopoldo, RS (Brazil)], E-mail: ppaim@unisinos.br; Garcia, Antonio Jorge Vasconcellos [Universidade Federal de Sergipe (UFS), Aracaju, SE (Brazil)], E-mail: garciageo@pq.cnpq.br

    2009-05-15

    A high resolution stratigraphic study applied to reservoir characterization, based on well logs, cuts and cores from the Furado Field, a mature oil field of the Alagoas Sub-basin, was carried out on deltaic strata of the lower portion of the Barra de Itiuba Formation (early rifting of the Sergipe-Alagoas Basin). Three lacustrine systems tracts were recognized within a 3rd order sequence: the low stand systems tract (tectonic pulse initiation) that includes extensive, medium- to coarse-grained fluvial-deltaic sandstones that display good reservoir quality; the transgressive systems tract (tectonic climax), which comprises lacustrine and pro delta shale and distal delta front, fine- to very fine-grained sandstone; and the high stand system tract (tectonic quiescence) that encompasses several cycles of delta front progradation and related poor quality reservoirs relative to those of the low stand system tract. The 4th order sequences are represented by climate-driven transgressive-regressive cycles that constitute independent reservoirs, equivalent to a reservoir zones. This high resolution stratigraphic framework was then used on the building of the 3D geologic model, which honored the systems tracts geometry, and related facies, as well as the paleostructure, including a syn-depositional fault propagation anticline. Several normal faults split the reservoirs at different scales. Their potential impact on reservoir fragmentation was approached through the use of fault juxtaposition and shale gouge ratio diagrams. (author)

  4. The 2002 June 22 Changureh (Avaj) earthquake in Qazvin province, northwest Iran: epicentral relocation, source parameters, surface deformation and geomorphology

    Science.gov (United States)

    Walker, Richard T.; Bergman, Eric; Jackson, James; Ghorashi, Manoucher; Talebian, Morteza

    2005-02-01

    The Mw 6.4 Changureh (Avaj) earthquake occurred on 2002 June 22, in Qazvin province, northwest Iran. We use observations from seismology, field investigation and analysis of satellite imagery and digital topography to suggest that slip on a previously unrecognized thrust fault (herein named the Abdarreh fault) was responsible for the earthquake. Inversion of long-period P and SH body wave seismograms shows rupture on a thrust fault dipping 49° to the southwest and with a centroid depth of ~10 km. Multiple-event relocation of the main shock and aftershock epicentres and discontinuous surface ruptures observed after the earthquake are compatible with a northwest-propagating rupture on a southwest-dipping thrust, but maximum recorded displacements are much less than expected from seismology, suggesting that much of the slip failed to reach the surface and was accommodated as folding at the surface instead. Long-term folding is difficult to see in the topography of the epicentral region as the Abdarreh fold is growing through a relict Neogene topography. Anticlinal uplift can, however, be inferred from drainage disruption and stream incision. The 2002 June 22 Changureh earthquake shows the importance of being able to interpret diagnostic features of active faulting in the landscape.

  5. The 22 June 2002 Changureh (Avaj) Earthquake in Qazvin Province, NW Iran: Epicentral Re-location, Source Parameters, Surface Deformation and Geomorphology.

    Science.gov (United States)

    Walker, R. T.; Bergman, E.; Jackson, J. A.; Ghorashi, M.; Talebian, M.

    2004-12-01

    The Mw 6.4 Changureh (Avaj) earthquake occurred on the 22 June, 2002 in Qazvin province, NW Iran. We use observations from seismology, field investigation and analysis of satellite imagery and digital topography to suggest that slip on a previously unrecognised thrust fault (herein named the Abdarreh fault) was responsible for the earthquake. Inversion of long-period P and SH body-wave seismograms shows rupture on a thrust fault dipping 49 degrees to the southwest and with a centroid depth of about 10 km. Multiple-event relocation of the main-shock and aftershock epicentres, and discontinuous surface ruptures observed after the earthquake are compatible with a NW propagating rupture on a SW-dipping thrust, but maximum recorded displacements are much less than expected from seismology, suggesting that much of the slip failed to reach the surface and was accommodated as folding at the surface instead. Long-term folding is difficult to see in the topography of the epicentral region as the Abdarreh fold is growing through a relict Neogene topography. Anticlinal uplift can however be inferred from drainage disruption and stream incision. The 22 June, 2002 Changureh earthquake shows the importance of being able to interpret diagnostic features of active faulting in the landscape.

  6. Fold-to-Fault Progression of a Major Thrust Zone Revealed in Horses of the North Mountain Fault Zone, Virginia and West Virginia, USA

    Directory of Open Access Journals (Sweden)

    Randall C. Orndorff

    2012-01-01

    Full Text Available The method of emplacement and sequential deformation of major thrust zones may be deciphered by detailed geologic mapping of these important structures. Thrust fault zones may have added complexity when horse blocks are contained within them. However, these horses can be an important indicator of the fault development holding information on fault-propagation folding or fold-to-fault progression. The North Mountain fault zone of the Central Appalachians, USA, was studied in order to better understand the relationships of horse blocks to hanging wall and footwall structures. The North Mountain fault zone in northwestern Virginia and eastern panhandle of West Virginia is the Late Mississippian to Permian Alleghanian structure that developed after regional-scale folding. Evidence for this deformation sequence is a consistent progression of right-side up to overturned strata in horses within the fault zone. Rocks on the southeast side (hinterland of the zone are almost exclusively right-side up, whereas rocks on the northwest side (foreland of the zone are almost exclusively overturned. This suggests that the fault zone developed along the overturned southeast limb of a syncline to the northwest and the adjacent upright limb of a faulted anticline to the southeast.

  7. Field trip guide to selected outcrops, Arbuckle Mountains, Oklahoma

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1991-11-17

    The Arbuckle Mountains, named for Brigadier General Matthew Arbuckle, are located in south-central Oklahoma. The formations that comprise the Arbuckle Mountains have been extensively studied for hydrocarbon source rock and reservoir rock characteristics that can be applied to the subsurface in the adjacent Anadarko and Ardmore basins. Numerous reports and guidebooks have been written concerning the Arbuckle Mountains. A few important general publications are provided in the list of selected references. The purpose of this handout is to provide general information on the geology of the Arbuckle Mountains and specific information on the four field trip stops, adapted from the literature. The four stops were at: (1) Sooner Rock and Sand Quarry; (2) Woodford Shale; (3) Hunton Anticline and Hunton Quarry; and (4) Tar Sands of Sulfur Area. As part of this report, two papers are included for more detail: Paleomagnetic dating of basinal fluid migration, base-metal mineralization, and hydrocarbon maturation in the Arbuckle Mountains, Oklahoma and Laminated black shale-bedded chert cyclicity in the Woodford Formation, southern Oklahoma.

  8. Morphometric analysis of epidermal differentiation in primary roots of Zea mays

    Science.gov (United States)

    Moore, R.; Smith, H. S.

    1990-01-01

    Epidermal differentiation in primary roots of Zea mays was divided into six cell types based on cellular shape and cytoplasmic appearance. These six cell types are: 1) apical protoderm, located at the tip of the root pole and characterized by periclinally flattened cells; 2) cuboidal protoderm, located approximately 230 microns from the root pole and characterized by cuboidal cells; 3) tabular epidermis, located approximately 450 microns from the root pole and characterized by anticlinally flattened cells; 4) cuboidal epidermis, located approximately 900 microns from the root pole and characterized by cuboidal cells having numerous small vacuoles; 5) vacuolate cuboidal epidermis, located approximately 1,500 microns from the root pole and characterized by cuboidal cells containing several large vacuoles; and 6) columnar epidermis, located approximately 2,200 microns from the root pole (i.e., at the beginning of the zone of elongation) and characterized by elongated cells. We also used stereology to quantify the cellular changes associated with epidermal differentiation. The quiescent center and the apical protoderm have significantly different ultrastructures. The relative volume of dictyosomes increases dramatically during the early stages of epidermal differentiation. This increase correlates inversely with the amount of coverage provided by the root cap and mucilage.

  9. Assessment of Geo-Tourism Structure in Bojnoord City Sustainable Tourism Development

    Directory of Open Access Journals (Sweden)

    Pegah Kharazian

    2015-06-01

    Full Text Available Nowadays, issues such as population growth, gradual reduction of natural resources, increasing pollution, unbalanced distribution in resources, the crisis of ecological conservation, urbanization growth and increasing human awareness are as a result of social changes in human life. Even changes in the attitude of people toward the trip phenomenon lead to several changes in this industry. The concept of ecotourism, geo-tourism, geo-park and sustainable tourism represent the evolution of ideas, including new solutions that will meet the modern world's needs with valued targets in its plan. The emphasis of this article is on morphological characteristics in line with sustainable development goals and ecological resources protection of the region to attract certain tourists through the identification and introducing the potential attraction of the area. Analytical and experimental research methods are based on statistical data, quantitative analysis methods and data collection methods in library and field methods. This case study (Bojnoord city presents comprehensive image about geomorphological attractions of Bojnoord city. The results indicated that through the internal and external processes of land phenomena, beautiful landscapes such as anticlines, synclines, straits and erosional forms, springs, waterfalls, peaks and valleys with special and unique effects can attract tourists in different ages and educational levels in different seasons of the year. Keywords:  Geo-tourism, Ecotourism, Geo-parks, Sustainable tourism, Bojnoord city

  10. The multi-factor recombination and processes superimposition model for hydrocarbon accumulation: application to the Silurian in the Tarim Basin

    Institute of Scientific and Technical Information of China (English)

    Meng Qingyang; Pang Xiongqi; Gao Jianbo

    2008-01-01

    The multi-factor recombination and processes superimposition model for hydrocarbon accumulation is put forward in view of the hydrocarbon geological characteristics of multiple episodes of structural evolution, multiple sets of source-reservoir-seal assemblage, multiple cycles of hydrocarbon accumulation and multiple episodes of readjustment and reconstruction in the complex superimposed basins in China. It is a system including theories and methods that can help to predict favorable exploration regions. According to this model, the basic discipline for hydrocarbon generation, evolution and distribution in the superimposed basins can be summarized in multi-factor recombination, processes superimposition, multiple stages of oil filling and latest stage preservation. With the Silurian of the Tarim basin as an example, based on the reconstruction of the evolution history of the four factors (paleo-anticline,source rock, regional cap rock and kinematic equilibrium belt) controlling hydrocarbon accumulation,this model was adopted to predict favorable hydrocarbon accumulation areas and favorable exploration regions following structural destruction in three stages of oil filling, to provide guidance for further exploration of oil and gas in the Silurian of the Tarim basin.

  11. The Influence of fold and fracture development on reservoir behavior of the Lisburne Group of northern Alaska

    Energy Technology Data Exchange (ETDEWEB)

    Wesley K. Wallace; Catherine L. Hanks; Jerry Jensen: Michael T. Whalen; Paul Atkinson; Joseph Brinton; Thang Bui; Margarete Jadamec; Alexandre Karpov; John Lorenz; Michelle M. McGee; T.M. Parris; Ryan Shackleton

    2004-07-01

    The Carboniferous Lisburne Group is a major carbonate reservoir unit in northern Alaska. The Lisburne is folded and thrust faulted where it is exposed throughout the Brooks Range, but is relatively undeformed in areas of current production in the subsurface of the North Slope. The objectives of this study were to develop a better understanding of four major aspects of the Lisburne: (1) The geometry and kinematics of folds and their truncation by thrust faults. (2) The influence of folding on fracture patterns. (3) The influence of deformation on fluid flow. (4) Lithostratigraphy and its influence on folding, faulting, fracturing, and reservoir characteristics. Symmetrical detachment folds characterize the Lisburne in the northeastern Brooks Range. In contrast, Lisburne in the main axis of the Brooks Range is deformed into imbricate thrust sheets with asymmetrical hangingwall anticlines and footwall synclines. The Continental Divide thrust front separates these different structural styles in the Lisburne and also marks the southern boundary of the northeastern Brooks Range. Field studies were conducted for this project during 1999 to 2001 in various locations in the northeastern Brooks Range and in the vicinity of Porcupine Lake, immediately south of the Continental Divide thrust front. Results are summarized below for the four main subject areas of the study.

  12. Fluid pressure arrival time tomography: Estimation and assessment in the presence of inequality constraints, with an application to a producing gas field at Krechba, Algeria

    Energy Technology Data Exchange (ETDEWEB)

    Rucci, A.; Vasco, D.W.; Novali, F.

    2010-04-01

    Deformation in the overburden proves useful in deducing spatial and temporal changes in the volume of a producing reservoir. Based upon these changes we estimate diffusive travel times associated with the transient flow due to production, and then, as the solution of a linear inverse problem, the effective permeability of the reservoir. An advantage an approach based upon travel times, as opposed to one based upon the amplitude of surface deformation, is that it is much less sensitive to the exact geomechanical properties of the reservoir and overburden. Inequalities constrain the inversion, under the assumption that the fluid production only results in pore volume decreases within the reservoir. We apply the formulation to satellite-based estimates of deformation in the material overlying a thin gas production zone at the Krechba field in Algeria. The peak displacement after three years of gas production is approximately 0.5 cm, overlying the eastern margin of the anticlinal structure defining the gas field. Using data from 15 irregularly-spaced images of range change, we calculate the diffusive travel times associated with the startup of a gas production well. The inequality constraints are incorporated into the estimates of model parameter resolution and covariance, improving the resolution by roughly 30 to 40%.

  13. Estimating permeability from quasi-static deformation: Temporal variations and arrival time inversion

    Energy Technology Data Exchange (ETDEWEB)

    Vasco, D.W.; Ferretti, Alessandro; Novali, Fabrizio

    2008-05-01

    Transient pressure variations within a reservoir can be treated as a propagating front and analyzed using an asymptotic formulation. From this perspective one can define a pressure 'arrival time' and formulate solutions along trajectories, in the manner of ray theory. We combine this methodology and a technique for mapping overburden deformation into reservoir volume change as a means to estimate reservoir flow properties, such as permeability. Given the entire 'travel time' or phase field, obtained from the deformation data, we can construct the trajectories directly, there-by linearizing the inverse problem. A numerical study indicates that, using this approach, we can infer large-scale variations in flow properties. In an application to Interferometric Synthetic Aperture (InSAR) observations associated with a CO{sub 2} injection at the Krechba field, Algeria, we image pressure propagation to the northwest. An inversion for flow properties indicates a linear trend of high permeability. The high permeability correlates with a northwest trending fault on the flank of the anticline which defines the field.

  14. Late-stage Hydrocarbon Accumulation in the Bozhong Depression of the Bohai Bay Basin as Controlled by Neotectonism

    Institute of Scientific and Technical Information of China (English)

    GONG Zaisheng; ZHANG Gongcheng; CAI Dongsheng; HE Shibin

    2004-01-01

    Neotectonism occurred intensively in the Bozhong depression in the Bohai Bay Basin, which was reflected vertically by dramatic subsidence and a number of uplifts and laterally by notable fault movements. This particularity has resulted in the special petroleum geological conditions of the Bozhong depression which are different from those of adjacent lands. For example, the source rocks of the Shahejie Formation were overpressured and hydrocarbon generation occurred in the late stage; the Dongying Formation was deeply buried below the hydrocarbon-generating threshold,therefore there were sufficient oil sources. The rapid subsidence led to starved sedimentation of the Guantao Formation fine sandstone and the regional Minghuazhen Formation lacustrine shale, which formed the Neogene regional reservoircaprock association. The active faults formed in the neotectonism became passages for oil to migrate from the Paleogene to Neogene. The traps formed by late fault activity and accompanied anticlines provided spaces for the formation of reservoirs. All the above factors match well with one another in the Bozhong depression, providing favorable conditions for the formation of a series of large oilfields in the region

  15. The Fold Analysis Challenge: A virtual globe-based educational resource

    Science.gov (United States)

    De Paor, Declan G.; Dordevic, Mladen M.; Karabinos, Paul; Tewksbury, Barbara J.; Whitmeyer, Steven J.

    2016-04-01

    We present an undergraduate structural geology laboratory exercise using the Google Earth virtual globe with COLLADA models, optionally including an interactive stereographic projection and JavaScript controls. The learning resource challenges students to identify bedding traces and estimate bedding orientation at several locations on a fold, to fit the fold axis and axial plane to stereographic projection data, and to fit a doubly-plunging fold model to the large-scale structure. The chosen fold is the Sheep Mountain Anticline, a Laramide uplift in the Big Horn Basin of Wyoming. We take an education research-based approach, guiding students through three levels of difficulty. The exercise aims to counter common student misconceptions and stumbling blocks regarding penetrative structures. It can be used in preparation for an in-person field trip, for post-trip reinforcement, or as a virtual field experience in an online-only course. Our KML scripts can be easily transferred to other fold structures around the globe.

  16. On Geodynamic Evolution of Simao Region (Southwestern Yunnan, China) during Late Paleozoic and Triassic

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Over the last years, the Simao region, southwestern Yunnan, China, turned out to be a very promising target to elucidate plate-tectonic processes around the Permian-Triassic boundary within the Tethyan domain of Asia. New data from this area reveal that Upper Paleozoic compressional deformations occurred along the Lancangjiang and in areas to the east. Along Lancangjiang, an angular unconformity is exposed, which separates quartz-phyllites-formed during a Carboniferous tectono-metamorphic event-from Triassic red beds to roofing rhyolites. The acidic volcanics were often said to be remnants of a volcanic arc that was active during the Triassic subduction and closure of an oceanic realm along the Lancangjiang zone. According to our new data, however, these volcanics indicate most probably an Upper Triassic stage of rifting. In the Yunxian anticline (NW of Simao), an angular unconformity of intra-Permian age is exposed where Carboniferous to lower Middle Permian strata, which were deposited in a rather deep basin, are unconformably overlain by a shallow marine sequence of upper Middle to Upper Permian sediments. The angular unconformity is of the same age as the syn-orogenous sediments filst described and dated from the Phetchabun region in Thailand and hence a convincing argument for a Late Variscan orogeny forming an extensive zone of mountain-building that can be traced through the central parts of mainland Southeast-Asia.``

  17. Report on the geothermal development promotion survey. No.34. Kaminoyu/Santai area; Chinetsu kaihatsu sokushin chosa hokokusho. No. 34 Kaminoyu Santai chiiki

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1994-03-01

    The paper summed up the results of the geothermal development promotion survey 'Kaminoyu/Santai area' which was carried out at Yakumo town, Yamakoshi county, and Mori town, Kayabe county, Hokkaido, from FY 1990 to FY 1992. In the survey, the following were conducted for the comprehensive analysis: surface survey such as geology/alteration zone survey, geochemical survey and gravity exploration, test to induce jetting of geothermal fluids by drilling 7 boreholes, temperature/pressure log, etc. The geological structure of this area is featured by the uplift structure/caldera structure and the anticline structure. In the wide-area geothermal system, it is thought that the low-temperature seawater permeates underground by mixture with meteoric water, is heated, and forms the deep geothermal water. It is thought that the hot spring water in this area is stored in the hot spring reservoir by mixture with the surface water, and it is gushing. In the area, the region which is regarded as favorable as passage/storage place of geothermal fluid is a region of 1.5km width extending linearly in the E-W direction from the Nigorikawa basin to Kaminoyu. Further, it is thought that fractures were unfavorably developed in the Santai/Kaminoyu area. (NEDO)

  18. Olistostromes are the Source of Melange in Diapirs in the Cascadia-Olympics Accretionary Wedge , NW USA

    Science.gov (United States)

    Cowan, D. S.; Brandon, M. T.

    2011-12-01

    Diapirs consisting of block-in-matrix mélange are common in the ocean-ward part of the active Cascadia-Olympics wedge. Some of these bodies and similar Neogene mélanges ["Hoh mélange"] have been interpreted as having originated in shear zones related to accretion as oceanic crust of the Juan de Fuca plate was thrust beneath the wedge. However, this interpretation is untenable. The Hoh mélange contains fragments and blocks, ranging from centimeters to kilometers in size, of basalt. The chemistry of the basalt, and the microfossils in associated mudstone, prove that the basalt is Eocene: these basalts were derived from the Crescent Formation, not the much younger oceanic crust of the Juan de Fuca plate. The Crescent basalts originally formed the lid beneath which the Cascadia-Olympics wedge of sediments was underplated. Much of the lid has been eroded, but in Miocene time it extended to the coast and contributed fragments and blocks to muddy debris flows, which were deposited as olistostromes on the subducting Juan de Fuca plate. Younger sediments buried the olistostromes, which became overpressured and mobilized as mobile masses that have intruded as diapirs and anticlinal ridges. Analogous diapiric bodies, in the broad sense, are present in other active accretionary wedges, such as the in the Lesser Antilles.

  19. An integrated geophysical study wajid formation of water-bearing aquifers: Case study at Wadi Aldwasir area-Saudi Arabia

    Science.gov (United States)

    Alasmari, Abdulsalam; Suliman, Asim

    2015-04-01

    Wadi Aldwasir area is very important province in Saudi Arabia. It contains the main water aquifer that attains a proven groundwater reserve (Wajid aquifer). This study aims to investigate the subsurface features of this aquifer (thickness, depth to basement, overlying section and the structural elements) using an integrated gravity survey (2D profiles) and aeromagnetic interpretation (RTP, low pass and high-pass maps). Gravity data are measured in the field using CG-5 AutoGrav, while magnetic data are taken from a survey made by Saudi Geological Survey. The interpretation of aeromagnetic data revealed structural elements trending towards N-S, NNE-SSW, WNW and NNW-SSE directions. Positive magnetic anomalies are found indicating the presence of anticlinal blocks and strike-slip fault patterns. These structural elements are associated with the prevailing Najd fault and the transform fault systems. Gravity data showed that the depth to basement vary from 600 m to 1150 m, giving rise to a considerable range for aquifer thickness of 250 m to 700 m. Local basins of good thicknesses are indicated. Finally, a basement relief map is conducted based on an integrated interpretation of the magnetic and gravity outputs. It shows an increase of depth from south to north (good aquifer thickness).

  20. On the tectonics and metallogenesis of West Africa: a model incorporating new geophysical data

    Science.gov (United States)

    Hastings, David A.

    1982-01-01

    The gold, diamond and manganese deposits of Ghana have attracted commercial interest, but appropriate geophysical data to delineate the tectonic setting of these and other deposits have been lacking until recently. Recent gravity surveys, however, now cover about 75% of the country. When used in a synthesis of the sometimes contradictory existing theories about the geology and metallogenesis of West Africa, the available gravity, magnetic, and seismic data lead to a preliminary tectonic model that postulates rifting at the time of the (1800-2000 m.y. old) Eburnean orogeny and is consistent with the occurrences of mineral deposits in the region. In this model, diamond-bearing kimberlites formed during the commencement of rifting during the Eburnean orogenesis. Later emplacement of kimberlites was associated with the initiation of Mesozoic rifting of Gondwanaland. Primary gold vein deposits were probably formed by the migration of hydrothermal fluids (associated with the formation of granitoids) into dilatant zones, such as rift-related faults and anticlinal axial areas, toward the end of the Eburnean orogeny. At this time, the major concordant granitoids were formed, with smaller plutonic granitoids forming on the fringes of the concordant masses as partial melting fractions of the latter. Sedimentary manganese deposits were formed along the margins of rift lakes toward the end of the orogeny.

  1. Paleostress field reconstruction and revised tectonic history of the Donbas fold and thrust belt (Ukraine and Russia)

    Science.gov (United States)

    Saintot, Aline; Stephenson, Randell; Brem, Arjan; Stovba, Sergiy; Privalov, Vitaliy

    2003-10-01

    In the WNW-ESE Donbas fold belt (DF), inversion of 3500 microtectonic data collected at 135 sites, in Proterozoic, Devonian, Carboniferous, and Cretaceous competent rocks allowed reconstruction of 123 local stress states. Accordingly, four successive paleostress fields reveal the tectonic evolution of the DF. At the numerous sites that have been affected by polyphase tectonics, the chronology between local paleostress states (also paleostress fields) was established using classical criteria (crosscutting striae, pre- or post-folding stress states, stratigraphic control). The oldest event is an extensional stress field with NNE-SSW σ3. It corresponds to the rifting phases that generated the basin in Devonian times and its early Visean reactivation. Later, the DF was affected by a transtension, with NW-SE σ3 characterizing Early Permian tectonism, including the development of the "Main Anticline" of the DF and the pronounced uplift of its southern margin and Ukrainian Shield. Two paleostress fields characterize the Cretaceous/Paleocene inversion of the DF, which was accompanied by folding and thrusting. Both are compressional in type but differ by the trend of σ1, which was first NW-SE and subsequently N-S. The discrete paleostress history of the DF allows a revised interpretation of its tectonic evolution with significant implications for understanding the geodynamic evolution of the southern margin of the East European Craton.

  2. Pharmacobotanical study of the leaf and stem of Mikania lanuginosa for its quality control

    Directory of Open Access Journals (Sweden)

    Mariana Amorin

    2014-10-01

    Full Text Available Mikania lanuginosa DC, Asteraceae, is popularly known as "cipó-cabeludo" in Brazil due to a remarkable number of trichomes on its leaves and stems. It shows antimicrobial activity against Staphylococcus aureus, S. epidermidis and Bacillus cereus. This species can be confused with M. microlepis Baker and M. hirsutissima DC for substitution and tampering purposes. The aim of this study was to investigate the morpho-anatomy of leaf and stem of M. lanuginosa to obtain pharmacobotanical data that may contribute to its identification and taxonomic definition from other species of Mikania. The leaves and stems were investigated using scanning electron microscopy and light microscopy techniques. Mikania lanuginosa shows a uniseriate epidermis covered by a thin and smooth cuticle. The epidermal cells present sinuous anticlinal walls on both sides and anomocytic stomata were observed. A few glandular trichomes and numerous non-glandular trichomes were identified on both surfaces. The mesophyll is dorsiventral, the midrib has a biconvex contour and the petiole shows a circular shape in a cross-section. The stem has a circular shape. These pharmacobotanical features described for M. lanuginosa support data for its identification and taxonomic delimitation from other Mikania species, and are a contribution for the quality control of herbal drugs.

  3. Geometry of the inverted Cretaceous Chañarcillo Basin based on 2-D gravity and field data. An approach to the structure of the western Central Andes of northern Chile

    Directory of Open Access Journals (Sweden)

    F. Martínez

    2015-08-01

    Full Text Available This paper discusses an integrated approach that provides new ideas about the structural geometry of the NNE-striking, Cretaceous Chañarcillo Basin located along the eastern Coastal Cordillera in the western Central Andes of northern Chile (27–28° S. The results obtained from the integration of two transverse (E–W gravity profiles with previous geological information, show that the architecture of this basin is defined by a large NNE–SSE-trending and east-vergent anticline ("Tierra Amarilla Anticlinorium", which is related to the positive reactivation of a former Cretaceous normal fault (Elisa de Bordos Master Fault. Moreover, intercalations of high and low gravity anomalies and steep gravity gradients reveal a set of buried, west-tilted half-grabens associated with a synthetic normal fault pattern. These results, together with the uplift and folding style of the Cretaceous syn-rift recognized within the basin, suggest that their complete structural geometry could be explained by an inverted fault system linked to the shortening of pre-existing Cretaceous normal fault systems. Ages of the synorogenic deposits exposed unconformably over the frontal limb of the Tierra Amarilla Anticlinorium confirm a Late Cretaceous age for the Andean deformation and tectonic inversion of the basin.

  4. Comparative study of three Marantodes pumilum varieties by microscopy, spectroscopy and chromatography

    Directory of Open Access Journals (Sweden)

    Nor-Ashila Aladdin

    2016-02-01

    Full Text Available Abstract Marantodes pumilum (Blume Kuntze (synonym: Labisia pumila (Blume Fern.-Vill, Primulaceae, is well known for its traditional use as a post-partum medication among women in Malaysia. Three varieties of M. pumilum, var. alata Scheff., var. pumila and var. lanceolata (Scheff. Mez. are commonly used. Nowadays, M. pumilum powder or extracts are commercially available as herbal supplements and beverages. Authentication of the variety is an important component of product quality control. Thus, the present work was aimed to compare the three varieties using microscopic, spectroscopic and chromatographic techniques. Microscopic anatomical examination and powder microscopy were performed on fresh and dried plant materials, respectively. Fingerprint profiles of the varieties were obtained using attenuated total reflectance-Fourier transform infrared spectrophotometer, high performance thin layer chromatography and high performance liquid chromatography. The microscopic examination showed presence of anisocytic stomata, scale and capitate glandular trichome in all varieties. The type of stomata and trichomes, outline structure of stem and leaf margin, petiole and midrib, organization of vascular system, areolar venation, pattern of anticlinal walls, the distribution of secretory canals and cell inclusion as well as the measurement of selected structures could be used to distinguish and identify each variety of M. pumilum. In addition, spectroscopic and chromatographic fingerprint analyses of the three varieties exhibited distinguishable profiles based on the intensity of certain peaks or bands. The findings from this study will provide systematic identification for these varieties.

  5. Consolidation of geologic studies of geopressured geothermal resources in Texas. 1982 annual report

    Energy Technology Data Exchange (ETDEWEB)

    Morton, R.A.; Ewing, T.E.; Kaiser, W.R.; Finley, R.J.

    1983-03-01

    Detailed structural mapping at several horizons in selected study areas within the Frio growth-fault trend demonstrates a pronounced variability in structural style. At Sarita in South Texas, shale mobilization produced one or more shale ridges, one of which localized a low-angle growth fault trapping a wedge of deltaic sediments. At Corpus Christi, shale mobilization produced a series of large growth faults, shale-cored domed anticlines, and shale-withdrawal basins, which become progressively younger basinward. At Blessing, major growth faults trapped sands of the Greta/Carancahua barrier system with little progradation. At Pleasant Bayou, a major early growth-fault pattern was overprinted by later salt tectonics - the intrusion of Danbury Dome and the development of a salt-withdrawal basin. At Port Arthur, low-displacement, long-lived faults formed on a sand-poor shelf margin contemporaneously with broad salt uplifts and basins. Variability in styles is related to the nature and extent of Frio sedimentation and shelf-margin progradation and to the presence or absence of salt. Structural styles that are conducive to the development of large geothermal reservoirs include blocks between widely spaced growth faults having dip reversal, salt-withdrawal basins, and shale-withdrawal basins. These styles are widespread on the Texas Gulf Coast. However, actually finding a large reservoir depends on demonstrating the existence of sufficient sandstone with adequate quality to support geopressured geothermal energy production.

  6. Relative tectonic activity classification in Kermanshah area, west Iran

    Directory of Open Access Journals (Sweden)

    M. Arian

    2014-07-01

    Full Text Available The High Zagros region because of closing to subduction zone and the collision of the Arabian and Eurasian plates is imposed under the most tectonic variations. In this research, Gharasu river basin that it has located in Kermanshah area was selected as the study area and 6 geomorphic indices were calculated and the results of each ones were divided in 3 classes. Then, using the indices, relative tectonic activity was calculated and the values were classified and analyzed in 4 groups. Regions were identified as very high, high, moderate and low. In analyzing the results and combining them with field observation and regional geology the results are often associated and justified with field evidences. The highest value is located on Dokeral anticline in crush zone in Zagros Most of the areas with high and moderate values of lat are located on crush zone in Zagros too. Crushing of this zone is because of main faults mechanism of Zagros region. The result of this paper confirms previous researches in this region. At the end of the eastern part of the study area, the value of Iat is high that could be the result of Sarab and Koh-e Sefid faults mechanism.

  7. Stratigraphic and structural framework of ellesmerian and older sequences in Sadlerochit and Shublik Mountains, Arctic National Wildlife Refuge (ANWR), northeastern Alaska

    Energy Technology Data Exchange (ETDEWEB)

    Robinson, M.S.; Decker, J.; Clough, J.G.; Dillon, J.T.

    1988-01-01

    Detailed geological mapping (1:25,000 scale) and stratigraphic reconstructions in the Sadlerochit and Shublik Mountains of northeastern Alaska, immediately south of the ANWR coastal plain, indicate a compressive structural province dominated by major thrust-ramp-related anticlinal uplifts. The Katakturuk Dolomite, a Proterozoic sequence, has been subdivided into 15 lithostratigraphic units that can be traced the entire length of both the Sadlerochit and Shublik Mountains. Overlying the Katakturuk Dolomite in these ranges in the Middle Devonian to Cambrian or older Nanook Limestone. In the Early Mississippian a major erosional event produced the pre-Mississippian unconformity upon which a Mississippian through Triassic sequence was deposited: Kayak Shale; Lisburne Group carbonates; and Sadlerochit Group clastic rocks. In the northern Sadlerochit Mountains, basal units of the Mississippian Alapah Limestone lie on the pre-Mississippian unconformity with no intervening Kayak Shale. The basal Alapah contains lithologies derived from the rock units on which it rests, indicating that the contact between the Alapah and the underlying units is depositional.

  8. Stratigraphic and structural framework of Ellesmerian and older sequences in Sadlerochit and Shublik Mountains, Arctic National Wildlife Refuge (ANWR), northeastern Alaska

    Energy Technology Data Exchange (ETDEWEB)

    Robinson, M.S.; Decker, J.; Clough, J.G.; Dillon, J.T.; Wallace, W.K.; Crowder, K.; Watts, K. (Alaska Division of Geological and Geophysical Surveys, Fairbanks (USA))

    1988-02-01

    Detailed geological mapping (1:25,000 scale) and stratigraphic reconstructions in the Sadlerochit and Shublik Mountains of northeastern Alaska, immediately south of the ANWR coastal plain, indicate a compressive structural province dominated by major thrust-ramp-related anticlinal uplifts. The Katakturuk Dolomite, a Proterozoic sequence, has been subdivided into 15 lithostratigraphic units that can be traced the entire length of both the Sadlerochit and Shublik Mountains. Overlying the Katakturuk Dolomite in these ranges is the Middle Devonian to Cambrian or older Nanook Limestone. In the Early Mississippian a major erosional event produced the pre-Mississippian unconformity upon which a Mississippian through Triassic sequence was deposited: (A) Kayak Shale; (B) Lisburne Group carbonates; and (C) Sadlerochit Group clastic rocks. In the northern Sadlerochit Mountains, basal units of the Mississippian Alapah Limestone lie on the pre-Mississippian unconformity with no intervening Kayak Shale. The basal Alapah contains lithologies derived from the rocks units on which it rests, indicating that the contact between the Alapah and the underlying units is depositional. A regional decollement, localized along the pre-Mississippian unconformity in the Kayak Shale, is not a significant detachment surface north of the Shublik Mountains because the Kayak Shale is depositionally discontinuous and thin in the Sadlerochit Mountains.

  9. Geothermal investigations in Idaho. Part 12. Stable isotopic evaluation of thermal water occurrences in the Weiser and Little Salmon River drainage basins and adjacent areas, west-central Idaho with attendant gravity and magnetic data on the Weiser area

    Energy Technology Data Exchange (ETDEWEB)

    Mitchell, J.C.; Bideganeta, K.; Palmer, M.A.

    1984-12-01

    Fifteen thermal springs, two thermal wells, and eight cold springs in the Weiser and Little Salmon river drainages were sampled for deuterium and oxygen-18 analysis during the fall of 1981. The straight-line fit of delta D and delta /sup 18/O versus latitude and longitude observed in the data is what would be expected if the recharge areas for the thermal and non-thermal waters were in close proximity to their respective discharge points. The discrete values of delta D and delta /sup 18/O for each thermal discharge suggest that none of the sampled thermal systems have common sources. The depleted deuterium and oxygen-18 contents of most thermal relative to non-thermal waters sampled suggests that the thermal waters might be Pleistocene age precipitation. The isotopic data suggest little or no evidence for mixing of thermal and non-thermal water for the sampled discharges. Thermal waters from Weiser, Crane Creek, Cove Creek, and White Licks hot springs show enrichment in oxygen-18 suggesting that these waters have been at elevated temperatures relative to other sampled thermal discharges in the area. Gravity and magnetic data gathered by the Idaho State University Geology Department in the Weiser Hot Springs area suggest that southeastward plunging synclinal-anticlinal couples, which underlie the hot springs, are cut south of the springs by a northeast trending boundary fault.

  10. Sedimentary facies and hydrocarbon accumulation in the Third member of Shahejie Formation in Beijing-Tianjin Depression

    Energy Technology Data Exchange (ETDEWEB)

    Jin, X.; Zhang, Z.

    1986-01-01

    The exploration practice in the Beijing-Tianjin area shows that the key point of improving seismic interpretation level in a complex district lies in the high accuracy of seismic work, extraction of available seismic information and the use of the comprehensive interpretation method basing on both structure interpretation and seismic stratigraphy. This paper presents the geological interpretation results of analyzing the Third member of Shahejie Formation in Beijing-Tianjin Depression by using the method stated above. It describes the seismic facies, sedimentary facies as well as the generation, accumulation and distribution of hydrocarbons, and points out that the lower part of the member is a subaqueous fan and point bar deposit, while the middle part is a fan-delta deposit. According to the thermo-evolution-profile and TTI estimated, it is assumed that the lower part of the member is source rock with sandstone development and is also a very good reservoir rock because of having two sets of source rock reservoir and seal rock. Having structures such as Jiuzhou anticline and its down dip and Liuquan fault structure, it is favorable for hydrocarbon accumulation. 4 figures.

  11. INTEGRATION OF PALSAR AND ASTER SATELLITE DATA FOR GEOLOGICAL MAPPING IN TROPICS

    Directory of Open Access Journals (Sweden)

    A. Beiranvand Pour

    2015-10-01

    Full Text Available This research investigates the integration of the Phased Array type L-band Synthetic Aperture Radar (PALSAR and the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER satellite data for geological mapping applications in tropical environments. The eastern part of the central belt of peninsular Malaysia has been investigated to identify structural features and mineral mapping using PALSAR and ASTER data. Adaptive local sigma and directional filters were applied to PALSAR data for detecting geological structure elements in the study area. The vegetation, mineralogic and lithologic indices for ASTER bands were tested in tropical climate. Lineaments (fault and fractures and curvilinear (anticline or syncline were detected using PALSAR fused image of directional filters (N-S, NE-SW, and NW-SE.Vegetation index image map show vegetation cover by fusing ASTER VNIR bands. High concentration of clay minerals zone was detected using fused image map derived from ASTER SWIR bands. Fusion of ASTER TIR bands produced image map of the lithological units. Results indicate that data integration and data fusion from PALSAR and ASTER sources enhanced information extraction for geological mapping in tropical environments.

  12. Fractal interrelationship in field and seismic data. Fifth quarterly technical report, March 21--June 21, 1996

    Energy Technology Data Exchange (ETDEWEB)

    Wilson, T.H.; Dominic, J.; Halverson, J.

    1996-12-31

    The primary goal of this study is to evaluate the possibility that the fractal characteristics of reservoir fracture systems might be inferred from the fractal characteristics of the reservoir reflector. Results discussed in the summary below provide support for such a view. The matter will, however, remain unresolved until fracture data acquired from core or FMS logs can be compared to reflection seismic data from the core areas. A series of cross sections along the Middle Mountain syncline and Elkhorn Mountain anticline were evaluated. Near-surface deformation in the Middle Mountain and Elkhorn mountain area of the Valley and Ridge province is significant. In this area the fractal dimension of topography is linearly related to the fractal dimension of underlying structure. Comparison of the fractal variability of Valley and Ridge structures with those observed in seismic data from the Plateau indicate that the increased fractal dimension of reflection events implies greater relative abundance of higher order or smaller wavelength structures. Results from the seismic evaluation suggest that fractal analysis might provide a useful exploration tool in cases where one is interested in locating subtle detached structures or identifying fractured reservoirs. Results from the Valley and a Ridge area suggest that, in active tectonic areas, fractal analysis may provide a means to assess the relative frequency of earthquake activity over time periods that extend beyond the historical record.

  13. The distribution of the oil derived from Cambrian source rocks in Lunnan area, the Tarim Basin, China

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    There are great differences in biomarks between Cambrian oil and Middle-Upper Ordoviclan oil. In this stuty, the authors analyzed 40 oils found in Lunnan area by GC-MS and calculated the content of Cambrian oil in the 40 oils according to the steroid indexes of typical oil mixture and match experiment. The results show that it is a general phenomenon in Ordovician reservoir that the oil derived from Cambrian source rock mixed with the oil derived from Middle-Upper Ordovician source rock in Lunnan area, the mixture degree of the two oils is lower in Carboniferous reservoir than in Ordovician reservoir, and the oils kept in Triassic reservoir have single source, Middle-Upper Ordovician source rock. The mixture oils mainly composed of Cambrian oil (>50%) distributed in Sangtamu fault zone, and the oils found in Lunnan fault zone are Middle-Upper Ordovician oil. This distribution of oils in Lunnan area is owing to that Lunnan fault zone is located in anticline axis part, Lunnan fault zone underwent serious erosion, and the oils from Cambrian source rock accumulated in Lunnan fault zone were degraded completely during Caledonian-Hercynian movement. But the Cambrian oil accumulated in Sangtamu fault zone was not degraded completely and some of them were left for the location of Sangtamu fault zone is lower than Lunnan fault zone. Later, the oil derived from Middle-Upper Ordovician source rock mixed with the remained Cambrian oil, and the mixture oil formed in Sangtamu fault zone.

  14. Analysis of deep seismic reflection and other data from the southern Washington Cascades. Final report, September 15, 1992--December 31, 1993

    Energy Technology Data Exchange (ETDEWEB)

    Stanley, W.D.; Johnson, S.Y.; Nuccio, V.F.

    1993-12-01

    This report describes results of a synthesis of geological, geological, geophysical and geochemical data from a largely volcanic rock covered region in southwestern Washington that has been identified as a underlain by thick marine sedimentary rocks. The work was funded by the Deep Source Gas projects at the Morgantown Energy Technology Center (METC). The subproject which resulted in this report is centered in the Branch of Geophysics, US Geological Survey (USGS) has involved one task focused on the application of geophysical methods to the study of phenomena associated with fossil and active subduction zones and non-subduction suture zones that may have deeply emplaced sedimentary rocks. This report represents a summary synthesis of several geophysical and geological data sets. The Southern Washington Cascades Conductor (SWCC) has been examined using several types of data in addition to MT, seismic, magnetic, and gravity Specific geological mapping tasks have been completed trough funding by the Department of Energy and the USGS in the western part of the proposed basin near Morton, WA. Other regional geological studies using wells and outcrops done as part of the USGS Evolution of Sedimentary Basins programs have added information that constraint the possible nature of the SWCC rocks and their tectonic setting. Recently, evaluation of patterns of seismicity in the SWCC region has demonstrated the likelihood of several parallel and step-over strike-slip faults that may have produced the proposed basin or altered its geometry. In addition, the seismicity patterns trace the axis of key anticlinal structures and thrusts.

  15. Time domain electromagnetic method for petroleum exploration. Part 3. Case study in Yoneyama area; Sekiyu tansa ni okeru TDEM ho data shutoku to kaiseki ni tsuite. 3. Niigataken Yoneyama chiiki deno tekiyorei

    Energy Technology Data Exchange (ETDEWEB)

    Ishikawa, H.; Mitsuhata, Y. [Japan National Oil Corp., Tokyo (Japan); Shiga, N. [Mitsui Mineral Development Engineering Co. Ltd., Tokyo (Japan)

    1996-05-01

    The result is reported of a TDEM method-based survey for oil exploration conducted in the Yoneyama district, Niigata Prefecture. The survey covered the southern part of the sedimentary basin in the prefecture, known for the poor quality of the seismic prospecting data that had been recorded. The purpose of the TDEM method-assisted survey was to probe the high-resistivity volcanic rock structure and low-resistivity sedimentary layer, and to know their details. The obtained data were subjected to interpretation by use of the 1D inversion method. A 4000m-deep level was subjected to interpretation, 34 data were inputted, and the early model consisted of 20 layers. As the result, it was found that there was a high-resistivity layer ranging from the ground surface down to a depth of approximately 500m, that a low-resistivity layer 2500-3000m in thickness lay thereunder, and that the lowest layer had a high resistivity of approximately 100 Ohm m. By comparing these data with the geological structure, structures were disclosed corresponding to the rock bed depth, Ukawa syncline, Ishiguro anticline, and Yoneyama mountain mass. 3 refs., 10 figs., 1 tab.

  16. New ages and chemical analysis on Lower Jurassic volcanism close to the dorsal de Huincul, Neuquén

    Directory of Open Access Journals (Sweden)

    Mario SCHIUMA

    2008-12-01

    Full Text Available New single zircon ages from hydrocarbon well cores in the A-1 Norte de la Dorsal and Anticlinal Campamento area of the Neuquén basin indicate that 199.0 ± 1.5 Ma andesite lava flow and 203.75 ± 0.26 Ma dacite breccia overlie a 286.5 ± 2.3 Ma granodiorite and 284.0 ± 1.3 Ma andesite dike. The Lower Jurassic volcanics were deposited on a regional erosion surface affecting the Permian rocks. In the studied area there is no record of Middle to Upper Triassic volcanics as in other areas of the basin. Exotic zircon crystals gave ages of Mesoproterozoic, Middle Cambian, Early Devonian and Early Carboniferous, suggesting a poliphasic basement. Chemical analyses of three selected samples show a calc-alkaline signature, supporting the existence of a volcanic arc at the Early Jurassic as it has been proposed for the center of the basin.

  17. Pliocene-Quaternary contourite depositional system along the south-western Adriatic margin: changes in sedimentary stacking pattern and associated bottom currents

    Science.gov (United States)

    Pellegrini, Claudio; Maselli, Vittorio; Trincardi, Fabio

    2016-02-01

    The Pliocene-Quaternary history of the south-western Adriatic margin, represented by a complex contourite depositional system, records the palaeoceanography of the basin and the interactions between oceanographic processes and the uneven slope morphology that resulted from tectonic deformation. Three main stages can be recognized: (1) during the Pliocene, a giant sediment drift formed on the southern flank of the slope-transverse Gondola anticline that focused and accelerated the flow of slope-parallel bottom currents; (2) since the early to middle Pleistocene transition, a reorganization of bottom-current pathways led to a sharp change in the sedimentary architecture of the margin that became dominated by the growth of contourite deposits; (3) as of 350 ka, landward-migrating contourites on the outer shelf (less than 120 m water depth) reflect the presence of bottom currents also in shallow waters. This analysis of the sedimentary stacking pattern of the contourite depositional system that developed along the south-western Adriatic margin since the Pliocene enables disentangling the processes that controlled changes in bottom-current activity, demonstrating that bottom-current deposits constitute the bulk of depositional sequences at the Milankovitch timescale.

  18. Morphostructural record of iron deposits in paleosols, cretaceous Nubia Sandstone of Lake Naser basin, Egypt, Western Desert, Egypt

    Directory of Open Access Journals (Sweden)

    S.M. Salem

    2013-06-01

    Full Text Available The use of processed Landsat ETM + images and the application of geomorphotectonic concepts supplemented by extensive geological field work enabled the effective record of iron occurrences in the area located to the west of Lake Nasser. Three clearly newly differentiated landforms are evaluated for the possible presence of iron occurrences. Each landform is controlled by a specific tectonic environment and includes one of the three stratigraphic formations hosting iron deposits in the area. These landforms are: Area 1 (Kurkur landform, including plunging anticlines and domes affecting the Abu Aggag Formation. This formation is unconformably overlain by horizontal sandstone beds belonging to the Temsah Formation. The unconformity surface includes paleosols rich in limonite, crystallized gypsum in the form of roses and clay minerals. Area 2 (Tushka landform extends to the south of the Allaqi fault. The area includes yardangs carved in horizontal sandstone beds interstratified with some hematite bed, in addition to several fragments of hematite and magnetite as wadi deposits and desert varnish. Area 3 (Abu Simbel landform includes conical hills constituted by flattened horizontal beds belonging to the El Burg Formation. Each hill is capped by thick hematite/magnetite beds extending from Tushka to the border with Sudan. The Nubia Sandstone, here, includes three formations, namely: the Abu Aggag, Temsah, and Um Baramil.

  19. Geology, Murzuk oil development could boost S. W. Libya prospects

    Energy Technology Data Exchange (ETDEWEB)

    Thomas, D. (Thomas and Associates, Hastings (United Kingdom))

    1995-03-06

    With the recent involvement of Repsol, Total, and OMV in developing the 2 billion bbl oil-in-place Murzuk field complex, an infrastructure will be finally constructed in western Libya which will act as a precursor to more exploration activity and development projects in the Murzuk and Ghadames basins. Murzuk, an intra-cratonic sag basin, is a huge ladle-shaped structural basin covering more than 400,000 sq km and extending beyond the borders of southern Libya. The structure of the area is quite simple. The sub-horizontal or gently dipping strata are faulted and the faults are most frequently parallel to the anticlinal axis. Tectonic movements affected the basin to a greater or lesser degree from early Paleozoic (Caledonian) to post-Eocene (Alpine) times. The paper describes the exploration history; stratigraphy; the Ordovician, Silurian and Devonian, and Carboniferous reservoirs; source rocks; oil gravity and gas content; hydrogeologic constraints; aquifer influence on hydrocarbon accumulation; geologic structures; Murzuk field development; and acreage availability.

  20. Petroleum systems of the Malay Basin Province, Malaysia

    Science.gov (United States)

    Bishop, Michele G.

    2002-01-01

    The offshore Malay Basin province is a Tertiary oil and gas province composed of a complex of half grabens that were filled by lacustrine shales and continental clastics.These deposits were overlain by clastics of a large delta system that covered the basin.Delta progradation was interupted by transgressions of the South China Sea to the southeast, which finally flooded the basin to form the Gulf of Thailand.Oil and gas from the Oligocene to Miocene lacustrine shales and Miocene deltaic coals is trapped primarily in anticlines formed by inversion of the half grabens during the late Miocene.Hydrocarbon reserves that have been discovered amount to 12 billion barrels of oil equivalent.The U.S. Geological Survey assessment of the estimated quantities of conventional oil, gas and condensate that have the potential to be added to reserves by the year 2025 for this province is 6.3 billion barrels of oil equivalent (BBOE) (U. S. Geological Survey World Energy Assessment Team, 2000).

  1. Integration of Seismic and Petrophysics to Characterize Reservoirs in “ALA” Oil Field, Niger Delta

    Directory of Open Access Journals (Sweden)

    P. A. Alao

    2013-01-01

    Full Text Available In the exploration and production business, by far the largest component of geophysical spending is driven by the need to characterize (potential reservoirs. The simple reason is that better reservoir characterization means higher success rates and fewer wells for reservoir exploitation. In this research work, seismic and well log data were integrated in characterizing the reservoirs on “ALA” field in Niger Delta. Three-dimensional seismic data was used to identify the faults and map the horizons. Petrophysical parameters and time-depth structure maps were obtained. Seismic attributes was also employed in characterizing the reservoirs. Seven hydrocarbon-bearing reservoirs with thickness ranging from 9.9 to 71.6 m were delineated. Structural maps of horizons in six wells containing hydrocarbon-bearing zones with tops and bottoms at range of −2,453 to −3,950 m were generated; this portrayed the trapping mechanism to be mainly fault-assisted anticlinal closures. The identified prospective zones have good porosity, permeability, and hydrocarbon saturation. The environments of deposition were identified from log shapes which indicate a transitional-to-deltaic depositional environment. In this research work, new prospects have been recommended for drilling and further research work. Geochemical and biostratigraphic studies should be done to better characterize the reservoirs and reliably interpret the depositional environments.

  2. Electro-optical and dielectric properties of a high tilt antiferroelectric liquid crystal mixture (W-193B)

    Energy Technology Data Exchange (ETDEWEB)

    Nayek, Prasenjit; Ghosh, Sharmistha; Kundu, Sudarshan; Roy, Subir Kr [Department of Spectroscopy, Indian Association for the Cultivation of Science, Jadavpur, Calcutta-700032 (India); Majumder, Tapas Pal [Department of Physics, University of Kalyani, Kalyani-741235, West Bengal (India); Bennis, Noureddine; Oton, Jose Manuel [Department of TecnologIa Fotonica, ETSI Telecomunicacion, Universidad Politecnica de Madrid, Ciudad Universitaria, 28040 Madrid (Spain); Dabrowski, Roman, E-mail: spskr@iacs.res.i [Institute of Chemistry, Military University of Technology, 00-908 Warsaw (Poland)

    2009-11-21

    The electro-optical properties and dielectric relaxation have been investigated for an antiferroelectric liquid crystal mixture W-193B. The material exhibits smectic A*, smectic C* and a wide range of anticlinic smectic C{sub A}{sup *} phases. The high tilt and broad room temperature smectic C{sub A}{sup *} phase make it a good candidate for antiferroelectric display materials. Dielectric studies have been made in a planarly aligned cell in the frequency range 10 Hz-13 MHz. Dielectric spectroscopy reveals the existence of soft mode in the smectic A* phase and Goldstone mode in the smectic C* phase. In the smectic C{sub A}{sup *} phase the dielectric spectrum of the material exhibits two absorption peaks related to the rotational fluctuation around the short axis of the molecules and antiphase azimuthal angle fluctuation, respectively, and are separated by about two orders of frequency. Electro-optical response using a low frequency triangular wave showed a very high quasi-static contrast ratio of 132 : 1, threshold voltage of around 7 V and saturation of 17 V. Surface-stabilized, low thickness cells of this mixture showed a perfect double hysteresis loop with a 1 Hz triangular signal, reaching different transmission levels for different voltage amplitudes. These levels can be stabilized with a single holding voltage, making it possible for the material to be passively multiplexed at video rate.

  3. Morphological, Anatomical and Palynological Studies on Endemic Matthiola anchoniifolia Hub. -Mor. (Brassicaceae

    Directory of Open Access Journals (Sweden)

    Mehmet TEKIN

    2013-05-01

    Full Text Available In this paper, anatomical, palynological and seed micromorphological properties of an endemic plant Matthiola anchoniifolia Hub.-Mor. are recorded for the first time. A description and descriptive illustrations of the species are given based on the collected specimens for morphological study. Seed surface of M. anchoniifolia is examined by scanning electron microscope. The seed of M. anchoniifolia was compressed, brownish in colour and the cells of testa were nearly 60-80 μm in diameter and ranged from isodiametric, tetragonal or pentagonal. The anticlinal walls were straight or weakly curved while the outer periclinal walls were concave to flat with smooth surface. In anatomical study, cross sections of root, stem and stem leaf are examined. The root had secondary structure. Periderm consists of 5-8 layers of cells for phellem. Cortex consists of 9-12 layered parenchymatic tissue under the periderm. Secondary phloem ring-shaped, 6-9 layered and consists of companion cells and grouped sieve tubes. Stem had primary structure when analyzed. It is circular with a few irregular ribs in cross section. Cortex is 8-12 layered and parenchymatous. Stoma cells are present on both epidermis. Leaf is isobilateral. There are unicellular and ramified hairs on both surface. Palisade parenchyma cells are 1-2 layered and spongy parenchyma cells are 5-12 layered. M. anchoniifolia has tricolpate pollen type, prolate pollen shape and reticulate exine ornamentation.

  4. Magnetic properties of the remagnetized Middle-Ordovician limestones of the Ponón Trehué Formation (San Rafael Block, central-western Argentina): Insights into the Permian widespread Sanrafaelic overprint

    Science.gov (United States)

    Fazzito, Sabrina Y.; Rapalini, Augusto E.

    2016-10-01

    The widespread Sanrafaelic remagnetization reset most of the early Cambrian to mid-Ordovician carbonate platform of the Argentine Precordillera and the calcareous units of the San Rafael Block. We conducted a detailed rock-magnetic study on the Middle-Ordovician limestones of the Ponón Trehué Formation at both limbs of a tight anticline exposed in the San Rafael Block (Mendoza province, central-western Argentina) that are carriers of a syntectonic magnetization of Permian age. We found that the magnetic overprint in the Ponón Trehué Formation is carried by both pyrrhotite and magnetite, with goethite and subordinate haematite likely related to weathering. Hysteresis parameters, frequency dependence of magnetic susceptibility, Cisowski and modified Lowrie-Fuller tests suggest the presence of ultrafine particles of chemical origin. Demagnetization of natural remanent magnetization and of three-axis isothermal remanence confirm pyrrhotite and magnetite as important contributors to the remanence. Both minerals carry the same magnetic syntectonic component suggesting a coeval or nearly coeval remanence acquisition and therefore mineral formation. This and the results of the magnetic fabric analyses indicate an authigenic origin of the magnetic minerals during folding associated with the Sanrafaelic tectonic phase (ca. 280 Ma). Although the chemically active (oxidizing?) fluids expelled from the orogen as it developed in the early Permian is a viable explanation for the Sanrafaelic remagnetization, the role of the nearly coeval magmatism in Precordillera and the San Rafael Block remains to be properly evaluated.

  5. Hydrogeological investigation of shallow aquifers in an arid data-scarce coastal region (El Daba'a, northwestern Egypt)

    Science.gov (United States)

    Yousif, Mohamed; van Geldern, Robert; Bubenzer, Olaf

    2016-02-01

    Hydrogeological investigations in arid regions are particularly important to support sustainable development. The study area, El Daba'a in northwestern Egypt, faces scarce water resources as a result of reported climate change that particularly affects the southern Mediterranean coast and increases stress on the local groundwater reserves. This change in climate affects the area in terms of drought, over-pumping and unregulated exploration of groundwater for irrigation purposes. The hydrogeological investigation is based on a multidisciplinary data-layer analysis that includes geomorphology, geology, slope, drainage lines, soil type, structural lineaments, subsurface data, stable isotopes, and chemical analyses. The study area contains Pleistocene and middle Miocene marine limestone aquifers. Based on lithology and microfacies analysis, the middle Miocene aquifer is subdivided into two water-bearing zones. The area is affected by sets of faults and anticline folds, and these structures are associated with fractures and joints that increase permeability and facilitate the recharge of groundwater. Stable isotope data indicate that groundwater of both the Pleistocene and middle Miocene aquifers is recharged by modern precipitation. The high salinity values observed in some groundwater wells that tap both aquifers could be attributed to leaching and dissolution processes of marine salts from the aquifers' marine limestone matrix. In addition, human activities can also contribute to an increase in groundwater salinity. A future water exploration strategy, based on the results from the multidisciplinary data-layer analysis, is proposed for the area. The derived scientific approach is transferable to other arid coastal areas with comparable conditions.

  6. Styles of neotectonic fault reactivation within a formerly extended continental margin, North West Shelf, Australia

    Science.gov (United States)

    Whitney, Beau B.; Hengesh, James V.; Gillam, Dan

    2016-08-01

    We have investigated the locations and patterns of neotectonic deformation in the Carnarvon basin along the Mesozoic rifted margin of Western Australia to evaluate the characteristics of post-Neogene tectonic reactivation. Geological, geophysical, geotechnical, and bathymetric data demonstrate that preferentially oriented rift-era structures have been reactivated under the current neotectonic stress regime. The most recent pulse of neotectonic reactivation initiated during the Plio-Pleistocene (4.0 to 1.8 million years ago) and is ongoing. Reactivated structures in the region demonstrate a variety of styles of deformation consistent with dextral-transpression. Structural styles include both positive and negative flower structures, restraining and releasing bends, and hourglass structures. Barrow Island lies within a broad kinematic restraining bend that appears to warp the MIS 5e marine terrace on the island. Fold reconstructions of Neogene strata on the Cape Range and Barrow anticlines yield uplift rates consistent with uplift rates determined from folded late Pleistocene units in the Cape region. Although tectonic rates are low compared to interplate settings, evidence for active tectonic deformation precludes this part of the Australian plate from being classified as a Stable Continental Region.

  7. Geology of the Pine Mountain quadrangle, Mesa county, Colorado

    Science.gov (United States)

    Cater, Fred W.

    1953-01-01

    The Pine Mountain quadrangle is one of eighteen 7 1/2-minute quadrangles covering the principal carnotite-producing area of southwestern Colorado. The geology of these quadrangles was mapped by the U.S. Geological Survey for the Atomic Energy Commission as part of a comprehensive study of carnotite deposits. The rocks exposed in the eighteen quadrangles consist of crystalline rocks of pre-Cambrian age and sedimentary rocks that range in age from Paleozoic to Quaternary. Over mush of the area the sedimentary rocks are flat lying, but in places the rocks are disrupted by high-angle faults, and northwest-trending folds. Conspicuous among the folds are large anticlines having cores of intrusive salt and gypsum. Most of the carnotite deposits are confines to the Salt Wash sandstone member of the Jurassic Morrison formation. Within this sandstone, most of the deposits are spottily distributed through an arcuate zone known as the "Uravan Mineral Belt". Individual deposits range in sizer from irregular masses containing only a few ton of ore to large, tabular masses containing many thousands of tons. The ore consists largely of sandstone selectively impregnated and in part replaced by uranium and vanadium minerals. Most of the deposits appear to be related to certain sedimentary structures in sandstones of favorable composition.

  8. Geology of the Horse Range Mesa quadrangle, Colorado

    Science.gov (United States)

    Cater, Fred W.; Bush, A.L.; Bell, Henry; Withington, C.F.

    1953-01-01

    The Horse Range Mesa quadrangle is one of eighteen 7 1/2-minute quadrangles covering the principal carnotite-producing area of southwestern Colorado. The geology of the quadrangles was mapped by the U.S. Geological Survey for the Atomic Energy Commission as part of a comprehensive study of carnotite deposits. The rocks exposed in the eighteen quadrangles consist of crystalline rocks of pre-Cambrian age and sedimentary rocks that range in age from late Paleozoic to Quaternary. Over much of the area the sedimentary rocks are flat lying, but in places the rocks are disrupted by high-angle faults, and northwest-trending folds. Conspicuous among the folds are large anticlines having cores of intrusive salt and gypsum. Most of the carnotite deposits are confined to the Salt Wash sandstone member of the Jurassic Morrison formation. Within this sandstone, most of the deposits are spottily distributed through an arcuate zone known as the "Uravan Mineral Belt". Individual deposits range in size from irregular masses containing only a few tons of ore to large, tabular masses containing many thousands of tons. The ore consists largely of sandstone selectively impregnated and in part replaced by uranium and vanadium minerals. Most of the deposits appear to be related to certain sedimentary strictures in sandstones of favorable composition.

  9. Geology of the Joe Davis Hill quadrangle, Dolores and San Miguel counties, Colorado

    Science.gov (United States)

    Cater, Fred W.; Bell, Henry

    1953-01-01

    The Joe Davis Hill quadrangle is one of eighteen 7 1/2-minute quadrangles covering the principal carnotite-producing area of southwestern Colorado. The geology of these quadrangles was mapped by the U.S. Geological Survey for the Atomic Energy Commission as part of a comprehensive study of carnotite deposits. The rocks exposed in the eighteen quadrangles consist of crystalline rocks of pre-Cambrian age and sedimentary rocks that range in age from late Paleozoic to Quaternary. Over much of the area the sedimentary rocks are flat lying, but in places the rocks are disrupted by hih-angle faults, and northwest-trending folds. Conspicuous among the folds are large anticlines having cores of intrusive salt and gypsum. Most of the carnotite deposits are confined to Salt Wash sandstone member of the Jurassic Morrison formation. Within this sandstone, most of the deposits are spottily distributed through an arcuate zone known as the "Uravan Mineral Belt". Individual deposits range in size from irregular masses containing only a few tons of ore to large, tabular masses containing many thousands of tons. The ore consists largely of sandstone selectively impregnated and in part replaced by uranium and vanadium minerals. Most of the deposits appear to be related to certain sedimentary structures in sandstones of favorable composition.

  10. Geology of the Red Canyon quadrangle, Montrose county, Colorado

    Science.gov (United States)

    McKay, E.J.; Jobin, D.A.

    1953-01-01

    The Red Canyon quadrangle is one of eighteen 7 1/2-minute quadrangles covering the principal carnotite-producing area of southwestern Colorado. The geology of these quadrangles was mapped by the U.S. Geological Survey for the Atomic Energy Commission as part of a comprehensive study of carnotite deposits. The rocks exposed in the eighteen quadrangles consist of crystalline rocks of pre-Cambrian age and sedimentary rocks that range in age from late Paleozoic to Quaternary. Over much of the area the sedimentary rocks are flat lying, but in places the rocks are disrupted by high-angle faults, and northwest-trending folds. Conspicuous among the folds are large anticlines having cores of intrusive salt and gypsum. Most of the carnotite deposits are confined to the Salt Wash sandstone member of the Jurassic Morrison formation. Within this sandstone, most of the deposits are spottily distributed through an arcuate zone known as the "Uruvan Mineral Belt". Individual deposits range in size from irregular masses containing only a few tons of ore to large, tabular masses containing many thousands of tons. The ore consists largely of sandstone selectively impregnated and in part replaced by uranium and vanadium, minerals. Most of the deposits appear to be related to certain sedimentary structures in sandstones of favorable composition.

  11. Geology of the Paradox quadrangle, Montrose county, Colorado

    Science.gov (United States)

    Withington, C.F.

    1954-01-01

    The Paradox quadrangle is one of eighteen 7 1/2-minute quadrangles covering the principal carnotite-producing area of southwestern Colorado. The geology of these quadrangles was mapped by the U.S. Geological Survey for the Atomic Energy Commission as part of a comprehensive study of carnotite deposits. The rocks exposed in the eighteen quadrangles consist of crystalline rocks of pre-Cambrian age and sedimentary rocks that range in age from late Paleozoic to Quaternary. Over much of the area the sedimentary rocks are flat lying, but in places the rocks are disrupted by high-angle faults, and northwest-trending folds. Conspicuous among the folds are large anticlines having cores of intrusive salt and gypsum. Most of the carnotite deposits are confined to the Salt Wash sandstone member of the Jurassic Morrison formation, Within this sandstone, most of the deposits are spottily distributed through an arcuate zone known as the "Uravan Mineral Belt". Individual deposits range in size from irregular masses containing only a few tons of ore to large, tabular masses containing thousands of tons. The ore consists largely of sandstone selectively impregnated and in part replaced by uranium and vanadium minerals. Most of the deposits appear to be related to certain sedimentary structures in sandstones of favorable composition.

  12. Geology of the Gypsum Gap quadrangle, Colorado

    Science.gov (United States)

    Cater, Fred W.

    1953-01-01

    The Gypsum Gap quadrangle is one eighteen 7 1/2-minute quadrangles covering the principal carnotite-producing area of southwestern Colorado. The geology of these quadrangles was mapped by the U.S. Geological Survey for the Atomic Energy Commission as part of a comparative study of carnotite deposits. The rocks exposed in the eighteen quadrangles consist of crystalline rocks of pre-Cambrian age and sedimentary rocks that range in age from late Paleozoic to Quaternary. Over much of the area the sedimentary rocks are flat lying, but in places the rocks are disrupted by high-angle faults, and northwest-trending folds. Conspicuous among the folds are large anticlines having cores of intrusive salt and gypsum. Most of the carnotite deposits are confined to the Salt Wash sandstone member of the Jurassic Morrison formation. Within this sandstone, most of the deposits are spottily distributed through a arcuate zone known as the "Uravan Mineral Belt". Individual deposits range in size from irregular masses containing only a few tons of ore to large, tabular masses containing many thousands of tons. The core consists largely of sandstone selectively impregnated and in part replaced by uranium and vanadium minerals. Most of the deposits appear to be related to certain sedimentary structures in sandstones of favorable composition.

  13. Geology of the Davis Mesa quadrangle, Colorado

    Science.gov (United States)

    Cater, Fred W.; Bryner, Leonid

    1953-01-01

    The Davis Mesa quadrangle is one of eighteen 7 1/2-minute quadrangles covering the principal carnotite-producing area of southwestern Colorado. The geology of these quadrangles was mapped by the U.S. Geological Survey for the Atomic Energy Commission as part of a comprehensive study of carnotite deposits. The rocks exposed in the eighteen quadrangles consist of crystalline rocks of pre-Cambrian age and sedimentary rocks that range in age from late Paleozoic to Quaternary. Over much of the area the sedimentary rocks are flat lying, but in places the rocks are disrupted by hih-angle faults, and northwest-trending folds. Conspicuous among the folds are large anticlines having cores of intrusive salt and gypsum. Most of the carnotite deposits are confined to the Salt Wash sandstone member of Jurassic Morrison formation. Within this sandstone, most of the deposits are spottily distributed through an arcuate zone known as "Uruvan Mineral Belt". Individual deposits range in size from irregular masses containing only a few tons of ore to large, tabular masses containing many thousands of tons. The ore consists largely of sandstone selectively impregnated and in part replaced by uranium and vanadium minerals. Most of the deposits appear to be related to certain sedimentary structures in sandstones of favorable composition.

  14. Geology of the Atkinson Creek quadrangle, Montrose county, Colorado

    Science.gov (United States)

    McKay, E.J.

    1953-01-01

    The Atkinson Creek quadrangle is one of eighteen 7 1/2-minute quadrangles covering the principal carnotite-producing area of southwestern Colorado. The geology of the quadrangles was mapped by the U.S. Geological Survey for the Atomic Energy Commission as part of a comprehensive study of carnotite deposits. The rocks exposed in the eighteen quadrangles consist of crystalline rocks of pre-Cambrian age and sedimentary rocks that rangein age from late Paleozoic to Quaternary. Over much of the area the sedimentary rocks are flat lying, but in places the rocks are disrupted by high-angle faults, and northwest-trending folds. Conspicuous among the folds are large anticlines having cores of intrusive salt and gypsum. Most of the carnotite deposits are confines to the Salt Wash sandstone member of the Jurassic Morrison formation. Within this sandstone, most of the deposits are spottily distributed through an arcuate zone known as the "Uravan Mineral Bath". Individual deposits range in size from irregular masses containing only a few tons of ore to large, tabular masses containing many thousands of tons. The ore consists largely of sandstone selectively impregnated and in part replaced by uranium and vanadium minerals. Most of the deposits appear to be related to certain sedimentary structures in sandstone of favorable composition.

  15. Geology of the Anderson Mesa quadrangle, Colorado

    Science.gov (United States)

    Cater, Fred W.; Withington, C.F.

    1953-01-01

    The Anderson Mesa quadrangle is one of the eighteen 7 1/2-minute quadrangles covering the principal carnotite-producing area of the southwestern Colorado. The geology of these quadrangles was mapped by the U.S. Geological Survey for the Atomic Energy Commission as part of a comprehensive study of carnotite deposits. The rocks exposed in the eighteenth quadrangles consist of crystalline rocks of pre-Cambrian age and sedimentary rocks that range in age from late Paleozoic to Quarternary. Over much of the area the sedimentary rocks are flat lying, but in places the rocks are disrupted by high-angle faults, and northwest-tending folds. Conspicuous among the folds are large anticlines having cores of intrusive slat and gypsum. Most of the carnotite deposits are confined to the Salt Wash sandstone member of the Jurassic Morrison formation. Within this sandstone, most of the deposits are spottily distributed through an arcuate zone known as the "Uravan Mineral Belt". Individual deposits range in size from irregular masses containing many thousands of tons. The ore consists of largely of sandstone selectively impregnated and in part replaced by uranium and vanadium minerals. Most of the deposits appear to be related to certain sedimentary structures in sandstones of favorable composition.

  16. Geology of the Egnar quadrangle, Dolores and San Miguel counties, Colorado

    Science.gov (United States)

    Cater, Fred W.; Bush, A.L.; Bell, Henry

    1954-01-01

    The Egnar quadrangle is one of eighteen 7 1/2-minute quadrangles covering the principal carnotite-producing area of southwestern Colorado. The geology of these quadrangles was mapped by the U.S. Geological Survey for the Atomic Energy Commission as part of a comprehensive study of carnotite deposits. The rocks exposed in the eighteen quadrangles consist of crystalline rocks of pre-Cambrian age and sedimentary rocks that range in age from late Paleozoic to Quaternary. Over much of the area the sedimentary rocks are flat lying, but in places the rocks are disrupted by hih-angle faults, and northwest-trending folds. Conspicuous among the folds are large anticlines having cores of intrusive salt and gypsum. Most of the carnotite deposits are confined to the Salt Wash sandstone member of Jurassic Morrison formation. Within this sandstone, most of the deposits are spottily distributed through an arcuate zone known as "Uruvan Mineral Belt". Individual deposits range in size from irregular masses containing only a few tons of ore to large, tabular masses containing many thousands of tons. The ore consists largely of sandstone selectively impregnated and in part replaced by uranium and vanadium minerals. Most of the deposits appear to be related to certain sedimentary structures in sandstones of favorable composition.

  17. Geology of Bull Canyon quadrangle, Montrose and San Miguel counties, Colorado

    Science.gov (United States)

    Cater, Fred W.

    1953-01-01

    The Bull Canyon quadrangle is one of eighteen 7 1/2-minute quadrangles covering the principal carnotite-producing area of southwestern Colorado. The geology of these quadrangles was mapped by the U.S. Geological Survey for the Atomic Energy Commission as part of a comprehensive study of carnotite depots. The rocks exposed in the eighteen quadrangles consist of crystalline rocks of pre-Cambrian age and sedimentary rocks that range in age from late Paleozoic to Quaternary. Over much of the area the sedimentary rocks are flat lying, but in places the rocks are disrupted by high-angle faults and northwest-trending folds. Conspicuous among the folds are large anticlines having cores of intrusive salt and gypsum. Most of the carnotite deposits are confined to the Salt Wash sandstone member of the Jurassic Morrison formation. Within this sandstone, most of the deposits are spottily distributed through an arcuate zone known as the "Uravan Mineral Belt". Individual deposits range in size from irregular masses containing only a few tons of ore to large, tabular masses containing many thousands of tones. The ore consists largely of sandstone selectively impregnated and in part replaced by uranium and vanadium minerals. Most of the deposits appear to be related to certain sedimentary structures in sandstones of favorable composition.

  18. Geology of the Roc Creek quadrangle, Montrose county, Colorado

    Science.gov (United States)

    Shoemaker, E.M.

    1954-01-01

    The Roc Creek quadrangle is one of eighteen 7 1/2-minute quadrangles covering the principal carnotite-producing area of southwestern Colorado. The geology of these quadrangles was mapped by the U.S. Geological Survey for the U.S. Atomic Energy Commission as part of a comprehensive study of carnotite deposits. The rocks exposed in the eighteen quadrangles consist of crystalline rocks of pre-Cambrian age and sedimentary rocks that range in age from late Paleozoic to Quaternary. Over much of the area the sedimentary rocks are flat lying, but in places the rocks are disrupted by high-angle faults and northwest-trending folds. Conspicuous among the folds are large anticlines having cores of intrusive salt and gypsum. Most of the carnotite deposits are confined to the Salt Wash sandstone member of the Jurassic Morrison formation. Within this sandstone, most of the deposits are spottily distributed through an arcuate zone known as the "Uravan mineral belt". Individual deposits range in size from irregular masses containing only a few tons of ore to large, tabular masses containing many thousands of tons. The ore consists largely of sandstone selectively impregnated and in part replaced by uranium and vanadium minerals. Most of the deposits appear to be related to certain sedimentary in sandstones of favorable composition.

  19. Geology of the Hamm Canyon quadrangle, Colorado

    Science.gov (United States)

    Cater, Fred W.

    1953-01-01

    The Hamm Canyon quadrangle is on eof eighteen 7 1/2-minute quadrangles covering the principal carnotite-producing area of southwestern Colorado. The geology of these quadrangles was mapped by the U.S. Geological Survey for the Atomic Energy Commission as part of a comprehensive study of carnotite deposits. The rocks exposed in the eighteen quadrangles consist of crystalline rocks of pre-Cambrian age and sedimentary rocks that range in age from late Paleozoic to Quaternary. Over much of the area the sedimentary rocks are flat lying, but in places the rocks are disrupted by high-angle faults, and northwest-trending folds. Conspicuous among the folds are large anticlines having cores of intrusive salt and gypsum. Most of the carnotite deposits are confined to the Salt Wash sandstone member of the Jurassic Morrison formation. Within this sandstone, most of the deposits are spottily distributed through an arcuate zone known as the "Uravan Mineral Belt". Individual deposits range in size from irregular masses containing only a few tons of ore to large, tabular masses containing many thousands of tons. The ore consists largely of sandstone selectively impregnated and in part replaced by uranium and vanadium minerals. Most of the deposits appear to be related to certain sedimentary structures in sandstones of favorable composition.

  20. Geology of the Juanita Arch quadrangle, Mesa county, Colorado

    Science.gov (United States)

    Shoemaker, Eugene M.

    1954-01-01

    The Juanita Arch quadrangle is one of eighteen 7 1/2-minute quadrangles covering the principal carnotite-producing area of southwestern Colorado. The geology of these quadrangles was mapped by the U.S. Geological Survey for the Atomic Energy Commission as part of a comprehensive study of carnotite deposits. The rocks exposed in the eighteen quadrangles consist of crystalline rocks of pre-Cambrian age and sedimentary rocks that range in age from late Paleozoic to Quaternary. Over much of the area the sedimentary rocks are flat lying, but in places the rocks are disrupted by high-angle faults and northwest-trending folds. Conspicuous among the folds are large anticlines having cores of intrusive salt and gypsum. Most of the carnotite deposits are confined to the Salt Wash sandstone member of the Jurassic Morrison formation. Within this sandstone, most of the deposits are spottily distributed through an arcuate zone known as the "Uravan Mineral Belt". Individual deposits range in size from irregular masses containing only a few tons of ore ro large, tabular masses containing many thousands of tons. The ore consists largely of sandstone selectively impregnated and in part replaced by uranium and vanadium minerals. Most of the deposits appear to be related to certain sedimentary structures in sandstone of favorable construction.

  1. Geology of the Uravan quadrangle, Montrose county, Colorado

    Science.gov (United States)

    Cater, Fred W.; Butler, A.P.; McKay, E.J.; Boardman, Robert L.

    1954-01-01

    The Uravan quadrangle is one of eighteen 7 1/2-minute quadrangles covering the principal carnotite-producing area of the southwestern Colorado. The geology of these quadrangles was mapped by the U.S. Geological Survey for the Atomic Energy Commission as part of a comprehensive study of carnotite deposits. The rocks exposed in the eighteen quadrangles consist of crystalline rocks of pre-Cambrian age and sedimentary rocks that range in age from late Paleozoic to Quaternary. Over much of the area the sedimentary rocks are flat lying, but in places the rocks are disrupted by high-angle faults, and northwest-trending folds. Conspicuous among the folds are large anticlines having cores of intrusive salt and gypsum. Most of the carnotite deposits are confined to the Salt Wash sandstone member of the Jurassic Morrison formation. Within this sandstone, most of the deposits are spottily distributed through an arcuate zone known as the "Uravan Mineral Belt". Individual deposits range in size from irregular masses containing only a few tons of ore to large, tabular masses containing many thousands of tons. The ore consists largely of sandstone selectively impregnated and in part replaced by uranium and vanadium minerals. Most of the deposits appear to the related to certain sedimentary structures in sandstones of favorable composition.

  2. Geology of the Calamity Mesa quadrangle, Mesa county, Colorado

    Science.gov (United States)

    Cater, Fred W.; Stager, Harold K.

    1953-01-01

    The Calamity Mesa quadrangle is one of eighteen 7 1/2-minute quadrangles covering the principal carnotite-producing area of southwestern Colorado. The geology of these quadrangles was mapped by the U.S. Geological Survey for the Atomic Energy Commission as part of a comprehensive study of carnotite deposits. The rocks exposed in the eighteen quadrangles consist of crystalline rocks of pre-Cambrian age and sedimentary rocks the range in age from late Paleozoic to Quaternary. Over much of the area the sedimentary rocks are flat lying, but in places the rocks are disrupted by high-angle faults, and northwest-trending folds. Conspicuous among the folds are large anticlines having cores of intrusive salt and gypsum. Most of the carnotite deposits are confined to the Salt Wash sandstone member of the Jurassic Morrison formation. Within this sandstone, most of the deposits are spottily distributed through an arcuate zone known as the "Uravan Mineral Belt". Individual deposits range in size from irregular masses containing only a few tons of ore to large tabular masses containing many thousands of tons. The ore consists largely of sandstone selectively impregnated and in part replaced by uranium and vanadium minerals. Most of the deposits appear to be related to certain sedimentary structures in sandstones of favorable composition.

  3. Geology of the Naturita NW quadrangle, Colorado

    Science.gov (United States)

    Cater, Fred W.; Vogel, J.D.

    1953-01-01

    The Naturita NW quadrangle is one of eighteen 7 1/2-minute quadrangles covering the principal carnotite-producing area of southwestern Colorado. The geology of these quadrangles were mapped by the U.S. Geological Survey on behalf of the U.S. Atomic Energy Commission as part of a comprehensive study of carnotite deposits. The rocks exposed in the eighteen quadrangles consist of crystalline rocks of pre-Cambrian age and sedimentary rocks that range in age from late Paleozoic to Quaternary. Over much of the area the sedimentary rocks are flat lying, but in places the rocks are disrupted by high-angle faults, and northwest-trending folds. Conspicuous among the folds are large anticlines having cores of intrusive salt and gypsum. Most of the carnotite deposits are confined to the Salt Wash sandstone member of the Jurassic Morrison formation. Within this sandstone, most of the deposits are spottily distributed through an arcuate zone known as the "Uravan Mineral Belt". Individual deposits range in size from irregular masses containing only a few tons of ore to large, tabular masses containing many thousands of tons. The ore consists largely of sandstone selectively impregnated and in part replaced by uranium and vanadium minerals. Most of the deposits appear ro be related to certain sedimentary structures in sandstones of favorable composition.

  4. Geology of the Gateway quadrangle, Mesa county Colorado

    Science.gov (United States)

    Cater, Fred W.

    1953-01-01

    The Gateway quadrangle is one of eighteen 7 1/2-minute quadrangles covering the principal carnotite-producing area of southwestern Colorado. The geology of these quadrangles was mapped by the U.S. Geological Survey for the Atomic Energy Commission as part of a comprehensive study of carnotite deposits. The rocks exposed in the eighteen quadrangles consist of crystalline rocks of pre-Cambrian age and sedimentary rocks that range in age from late Paleozoic to Quaternary. Over much of the area the sedimentary rocks are flat lying, but in places the rocks are disrupted by hih-angle faults, and northwest-trending folds. Conspicuous among the folds are large anticlines having cores of intrusive salt and gypsum. Most of the carnotite deposits are confined to the Salt Wash sandstone member of Jurassic Morrison formation. Within this sandstone, most of the deposits are spottily distributed through an arcuate zone known as "Uruvan Mineral Belt". Individual deposits range in size from irregular masses containing only a few tons of ore to large, tabular masses containing many thousands of tons. The ore consists largely of sandstone selectively impregnated and in part replaced by uranium and vanadium minerals. Most of the deposits appear to be related to certain sedimentary structures in sandstones of favorable composition.

  5. The Calvin 28 cryptoexplosive disturbance, Cass County, Michigan: Evidence for impact origin

    Science.gov (United States)

    Milstein, Randall L.

    1988-01-01

    The Calvin 28 cryptoexplosive disturbance is an isolated, nearly circular subsurface structure of Late Ordovician age in southwestern Michigan. The structure is defined by 107 wells, is about 7.24 km in diameter and consists of a central dome, an annular depression and an encircling anticlinal rim. Seismic and geophysical well log data confirm that an intricate system of faults and structural derangement exists within the structure. Deformation decreases with depth and distance from the structure. U.S.G.S. topographic maps and aerial imagery show the structure is reflected as a subtle surface topographic rise controlling local drainage. Igneous or diapiric intrusion and solution collapse are rejected as possible origins for Calvin 28 on the basis of stratigraphic, structural and geophysical evidence. A volcanic origin is inconsistent with calculated energy requirements and an absence of igneous material. Although shock-metamorphic features are unidentified, microbreccias occur in deep wells that penetrate the structure. Morphology and structural parameters support an impact origin.

  6. The Santa Cruz - Tarija Province of Central South America: Los Monos - Machareti(!) Petroleum System

    Science.gov (United States)

    Lindquist, Sandra J.

    1999-01-01

    The Los Monos - Machareti(!) total petroleum system is in the Santa Cruz - Tarija Province of Bolivia, Argentina and Paraguay. Province history is that of a Paleozoic, intracratonic, siliciclastic rift basin that evolved into a Miocene (Andean) foreland fold and thrust belt. Existing fields are typified by alternating reservoir and seal rocks in post-Ordovician sandstones and shales on anticlines. Thick Devonian and Silurian shale source rocks, depositionally and erosionally confined to this province, at a minimum have generated 4.1 BBOE known ultimate recoverable reserves (as of 1995, 77% gas, 15% condensate, 8% oil) into dominantly Carboniferous reservoirs with average 20% porosity and 156 md permeability. Major detachment surfaces within the source rocks contributed to the thin-skinned and laterally continuous nature of the deformation. Tertiary foreland burial adequate for significant source maturation coincided with the formation of compressional traps. Further hydrocarbon discovery in the fold and thrust belt is expected. In the foreland basin, higher thermal gradients and variable burial history - combined with the presence of unconformity and onlap wedges - create potential there for stratigraphic traps and pre-Andean, block-fault and forced-fold traps.

  7. Palaeogene fossil Populus leaves from Lanzhou Basin and their palaeoclimatic significance

    Institute of Scientific and Technical Information of China (English)

    SUN Bainian; YAN Defei; XIE Sanping; CONG Peiyun; XIN Cunlin; YUN Fei

    2004-01-01

    An angiosperm compression flora is found in Palaeogene from Lanzhou Basin and the cuticular analysis of Populus davidiana Dode in the flora is carefully made. Furthermore, the fossil cuticles are compared with the epidermal structures of extant Populus leaves growing in different environments, I.e. Moist, semimoist, and semiarid to arid climatic regions. The present experiments indicate that mature leaves of P. Davidiana show leaf size from big to small, leaf cuticles from thick to thin and anticlinal walls of epidermal cells from faintness to clarity along with the increase of latitudes of the plant distributions, the climatic variation from moist to arid, the annual precipitation from more to less and the annual mean temperature from high to low. The fossil P.davidiana differs from the specimens collected from Shandan in semiarid to arid climatic regions but closely resembles the Wushan leaves in a semi-moist climatic area in a lot of features. In a word, the new research may reflect that the flora lives in a semi-moist climatic environment. The present discovery of compression of Paleogene Populus davidiana is of great significance to studying vegetation types, climatic and environmental changes during the primal uplifting of the Qinghai-Tibet Plateau.

  8. Light-dependent intracellular positioning of mitochondria in Arabidopsis thaliana mesophyll cells.

    Science.gov (United States)

    Islam, Md Sayeedul; Niwa, Yasuo; Takagi, Shingo

    2009-06-01

    Mitochondria, the power house of the cell, are one of the most dynamic cell organelles. Although there are several reports on actin- or microtubule-dependent movement of mitochondria in plant cells, intracellular positioning and motility of mitochondria under different light conditions remain open questions. Mitochondria were visualized in living Arabidopsis thaliana leaf cells using green fluorescent protein fused to a mitochondrion-targeting signal. In darkness, mitochondria were distributed randomly in palisade cells. In contrast, mitochondria accumulated along the periclinal walls, similar to the accumulation response of chloroplasts, when treated with weak blue light (470 nm, 4 micromol m(-2) s(-1)). Under strong blue light (100 micromol m(-2) s(-1)), mitochondria occupied the anticlinal positions similar to the avoidance response of chloroplasts and nuclei. While strong red light (660 nm, 100 micromol m(-2) s(-1)) induced the accumulation of mitochondria along the inner periclinal walls, green light exhibited little effect on the distribution of mitochondria. In addition, the mode of movement of individual mitochondria along the outer periclinal walls under different light conditions was precisely analyzed by time-lapse fluorescence microscopy. A gradual increase in the number of static mitochondria located in the vicinity of chloroplasts with a time period of blue light illumination clearly demonstrated the accumulation response of mitochondria. Light-induced co-localization of mitochondria with chloroplasts strongly suggested their mutual metabolic interactions. This is the first characterization of the light-dependent redistribution of mitochondria in plant cells.

  9. 斑岩铜矿床原生晕分带模式及其控制因素

    Institute of Scientific and Technical Information of China (English)

    黄书俊

    1983-01-01

    The primary halos of porphyry copper deposits are characterized by compositional zonhag in three dimensions. Two ideal zoning patterns can be divided in accordance with the shape of primary halos in space: bell-shaped and anticline-shaped, In the process oF alteration-minerallzation, K, Si, (OH), Fe, Cu, Mo, Ag, S, Ba, Rb,Pb, Zn, As, etc. were imported, while Na, Ca, Mg, Fe, Al, Ti, Mn, V, Co, Sr, Pb, Zn, etc.were exported or became activated, and then transported and reprecipitated. Both import and export of Fe, Pb and Zn may have taken place. The foundamental factors controlling the zoning of primary halos are: the stability of complexes and the activity of elements; pH, Eh, the behaviour of sulfur and the sulphophile character of elements; regularities governing the concentration of a constituent and isomorphism; temperature and pressure; and tectonic setting and country-rock characters. The authors consider that the zoning patterns of primary halos in porphyry copper deposits are tke outcome of integrated effects of the factors mentioned above.

  10. Seasonal Effect of Geomorphological Chronosequence Features on Soil Biota Dynamics

    Institute of Scientific and Technical Information of China (English)

    S.PEN-MOURATOV; N.GENZER; N.SHUKUROV; J.PLAKHT; Y.STEINBERGER

    2010-01-01

    Numerous studies have been devoted to the physical-chemical weathering processes leading to the creation of unique soil formations having their own history that induce soil-biotic diversity.However,the extent to which unique geomorphic formations influence soil biotic seasonal variation is not clear.Our aim was to define seasonal variations of soil biota in soils of different-aged terraces of the Makhtesh Ramon anticline erosional cirque in southern Israel.The strong effect of Makhtesh Ramon(Ramon crater)erosional fluvial terrace age initiated by climatic changes during the Late Pleistocene-Early Holocene period on seasonal variations in both soil properties and the abundance and composition of soil biota were demonstrated.However,age dependence was not constant and values for observed soil properties and microbial activity were negligible between younger and older terraces for certain seasons,while free-living nematodes along with bacterial-feeding group were strongly dependent on the geomorphic features of the ages throughout the study period.

  11. Synergistic effect of flyash and SO{sub 2} on development of cucumber (Cucumis sativus L.) leaf injury

    Energy Technology Data Exchange (ETDEWEB)

    Tung, G.; McIlveen, W.D.; Jones, R.D. [Ontario Ministry of Environment and Energy, Etobicoke, Ontario (Canada)

    1995-10-01

    In a two-factorial experiment, sulfur dioxide alone at concentration of 131 {micro}g/m{sup 3} over long exposures or flyash for either coal or oil combustion alone applied onto cucumber (Cucumis sativus L.) foliage causes no visible injury. However, if both flyash and sulfur dioxide were presented simultaneously, a specific mosaic-chlorosis symptom developed on leaves. A synergistic effect was thus demonstrated. Histopathology of the mosaic-chlorosis symptom was studied. An unusual pattern of tissue abnormally initiated from the collapse of the anticlinal cell walls of the upper epidermal cells and progressed along cell walls into mesophyll tissues. Cellular injury at the lower spongy tissues typical of that caused by SO{sub 2} was also observed. A significant elevation of sulfate-sulfur in the leaves treated with a combination of SO{sub 2} and flyash was demonstrated. Significant interactions between the two factors were found for both injury and sulfur chemistry. This suggests that flyash deposits on the leaf surface play a catalytic role in oxidizing atmospheric sulfur dioxide continuously to form sulfuric acid (H{sub 2}SO{sub 4}) in situ. This acid could infiltrate into mesophyll damage cells and tissues en route.

  12. Halogenated auxins affect microtubules and root elongation in Lactuca sativa

    Science.gov (United States)

    Zhang, N.; Hasenstein, K. H.

    2000-01-01

    We studied the effect of 4,4,4-trifluoro-3-(indole-3-)butyric acid (TFIBA), a recently described root growth stimulator, and 5,6-dichloro-indole-3-acetic acid (DCIAA) on growth and microtubule (MT) organization in roots of Lactuca sativa L. DCIAA and indole-3-butyric acid (IBA) inhibited root elongation and depolymerized MTs in the cortex of the elongation zone, inhibited the elongation of stele cells, and promoted xylem maturation. Both auxins caused the plane of cell division to shift from anticlinal to periclinal. In contrast, TFIBA (100 micromolar) promoted elongation of primary roots by 40% and stimulated the elongation of lateral roots, even in the presence of IBA, the microtubular inhibitors oryzalin and taxol, or the auxin transport inhibitor naphthylphthalamic acid. However, TFIBA inhibited the formation of lateral root primordia. Immunostaining showed that TFIBA stabilized MTs orientation perpendicular to the root axis, doubled the cortical cell length, but delayed xylem maturation. The data indicate that the auxin-induced inhibition of elongation and swelling of roots results from reoriented phragmoplasts, the destabilization of MTs in elongating cells, and promotion of vessel formation. In contrast, TFIBA induced promotion of root elongation by enhancing cell length, prolonging transverse MT orientation, delaying cell and xylem maturation.

  13. Plinia edulis - leaf architecture and scanning electron micrographs

    Directory of Open Access Journals (Sweden)

    Ana M. Donato

    2013-06-01

    Full Text Available Many species of Myrtaceae, including Plinia edulis (Vell. Sobral (cambucá, have pharmacological properties and are used as hypoglycemiants and therapeutic agents against stomach problems and throat infections. Samples were collected from Tijuca Forest in Rio de Janeiro, and the morpho-anatomical data were compared with other specimens obtained from Trindade, Paraty, found in the literature. Variations in leaf anatomy were observed, and the possible causes for these effects are discussed. The plant material collected from Tijuca Forest was analyzed using scanning electron and optical microscopy. Histochemical tests were applied to identify starch, lipids, phenolic compounds and lignin. The epidermal cells exhibit straight or slightly sinuous anticlinal walls covered by a smooth cuticle with granules of wax. Simple trichomes are restricted to the midrib region, and paracytic stomata are only observed on the abaxial leaf surface. The mesophyll is dorsiventral, with conspicuous intercellular spaces in the spongy parenchyma. Intercalated columns of crystalliferous cells and subepidermal secretory cavities are observed in the single layer of palisade parenchyma. The samples obtained from Trindade, Paraty, show larger leaves, anomocytic stomata and trichomes scattered throughout the leaf surface. This plasticity might reflect leaf adaptations to environmental factors or different stages of leaf development.

  14. Petrogenesis of Mount Rainier andesite: magma flux and geologic controls on the contrasting differentiation styles at stratovolcanoes of the southern Washington Cascades

    Science.gov (United States)

    Sisson, Thomas W.; Salters, V.J.M.; Larson, P.B.

    2013-01-01

    Quaternary Mount Rainier (Washington, USA) of the Cascades magmatic arc consists of porphyritic calc-alkaline andesites and subordinate dacites, with common evidence for mingling and mixing with less evolved magmas encompassing andesites, basaltic andesites, and rarely, basalts. Basaltic andesites and amphibole andesites (spessartites) that erupted from vents at the north foot of the volcano represent some of Mount Rainier's immediate parents and overlap in composition with regional basalts and basaltic andesites. Geochemical (major and trace elements) and isotopic (Sr, Nd, Pb, O) compositions of Mount Rainier andesites and dacites are consistent with modest assimilation (typically ≤20 wt%) of evolved sediment or sediment partial melt. Sandstones and shales of the Eocene Puget Group, derived from the continental interior, are exposed in regional anticlines flanking the volcano, and probably underlie it in the middle to lower crust, accounting for their assimilation. Mesozoic and Cenozoic igneous basement rocks are unsuitable as assimilants due to their high 143Nd/144Nd, diverse206Pb/204Pb, and generally high δ18O.

  15. Geological evidence for fluid overpressure, hydraulic fracturing and strong heating during maturation and migration of hydrocarbons in Mesozoic rocks of the northern Neuquén Basin, Mendoza Province, Argentina

    Science.gov (United States)

    Zanella, Alain; Cobbold, Peter R.; Ruffet, Gilles; Leanza, Hector A.

    2015-10-01

    In the northern Neuquén Basin of Argentina (especially in Mendoza Province), there is strong geological evidence for fluid overpressure in the past. The evidence takes the form of bitumen veins and bedding-parallel veins of fibrous calcite ('beef'). Such veins are widespread in the fold-and-thrust belt of the Malargűe area, where bitumen mining has been active for a century or so. So as to collect information on the development of fluid overpressure in this part of the Neuquén Basin, several old mines were visited and studied in the Malargűe area. Here the bitumen veins have intruded mainly the Late Jurassic to Early Cretaceous Mendoza Group, but also the Late Cretaceous Neuquén Group. The veins have the forms of bedding-parallel sills or dykes and they are especially thick within anticlines, forming saddle-reefs in several places. Beef veins are also numerous in the Malargűe area. They contain bitumen and therefore seem to have formed at the same time as the bitumen veins. Near many outcrops of bitumen and beef, we have found fine-grained volcanic intrusive bodies. The best examples are from the La Valenciana syncline. According to 39Ar-40Ar dating, these bodies are mainly of Mid-Miocene age. More generally, volcanism, deformation and maturation of source rocks seem to have reached a climax in Miocene times, when the subducting Pacific slab became relatively flat.

  16. Nonparallelism of cambium cells in neighboring rows

    Directory of Open Access Journals (Sweden)

    Wiesław Włoch

    2014-02-01

    Full Text Available The periclinal walls of cambial cells in neighboring lineages (rows may not be parallel when viewed in their radial aspect. This lack of longitudinal parallelism may be so extensive that in active cambium pairs of cells from neighboring rows may be in contact only along restricted segments. This means that the initial cells, rather than farming a continuous layer, may be arranged in an irregular network pattern from which some parts project inward or outward from the layer of their mutual cantacts. The longitudinal nonparallelism of cambial cells becomes more pronounced during symplasitic radial growth. Unequal periclinal divisions counteract this, and in initial cells abscission of the parts projecting from the layer of mutual contact occurs. When the cambium passes from a period of activity to a Period of rest a continuous layer of initials is reestabhshed. This involves elongation by intrusive growth of those cells previously shortened as the result of irregular periclinal divisions. The division walls in cambial cells may be warped, that is they change their orientation along the longitudinal direction perhaps even similar to an aircraft propeller. A division wall may thus be periclinal in one part of the cell and anticlinal in another.

  17. Research of the Activity of Earthquakes Induced by Water Injection of Salt Mining in Changning County, Sichuan Province

    Institute of Scientific and Technical Information of China (English)

    Ruan Xiang; Cheng Wanzheng; Zhang Yongjiu; Li Jun; Chen Yin

    2009-01-01

    According to information from on-the-spot investigations, the tectonics of salt mining areas and digital seismic records, we studied the activity of earthquakes induced by water pumping in and out of the salt mines in Shuanghe town, Changning county, Sichuan Province. The study found that the rates of water injection and extraction in the Shuanghe salt mining region were evenly matched before April 2006 and earthquake activity was stable. On the other hand, shallow small and moderate earthquake numbers increased sharply after the water injection rate became much larger than the water extraction rate. Large injection over a long time may causes the permeation of water through pre-existing small fractures and micro-cracks in the Changning anticlinal and accelerate the rupture of micro tectonic formations in nearby regions, inducing small earthquake swarm activity. The Q value calculated by using digital earthquake records indicates a relatively inhomogeneous medium in this area. The results of the accurate location of small earthquakes show that sources are relatively shallow and are concentrated at a depth of 2km to 3km. Focal mechanism solutions reveal a normal dip-slip character of shallow earthquakes. All of these show certain characteristics of earthquake activity induced by water injection.

  18. The mechanics of intersecting echelon veins and pressure solution seams in limestone

    Science.gov (United States)

    Seyum, Solomon; Pollard, David D.

    2016-08-01

    Many studies that describe the formation of echelon vein arrays relate the causative stresses implicitly to the deformation, reliant on simple shear kinematics, such that the vein-to-array angle and the array width are the primary physical quantities. In contrast, we identify twelve physical quantities to describe echelon veins in two dimensions, including coeval, vein-intersecting, pressure solution seams. A finite element method is used to reproduce vein shapes in linear elastic and elastic-perfectly plastic model limestone. Model vein geometries are designed using values within the range of geometries measured from echelon veins at Raplee Anticline and Comb Monocline, Utah. Four physical quantities are significant for describing echelon vein shapes: vein spacing, vein-array angle, limestone elastic stiffness, and closing of orthogonal pressure solution seams. Pressure solution seam closing influences the mechanical interaction between adjacent veins, and for a range of conditions, causes a nearly linear vein opening distribution (triangular shapes) and encourages straight vein propagation, both of which approximate field measurements. Model results show that small spacing of veins with seams and large vein-array angles promote straight vein traces in limestone with stiffness typical of laboratory measurements, given the physical geologic conditions inferred from the burial history of the limestone strata.

  19. Topographic controls on the propagation of carbon dioxide in geological reservoirs

    Science.gov (United States)

    Pegler, Sam; Huppert, Herbert; Neufeld, Jerome

    2014-05-01

    The propagation of carbon dioxide (CO2) in saline aquifers can be controlled by the topography of the caprock along which it flows. The influence of topographic trapping in basin-like structures, such as that of the Sleipner Field, is central to understanding the long-term flow and containment of CO2. We present a theoretical and experimental study of the flow of gravity currents in porous media with variations in the topography along which they flow. Our results provide a general assessment of the role of topography in the entrapment of CO2. We consider cases where the height of the topography forms an anticline from a line or point source. In all cases, it is found that the flow of CO2 transitions towards a long-term regime controlled by the shape of the caprock. We identify an intrinsic time scale before which the flow is controlled by gravitational spreading due to gradients in hydrostatic pressure, and beyond which the variations in topography are dominant. Our theoretical predictions compare well with data from a new series of laboratory experiments. Comparison between our mathematical solutions and seismic data gathered from the Sleipner Field indicates that topographic control is unlikely to explain the observed non-axisymmetric flow of CO2 plumes.

  20. Epiderme e padrão de venação foliar de espécies de Lauraceae Epiderm and leaf venation pattern of Lauraceae species

    Directory of Open Access Journals (Sweden)

    Pedro Luís Rodrigues de Moraes

    1999-04-01

    Full Text Available São descritas as características da epiderme e do padrão de venação foliar de eófilos e nomófilos de Cryptocarya moschata Nees, Endlicheria paniculata (Spreng. MacBride e Ocotea catharinensis Mez. Tanto C. moschata, como O. catharinensis, mostraram variação considerável no grau de sinuosidade das paredes celulares anticlinais e na venação foliar microscópica de nomófilos, dificultando o uso destes caracteres para fins taxonômicos.The epidermal and leaf venation pattern of eophylls and nomophylls of Ctyptocarya moschata Nees, Endlicheria paniculata (Spreng. MacBride, and Ocotea catharinensis Mez are described. Both C. moschata and O. catharinensis presented a pronounced variation in the rate of ondulation in the anticlinal cell walls as well as in the minor venation of nomophylls. This makes it difficult to use these features for taxonomical purposes.

  1. The avoidance and aggregative movements of mesophyll chloroplasts in C(4) monocots in response to blue light and abscisic acid.

    Science.gov (United States)

    Maai, Eri; Shimada, Shouu; Yamada, Masahiro; Sugiyama, Tatsuo; Miyake, Hiroshi; Taniguchi, Mitsutaka

    2011-05-01

    In C(4) plants, mesophyll (M) chloroplasts are randomly distributed along the cell walls, whereas bundle sheath chloroplasts are located in either a centripetal or centrifugal position. It was reported previously that only M chloroplasts aggregatively redistribute to the bundle sheath side in response to extremely strong light or environmental stresses. The aggregative movement of M chloroplasts is also induced in a light-dependent fashion upon incubation with abscisic acid (ABA). The involvement of reactive oxygen species (ROS) and red/blue light in the aggregative movement of M chloroplasts are examined here in two distinct subtypes of C(4) plants, finger millet and maize. Exogenously applied hydrogen peroxide or ROS scavengers could not change the response patterns of M chloroplast movement to light and ABA. Blue light irradiation essentially induced the rearrangement of M chloroplasts along the sides of anticlinal walls, parallel to the direction of the incident light, which is analogous to the avoidance movement of C(3) chloroplasts. In the presence of ABA, most of the M chloroplasts showed the aggregative movement in response to blue light but not red light. Together these results suggest that ROS are not involved in signal transduction for the aggregative movement, and ABA can shift the blue light-induced avoidance movement of C(4)-M chloroplasts to the aggregative movement.

  2. Chloroplast avoidance movement is not functional in plants grown under strong sunlight.

    Science.gov (United States)

    Higa, Takeshi; Wada, Masamitsu

    2016-04-01

    Chloroplast movement in nine climbing plant species was investigated. It is thought that chloroplasts generally escape from strong light to avoid photodamage but accumulate towards weak light to perform photosynthesis effectively. Unexpectedly, however, the leaves of climbing plants grown under strong sunlight showed very low or no chloroplast photorelocation responses to either weak or strong blue light when detected by red light transmittance through leaves. Direct observations of Cayratia japonica leaves, for example, revealed that the average number of chloroplasts in upper periclinal walls of palisade tissue cells was only 1.2 after weak blue-light irradiation and almost all of the chloroplasts remained at the anticlinal wall, the state of chloroplast avoidance response. The leaves grown under strong light have thin and columnar palisade tissue cells comparing with the leaves grown under low light. Depending on our analyses and our schematic model, the thinner cells in a unit leaf area have a wider total plasma membrane area, such that more chloroplasts can exist on the plasma membrane in the thinner cells than in the thicker cells in a unit leaf-area basis. The same strategy might be used in other plant leaves grown under direct sunlight.

  3. Integration of Phot1, Phot2, and PhyB signalling in light-induced chloroplast movements.

    Science.gov (United States)

    Luesse, Darron R; DeBlasio, Stacy L; Hangarter, Roger P

    2010-10-01

    In Arabidopsis thaliana, chloroplasts move towards the periclinal cell walls upon exposure to low blue light intensities and to anticlinal walls under high light. The regulation of these chloroplast movements involves members of both the phototropin and phytochrome families of photoreceptors. Examination of fluence-rate response dependencies in phot1 and phot2 mutants revealed that although both photoreceptors are capable of inducing chloroplast accumulation under low-light conditions, the signals from these photoreceptors appear to be antagonistic. Chloroplast movements in wild-type plants were intermediate between those of the single phot mutants, consistent with each operating through separate signalling cascades. Mutants in phot2 showed transient chloroplast avoidance responses upon exposure to intense blue light, and slow but sustained chloroplast avoidance under intense white light, indicating that in the absence of phot2, phot1 is capable of generating both a low and a high-light response signal. Mutations in phytochrome B (phyB) caused an enhanced avoidance response at intermediate and high light intensities. Examination of phyB, phot1phyB, and phot2phyB mutants indicated that this enhancement is caused by PhyB inhibition of the high-light avoidance response in wild-type plants. In addition, our results suggest that the inhibition by PhyB is not exclusive to either of the phot1 or phot2 signalling pathways.

  4. The Lennox oil and gas field

    Energy Technology Data Exchange (ETDEWEB)

    Haig, D.B.; Pickering, S.C.; Probert, R. [BHP Petroleum Ltd., London (United Kingdom)

    1997-12-31

    The Lennox oil and gas field is located in Block 110/15 of the East Irish Sea, approximately 10 km west of Southport, Lancashire. The field was discovered in 1992 with well 110/15-6 drilled by the P791 BHP group. The Lennox structure is a rollover anticline in Permo-Triassic sediments formed in the hanging wall of the Formby Point Fault. The reservoir comprises the Triassic Sherwood Sandstone Group, and is characterized by excellent permeability aeolian and fluvial sandstones. The structure is sealed by the overlying shales and evaporites of the Mercia Mudstone Group. To date four wells have been drilled on the Lennox Field and have delineated a free gas cap in communication with a constant thickness oil rim. The hydrocarbons have been sourced from Namurian Holywell shales and reflect complex migration into the Lennox structure. Reservoir studies indicate likely hydrocarbons-in-place of 463 BCF of gas and 218 MMBO of oil. Development approval for the Lennox Field was granted in 1993 with production due to commence in late 1995 from a series of horizontal oil producers. (author)

  5. Fluid generation and distribution in the highest sediment input accretionary margin, the Makran

    Science.gov (United States)

    Smith, Gemma L.; McNeill, Lisa C.; Henstock, Timothy J.; Arraiz, Daniel; Spiess, Volkhard

    2014-10-01

    Fluids in subduction zones can influence seismogenic behaviour and prism morphology. The Eastern Makran subduction zone, offshore Pakistan, has a very thick incoming sediment section of up to 7.5 km, providing a large potential fluid source to the accretionary prism. A hydrate-related bottom simulating reflector (BSR), zones of high amplitude reflectivity, seafloor seep sites and reflective thrust faults are present across the accretionary prism, indicating the presence of fluids and suggesting active fluid migration. High amplitude free gas zones and seep sites are primarily associated with anticlinal hinge traps, and fluids here appear to be sourced from shallow biogenic sources and migrate to the seafloor along minor normal faults. There are no observed seep sites associated with the surface expression of the wedge thrust faults, potentially due to burial of the surface trace by failure of the steep thrust ridge slopes. Thrust fault reflectivity is restricted to the upper 3 km of sediment and the deeper décollement is non-reflective. We interpret that fluids and overpressure are not common in the deeper stratigraphic section. Thermal modelling of sediments at the deformation front suggests that the deeper sediment section is relatively dewatered and not currently contributing to fluid expulsion in the Makran accretionary prism.

  6. Secretory structures of Ipomoea asarifolia: anatomy and histochemistry

    Directory of Open Access Journals (Sweden)

    Fabiano M. Martins

    2012-02-01

    Full Text Available Ipomoea asarifolia (Desr. Roem. & Schult., Convolvulaceae, is a weed that infests agricultural areas and is toxic to cattle. In spite of its toxicity, the leaves of this plant are used in traditional remedies in the state of Bahia, Brazil. The present work describes the leaf anatomy of I. asarifolia and characterizes the exudates of its secretory structures. The leaves have a unistratified epidermis composed of ordinary cells with straight to slightly sinuous anticlinal walls and thin cuticles. Paracytic stomata are found on both surfaces of the leaves at the same level as the ordinary epidermal cells. Trichomes producing polysaccharide secretions occur on the petiole and leaf blade and are considered colleters. The mesophyll is dorsiventral and the vascular bundle of the central vein is bicollateral. Two opposed nectaries occur on the petiole near the leaf blade. Each nectary is composed of a small canal with internal ramifications and numerous secretory trichomes. The laticiferous glands are articulated, not anastomosed, and are composed of large diameter cells with thin cell walls. The secretions of the laticiferous glands are lipidic.

  7. ENVIRONMENTAL SCANNING ELECTRON MICROSCOPY (ESEM OF Morinda citrifolia L. (Rubiaceae COLLETERS

    Directory of Open Access Journals (Sweden)

    Sergimar Kennedy de Paiva PINHEIRO

    2015-12-01

    Full Text Available This study describes the colleters of Morinda citrifolia L. (Rubiaceae by using environmental scanning electron microscopy (ESEM and energy dispersive x-ray spectroscopy (EDS. Two different developmental stages were characterized as well as the chemical composition of secretion. Colleters are secretory structures that produce mucilage protecting the meristems and leaf primordia against desiccation and/or pathogens. Although these secretory structures are common on Rubiaceae, the results reported here is to the best of our knowledge the first record of colleters on Morinda genus. Colleters are present at the stipule adaxial surface, distributed in lines. These secretory structures are standard type and have no base constriction, differently from all studied species until now. In order to better understand the colleters structure and secretion, two phases were distinguished: a secretory phase and a senescence one. On secretory phase standard type colleters were visualized between leaf primordia and stipule, emerge on secretion. They present smooth surface, however was also possible to observe the contours of secretory cells anticlinal walls. In senescent phase colleters morphology was alternated exhibiting rough surface and blunt to point tips. The surface was rough and on stipule sections was possible to observe idioblasts with raphides bundles. The secretion process of M. citrifolia colleters occurs with the disruption of cuticle and the chemical elements are mostly dominated by carbon and oxygen.

  8. Early detection of injuries in leaves of Clusia hilariana Schltdl. (Clusiaceae caused by particulate deposition of iron

    Directory of Open Access Journals (Sweden)

    Diego Ismael Rocha

    2014-06-01

    Full Text Available This study aims to evaluate the prognostic value of microscopic parameters of asymptomatic leaves of Clusia hilariana Schltdl. subjected to particulate deposition of iron (2.14 mg cm-2 day-1 for 45 consecutive days. Samples of young and expanded leaves without symptoms were collected and subjected to light and scanning electron microscopy techniques. The height of the epidermal cells on both surfaces of the leaf and the thickness of the hypodermis, the chlorophyll parenchyma, and the leaf blade were measured. Micromorphological injury occurred in the abaxial surface of young leaves and on both surfaces of expanded leaves. Erosion of the epicuticular wax and cuticle rupture were frequent on the adaxial surface, while on the abaxial surface of both leaves there was a loss of sinuosity on the anticlinal wall of the epidermal cells, stomatal deformity and obstruction. Micromorphometric alterations were seen in all leaf tissues except in the height of epidermic cells, probably due to the thick cuticle and prominent cuticular flanges. The highest difference in thickness of the leaf blade was seen in young leaves of plants subjected to SPMFe, indicating greater sensibility to particulate iron in comparison to the expanded leaves. The micromorphological and micromorphometric alterations in the leaf blade of Clusia hilariana Schltdl. showed the prognostic potential of these tools on the evaluation of impacts caused by the deposition of particulate matter, especially in the 'Restinga' natural vegetation, where the exposure is increasing due to the presence of iron ore industry in their surroundings.

  9. Structural Evolution of the Eastern Qiulitagh Fold and Thrust Belt, Northern Tarim Basin, China

    Institute of Scientific and Technical Information of China (English)

    YANG Minghui; JIN Zhijun; LU Xiuxiang; SUN Dongsheng; TANG Xuan; PENG Gengxin; LEI Ganglin

    2009-01-01

    The eastern Qiulitagh fold and thrust belt (EQFTB) is part of the active Kuqa fold and thrust belts of the northern Tarirn Basin. Seismic reflection profiles have been integrated with surface geologic and drill data to examine the deformation and structure style of the EQFTB, particularly the deformational history of the Dina 2 gas field. Seismic interpretations suggest that Dongqiu 8 is overall a duplex structure developed beneath a passive roof thrust, which generated from a tipline in the Miocene Jidike Formation, and the sole thrust was initiated from the same Jidike Formation evaporite zone that extends westward beneath the Kuqatawu anticline. Dongqiu 5 is a pop-up structure at the western part of the EQFTB, also developed beneath the Jidike Formation evaporite. Very gentle basement dip and steep dipping topographic slope in the EQFTB suggest that the Jidike Formation salt provides effective decoupling. The strong deformation in the EQFTB appears to have developed further south, in an area where evaporite may be lacking. Since the Pliocene, the EQFTB has moved farther south over the evaporite and reached the Yaken area. Restoring a balanced cross-section suggests that the minimum shortening across the EQFTB is more than 7800 m. Assuming that this shortening occurred during the 5.3 Ma timespan, the shortening rate is approximately 1.47 ram/year.

  10. THE CM-, MM-, AND SUB-MM-WAVE SPECTRUM OF ALLYL ISOCYANIDE AND RADIOASTRONOMICAL OBSERVATIONS IN ORION KL AND THE SgrB2 LINE SURVEYS

    Energy Technology Data Exchange (ETDEWEB)

    Haykal, I.; Margulès, L.; Huet, T. R.; Motyienko, R. A. [Laboratoire de Physique des Lasers, Atomes, et Molécules, UMR CNRS 8523, Université de Lille 1, F-59655 Villeneuve d' Ascq Cédex (France); Écija, P.; Cocinero, E. J.; Basterretxea, F.; Fernández, J. A.; Castaño, F. [Departamento de Química Física, Facultad de Ciencia y Tecnología, Universidad del País Vasco, Barrio Sarriena s/n, E-48940 Leioa (Spain); Lesarri, A. [Departamento de Química Física y Química Inorgánica, Facultad de Ciencias, Universidad de Valladolid, E-47011 Valladolid (Spain); Guillemin, J. C. [Institut des Sciences Chimiques de Rennes, Ecole Nationale Supérieure de Chimie de Rennes, CNRS, UMR 6226, Allèe de Beaulieu, CS 50837, F-35708 Rennes Cedex 7 (France); Tercero, B.; Cernicharo, J., E-mail: laurent.margules@univ-lille1.fr [Centro de Astrobiología (CSIC-INTA), Laboratory of Molecular Astrophysics, Department of Astrophysics, Ctra. De Ajalvir, km 4, E-28850 Torrejón de Ardoz, Madrid (Spain)

    2013-11-10

    Organic isocyanides have an interesting astrochemistry and some of these molecules have been detected in the interstellar medium (ISM). However, rotational spectral data for this class of compounds are still scarce. We provide laboratory spectra of the four-carbon allyl isocyanide covering the full microwave region, thus allowing a potential astrophysical identification in the ISM. We assigned the rotational spectrum of the two cis (synperiplanar) and gauche (anticlinal) conformations of allyl isocyanide in the centimeter-wave region (4-18 GHz), resolved its {sup 14}N nuclear quadrupole coupling (NQC) hyperfine structure, and extended the measurements into the millimeter and submillimeter-wave (150-900 GHz) ranges for the title compound. Rotational constants for all the monosubstituted {sup 13}C and {sup 15}N isotopologues are additionally provided. Laboratory observations are supplemented with initial radioastronomical observations. Following analysis of an extensive dataset (>11000 rotational transitions), accurate ground-state molecular parameters are reported for the cis and gauche conformations of the molecule, including rotational constants, NQC parameters, and centrifugal distortion terms up to octic contributions. Molecular parameters have also been obtained for the two first excited states of the cis conformation, with a dataset of more than 3300 lines. The isotopic data allowed determining substitution and effective structures for the title compound. We did not detect allyl isocyanide either in the IRAM 30 m line survey of Orion KL or in the PRIMOS survey toward SgrB2. Nevertheless, we provided an upper limit to its column density in Orion KL.

  11. Hydro-geophysical characterization for groundwater resources potential of fractured limestone reservoirs in Amdoun Monts (North-western Tunisia)

    Science.gov (United States)

    Redhaounia, Belgacem; Bédir, Mourad; Gabtni, Hakim; Batobo, Ountsche Ilondo; Dhaoui, Mohamed; Chabaane, Achref; Khomsi, Sami

    2016-05-01

    This study has led to the identification of the Upper Cretaceous and Lower Eocene (Abiod, Boudabbous/El Gueria Formations) fractured and karstic aquifers in the Amdoun region (Northwestern Tunisia). Geological information (litho-stratigraphy and fractures network study) and geophysical (gravity, wells analysis, seismic reflection, Electrical Resistivity Tomography (ERT)) investigations performed in the area have highlighted, with some detail, images of structures of carbonate aquifers near anticline flanks and along perched synclines. Some factors such as fracture intensity, karsts evolution and structural position have an important influence on the hydrologic productivity of Abiod and Boudabbous/El Gueria reservoirs. Different methodologies were used to characterize the geological and hydro-geological perched aquifers and produce the 3D geo-electrical model of near surface karstic features and cavities of the carbonate limestone in the Aïn Sallem site. This study integrates the geological and geophysical information available and can serve as a representative example in the description of the most important hydraulic reserves in the North-western Tunisia.

  12. SYNSEDIMENTARY TECTONICS AND SEDIMENTATION IN THE TERTIARY PIEDMONT BASIN, NORTHWESTERN ITALY

    Directory of Open Access Journals (Sweden)

    ROMANO GELATI

    1998-07-01

    Full Text Available The Late Oligocene/Early Miocene tectonic and sedimentary evolution of the eastern sector of the Langhe Sub-Basin (Teriary Piedmont Basin is proposed and discussed. The area is located between the villages of Roccaverano and Mombaldone, along the western side of the Bormida di Spigno River Valley (see attached geologic map. Synsedimentary tectonics strongly influenced the geologic evolution of the region during the time span examined, being particularly evident at three specific "times" that were chosen as models. During "Time 1" (Late Oligocene gentle anticlines, aligned WNW-ESE and NW-SE, started to form, affecting only hemipelagic mudstones and creating structural highs that controlled the areal distribution of both turbidites (i.e.T. Ovrano High and a thick pelitic slump sheet (i.e.M. Pisone High. During "Time 2"(Aquitanian the C. Mazzurini Half-Graben developed, separated by W-E and WNW-ESE growth faults from the M. Ovrano High to the north and gradually connecting, through a gently sloping ramp, with the Rocchetta High to the south. Turbidity currents and debris flows were channeled into the half-graben, while hemipelagic limestones were deposited onto the adjacent higher areas. During "Time 3" (Early Burdigalian the depocenter of the depression shifted southward, while the half-graben evolved into a wide trough (Piantivello Trough characterized by turbidites. Subsequently, the strongly irregular topography was progressively leveled to the quite homogeneous landscape on which the Cortemilia Formation (Late Burdigalian was deposited. 

  13. CO$_2$ dissolution controlled by buoyancy driven shear dispersion in a background hydrological flow

    CERN Document Server

    Unwin, H Juliette T; Woods, Andrew W

    2015-01-01

    We present an analytical and numerical study of the long-time flow which controls the dissolution of a plume of CO$_2$ following injection into an anticline structure in a deep saline aquifer of finite vertical extent. Over times of tens to thousands of years, some of the CO$_2$ will dissolve into the underlying groundwater to produce a region of relatively dense, CO$_2$ saturated water directly below the plume of CO$_2$. Continued dissolution then requires the supply of CO$_2$ unsaturated aquifer water. This may be provided by a background hydrological flow or buoyancy driven flow caused by the density contrast between the CO$_2$ saturated and unsaturated water in the aquifer. At long times, the interaction of the cross-layer diffusive mixing with the buoyancy, leads to buoyancy driven shear dispersion of the CO$_2$. With a background hydrological flow, the upstream transport of dissolved CO$_2$ by this dispersion becomes balanced by the oncoming hydrological flow so that CO$_2$ rich water can only spread a ...

  14. Natural and historic heritage of the Bochnia Salt Mine (South Poland

    Directory of Open Access Journals (Sweden)

    Janusz Wiewiorka

    2009-06-01

    Full Text Available The Bochnia Salt Mine, presented in this paper, is situated ca. 40 km E of Cracow, in the southern part of the Neogene Carpathian Foredeep, close to the Carpathian edge. In this region the rock-salt deposits formed as a result of the Late Miocene folding and local tectonic thickening of Badenian evaporites. The Bochnia deposit, situated in the almost vertical N limb of the Bochnia Anticline, stretches ca. 7 km WE, but only 15-200 m NS. Salt mining in Bochnia began in the thirteenth c. and continued until 1990. The historic part of the mine, since 1995 operated by a company supplying health and tourism services, is an officially listed monument of historic heritage. Legal protection also comprises 27 sites of key value for the geology of the deposit. These documentation sites record the whole profile of the evaporite series and the adjacent beds, main and minor tectonic structures, as well as mineralogical curiosities, such as fibrous halite and enterolithic anhydrite. For some years, efforts have been made to enter the Bochnia Salt Mine, in 2008 visited by over 140 000 tourists, on the UNESCO World List of Cultural and Natural Heritage.

  15. Functional-adaptive anatomy of the axial skeleton of some extant marsupials and the paleobiology of the paleocene marsupials Mayulestes ferox and Pucadelphys andinus.

    Science.gov (United States)

    Argot, Christine

    2003-03-01

    In this study, the axial skeletons of two Early Paleocene marsupials, Mayulestes ferox and Pucadelphys andinus, were analyzed functionally and compared to that of six South American and three Australian species of extant marsupials. In the case of the South American opossums, myological data of the epaxial musculature were collected and analyzed and osteological-myological associations were related to locomotor behavior. Various features of the vertebral column that relate to diet or to locomotor or postural patterns were pointed out. These features include: the craniocaudal development of the neural process of the axis; the position of the anticlinal vertebra; the morphology of the neural processes of the thoracolumbar vertebrae (orientation, length, and craniocaudal width); the length, orientation, and curvature of the transverse processes of the lumbar vertebrae; and the length and robustness of the caudal vertebrae. In both fossil forms the vertebral column is mobile and allows a great range of flexion and extension of the spine, more so than in most of the living didelphids. It is emphasized here that the analysis of the axial skeleton complements and improves the conclusions provided by the forelimb and hindlimb analyses. It is proposed that Mayulestes and Pucadelphys represent an ancestral morphotype suggesting that the generalized type of locomotion of Paleocene marsupials was partly terrestrial with some climbing ability.

  16. Using structure restoration maps to comprehensively identify potential faults and fractures in compressional structures

    Institute of Scientific and Technical Information of China (English)

    OU Cheng-hua; CHEN Wei; LI Chao-chun

    2016-01-01

    Faults and fractures of multiple scales are frequently induced and generated in compressional structural system. Comprehensive identification of these potential faults and fractures that cannot be distinguished directly from seismic profile of the complex structures is still an unanswered problem. Based on the compressional structural geometry and kinematics theories as well as the structural interpretation from seismic data, a set of techniques is established for the identification of potential faults and fractures in compressional structures. Firstly, three-dimensional (3D) patterns and characteristics of the faults directly interpreted from seismic profile were illustrated by 3D structural model. Then, the unfolding index maps, the principal structural curvature maps, and tectonic stress field maps were obtained from structural restoration. Moreover, potential faults and fractures in compressional structures were quantitatively identified relying on comprehensive analysis of these three maps. Successful identification of the potential faults and fractures in Mishrif limestone formation and in Asmari dolomite formation of Buzurgan anticline in Iraq demonstrates the applicability and reliability of these techniques.

  17. Interplay of thrust, back-thrust, strike-slip and salt tectonics in a fold and thrust belt system: an example from Zakynthos Island, Greece

    Science.gov (United States)

    Zelilidis, A.; Papatheodorou, G.; Maravelis, A. G.; Christodoulou, D.; Tserolas, P.; Fakiris, E.; Dimas, X.; Georgiou, N.; Ferentinos, G.

    2016-10-01

    The southwestern flank of the Hellenic fold and thrust belt, situated along the southern edge of the Dinarides-Albanides-Hellenides continental convergent zone, was examined for reconstructing the tectonic deformation. This investigation presents an integrated study of onshore sedimentological and structural analyses, as well as offshore seismic lines, across the Pliocene-Pleistocene sedimentary succession in Zakynthos Island. Back-thrust faults, using the Triassic evaporites as decollement surface, during the Pliocene, and coeval diapiric intrusions formed three sub-basins on the hangingwall of the Kalamaki back-thrust fault. This interaction is responsible for the growth of the Skopos Mountain and the soft sediment deformation that formed synclines and slumps, respectively. Back-thrust and strike-slip faults were active during the early Pleistocene, and diapiric intrusions modified the bathymetry on the sea floor, giving rise to slumps and recumbent folds. At least five events of synsedimentary diapiric intrusions have been recognized and are marked by five slump horizons. During the Holocene, the diapiric intrusions between the Kalamaki back-thrust and the Vrachionas anticline could be either related to normal faults or gravitationally driven.

  18. Blue-light-induced rapid chloroplast de-anchoring in Vallisneria epidermal cells

    Institute of Scientific and Technical Information of China (English)

    Yuuki Sakai; Shin-Ichiro Inoue; Akiko Harada; Ken-Ichiro Shimazaki; Shingo Takagi

    2015-01-01

    In the outer periclinal cytoplasm of leaf epidermal cells of an aquatic angiosperm Vallisneria, blue light induces “chloroplast de‐anchoring”, a rapid decline in the resistance of chloroplasts against centrifugal force. Chloroplast deanchoring is known induced within 1 min of irradiation with high‐fluence‐rate blue light specifically, preceding the commencement of chloroplasts migration toward the anticlinal cytoplasm. However, its regulatory mechanism has remained elusive, although pharmacological analysis suggested that a calcium release from intracellular calcium stores is necessary for the response. In search of the responsible photoreceptors, immunoblotting analysis using antibodies against phototropins demonstrated that cross‐reactive polypeptides of 120‐kDa exist in the plasma‐membrane fraction prepared from the leaves. In vitro phosphorylation analysis revealed that 120‐kDa polypeptides were phosphorylated by exposure to blue light in a fluence‐dependent manner. The blue‐light‐induced phosphorylation activity was sensitive to a Ser/Thr kinase inhibitor, staurosporine, and unusually was retained at a high level for a long time in darkness. Furthermore, phototropin gene homologs (Vallisneria PHOTOTROPIN1 and PHOTOTROPIN2) expressed in leaves were isolated. We propose that calciumregulated chloroplast de‐anchoring, possibly mediated by phototropins, is an initial process of the blue‐light‐induced avoidance response of chloroplasts in Vallisneria.

  19. Structure of Kalanchoë pumila Bak. leaves (Crassulaceae DC.

    Directory of Open Access Journals (Sweden)

    Mykhaylo Chernetskyy

    2012-12-01

    Full Text Available The structure of Kalanchoё pumila Bak. was studied with the use of stereoscopic, light, scanning and transmission electron microscopy. It was found that the chlorenchymatic tissue was divided into subepidermal small-celled mesophyll and large-celled (water transporting, CAM type mesophyll, placed in the central part of the leaf. The mesophyll structure and its cell ultrastructure indicate C3 photosynthesis in this taxon, whereas CAM photosynthesis, being an adaptive syndrome, is induced by external factors. Three groups of xeromorphic traits were observed in the structure of K. pumila leaves, related to: 1 storing water in the ground and epidermal tissues, 2 decreased transpiration (the closing of stomata during heat, 3 avoiding excess insolation of the mesophyll and overheating of the leaf (striated cuticula, anthocyan pigments, tannin storage. The last two groups of xeromorphic traits also include thickening of the outer walls of cuticular cells, a thick-layered cuticula, and the presence of epicuticular wax and calcium carbonate deposits. Microchannels which enhance transpiration efficiency in developing K. pumila leaves were found in the vicinity of anticlinal walls in the outer walls of epidermal cells. Calcium deposits produced on the leaf surfaces protect them in extreme conditions. Adaptive traits in the structure of K. pumila leaves are conservative and they confirm the relations between this taxon and the conditions in their native land.

  20. ANALYSIS ON TUNNEL WATER GUSHING OF SHIZUI COPPER MINE IN PANSHI CITY%磐石石咀铜矿坑道涌水分析

    Institute of Scientific and Technical Information of China (English)

    王岩; 田广明

    2015-01-01

    磐石石咀铜矿位于吉林省中南部磐石-明城背斜的东翼,区内经历了多期多阶段构造运动.矿体赋存于石咀子组大理岩、硅质条带大理岩中,岩石溶隙、溶洞较发育,地质条件复杂.从矿区水文地质特征、地下水补迳排关系、矿坑充水因素等要素入手,综合分析坑道涌水特点、涌水规律,并预测其涌水量,指导矿山水文地质工作.%The Shizui copper mine of Panshi is located at the east limb of Mingcheng anticline in Jilin province. It has undergone multi-stage tectonic movements. The ore bodies occur in marble and Siliceous bands marble of Shizuizi Formation. The solution fissure and karst cave developed well in rock, and the geological condition is complex. According to the hydrogeological feature, the groundwater recharge, flow and discharge relationship as well as mining water filling factors, we analysed the feature and the law of tunnel water gushing synthetically and predicted the water yield in order to guide the hydrogeological work.

  1. SUPERPOSE-An excel visual basic program for fracture modeling based on the stress superposition method

    Science.gov (United States)

    Ismail Ozkaya, Sait

    2014-03-01

    An Excel Visual Basic program, SUPERPOSE, is presented to predict the distribution, relative size and strike of tensile and shear fractures on anticlinal structures. The program is based on the concept of stress superposition; addition of curvature-related local tensile stress and regional far-field stress. The method accurately predicts fractures on many Middle East Oil Fields that were formed under a strike slip regime as duplexes, flower structures or inverted structures. The program operates on the Excel platform. The program reads the parameters and structural grid data from an Excel template and writes the results to the same template. The program has two routines to import structural grid data in the Eclipse and Zmap formats. The platform of SUPERPOSE is a single layer structural grid of a given cell size (e.g. 50×50 m). In the final output, a single tensile or two conjugate shear fractures are placed in each cell if fracturing criteria are satisfied; otherwise the cell is left blank. Strike of the representative fracture(s) is calculated and exact, but the length is an index of fracture porosity (fracture density×length×aperture) within that cell.

  2. New material of microfossils from the Ediacaran Doushantuo Formation in the Zhangcunping area,Yichang, Hubei Province and its zircon SHRIMP U-Pb age

    Institute of Scientific and Technical Information of China (English)

    LIU PengJu; YIN ChongYu; GAO LinZhi; TANG Feng; CHEN ShouMing

    2009-01-01

    The Zhangcunping area is located at the north limb of the Huangling anticline in Yichang, Hubei Province. Here, the sedimentary succession of the Ediacaran Doushantuo Formation is similar with that in the Weng'an area, Guizhou Province. A large number of new microfossils (mainly acanthoacritarchs) from the Doushantuo Formation in this area are reported in this paper. The fossil assemblage shows similarity as the phosphatized biota of the Doushantuo Formation at Wang'an, Guizhou Province and the silicified biota of the Doushantuo Formation at the Yangtze Gorges, which suggests that the Zhangcunping area is a key for correlation of the Doushantuo Formation between the Weng'an area,Guizhou Province and the Yangtze Gorges. Besides, a new zircon SHRIMP U-Pb age (614.0±7.6 Ma) is first obtained from a horizon underneath the exposed surface in the middle of the Doushantuo Formation in the Zhangcunping area. This age not only provides a new datum for subdivision of the Ediacaran Doushantuo Formation, but also indicates that the age of the exposed surface in the middle of the Doushantuo Formation in the Yangtze Platform should be posterior to 614.0±7.6 Ma. Due to the horizon of the Weng'an biota situated above the exposed surface, the age of the Wang'an biota should be posterior to 614.0±7.6 Ma as well.

  3. Uranium favorability of the San Rafael Swell area, east-central Utah

    Energy Technology Data Exchange (ETDEWEB)

    Mickle, D G; Jones, C A; Gallagher, G L; Young, P; Dubyk, W S

    1977-10-01

    The San Rafael Swell project area in east-central Utah is approximately 3,000 sq mi and includes the San Rafael Swell anticline and the northern part of the Waterpocket Fold monocline at Capitol Reef. Rocks in the area are predominantly sedimentary rocks of Pennsylvanian through Cretaceous age. Important deposits of uranium in the project area are restricted to two formations, the Chinle (Triassic) and Morrison (Jurassic) Formations. A third formation, the White Rim Sandstone (Permian), was also studied because of reported exploration activity. The White Rim Sandstone is considered generally unfavorable on the basis of lithologic characteristics, distance from a possible source of uranium, lack of apparent mineralization, and the scarcity of anomalies on gamma-ray logs or in rock, water, and stream-sediment samples. The lower Chinle from the Moss Back Member down to the base of the formation is favorable because it is a known producer. New areas for exploration are all subsurface. Both Salt Wash and Brushy Basin Members of the Morrison Formation are favorable. The Salt Wash Member is favorable because it is a known producer. The Brushy Basin Member is favorable as a low-grade resource.

  4. Geologic description of middle Devonian Chert Reservoir, Block 31 field, Crane County, Texas

    Energy Technology Data Exchange (ETDEWEB)

    Ebanks, W.J. Jr.

    1988-01-01

    Block 31 field is a large anticlinal structure that produces from six pay zones. The first miscible gas-injection enhanced oil recovery project has been operated by ARCO since 1952 in the middle Devonian reservoir, which is the main producing interval in the field. The middle Devonian unit was deposited as a siliceous, calcareous ooze in a basin-slope environment in the ancient Tobosa basin. Sedimentation buried earlier fault blocks, as the slope deposits aggraded and prograded mainly from the west and south. Subsequent diagenesis converted the ooze into calcareous chert. Reservoir quality of the chert depends on degree of compaction and quartz cementation. Gray, dense, glassy chert at the base of the sequence is nonporous except for small, incipient fractures in the brittle matrix. Creamy white, evenly laminated, microporous, calcareous chert, which alternates with and overlies the dense chert in the lower half of the middle Devonian interval, has porosity of 10-30% and permeability as great as 10 md. The upper half of the reservoir interval consists mainly of light-gray and white, partially porous, heterogeneous, calcareous chert. This rock type has porosity of 5-20%, but permeability is usually less than 3 md. Patchy silica cement, discontinuous low-permeability laminae, and thin beds of dense limestone reduce its effectiveness as a reservoir.

  5. Developmental anatomy and morphology of the ovule and seed of heliconia (heliconiaceae, zingiberales).

    Science.gov (United States)

    Simão, D G; Scatena, V L; Bouman, F

    2006-01-01

    The developmental anatomy and morphology of the ovule and seed in several species of Heliconia were investigated as part of an embryological study of the Heliconiaceae and to provide a better understanding of their relationships with the other families of the Zingiberales. Heliconia species have an ovule primordium with an outer integument of both dermal and subdermal origin. The archesporial cell is divided into a megasporocyte and a single parietal cell, which in turn are divided only anticlinally to form a single parietal layer, disintegrating later during gametogenesis. The embryo sac was fully developed prior to anthesis. In the developing seed, the endosperm was nuclear, with wall formation in the globular stage; a nucellar pad was observed during embryo development, but later became compressed. The ripe fruit contained seeds enveloped by a lignified endocarp that formed the pyrenes, with each pyrene having an operculum at the basal end; the embryo was considered to be differentiated. Most of these characteristics are shared with other Zingiberales, although the derivation of the operculum from the funicle and the formation of the main mechanical layer by the endocarp are unique to the Heliconiaceae.

  6. Association among active seafloor deformation, mound formation, and gas hydrate growth and accumulation within the seafloor of the Santa Monica Basin, offshore California

    Science.gov (United States)

    Paull, C.K.; Normark, W.R.; Ussler, W.; Caress, D.W.; Keaten, R.

    2008-01-01

    Seafloor blister-like mounds, methane migration and gas hydrate formation were investigated through detailed seafloor surveys in Santa Monica Basin, offshore of Los Angeles, California. Two distinct deep-water (??? 800??m water depth) topographic mounds were surveyed using an autonomous underwater vehicle (carrying a multibeam sonar and a chirp sub-bottom profiler) and one of these was explored with the remotely operated vehicle Tiburon. The mounds are > 10??m high and > 100??m wide dome-shaped bathymetric features. These mounds protrude from crests of broad anticlines (~ 20??m high and 1 to 3??km long) formed within latest Quaternary-aged seafloor sediment associated with compression between lateral offsets in regional faults. No allochthonous sediments were observed on the mounds, except slumped material off the steep slopes of the mounds. Continuous streams of methane gas bubbles emanate from the crest of the northeastern mound, and extensive methane-derived authigenic carbonate pavements and chemosynthetic communities mantle the mound surface. The large local vertical displacements needed to produce these mounds suggests a corresponding net mass accumulation has occurred within the immediate subsurface. Formation and accumulation of pure gas hydrate lenses in the subsurface is proposed as a mechanism to blister the seafloor and form these mounds. ?? 2008 Elsevier B.V. All rights reserved.

  7. Bottom Simulating Reflector and Gas Seepage in Okinawa Trough: Evidence of Gas Hydrate in an Active Back-Arc Basin

    Institute of Scientific and Technical Information of China (English)

    Luan Xiwu; Kelin Wang; Roy Hyndman; Eleanor Willoughby

    2008-01-01

    To look for gas hydrate, 22 multi-channel and 3 single-channel seismic lines on the East China Sea (ECS) shelf slope and at the bottom of the Okinawa Trough were examined. It was found that there was indeed bottom simulating reflector (BSR) occurrence, but it is very rare. Besides several BSRs, a gas seepage was also found. As shown by the data, both the BSR and gas seepage are all related with local geological structures, such as mud diapir, anticline, and fault-controlled graben-like structure. However, similar structural "anomalies" are quite common in the tectonically very active Okinawa Trough region, but very few of them have developed BSR or gas seepage. The article points out that the main reason is probably the low concentration of organic carbon of the sediment in this area. It was speculated that the rare occurrence of gas hydrates in this region is governed by structure-controlled fluid flow. Numerous faults and fractures form a network of high-permeability channels in the sediment and highly fractured igneous basement to allow fluid circulation and ventilation. Fluid flow in this tectonic environment is driven primarily by thermal buoyancy and takes place on a wide range of spatial scales. The fluid flow may play two roles to facilitate hydrate formation:to help gather enough methane into a small area and to modulate the thermal regime.

  8. Preuves de la non-stratification du Trias dans le Turonien de la Koudiat Sidii (Nord-Ouest de la Tunisie)Evidence of the non-interbedding of the Triassic evaporites within the Turonian sediments in the Koudiat Sidii area (north-western Tunisia)

    Science.gov (United States)

    Chikhaoui, Mongi; Braham, Ahmed; Turki, Mohamed Moncef

    2001-06-01

    The cartographic and biostratigraphic datings carried out at Koudiat Sidii do not confirm the interbedding of the Triassic rocks within the Turonian sediments. Interrelationships between cartographic, drill holes and gravimetric dating show that the Triassic rocks form the core of a large anticline, flanked by Cretaceous and Neogene outcrops. Of this structure, in large parts collapsed and buried under a thick Quaternary deposit, we only see the western flank, formed by dolomitic breccia of Triassic rocks supporting a set that spreads from Upper Cenomanian to Upper Senonian. The occurrence of Triassic debris flow reworked in the Turonian allows us to interpret the Triassic material as a diapiric extrusion, which reached the surface during the Turonian times, in the tectonic corner of ancient faults trending north-south and NE-SW. During the Tertiary tightening phases, oriented NW-SE, the induced folded structures are strongly controlled by these tectonic directions. Particularly, the meridian fold corresponds to the torsion of J. Hout NE-SW fold in the neighbourhood of the north-south palaeofaults.

  9. 沁水煤田流渠勘查区煤层赋存特征%Occurrence Features of Coal Seam of Flow Channel Exploration Area of Qinshui Coalfield

    Institute of Scientific and Technical Information of China (English)

    李重阳

    2014-01-01

    沁水煤田流渠勘查区构造简单,地层总体产状为走向北东,倾向北西的单斜。勘查区东部外侧有一小型背斜,背斜影响使范围内地层产状发生变换和地层产状的变换,导致各煤层底板标高及煤层间间距发生变换。%The flow channel exploration area of Qinshui coa-lfield has the advantages of simple structure;the coal strip ro-ughly stretches from the Northern East with monoclinic ten-dency towards Northern West. At the east lateral part of the exploration area is a small anticline which makes the change of the coal strip form in its governing scope, leading to the cha-nge of the elevation height of the coal seam floor and the seam spacing.

  10. Combined methods for the exploration of a new deep thermal water resource. Case of Yverdon-les-bains, south foot of the Swiss Jura

    Energy Technology Data Exchange (ETDEWEB)

    Vuataz, F.D.; Muralt, R. [Centre d`Hydrogeologie, Universite de Neuchatel (Switzerland)

    1997-12-01

    The major goal of this study is to evaluate the potential of warmer and deeper groundwater than the one presently produced at the Centre thermal of Yverdon-les-Bains. Numerous data originating from seismic lines and boreholes allowed to obtain a good understanding of the regional structural geology. However, these data are limited in the faulted zone of Pipechat-CHAMBLON-CHEVRESSY (PCC) crossing the city of Yverdon, and make difficult the detailed structural interpretation on the site of the old thermal spring and the 600 m-deep well. The latter drains the Malm limestone at about 100 m of the south fault plane, which indicates the importance on the hydraulic role played by the main fault or by network of associated faults. The results of a specific vibro-seismic survay carried out in the urban area of Yverdo, closeenough to the Centre thermal, showed the precise location of the anticline axis formed by the PCC fault zone. Individual reflectors have been deciphered and represent the thickness and the structure of the quaternary and molassic sediments, on both sides of fault zone. (orig.)

  11. Fold-to-fault progression of a major thrust zone revealed in horses of the North Mountain fault zone, Virginia and West Virginia, USA

    Science.gov (United States)

    Orndorff, Randall C.

    2012-01-01

    The method of emplacement and sequential deformation of major thrust zones may be deciphered by detailed geologic mapping of these important structures. Thrust fault zones may have added complexity when horse blocks are contained within them. However, these horses can be an important indicator of the fault development holding information on fault-propagation folding or fold-to-fault progression. The North Mountain fault zone of the Central Appalachians, USA, was studied in order to better understand the relationships of horse blocks to hanging wall and footwall structures. The North Mountain fault zone in northwestern Virginia and eastern panhandle of West Virginia is the Late Mississippian to Permian Alleghanian structure that developed after regional-scale folding. Evidence for this deformation sequence is a consistent progression of right-side up to overturned strata in horses within the fault zone. Rocks on the southeast side (hinterland) of the zone are almost exclusively right-side up, whereas rocks on the northwest side (foreland) of the zone are almost exclusively overturned. This suggests that the fault zone developed along the overturned southeast limb of a syncline to the northwest and the adjacent upright limb of a faulted anticline to the southeast.

  12. Fracture patterns in the Zagros fold-and-thrust belt, Kurdistan Region of Iraq

    Science.gov (United States)

    Reif, Daniel; Decker, Kurt; Grasemann, Bernhard; Peresson, Herwig

    2012-11-01

    Fracture data have been collected in the Kurdistan Region of Iraq, which is a poorly accessible and unexplored area of the Zagros. Pre to early folding NE-SW striking extensional fractures and NW-SE striking contractive elements represent the older set affecting the exposed multilayer of the area. These latter structures are early syn-folding and followed by folding-related mesostructural assemblages, which include elements striking parallel to the axial trend of major folds (longitudinal fractures). Bedding perpendicular joints and veins, and extensional faults belonging to this second fracture set are located in the outer arc of exposed anticlines, whilst longitudinal reverse faults locate in the inner arcs. Consistently, these elements are associated with syn-folding tangential longitudinal strain. The younger two sets are related to E-W extension and NNE-SSW to N-S shortening, frequently displaying reactivation of the older sets. The last shortening event, which is described along the entire Zagros Belt, probably relates with the onset of N-S compression induced by the northward movement of the Arabian plate relative to the Eurasian Plate. In comparison between the inferred palaeostrain directions and the kinematics of recent GPS measurements, we conclude that the N-S compression and the partitioning into NW-SE trending folds and NW to N trending strike-slip faults likely remained unchanged throughout the Neogene tectonic history of the investigated area.

  13. Feedback between erosion and active deformation: geomorphic constraints from the frontal Jura fold-and-thrust belt (eastern France)

    Science.gov (United States)

    Madritsch, Herfried; Fabbri, Olivier; Hagedorn, Eva-Marie; Preusser, Frank; Schmid, Stefan M.; Ziegler, Peter A.

    2010-10-01

    A regional tectono-geomorphic analysis indicates a Pliocene to recent rock uplift of the outermost segment of the Jura fold-and-thrust belt, which spatially coincides with the intra-continental Rhine-Bresse Transfer Zone. Elevated remnants of the partly eroded Middle Pliocene Sundgau-Forêt de Chaux Gravels identified by heavy mineral analyses allow for a paleo-topographic reconstruction that yields minimum regional Latest Pliocene to recent rock uplift rates of 0.05 ± 0.02 mm/year. This uplift also affected the Pleistocene evolution of the Ognon and Doubs drainage basins and is interpreted as being tectonically controlled. While the Ognon River was deflected from the uplifted region the Doubs deeply incised into it. Focused incision of the Doubs possibly sustained ongoing deformation along anticlines which were initiated during the Neogene evolution of the thin-skinned Jura fold-and-thrust belt. At present, this erosion-related active deformation is taking place synchronously with thick-skinned tectonics, controlling the inversion of the Rhine-Bresse Transfer Zone. This suggests local decoupling between seismogenic basement faulting and erosion-related deformation of the Mesozoic cover sequences.

  14. Recent earthquake activity in Trichonis region and its tectonic significance

    Directory of Open Access Journals (Sweden)

    N. DELIBASIS

    1977-06-01

    Full Text Available SUMMARY. - The aftershock activity associated with the central Greece
    (Trichonis Lake earthquake of |une-Dec. 1975, has been studied, with emphasis
    on the time and magnitude distribution. It has been found that the value of b,
    in Gutenberg - R i c h t e r ' s relationship was near the same for the primary as
    well as the secondary or second order aftershocks of the sequences, but depends
    upon the focal depth.
    A correlation between the calculated focal mechanisms and the associated
    stress components to the distribution pattern of meizoseismic effects as well
    as to the geological structure of the seismic region was found.
    The seismic region lies at the top of an anticline which was found moving
    downwards, apparently due to compressional stresses.
    Within the series of three earthquakes the progress of the destruction of
    the buildings was observed and reported. The interest is concentrated to modern
    buildings out of reinforced concrete and infill brick walls. The relatively unexpected
    rather bad performance of the later case of buildings was compared to that
    of the traditional small houses out of brick or stone masonry, the behaviour of
    which may be considered as better from what it was expected.

  15. The enrichment characteristics and geological controlling factors of coalbed methane occurrence in Laochang area, Yunnan Province

    Institute of Scientific and Technical Information of China (English)

    WU Cai-fang; CHEN Zhao-ying; WANG Cong; JIANG Wei

    2012-01-01

    The enriched characters of methane content in the main coal seam of Yunnan's Laochang coal mine was analyzed through combined with the geologic conditions of the research area:structure type,hydrogeology condition,coal reservoir's macerals,ash,water content,and so on.The geology factors of controlling gas in Laochang coal mine were illustrated; and the different geology models of controlling gas of geologic condition coupling were posed.Research shows that,in the region,the methane contents of the main coal seams decrease gradually from middle to all around it; the northeast and southeast is higher than the west.In the local area,the methane content of anticline axis is higher,and the gas content is reduced to both wings and plunging crown.On macroscopic view,the distribution of methane content in coal-beds was controlled by structural type.On microscopic view,the methane content in coal-beds is mainly involved in coal reservoir's macerals,ash content,and water content.The enriched characters of CBM in the research area are mainly the result of structure-hydrogeology-petrophysics coupling controls of CBM.On the basis of above analysis,according to the distribution character of methane content in coalbeds,the research area was divided into low gas area,middle gas area,and high gas area.

  16. Exploration and development of the fluvial deposits in the Potrerillos Formation, Cuyana Basin, Mendoza, Argentina

    Energy Technology Data Exchange (ETDEWEB)

    Fernandez, C.; Agraz, P. [YPF, S.A., Av. San Martin, Mendoza (Argentina)

    1996-08-01

    In the Barrancas area are located the oil fields related to structures developed in the Oriental axis of the Cuyana Basin. The anticlinal axis of the Barraticas oil field has a NNW-SSE strike and dips toward North. The Oriental flank is abruptly bounded by faulting whilst the Occidental one is gently dipping. The Barrancas oil field was developed between the 1940s and 1960s, having both Early Jurassic conglomerates of the Barrancas Formation and Triassic fluvial braided deposits from Las Cabras Formation as the main targets. The review of new plays within the Triassic fluvial cycles belonging to the Potrerillos Formation was encouraged by the success obtained in the recovery of important volumes of oil from the overlying Formations. The application of a sequence stratigraphy approach to the fluvial settings combined with petrophysics data from outcrop studies and a 3D seismic interpretation allowed a new play concept to be conceived. This new play concept will have application in zones far away from the study area, where Potrerillos Formation has exploration interest. A team integrate by geologists, geophysicists, and engineers has produced new opportunities on mature oil fields with up to 300 drilled wells.

  17. A developmental framework for complex plasmodesmata formation revealed by large-scale imaging of the Arabidopsis leaf epidermis.

    Science.gov (United States)

    Fitzgibbon, Jessica; Beck, Martina; Zhou, Ji; Faulkner, Christine; Robatzek, Silke; Oparka, Karl

    2013-01-01

    Plasmodesmata (PD) form tubular connections that function as intercellular communication channels. They are essential for transporting nutrients and for coordinating development. During cytokinesis, simple PDs are inserted into the developing cell plate, while during wall extension, more complex (branched) forms of PD are laid down. We show that complex PDs are derived from existing simple PDs in a pattern that is accelerated when leaves undergo the sink-source transition. Complex PDs are inserted initially at the three-way junctions between epidermal cells but develop most rapidly in the anisocytic complexes around stomata. For a quantitative analysis of complex PD formation, we established a high-throughput imaging platform and constructed PDQUANT, a custom algorithm that detected cell boundaries and PD numbers in different wall faces. For anticlinal walls, the number of complex PDs increased with increasing cell size, while for periclinal walls, the number of PDs decreased. Complex PD insertion was accelerated by up to threefold in response to salicylic acid treatment and challenges with mannitol. In a single 30-min run, we could derive data for up to 11k PDs from 3k epidermal cells. This facile approach opens the door to a large-scale analysis of the endogenous and exogenous factors that influence PD formation.

  18. Thrust-related, diapiric, and extensional doming in a frontal orogenic wedge: example of the Montagne Noire, Southern French Hercynian Belt

    Science.gov (United States)

    Soula, Jean-Claude; Debat, Pierre; Brusset, Stéphane; Bessière, Gilbert; Christophoul, Frédéric; Déramond, Joachim

    2001-11-01

    The Montagne Noire, which is situated at the toe of the orogenic wedge of the French Massif Central South European Variscides, appears to be a well-suited area for studying the origin and evolution of middle to upper crustal domes adjacent to foreland basins. The data reported in the present paper show that the Montagne Noire dome is a particular type of basement-involved frontal culmination in an orogenic wedge and foreland basin system. This frontal culmination is characterized by a syn-contractional HT decompression recorded by clockwise PTt paths and widespread strata overturning in thrust and fold structures, which controlled the sedimentation in the adjacent foreland basin. These unusual characteristics are interpreted to be a result of the succession of thrusting, diapirism and extensional collapse. Antiformal stacking of syn-metamorphic thrust sheets controlled the first stages of the foreland basin development. Diapirism was essentially responsible for the HT decompression and widespread strata overturning. Extensional doming was a result of late- to post-metamorphic collapse acting on the pre-existing high-amplitude dome. Diapirism and associated isothermal decompression metamorphism, which constitute the essential difference between the Montagne Noire and 'ordinary' frontal ridges in orogenic wedges, were probably enhanced by a local partial melting of the upper to middle crust. It is suggested that the occurrence of these phenomena in front of an orogenic wedge was related to local over-thickening due to the superposition of an upper crustal antiformal stack on top of a lower crustal ramp anticline.

  19. Evidence for an intra-Oligocene compressive event in the Marseille-Aubagne basins (SE France)

    Energy Technology Data Exchange (ETDEWEB)

    Villeneuve, M.; Nury, D.; Arihac, P.; Gartner, A.; Linnemann, U.; Pantaine, L.

    2016-10-01

    An Oligocene tectonic event has been suspected as the origin of thrusts and folds in several Oligocene troughs and basins of Provence, including the Marseille-Aubagne basins. Deformations are generally assumed to be to a post Oligocene extensional event. The Marseille-Aubagne basins are geographically and stratigraphically separated into three basins (Jarret, Prado and Aubagne) with each of them exhibiting their own sedimentary succession. However, each of the successions includes two main units: - The lower unit which includes several formations attributed to the Rupelian age. All of these sediments are strongly or slightly deformed depending on their location with respect to the main faults. - The upper unit which includes formations of mainly Chattian age. They are undeformed or slightly deformed. Geological sections across the southern Prado basin show a succession of anticlines and synclines. Additionally the thrusting of the Carpiagne massif over the Prado basin has been evidenced since 1952. These deformations are here related to a compressional event According to palaeontological data, the latest deformed strata are ascribed to the Late Rupelian, whereas the earliest undeformed strata are ascribed to the Latest Rupelian. This is in accordance with age determinations on detrital zircons extracted from the latest deformed sandstone, and from the youngest age of detrital zircons from the undeformed sandstone. Thus, the stratigraphic limit between the deformed and undeformed formations should be set around the Rupelian / Chattian limit (28.1 Ma) according to the latest chronostratigraphic chart. Finally, we discuss correlations with similar events occurring around the Mediterranean area. (Author)

  20. Micromorphological study (ultrastructure of lamina surface, seeds, ultrasculpture of pollen grains of Gladiolus L. species (Iridaceae Juss. of Ukrainian flora

    Directory of Open Access Journals (Sweden)

    Zhygalova Svitlana L.

    2014-12-01

    Full Text Available Micro-morphological characteristics of the four Gladiolus L. species of the Ukrainian flora (G. imbricatus L., G. italicus Mill., G. palustris Gaudin and G. tenuis M. Bieb. as regards leaves, seeds and pollens are presented with this investigation in a detailed way. An examination of the surface structure of the leaves, seeds and pollen grains of the Gladiolus species indicates that the characteristics of the ultrastructure of leaves and of pollen grains are not diagnostic for distinguishing species, but they could be important at genus level (leaves: features such as being amphistomatic, having the same quantity of immersed stomata on both surfaces and having a high stomata index, the presence and localisation of papillae, the shape of epidermal cells; pollen grains: monosulcate type with two operculums. However, the type of surface ultrastructure of the seed coat is a diagnostic feature as at genus level so for species. It can be mentioned that propose the use of features such as the shape and position of the cicatricle, the type of cuticle, the shape and boundaries of cells of testa, and the anticlinal cell walls as diagnostic features at genera level. The shape of seeds, the presence and disposition of wing, the level of the periclinal cell walls of the seed coat and types of relief are additional diagnostic features for distinguishing of Gladiolus species.

  1. Micromorfologia da superfície do fruto de espécies de Mikania Willd. (Asteraceae ocorrentes no estado do Rio Grande do Sul, Brasil Micromorphology of fruit surfaces in species of Mikania Willd. (Asteraceae occurring in Rio Grande do Sul State, Brazil

    Directory of Open Access Journals (Sweden)

    Mara Rejane Ritter

    2006-03-01

    Full Text Available A micromorfologia da superfície dos frutos de 15 táxons de Mikania Willd. em microscopia eletrônica de varredura (MEV é apresentada neste trabalho. Buscaram-se caracteres que auxiliassem a separação de espécies próximas, ocorrentes no Estado do Rio Grande do Sul. Para algumas delas, estes caracteres mostraram valor taxonômico. As espécies estudadas foram divididas em quatro grupos, de acordo com o padrão encontrado. O padrão que apresentou paredes periclinais estriadas e paredes anticlinais com projeções verrucosas foi o mais constante nas espécies de Mikania Willd. analisadas.This work presents the surface micromorphology of fruits of 15 taxa of Mikania Willd. studied under scanning electron microscopy (SEM. The aim was to find characters to separate close species that occur in Rio Grande do Sul State. Such characters had taxonomic value for some of them. The species were separated into four groups according to the pattern. The pattern with striated periclinal and anticlinal walls with verrucose projections was the most constant in the species of Mikania Willd. analyzed.

  2. Plume Migration of Different Carbon Dioxide Phases During Geological Storage in Deep Saline Aquifers

    Directory of Open Access Journals (Sweden)

    Chien-Hao Shen

    2015-01-01

    Full Text Available This study estimates the plume migration of mobile supercritical phase (flowing, aqueous phase (dissolved, and ionic phase CO2 (bicarbonate, and evaluates the spatial distribution of immobile supercritical phase (residual and mineral phase CO2 (carbonates when CO2 was sequestered. This utilized a simulation, in an anticline structure of a deep saline aquifer in the Tiechenshan (TCS field, Taiwan. All of the trapping mechanisms and different CO2 phases were studied using the fully coupled geochemical equation-of-state GEM compositional simulator. The mobile supercritical phase CO2 moved upward and then accumulated in the up-dip of the structure because of buoyancy. A large amount of immobile supercritical phase CO2 was formed at the rear of the moving plume where the imbibition process prevailed. Both the aqueous and ionic phase CO2 finally accumulated in the down-dip of the structure because of convection. The plume volume of aqueous phase CO2 was larger than that of the supercritical phase CO2, because the convection process increased vertical sweep efficiency. The up-dip of the structure was not the major location for mineralization, which is different from mobile supercritical phase CO2 accumulation.

  3. AHP6 inhibits cytokinin signaling to regulate the orientation of pericycle cell division during lateral root initiation.

    Directory of Open Access Journals (Sweden)

    Sofia Moreira

    Full Text Available In Arabidopsis thaliana, lateral roots (LRs initiate from anticlinal cell divisions of pericycle founder cells. The formation of LR primordia is regulated antagonistically by the phytohormones cytokinin and auxin. It has previously been shown that cytokinin has an inhibitory effect on the patterning events occurring during LR formation. However, the molecular players involved in cytokinin repression are still unknown. In a similar manner to protoxylem formation in Arabidopsis roots, in which AHP6 (ARABIDOPSIS HISTIDINE PHOSPHOTRANSFER PROTEIN 6 acts as a cytokinin inhibitor, we reveal that AHP6 also functions as a cytokinin repressor during early stages of LR development. We show that AHP6 is expressed at different developmental stages during LR formation and is required for the correct orientation of cell divisions at the onset of LR development. Moreover, we demonstrate that AHP6 influences the localization of the auxin efflux carrier PIN1, which is necessary for patterning the LR primordia. In summary, we show that the inhibition of cytokinin signaling through AHP6 is required to establish the correct pattern during LR initiation.

  4. A study of earthquakes induced by water injection in the Changning salt mine area, SW China

    Science.gov (United States)

    Sun, Xiaolong; Yang, Pengtao; Zhang, Zhiwei

    2017-04-01

    The features of earthquakes induced by water injection in the Changning salt mine area of China were analyzed using the pore pressure diffusion method. The relationships between maximum magnitude, cumulative seismic moment, and cumulative water loss volume were investigated. Results show that increased seismic activities near the Changning salt mine in recent years are closely related to water injection during salt mining. High-pressure water injection over a long period of time caused water to diffuse into rock cracks, which increased pore pressure on faults and induced ruptures. Injection-induced earthquakes were located below the injection sites, mainly aligned NW-SE, with most occurring southeast of the mine area. Such a distribution indicates that seismic activities were affected by anticline structures in the Changning area. Based on pore pressure diffusion considerations, the diffusion coefficient was estimated to be ∼0.15 m2/s, with a slightly lower value west of the injection site than to the east. A semi-logarithmic linear relationship was found between cumulative seismic moment and cumulative water loss volume, while maximum magnitude increased with increasing volume of cumulative water loss. This study may provide reference material for analysis of injection-induced earthquakes and evaluation of the danger of earthquakes induced by water injection.

  5. Permanent upper plate deformation in western Myanmar during the great 1762 earthquake: Implications for neotectonic behavior of the northern Sunda megathrust

    Science.gov (United States)

    Wang, Yu; Shyu, J. Bruce H.; Sieh, Kerry; Chiang, Hong-Wei; Wang, Chung-Che; Aung, Thura; Lin, Yu-Nung Nina; Shen, Chuan-Chou; Min, Soe; Than, Oo; Lin, Kyaw Kyaw; Tun, Soe Thura

    2013-03-01

    The 1762 Arakan earthquake resulted from rupture of the northern Sunda megathrust and is one of those rare preinstrumental earthquakes for which early historical accounts document ground deformations. In order to obtain more comprehensive and detailed measurements of coseismic uplift, we conducted comprehensive field investigations and geochronological analyses of marine terraces on the two largest islands in western Myanmar. We confirm 3-4 m of coseismic coastal emergence along southwestern Cheduba Island, diminishing northeastward to less than 1 m. Farther northeast, uplift associated with the earthquake ranges from slightly more than 1 m to 5-6 m along the western coast of Ramree Island but is insignificant along the island's eastern coast. This double-hump pattern of uplift coincides with the long-term anticlinal growth of these two islands. Thus, we propose that the 1762 earthquake resulted from slip on splay faults under the islands, in addition to rupture of the megathrust. Elastic modeling implies that fault slip during the 1762 earthquake ranges from about 9 to 16 m beneath the islands and corresponds to a magnitude of Mw 8.5 if the rupture length of the megathrust is ~500 km. The island's uplift histories suggest recurrence intervals of such events of about 500-700 years. Additional detailed paleoseismological studies would add significant additional detail to the history of large earthquakes in this region.

  6. Pharmacognostic Evaluation and Physicochemical Analysis of Paullinia pinnata L. (Sapindaceae

    Directory of Open Access Journals (Sweden)

    Annan K

    2013-07-01

    Full Text Available The current resurgence of public interest in herbal medicines calls for heightened studies on their quality and safety. The major setback in promoting the use of these herbal medicines is the lack of standardization and the confusion in the identification and authentication of these plants and their substitutes or adulterants. In this study, the pharmacognostic and physicochemical features of the leaves, stem bark and roots of Paullinia pinnata, an African shrub used traditionally for wound healing, treatment of dysentery and also as an aphrodisiac, was evaluated. The study included macroscopy, microscopy, physicochemical and phytochemical screening. Physicochemical parameters evaluated varied widely among the various parts studied which could be used in their identification. The study also revealed the presence of acicular calcium oxalate crystals, anomocytic stomata, wavy anticlinal walled epidermal cells and unicellular and multicelluar uniserate clothing trichomes in the leaves. Morphological, anatomical and physicochemical studies of P. pinnata provides simple and reliable standards which could be useful for the proper identification of P. pinnata.

  7. Use of relational databases to evaluate regional petroleum accumulation, groundwater flow, and CO2 sequestration in Kansas

    Science.gov (United States)

    Carr, T.R.; Merriam, D.F.; Bartley, J.D.

    2005-01-01

    Large-scale relational databases and geographic information system tools are used to integrate temperature, pressure, and water geo-chemistry data from numerous wells to better understand regional-scale geothermal and hydrogeological regimes of the lower Paleozoic aquifer systems in the mid-continent and to evaluate their potential for geologic CO2 sequestration. The lower Paleozoic (Cambrian to Mississippian) aquifer systems in Kansas, Missouri, and Oklahoma comprise one of the largest regional-scale saline aquifer systems in North America. Understanding hydrologic conditions and processes of these regional-scale aquifer systems provides insight to the evolution of the various sedimentary basins, migration of hydrocarbons out of the Anadarko and Arkoma basins, and the distribution of Arbuckle petroleum reservoirs across Kansas and provides a basis to evaluate CO2 sequestration potential. The Cambrian and Ordovician stratigraphic units form a saline aquifer that is in hydrologic continuity with the freshwater recharge from the Ozark plateau and along the Nemaha anticline. The hydrologic continuity with areas of freshwater recharge provides an explanation for the apparent underpressure in the Arbuckle Group. Copyright ?? 2005. The American Association of Petroleum Geologists. All rights reserved.

  8. Epidermal characteristics of toxic plants for cattle from the Salado River basin (Buenos Aires, Argentina Caracteres epidérmicos de las plantas tóxicas para el ganado de la Depresión del Salado (Buenos Aires, Argentina

    Directory of Open Access Journals (Sweden)

    Susana E. Freire

    2005-12-01

    Full Text Available One hundred and eighty species belonging to 41 families inhabiting the Salado River Basin of the province of Buenos Aires (Argentina were previously reported to be toxic for cattle. The purpose of this study was to provide a tool to distinguish the taxa when the plant material is desintegrated. In this way, an approach to the identification of these taxa through leaf epidermal features (anticlinal epidermal cell wall patterns, cuticular ornamentation, stomata, and hair types is performed. A key to the 180 species as well as illustrations of diagnostic characters are given.Las plantas tóxicas para el ganado están representadas en la Depresión del Salado (provincia de Buenos Aires, Argentina por 180 especies pertenecientes a 41 familias. El objetivo del presente trabajo es determinar estos taxa a partir de material desintegrado, utilizando caracteres epidérmicos foliares (paredes anticlinales de las células epidérmicas, ornamentación de la cutícula, tipos de estomas y pelos. Se brinda una clave para la determinación de las especies e ilustraciones de los caracteres diagnósticos.

  9. Endosperm Development in Autotetraploid Rice

    Institute of Scientific and Technical Information of China (English)

    WANG Lan; LIU Xiang-dong; LU Yong-gen; FENG Jiu-huan; XU Xue-bin; XU Shi-xiong (S.Y.Zee)

    2005-01-01

    By using the laser scanning confocal microscope and plastic (Leica 7022 historesin embedding kit) semi-thin sectioningtechnique, comparative studies on the development of endosperm were carried out between autotetraploid and diploid rices. Aboutone third of the ovaries in the autotetraploid showed normal endosperm development as those in the diploid. In these ovaries, one ofthe polar nuclei would fuse with the sperm nucleus, and the primary endosperm nucleus formed and underwent the first division in 4hours after pollination; the anticlinal wall began to grow centripetally between the free nuclei starting from the wall ingrowths of theembryo sac near the micropylar end, and some of the phragmoplasts formed transformed into periclinal walls. In addition, some of thecell wall situated in the middle of the endosperm appeared to originate from phragmoplasts, whereas others seemed to developrandomly without the obvious formation of phragmoplasts. Cellulose began to accumulate in the wall of aleurone cell layer at 6 daysafter pollination. The cellulose wall of the cells of the aleurone cell layer appeared to have completely formed within 7 to 8 days afterpollination. On the other hand, about two thirds of the ovaries in the autotetraploid showed abnormality in endosperm developmentwith various types, such as non-fertilization, abnormal fertilization, endosperm development-delay and non-synchronization in thedevelopment of cellulose wall of cells of the aleurone layer. These abnormalities usually resulted in decreased seed setting inautotetraploid rice.

  10. Miocene rifting in the Los Angeles basin: Evidence from the Puente Hills half-graben, volcanic rocks, and P-wave tomography

    Science.gov (United States)

    Bjorklund, Tom; Burke, Kevin; Zhou, Hua-Wei; Yeats, Robert S.

    2002-05-01

    Formation of the Puente Hills half-graben in the northeastern Los Angeles basin and eruption of the Glendora and El Modeno Volcanics (16 14 Ma) help to define the timing of extension in the basin. Normal faulting on the proto-Whittier fault ca. 14 Ma established the Puente Hills half-graben, in which sedimentary strata accumulated between ca. 14 and 10 Ma and into which diabase sills intruded. North-South contraction began to invert the Puente Hills half-graben ca. 7 Ma, leading to formation of the Puente Hills anticline and the Whittier fault. Our high-resolution three-dimensional P-wave velocity model shows two anomalous higher velocity (6.63 km/s) bodies at depths between 9 and 18 km, which we attribute to dioritic plutons named here for Whittier Narrows and El Modeno. The stocklike Whittier Narrows pluton could have been a source for the Glendora Volcanics and the diabase sills in the Puente Hills half-graben. The sill-shaped El Modeno pluton was a likely source for the El Modeno Volcanics. The northwesterly alignment of the plutons may mark the location of the northeastern Los Angeles basin rift boundary, which is associated with the clockwise rotation of the western Transverse Ranges. Three active faults, the Elysian Park blind thrust, the Puente Hills blind thrust, and the Whittier fault, converge on the Whittier Narrows pluton, which may have played a role in their location and segmentation.

  11. The boomerang area: An example of oil and gas fields related to a transfer zone development

    Energy Technology Data Exchange (ETDEWEB)

    Specht, M.; Colletta, B.; Letouzey, J. (Institut Francais de petrole, Ruiel-Malmaison (France)); Baby, P. (ORSTOM, Santa Cruz (Bolivia)); Oller, J.; Montemuro, G. (YPFB, Santa Cruz (Bolivia)); Guillier, B. (IFEA, Santa Cruz (Bolivia))

    1993-02-01

    We present results of a study realized from petroleum data of Yacimientos Petroliferos Fiscales Bolivianos of the most important transfer zone of the Bolivian Andean belt: the Santa Cruz transfer zone. Frontal part of the Bolivian Andean belt consists of a thick series (6 to 8 km) of paleozoic to cenozoic sedimentary rocks thrusted eastwards on a sole thrust located in paleozoic series. The frontal part of the belt, globally N-S oriented, undergoes an important deviation East of Santa Cruz with a left lateral offset of 100 Km. Taking into account the E-W shortening direction, this transfer zone can be interpreted as a lateral ramp. The Santa Cruz transfer zone coincide with a set of small oil and gas fields whereas frontal structures lack hydrocarbon occurrences. We are then faced with a two-fold problem: (1) what is the origin of the transfer zone (2) why are the oil and gas concentrated in the transfer zone Our synthesis shows that the transfer zone is superimposed on the limit of a detached Paleozoic basin whose border direction is oblique to the regional shortening direction. We then interpret the oil and gas formation in two steps: (1) source rock maturation and hydrocarbon migration towards the top of the Paleozoic sedimentary wedge before Andean deformation. (2) hydrocarbon dismigration towards anticlinal structures developed during the lateral ramp propagation. In order to test our interpretation we performed a set of analog model experiments whose 3D visualization was analyzed by computerized X-ray tomography.

  12. Fault-related-folding structures and reflection seismic sections. Study by seismic modeling and balanced cross section; Danso ga kaizaisuru shukyoku kozo no keitai to jishin tansa danmen. 2. Seismic modeling oyobi balanced cross section ni yoru study

    Energy Technology Data Exchange (ETDEWEB)

    Tamagawa, T.; Matsuoka, T. [Japan Petroleum Exploration Corp., Tokyo (Japan); Tsukui, R. [Japan National Oil Corp., Tokyo (Japan). Technology Research Center

    1997-05-27

    It occasionally happens that there exists a part where reflection near the thrust is not clearly observed in a thrust zone seismic survey cross section. For the effective interpretation of such an occurrence, the use of geological structures as well as the reflected pattern is effective. When the velocity structures for a fold structure having a listric fault caused anticline (unidirectionally inclined with a backlimb, without a forelimb) and for a fault propagation fold are involved, a wrong interpretation may be made since they look alike in reflection wave pattern despite their difference in geological structure. In the concept of balanced cross section, a check is performed, when the stratum after deformation is recovered to the time of deposition, as to whether the geologic stratum area is conserved without excess or shortage. An excess or shortage occurs if there is an error in the model, and this shows that the fault surface or fold structure is not correctly reflected. Positive application of geological knowledge is required in the processing and interpreting of data from a seismic survey. 6 refs., 6 figs.

  13. Fault-related-folding structure and reflection seismic sections. Construction of earth model using balanced cross section; Danso ga kaizaisuru shukyoku kozo no keitai to jishin tansa danmen. 1. Balanced cross section wo mochiita chika model no kochiku

    Energy Technology Data Exchange (ETDEWEB)

    Matsuoka, T.; Tamagawa, T. [Japan Petroleum Exploration Corp., Tokyo (Japan); Tsukui, R. [Japan National Oil Corp., Tokyo (Japan). Technology Research Center

    1997-05-27

    Pre-stacking depth migration treatment is studied for the estimation of the fold configuration from seismic survey cross sections. The estimation of a velocity structure is necessary for the execution of such treatment, and the utilization of structural-geological knowledge is required for its interpretation. The concept of balanced cross section in relation to the fault-bend fold constructs a stratum structure model under conditions that the deformation during fold and fault formation is a planar strain, that there is no change in volume due to deformation, and that a fold is a parallel fold. In addition to the above geometric and kinetic approach, there is another fold formation process simulation model using a Newtonian fluid for study from the viewpoint of dynamics. This simulation stands on the presumption that the boundary contains a ramp that had been in presence before fold formation and that an incompressible viscous matter is mounted on the top surface. The viscous matter flows and deforms for the formation of an anticline on the ramp. Such enables the reproduction of a fault-bend fold formation process, and helpful discussion may be furthered on the dynamic aspect of this simulation. 5 refs., 4 figs.

  14. How to Characterize a Potential Site for CO2 Storage with Sparse Data Coverage – a Danish Onshore Site Case

    Directory of Open Access Journals (Sweden)

    Nielsen Carsten Møller

    2015-04-01

    Full Text Available The paper demonstrates how a potential site for CO2 storage can be evaluated up to a sufficient level of characterization for compiling a storage permit application, even if the site is only sparsely explored. The focus of the paper is on a risk driven characterization procedure. In the initial state of a site characterization process with sparse data coverage, the regional geological and stratigraphic understanding of the area of interest can help strengthen a first model construction for predictive modeling. Static and dynamic modeling in combination with a comprehensive risk assessment can guide the different elements needed to be evaluated for fulfilling a permit application. Several essential parameters must be evaluated; the storage capacity for the site must be acceptable for the project life of the operation, the trap configuration must be efficient to secure long term containment, the injectivity must be sufficient to secure a longstanding stable operation and finally a satisfactory and operational measuring strategy must be designed. The characterization procedure is demonstrated for a deep onshore aquifer in the northern part of Denmark, the Vedsted site. The site is an anticlinal structural closure in an Upper Triassic – Lower Jurassic sandstone formation at 1 800-1 900 m depth.

  15. Geological, rare earth elemental and isotopic constraints on the origin of the Banbanqiao Zn-Pb deposit, southwest China

    Science.gov (United States)

    Li, Bo; Zhou, Jia-Xi; Huang, Zhi-Long; Yan, Zai-Fei; Bao, Guang-Ping; Sun, Hai-Rui

    2015-11-01

    The newly discovered Banbanqiao Zn-Pb deposit in the southeastern part of the Sichuan-Yunnan-Guizhou (SYG) Pb-Zn metallogenic province is located on the western Yangtze Block, southwest China. Ore bodies of the Banbanqiao deposit are stratiform type, host in dolomitic limestone and dolostone of the Lower Carboniferous Dapu Formation and occur within the NNE-trending Banbanqiao anticline. More than 1.5 million tones (Mt) Zn-Pb ores at grades of 0.26-10.32 wt.% Pb and 0.81-28.8 wt.% Zn have been controlled until now. δ13CPDB and δ18OSMOW values of calcite separates range from -2.8‰ to -0.7‰ (average -1.1‰) and +14.1‰ to +17.0‰ (average +15.5‰), respectively. The δ13CPDB values are similar to those of marine carbonate rocks, but higher than those of mantle and significantly different from those of sedimentary organic matter. However, the δ18OSMOW values are among those of mantle, marine carbonate rocks and sedimentary organic matter. δ34SCDT values of sulfide separates range from +3.2‰ to +9.9‰ (average +6.5‰), unlike mantle-derived sulfur (0 ± 3‰), whilst lower than evaporites (+22‰ to +28‰) within host strata. 206Pb/204Pb, 207Pb/204Pb and 208Pb/204Pb values of country shale and dolostone whole-rock samples are 18.47, 15.66 and 38.70, and 18.44-18.60, 15.66-15.85 and 38.70-39.14, respectively. Sulfide separates have 206Pb/204Pb, 207Pb/204Pb and 208Pb/204Pb values ranging from 18.03 to 18.73, 15.65 to 15.78 and 38.15 to 39.14, respectively. These Pb isotopic data indicate a clearly crustal source of Pb in the plot of 207Pb/204Pb vs. 206Pb/204Pb. Total REE (ΣREE) contents of country shale and dolostone whole-rock samples are 2.63 ppm and 0.72-86.2 ppm with δEu values are 2.79 and 0.34-0.70, respectively. Pyrite, sphalerite, galena and calcite samples have ΣREE contents of 5.3-36.4 ppm, 0.29-3.39 ppm, 0.52 ppm and 22.0-41.1 ppm, respectively, and δEu values of 0.64-0.86, 0.94-2.86, 0.32 and 0.21-0.45, respectively. These rare earth

  16. 叶片表皮指纹在杜鹃花属分类中的意义%Significance of the leaf epidermis fingerprint for taxonomy of Genus Rhododendron

    Institute of Scientific and Technical Information of China (English)

    王秀伟; 毛子军

    2006-01-01

    本实验于2004年在东北林业大学进行.用指甲油印记法在光学显微镜下观察了杜鹃花属6个种(牛皮杜鹃 Rh.aureaum,兴安杜鹃 Rh. Dauricum,照白杜鹃 Rh.micranthum,迎红杜鹃 Rh.mucronulatum,苞叶杜鹃 Rh.Redowskianum和大字杜鹃 Rh.schlippenbachii)的表皮指纹特征.对叶片的形态特征包括叶片下表皮气孔类型、保卫细胞和副卫细胞的特征、叶片两面的普通细胞(形状和垂周壁特征)和表皮毛进行了较详细的描述.所研究的6种杜鹃花中,有3种气孔类型,其中兴安杜鹃、照白杜鹃、和迎红杜鹃为单细胞型气孔(Pericytic型),苞叶杜鹃为不规则型气孔(Anomocytic型),牛皮杜鹃和大字杜鹃是平轴式气孔(Diacytic式).不同种间,单细胞型和平轴式气孔的副卫细胞类型在形状和表面特征上有所不同.普通表皮细胞的表面观为从四边形、六边形,多边形或不规则型,垂周壁呈平直或弯曲状.兴安杜鹃、照白杜鹃和迎红杜鹃3种的叶片两面均有腺鳞.所有这些叶片特点表明上述6种杜鹃花的表皮指纹具有种的特性.图4表2参29.%Leaf epidermal fingerprints of six species of Rhododendron ( Rh. Aureaum, Rh. dauricum, Rh. micranthum, Rh. Mucronulatum,Rh. Redowskianum, Rh. schlippenbachii) were observed by optical microscope with nail polish expression method in Key Laboratory of Forest Plant Ecology of MinistryEducation China in Northeast Forestry University in 2004. The leaf morphological features including of stomata types, characters of guard cells, subsidiary cells in lower epidermis were observed. And ordinary cells (in shape and anticlinal walls feature) as well as the trichomes in both sides of the leaves are described in detail. The results showed that there were three types of stoma in six investigated Rhododendron species, from which Pericytic stomata type exists in three species (Rh. dauricum, Rh. micranthum, and Rh.mucronulatum), Anomocytic stomatal type in Rh

  17. THE POST-SEDIMENTARY CHARACTER OF DEVELOPMENT OF INTRAPLATE DISLOCATIONS AS A REFLECTION OF IMPULSIVENESS OF DEFORMATION PROCESSES

    Directory of Open Access Journals (Sweden)

    V. I. Popkov

    2015-09-01

    Full Text Available The available data on well-studied areas of the Turan platform (as an example are reviewed and analyzed to reveal the role of con-sedimentation and post-sedimentation tectonic movements in formation of dislocations of the sedimentary cover. At the background of the long-term (tens and hundreds of million years quiet evolution of the territory under study, short-term intervals are distinguished, which duration amounts to the first millions of years (typically manifested in one or two stratigraphic layers; in such time intervals, tectonic movements were dramatically boosted and accompanied by land uplifting, sea regression, erosion of sediments accumulated earlier and manifestation of deformation processes.The paleotectonic reconstructions show that during such ‘revolutionary’ stages, large tectonic elements occurred along with local uplifts that added to their complexity. In the region under study, the Pre-Jurassic, Pre-Cretaceous (Late Okoma, Pre-Danish and the Pre-Middle Miocene gaps in sedimentation are studied in detail. It is shown that only during the above four periods of sedimentation gaps and accompanying erosion-denudation processes, the regional structures gained from 50 to 80% of their current amplitudes at the bottom of the cover, and the Pre-Danish and Pre-Middle Miocene washout periods were most important.Local uplift also developed impulsively and primarily due to the post-sedimentation movements. Cross-sections of anticlines studied in detail (Figures 1 to 3 are discussed as examples that clearly show the increase of erosional shearing of the sediments accumulated earlier towards domes of uplifts without any con-sedimentation decrease of their thicknesses. During these periods of the geologic history, regardless of their short duration, folded dislocation gained up to 65–90% of their current amplitudes. The periods of activation were separated by long relatively quiescent tectonic periods with the gradually slowing down

  18. Are Anomalous Stresses in Upper Cook Inlet Basin Linked to the Geometry of the Underlying Subducting Slab? Static and Time-Dependent Stress Models of the 1964 Great Alaska Earthquake

    Science.gov (United States)

    Willis, J. B.

    2010-12-01

    The current stress field of upper Cook Inlet basin is unusual in that the maximum horizontal stress is oriented ~45° counterclockwise from, rather than parallel to, the motion vector of the subducting Pacific Plate. A 3-dimensional, elastic dislocation model of the 1964, Mw 9.2, great Alaska earthquake demonstrates that sharp changes in geometry of the subduction interface may strongly influence the stress field in the upper plate and may account for the anomalous orientation of the principal stresses. The model accurately represents the current view of the 170,000 km2 event as rupturing across a subducted transform boundary that is characterized by complex, rapid changes in slab geometry. Static stress transfer from the 1964 event into the overlying North American plate altered Coulomb stresses on the Lake Clark-Castle Mountain fault system and on several blind, oblique thrust faults that core anticlines of the upper Cook Inlet petroleum province. Each of these faults presents a significant seismic hazard to the greater Anchorage area and to regional petroleum infrastructure and production. Modeled, static Coulomb stress changes caused by the 1964 event suggest a localized decrease in fault stability of the Castle Mountain fault and decreased stability of most east-dipping, upper Cook Inlet thrust faults. Notably, the local region of decreased fault stability along the Castle Mountain fault coincides with rapid changes in the geometry of the underlying subducting slab; models that do not account for changes in slab geometry tend to show increased stability along the length of the fault. The zone of decreased stability correlates with the western segment of the Castle Mountain fault, the only known upper plate fault in the greater Anchorage with unequivocal Holocene surface rupture. A time-dependent rheological, visco-elastic model of the 1964 event suggests that in regions where the subduction interface has not relocked, the regional stress field will evolve for

  19. 断层相关褶皱的三维构造几何学分析:以川西三维地震工区为例%Three-dimensional structural geometry of fault-related folds:Examples from 3-D seismic explored blocks in the western Sichuan Province,China

    Institute of Scientific and Technical Information of China (English)

    贾东; 李一泉; 王毛毛; 李海滨

    2011-01-01

    examples for the interpretations of the true 3D models. This research indicates that the Qiongxi anticline is a typical shear fault-bend fold and the Yanjinggou anticline a typical trishear fault-propagation fold. Through the comparison between the conceptual model and the true model, we find that the strike displacement gradients are the basic factor to control the 3D geometric features, whereas, the complexities of fault geometry and rocks mechanics anisotropy are the main difficulties to construct the true 3D conceptual model of the fault-related folds.

  20. Hydrocarbon accumulation pattern of Kayindike region in southern Junggar Basin%准噶尔盆地南缘卡因迪克地区油气成藏模式研究

    Institute of Scientific and Technical Information of China (English)

    林小云; 覃军; 聂婉; 倪倩

    2014-01-01

    Based on the static elements for reservoir formation, taking the dynamic evolution process of the ele-ments as the main line, the comparison of biomarkers and the analyses of source rock thermal evolutions, fluid inclusions and typical reservoirs were made to study the hydrocarbon source and accumulation process in the Ka-yindike region in the southern Junggar Basin. A hydrocarbon accumulation model was established to guide hydro-carbon exploration. Crude oils in the Kayindike region were classified into 3 types, respectively, from the Jura-ssic coal series, the Paleogene lacustrine mudstones and the two mixed, and the Jurassic coal series were more contributive. There were 2 major charging periods, about 10-8 and 2 Ma, respectively, and the ancient reser-voirs charged in the 1st period adjusted during the 2nd period. The permeable sand series in the Kayindike region were controlled by the northern source materials, and were poorly connected with the south. Hydrocarbon migra-ted mainly along regional unconformities, and faults played important roles in communicating deep source rocks and ancient reservoirs. Controlled by faults and anticlines, the reservoirs were mainly fault-controlled and squeeze anticline type. The main controlling factor for hydrocarbon accumulation was the faults communicating source rocks. The hydrocarbon accumulation model was featured by mixed sources, vertical migration and 2 accumula-tion periods, among which the 2nd period was the major one.%以油气藏形成的静态要素为基础、以各要素的动态演化过程为主线,通过生物标志化合物对比、烃源岩热演化、流体包裹体分析以及典型油气藏解剖,厘清了准噶尔盆地南缘卡因迪克地区油气来源、成藏过程,建立油气成藏模式。卡因迪克地区原油可分为3类,分别源自侏罗系煤系地层、古近系湖相泥岩以及二者混源,以侏罗系油源为主。该地区主要接受了2期油气充注,分别距今10

  1. 阿姆河盆地卡拉库里区块侏罗系油气地质条件分析%Analysis of Petroleum Geological Characteristics of the Jurassic in Karakul Block, Amu-Darya Basin

    Institute of Scientific and Technical Information of China (English)

    张津海; 柳益群; 周亮

    2012-01-01

    Karakul block is located in the Chardzhou terrace of the northern Amu-Darya basin in Uzbekistan. The main exploration target is upper Jurassic Callovian-Oxfordian carbonate rocks. The source rocks are dominated by dark gray mudstone, carbon mudstone and coal deposited in the Lower-Middle Jurassic coastal-delta fades, and medium-high organic matter abundance indicating sapropel-humic and humic organic types suggests good potential to generate hydrocarbon once the rocks enter mature stage. The Chardzhou terrace is located in the direction of the hydrocarbon migration, and this is favorable for accumulation of oil and gas. Oolitic limestone and calcarenite are the major types of reservoir rocks deposited in upper Callovian-Oxfordian terrace fades, and both form main reservoirs in the block. The reservoirs consists of intragranular dissolved pore, mould pore and solution stylolite. The carbonate reservoirs are of low porosity and low permeability, and of good accumulation capability if in company with relatively developed fractures. The formation water in the upper Jurassic carbonate rocks is highly mineralized and the ratios of Na/Cl and Ca/Mg are 0. 7 and 3. 5, which indicate a weak reduction environment. Moreover, the large thickness, widely distributed gypsum-salt deposited in Kimmeridgian-Tithonian tidal flat-lagoon facies as cap rocks, are favorable for gas accumulation and preservation. Based on structural interpretation of Karakul block, the main trap style is low amplitude anticlinal structure. The forming times of traps rationally matches with generation and migration of hydrocarobon. It is suggested that the potential plays may occur along the anticline belt in the south of Karakul block.%卡拉库里区块位于阿姆河盆地北部的查尔朱阶地上,勘探目的层为上侏罗统卡洛夫阶—牛津阶碳酸盐岩.烃源岩以下—中侏罗统滨海-三角洲相沉积的深灰色泥岩、碳质泥岩和煤层为主,有机质丰度中等—好,腐泥-

  2. Stratigraphic correlations of the Vaca Muerta formation in the southern Neuquén basin, Argentina

    Science.gov (United States)

    Nesma, Krim; Patrice, Imbert; Cedric, Bonnel; Charles, Aubourg

    2013-04-01

    The petroleum Neuquén basin, south west Argentina, contains a continuous late Triassic to Cenozoic succession including continental and marine sediments, deposited under a variety of tectonic regimes. The Vaca Muerta formation is one of the major source rocks of the Neuquén basin and was deposited during the Andic cycle. This formation consists of organic-rich dark brown to black shales and mudstones deposited during a major transgression, in euxinic conditions on a shelf and slope during the Tithonian. Over most of the basin, the Vaca Muerta formation overlies the continental deposits of the Tordillo formation. The contact between the two formations is isochronous throughout the basin and marks the Tithonian transgression (Leanza, 1981). After this transgression, prograding bodies were deposited and the Vaca Muerta corresponds to the distal part of this latest. It includes stages from Middle Tithonian in the south to Valanginian in the north (Leanza & Hugo, 1977). The Vaca Muerta formation is well exposed in the southern part of the Neuquén basin, from the Picun Leufu Anticline to the north of the town of Las Lajas. It corresponds in these two areas to a succession of dark to brown shales and carbonate beds. In details, we can divide it into two parts: the Lower Vaca Muerta and the Upper Vaca Muerta. Above, the Picun Leufu formation overlies the Vaca Muerta formation and consists of carbonaceous and siliciclastics prograditional bodies. This unit is absent in the "North Zapala Zone" and its lateral equivalent is less carbonaceous. In this poster; we propose eight detailed sedimentological logs, which are correlated along 120 km north-south trend (from the Picun Leufu Anticline to the south west to the Agrio thrust Belt (ATB) to the north). This correlation will be used to assess the vertical and lateral variability of the Vaca Muerta deposits and to define the palaeogeographic evolution of that region. This allowed us to identify two major prograding sequences

  3. A Systems Approach to Identifying Exploration and Development Opportunities in the Illinois Basin: Digital Portifolio of Plays in Underexplored Lower Paleozoic Rocks [Part 1 of 2

    Energy Technology Data Exchange (ETDEWEB)

    Seyler, Beverly; Harris, David; Keith, Brian; Huff, Bryan; Lasemi, Yaghoob

    2008-06-30

    Albany Shale is regarded as the source rock for petroleum in Silurian and younger strata in the Illinois Basin and has potential as a petroleum reservoir. Field studies of reservoirs in Devonian strata such as the Geneva Dolomite, Dutch Creek Sandstone and Grassy knob Chert suggest that there is much additional potential for expanding these plays beyond their current limits. These studies also suggest the potential for the discovery of additional plays using stratigraphic concepts to develop a subcrop play on the subkaskaskia unconformity boundary that separates lower Devonian strata from middle Devonian strata in portions of the basin. The lateral transition from Geneva Dolomite to Dutch Creek Sandstone also offers an avenue for developing exploration strategies in middle Devonian strata. Study of lower Devonian strata in the Sesser Oil Field and the region surrounding the field shows opportunities for development of a subcrop play where lower Devonian strata unconformably overlie Silurian strata. Field studies of Silurian reservoirs along the Sangamon Arch show that opportunities exist for overlooked pays in areas where wells do not penetrate deep enough to test all reservoir intervals in Niagaran rocks. Mapping of Silurian reservoirs in the Mt. Auburn trend along the Sangamon Arch shows that porous reservoir rock grades laterally to non-reservoir facies and several reservoir intervals may be encountered in the Silurian with numerous exploration wells testing only the uppermost reservoir intervals. Mapping of the Ordovician Trenton and shallower strata at Centralia Field show that the crest of the anticline shifted through geologic time. This study illustrates that the axes of anticlines may shift with depth and shallow structure maps may not accurately predict structurally favorable reservoir locations at depth.

  4. Along-strike structural variation and thermokinematic development of the Cenozoic Bitlis-Zagros fold-thrust belt, Turkey and Iraqi Kurdistan

    Science.gov (United States)

    Barber, Douglas E.; Stockli, Daniel F.; Koshnaw, Renas I.; Tamar-Agha, Mazin Y.; Yilmaz, Ismail O.

    2016-04-01

    to latest Miocene times, followed by out-of-sequence development of the Mountain Front Flexure (Qaradagh anticline) by ~5 Ma. In contrast, initial exhumation in the northern Bitlis belt occurred by mid-Eocene time, followed by collisional deformation that propagated southward into northern Iraqi Kurdistan during the middle to late Miocene. Plio-Pleistocene deformation was partitioned into out-of-sequence reactivation of the Ora thrust along the Iraq-Turkey border, concurrent with development of the Sinjar and Abdulaziz inversion structures at the edge of the Bitlis deformation front. Overall, these data suggest the Bitlis and Zagros trends evolved relatively independently during Cretaceous and early Cenozoic times, resulting in very different structural and stratigraphic inheritance, before being affected contemporaneously by major phase of in-sequence shortening during middle to latest Miocene and out-of-sequence deformation since the Pliocene. Limited seismic sections corroborate the notion that the structural style and trend of the Bitlis fold belt is dominated by inverted Mesozoic extensional faults, whereas the Zagros structures are interpreted mostly as fault-propagation folds above a Triassic décollement. These pre-existing heterogeneities in the Bitlis contributed to the lower shortening estimates, variable anticline orientation, and irregular fold spacing and the fundamentally different orientations of the Zagros-Bitlis belt in Iraqi Kurdistan and Turkey.

  5. Sucesiones lacustres postgondwánicas-preandinas en la región de Famatina (La Rioja y Catamarca Postgondwanic-preandean lacustrine successions in the Famatina Belt (La Rioja and Catamarca provinces

    Directory of Open Access Journals (Sweden)

    F.M. Dávila

    2005-03-01

    Full Text Available En el flanco oriental de la región central de Famatina al oeste de Angulos se describe una sucesión sedimentaria de ~180 m de espesor formada por niveles basales de silcretes grises, bancos de yeso blanquecinos y una sucesión de pelitas moradas y varicolores con intercalaciones de areniscas finas tabulares y bancos de dolomitas laminadas amarillentas. Esta localidad se conoce como La Yesera dado que, localmente, el banco de yeso engrosado tectónicamente alcanza 23 m de espesor. Esta sucesión suprayace en contacto neto a depósitos fluvio-eólicos del Pérmico reconocidos previamente en la región e infrayace en discordancia angular al Mioceno Inferior (Formación del Crestón. Las facies sedimentarias permiten interpretar que luego de una discontinuidad representada por el desarrollo de costras silicificadas se expandieron cuerpos lacustres hipersalinos, en condiciones de escaso relieve. La ubicación estratigráfica del intervalo estudiado junto a su comprobada extensión regional y los marcados contrastes litofaciales, de color y de la estratofábrica con los paquetes sedimentarios infra y suprayacentes permitiría considerar a este intervalo como una unidad litoestratigráfica independiente. Por tal razón, se propone denominarla Formación La Veteada, siendo su estratotipo la sección aflorante sobre el flanco oriental del anticlinal Los Colorados (La Yesera, próximo al cierre norte de dicha estructura. Análisis micropaleontológicos preliminares no han sido fértiles. No obstante, la correlación litoestratigráfica de este intervalo que ha sido también reconocido tanto en la vertiente occidental del Famatina como en las exposiciones de la región septentrional, junto a datos termocronológicos provenientes de la región circundante permitirían proponer una edad triásica a jurásica, aunque no puede descartarse una edad cretácica o hasta paleógena.On the eastern edge of the central Famatina Belt, west of the Angulos town, we

  6. A Systems Approach to Identifying Exploration and Development Opportunities in the Illinois Basin: Digital Portifolio of Plays in Underexplored Lower Paleozoic Rocks

    Energy Technology Data Exchange (ETDEWEB)

    Beverly Seyler; David Harris; Brian Keith; Bryan Huff; Yaghoob Lasemi

    2008-06-30

    Albany Shale is regarded as the source rock for petroleum in Silurian and younger strata in the Illinois Basin and has potential as a petroleum reservoir. Field studies of reservoirs in Devonian strata such as the Geneva Dolomite, Dutch Creek Sandstone and Grassy knob Chert suggest that there is much additional potential for expanding these plays beyond their current limits. These studies also suggest the potential for the discovery of additional plays using stratigraphic concepts to develop a subcrop play on the subkaskaskia unconformity boundary that separates lower Devonian strata from middle Devonian strata in portions of the basin. The lateral transition from Geneva Dolomite to Dutch Creek Sandstone also offers an avenue for developing exploration strategies in middle Devonian strata. Study of lower Devonian strata in the Sesser Oil Field and the region surrounding the field shows opportunities for development of a subcrop play where lower Devonian strata unconformably overlie Silurian strata. Field studies of Silurian reservoirs along the Sangamon Arch show that opportunities exist for overlooked pays in areas where wells do not penetrate deep enough to test all reservoir intervals in Niagaran rocks. Mapping of Silurian reservoirs in the Mt. Auburn trend along the Sangamon Arch shows that porous reservoir rock grades laterally to non-reservoir facies and several reservoir intervals may be encountered in the Silurian with numerous exploration wells testing only the uppermost reservoir intervals. Mapping of the Ordovician Trenton and shallower strata at Centralia Field show that the crest of the anticline shifted through geologic time. This study illustrates that the axes of anticlines may shift with depth and shallow structure maps may not accurately predict structurally favorable reservoir locations at depth.

  7. Petroleum prospectivity of the Canada Basin, Arctic Ocean

    Science.gov (United States)

    Grantz, A.; Hart, P.E.

    2011-01-01

    Reconnaissance seismic reflection data indicate that Canada Basin is a remnant of the Amerasia Basin of the Arctic Ocean that lies south of the Alpha-Mendeleev Large Igneous Province, which was constructed on the northern part of the Amerasia Basin between about 127 and 89-75 Ma. Canada Basin is filled with Early Jurassic to Holocene detritus from the Mackenzie River system, which drains the northern third of interior North America, with sizable contributions from Alaska and Northwest Canada. Except for the absence of a salt- and shale-bearing mobile substrate Canada Basin is analogous to the Mississippi Delta and the western Gulf of Mexico. Canada Basin contains about 7 to >14 km of sediment beneath the Mackenzie Prodelta on the southeast, 6 to 7 km of sediment beneath the abyssal plain on the west, and roughly 5 or 6 million cubic km of sediment. About three fourths of the basin fill generates low amplitude seismic reflections, interpreted to represent hemiplegic deposits, and a fourth of the fill generates interbedded lenses to extensive layers of moderate to high amplitude reflections interpreted to represent unconfined turbidite and amalgamated channel deposits. Extrapolation from Arctic Alaska and Northwest Canada suggests that three fourths of the section in Canada Basin may contain intervals of hydrocarbon source rocks and the apparent age of the basin suggests that it contains three of the six stratigraphic intervals that together provided >90?? of the World's discovered reserves of oil and gas.. Worldwide heat flow averages suggest that about two thirds of Canada Basin lies in the oil or gas window. At least five types of structural or stratigraphic features of local to regional occurrence offer exploration targets in Canada Basin. These consist of 1) a belt of late Eocene to Miocene shale-cored detachment folds containing with at least two anticlines that are capped by beds with bright spots, 2) numerous moderate to high amplitude reflection packets

  8. Portugues Marbles as Stone Heritage

    Science.gov (United States)

    Lopes, Luis; Martins, Ruben

    2013-04-01

    The main objective of this paper is to present and justify the reasons for the worldwide recognition of Portuguese Marbles as Stone Heritage. These marbles are also known as "Estremoz Marble" since was the first county were exploited. In the Estremoz Anticline marbles occupy an intermediate stratigraphic position being part of a volcano-sedimentary sequence of Cambrian age. The anticlinal structure has a Precambrian core and the younger rocks aged Devonian Period. This sequence has deformed by the Variscan Orogeny, which performed twice with different intensities both in ductile and brittle tension fields. The early Alpine Cycle also acts in the region and cause more fracturing of the marble. Practically in all the quarries is possible to perceive the spatial-temporal continuity of the deformation where one can describe a complete Wilson Cycle. Together all these geological features imprint the marbles beautiful aesthetic patterns that can be highlighted when used as dimension stone. Nowadays most of the quarries are placed in the counties of Borba and mainly in Vila Viçosa. This last city claims for itself the "Capital of the Marble" title and named the marble as "White Gold". In fact, according to the historical record, the marbles were quarried in Portuguese Alentejo's Province since the fourth century BC. Locally these geological materials are available easily accessible. Exhibit physical properties that allow the fabrication of structural and decorative elements and so were used since humans settled in the region and developed a structured Society. In the Roman period, the pieces of art made with Estremoz Marbles were exported abroad and today are represented in Museums and Archaeological Sites throughout Europe and North Africa countries. The Portuguese Marbles and Limestones, transformed into altars, stairways, columns, statues and pieces of wall cladding, were carried as ballast in the holds of ships. At the destination the Portuguese People had built

  9. 川东弧形带三维构造扩展的AFT记录%Cretaceous transportation of Eastern Sichuan arcuate fold belt in three dimensions: Insights from AFT analysis

    Institute of Scientific and Technical Information of China (English)

    王平; 刘少峰; 郜瑭珺; 王凯

    2012-01-01

    对川东弧形褶皱带北段、中段和南段的三条剖面,进行了7件样品的磷灰石裂变径迹(AFT)测试,结合前人已发表的4件样品,分析模拟了主要背斜的隆升—剥露热历史.结果表明川东弧形带主体构造变形时间为135→65 Ma,即早白垩世早期到晚白垩世晚期.进而建立并对比了三条剖面的构造变形时序,揭示出川东弧形带的三维构造扩展历史:(1)平行于构造线走向,表现为从中心向两翼的构造扩展,弧形带中段的构造变形最早,起始时间为早白垩世早期(约135 Ma),北段和南段的变形较晚,起始时间为早白垩世晚期(约100 Ma);(2)垂直于构造线走向,在弧形带北段和中段均表现为由东向西的构造扩展,而在弧形带南段,由于受到前缘华蓥山断裂的影响,表现为自西向东的变形时序.川东弧形带的三维构造扩展历史暗示了“弯山构造”的成因模式,以及华蓥山先存断裂对弧形构造的限制作用.%The Eastern Sichuan arcuate fold belt, the front of the South China orogen, has not been well dated, because no sediment record can be used for dating. In this paper, we used 11 apatite fission track (AFT) samples, including 7 new samples and 4 published samples, to analyze the exhumation history of the anticlines. The samples were collected along three profiles, with 3 samples along Northeastern Sichuan profile, 4 samples along Eastern Sichuan profile and 4 samples along Southeastern Sichuan profile. The AFT thermal history modeling showed that the rapid cooling event generally occurred from 135 to 65 Ma, indicating the structural deformation of the Eastern Sichuan fold belt was from early period of early Cretaceous to late period of late Cretaceous. Additionally, the transportation history of the Eastern Sichuan arcuate fold belt in three dimensions was revealed by the three profiles: Along the structural lines, the deformation was transported from the center to the two limbs of the

  10. Folding, thrusting and development of push-up structures during the Miocene tectonic inversion of the Austral Basin, Southern Patagonian Andes (50°S)

    Science.gov (United States)

    Zerfass, Henrique; Ramos, Victor A.; Ghiglione, Matias C.; Naipauer, Maximiliano; Belotti, Hugo J.; Carmo, Isabela O.

    2017-03-01

    Rift and post-rift sections of the Austral Basin in the Southern Patagonian fold and thrust belt were examined in outcrop and in 2D seismic reflection sections to evaluate geometric and kinematic aspects of the extension and subsequent inversion. The syn-rift section is composed of dacitic lava flows of the El Quemado Complex (Jurassic), the lowermost unit of the basin. The coastal sandstones of the Springhill Formation (Tithonian-Berriasian) and marine shales of the Río Mayer Formation (Berriasian-Albian) are thought to be sag units. However, field data suggest that these units are also part of the syn-rift successions, as evidenced by extensional growth strata in the lower levels of the Río Mayer Formation. A dacitic flow that is texturally and compositionally similar to those of the syn-rift phase and that is termed here the Río Guanaco dacite is interfingered with the basal strata of the Río Mayer Formation and has a U-Pb zircon crystallization age of c. 141 Ma (Berriasian). The outcropping section was inverted by compression in the early Miocene, according to structural and isotopic data of adjacent areas, producing a broad anticline with inverted and fossil extensional faults as well as newly generated thrusts. At the seismic scale, most of the extensional master faults present negligible reverse slip, and shortening was accommodated in hanging wall push-up structures. This situation is interpreted as a result of the competent metamorphic basement and volcanic syn-rift section, inducing frictional lock-up of the master faults.

  11. Neogene foreland tectonics in the southern Appenines

    Energy Technology Data Exchange (ETDEWEB)

    Roure, F.; Casero, P.; Moretti, I.; Mueller, C.; Sage, L.; Vially, R. (Institut Francais du Petrole, Rueil-Malmaison)

    1988-08-01

    Combined structural and biostratigraphic analyses and seismic interpretation help them to balance cross sections through the southern Apennines from the Adriatic to the Tyrrhenian Sea and to propose an overall model for the evolution of the belt. Three lithostratigraphic units have been distinguished according to their Mesozoic facies and style of deformation: the western platform (upper unit), the Lagonegro-Molise basin, and the eastern platform. Foreland deformation migrated from west to east, and external domains were reached progressively by synorogenic flysch deposits (foredeep) and later incorporated into the thrust sheets. Presently, only the most external part of the eastern platform is still unaffected by thrusting, while internal parts are building the overthrust belt at depth, which is masked on the surface by allochthonous basinal nappes. The evolutive geometry of thrust and piggy-back basins results from the continuous understacking of new material at the bottom of the tectonic prism. The deeper basement is also progressively involved in the deformation, giving rise to large nappe anticlines. Despite the early subsidence and deformation of the western platform and basinal domains in Langhian to Tortonian time, all the deformation of the eastern platform has occurred since Messinian time. These compressive structures are thus contemporaneous with the opening of the Tyrrhenian Sea. To the west, the upper tectonic units of the Apennines are indeed affected by listric normal faulting, with previous thrust planes having been locally reactivated during the distension. Post-Messinian shortening in the sedimentary cover is accompanied by a crustal thickening outlined by the Moho's geometry. The authors interpret it as a result of the subduction of the Apulian continental lithosphere. Recent uplift of the Apennines is indeed directly related to this crustal root.

  12. A Feasibility Study on Operating Large Scale Compressed Air Energy Storage in Porous Formations

    Science.gov (United States)

    Wang, B.; Pfeiffer, W. T.; Li, D.; Bauer, S.

    2015-12-01

    Compressed air energy storage (CAES) in porous formations has been considered as one promising option of large scale energy storage for decades. This study, hereby, aims at analyzing the feasibility of operating large scale CAES in porous formations and evaluating the performance of underground porous gas reservoirs. To address these issues quantitatively, a hypothetic CAES scenario with a typical anticline structure in northern Germany was numerically simulated. Because of the rapid growth in photovoltaics, the period of extraction in a daily cycle was set to the early morning and the late afternoon in order to bypass the massive solar energy production around noon. The gas turbine scenario was defined referring to the specifications of the Huntorf CAES power plant. The numerical simulations involved two stages, i.e. initial fill and cyclic operation, and both were carried out using the Eclipse E300 simulator (Schlumberger). Pressure loss in the gas wells was post analyzed using an analytical solution. The exergy concept was applied to evaluate the potential energy amount stored in the specific porous formation. The simulation results show that porous formations prove to be a feasible solution of large scale CAES. The initial fill with shut-in periods determines the spatial distribution of the gas phase and helps to achieve higher gas saturation around the wells, and thus higher deliverability. The performance evaluation shows that the overall exergy flow of stored compressed air is also determined by the permeability, which directly affects the deliverability of the gas reservoir and thus the number of wells required.

  13. Características geológicas de los pórfiros dacíticos y su roca hospedante, quebrada del Peñasquito, Precordillera occidental de San Juan

    Directory of Open Access Journals (Sweden)

    Gaido, María Fernanda

    2011-12-01

    Full Text Available Geological characteristics of the dacitic porphyries and their host rock, Quebrada del Peñasquito, western Precordillera of San Juan. At Peñasquito creek, in the sierra del Tontal (S 31º 40’ 44,5” - W69º 14’ 05”, western San Juan province, at an altitude of 2,953 m.s.n.m, a succession of dacitic dykes of unknown age are recognized, intruding subconcordantly sandstones of the Don Polo Formation of Ordovician age. The sandstones intruded by the dykes present short wavelength symmetrical folding (400 m. The dikes have attitudesof N0º/85ºO-N30º/75ºO, with thicknesses ranging between 3 and 25 m. Microscopically, they present a porfiric texture, composed of quartz, plagioclase, biotite and hematite. A deep alteration (oxidation confers a yellowish color to the dykes, easily visible by means of satellite imagery. There are numerous folded veins of quartz thataccompany the dikes, associated to anticline folds, fractures and shear zones, with sigmoid structures and cinematic indicators with dextral displacement indicators.The dikes may correspond to a Permian-Triasic or Miocene magmatism. The closest dacitic magmatism of Permian age has been recognized to the south of the area, in Pampa de los Pozos and Yalguaraz, with copper mineralization. However, Peñasquito´s dykes have a greater similarity with dacitic dikes described at Carrizal creek, 7 km to the north of the study area. For this reason are assigned to the Miocene magmatism recognized in the region.Exploratory studies are suggested to determine the presence of mineralization.

  14. Identifying Oil Exploration Leads using Intergrated Remote Sensing and Seismic Data Analysis, Lake Sakakawea, Fort Berthold Indian Reservation, Willistion Basin

    Energy Technology Data Exchange (ETDEWEB)

    Scott R. Reeves; Randal L. Billingsley

    2004-02-26

    The Fort Berthold Indian Reservation, inhabited by the Arikara, Mandan and Hidatsa Tribes (now united to form the Three Affiliated Tribes) covers a total area of 1530 mi{sup 2} (980,000 acres). The Reservation is located approximately 15 miles east of the depocenter of the Williston basin, and to the southeast of a major structural feature and petroleum producing province, the Nesson anticline. Several published studies document the widespread existence of mature source rocks, favorable reservoir/caprock combinations, and production throughout the Reservation and surrounding areas indicating high potential for undiscovered oil and gas resources. This technical assessment was performed to better define the oil exploration opportunity, and stimulate exploration and development activities for the benefit of the Tribes. The need for this assessment is underscored by the fact that, despite its considerable potential, there is currently no meaningful production on the Reservation, and only 2% of it is currently leased. Of particular interest (and the focus of this study) is the area under the Lake Sakakawea (formed as result of the Garrison Dam). This 'reservoir taking' area, which has never been drilled, encompasses an area of 150,000 acres, and represents the largest contiguous acreage block under control of the Tribes. Furthermore, these lands are Tribal (non-allotted), hence leasing requirements are relatively simple. The opportunity for exploration success insofar as identifying potential leads under the lake is high. According to the Bureau of Land Management, there have been 591 tests for oil and gas on or immediately adjacent to the Reservation, resulting in a total of 392 producing wells and 179 plugged and abandoned wells, for a success ratio of 69%. Based on statistical probability alone, the opportunity for success is high.

  15. Rapid hydrocarbon accumulation mechanism in later period in Kelasu thrust belt in Kuqa depression

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Based on the analyses of generation, migration and accumulation of oil and gas in the structures of Kela 1, Kela 2 and Kela 3 in Kasangtuokai anticlinal belt using a series of geological and geochemical evidence, this paper proposes that the rapid rate of hydrocarbon generation, main drain path for over-pressured fluid flow and converging conduit system are indispensable conditions for the rapid, late-stage gas accumulation in the Kelasu thrust belt in the Kuqa depression. Due to structural over-lapping and the resultant rapid burial, the maturity of the source rocks had been increased rapidly from 1.3 to 2.5% Ro within 2.3 Ma, with an average rate of Ro increase up to 0.539% Ro/Ma. The rapid matura-tion of the source rocks had provided sufficient gases for late-stage gas accumulation. The kelasu structural belt has a variety of faults, but only the fault that related with fault propagation fold and cut through the gypsiferous mudstone cap could act as the main path for overpressured fluid release and then for fast gas accumulation in low fluid potential area. All the evidence from surface structure map, seismic profile explanation, authigenic kaolinite and reservoir property demonstrates that the main drain path related with faults for overpressured fluid and the converging conduit system are the key point for the formation of the giant Kela 2 gas field. By contrast, the Kela 1 and Kela 3 structures lo-cated on both sides of Kela 2 structure, are not favourable for gas accumulation due to lacking con-verging conduit system.

  16. Rapid hydrocarbon accumulation mechanism in later period in Kelasu thrust belt in Kuqa depression

    Institute of Scientific and Technical Information of China (English)

    ZOU HuaYao; WANG HongJun; HAO Fang; LIU GuangDi; ZHANG BaiQiao

    2007-01-01

    Based on the analyses of generation, migration and accumulation of oil and gas in the structures of Kela 1, Kela 2 and Kela 3 in Kasangtuokai anticlinal belt using a series of geological and geochemical evidence, this paper proposes that the rapid rate of hydrocarbon generation, main drain path for overpressured fluid flow and converging conduit system are indispensable conditions for the rapid,late-stage gas accumulation in the Kelasu thrust belt in the Kuqa depression. Due to structural overlapping and the resultant rapid burial, the maturity of the source rocks had been increased rapidly from 1.3 to 2.5% Ro within 2.3 Ma, with an average rate of Ro increase up to 0.539% Ro/Ma. The rapid maturation of the source rocks had provided sufficient gases for late-stage gas accumulation. The kelasu structural belt has a variety of faults, but only the fault that related with fault propagation fold and cut through the gypsiferous mudstone cap could act as the main path for overpressured fluid release and then for fast gas accumulation in low fluid potential area. All the evidence from surface structure map,seismic profile explanation, authigenic kaolinite and reservoir property demonstrates that the main drain path related with faults for overpressured fluid and the converging conduit system are the key point for the formation of the giant Kela 2 gas field. By contrast, the Kela 1 and Kela 3 structures located on both sides of Kela 2 structure, are not favourable for gas accumulation due to lacking converging conduit system.

  17. A paleo-seismological study of the Dauki fault at Jaflong, Sylhet, Bangladesh: Historical seismic events and an attempted rupture segmentation model

    Science.gov (United States)

    Morino, Michio; Kamal, A. S. M. Maksud; Akhter, S. Humayun; Rahman, Md. Zillur; Ali, Reshad Md. Ekram; Talukder, Animesh; Khan, Md. Mahmood Hossain; Matsuo, Jun; Kaneko, Fumio

    2014-09-01

    A paleo-seismological study was conducted at Jaflong, Sylhet, Bangladesh, which is on the eastern part of the Dauki fault. The geomorphology around Jaflong is divided into the Shillong Plateau, the foothills, the lower terraces, and the alluvial plain from north to south. Because the foothills and lower terraces are considered to be uplifted tectonically, an active fault is inferred to the south of the lower terraces. This fault, which branches from the Dauki fault as a foreland migration, is known as the Jaflong fault in this paper. The trench investigation was conducted at the southern edge of the lower terrace. The angular unconformity accompanied by folding, which is thought to be the top of the growth strata, was identified in the trench. An asymmetric anticline with a steep southern limb and gentle northern limb is inferred from the back-tilted lower terrace and the folding of the gravel layer parallel to the lower terrace surface. The timing of the seismic event which formed the folding and unconformity is dated to between AD 840 and 920. The trench investigation at Gabrakhari, on the western part of the Dauki fault, revealed that the Dauki fault ruptured in AD 1548 (Morino et al., 2011). Because the 1897 great Indian earthquake (M ⩾ 8.0; Yeats et al., 1997) was caused by the rupture of the Dauki fault (Oldham, 1899), it is clear that the Dauki fault has ruptured three times in the past one thousand years. The timing of these seismic events coincides with that of the paleo-liquefactions confirmed on the Shillong Plateau. It is essential for the paleo-seismological study of the Dauki fault to determine the surface ruptures of the 1897 earthquake. The Dauki fault might be divided into four rupture segments, the western, central, eastern, and easternmost segments. The eastern and western segments ruptured in AD 840-920 and in 1548, respectively. The 1897 earthquake might have been caused by the rupture of the central segment.

  18. Petroleum in the Junggar basin, northwestern China

    Science.gov (United States)

    Taner, Irfan; Kamen-Kaye, Maurice; Meyerhoff, Arthur A.

    The Junggar basin occupies a large triangular area of some 130 000 km 2 in northwestern China. Situated between the Altay Shan (Altay Range) on the northeast and the Tian Shan (Tian Range) on the southwest, and between lesser ranges around the remainder of its periphery, the Junggar basin is completely intermontane. Its history as a basin began in the Permian, and continued as various uplifts and downwarps evolved. Through the Paleozoic the characteristics of the Junggar basin area were largely geosynclinal and marine. Its post-Permian development took place exclusively in continental regimes. Inhabitants of the Junggar basin have known and utilized its numerous oil and asphalt seeps and its spectacular spreads of asphalt for more than 2000 years, especially in the Karamay-Urho thrust belt near the northwestern rim. The first discovery of oil in the modern sense came at Dushanzi, one of the steeply folded anticlines of theÜrümqi foredeep near the southern rim. The first shallow oil in the Karamay-Urho thrust belt came in 1937, followed by commercial production in the Karamay field in 1955. Output continued to be modest until wells were drilled through local thrusts and reverse faults in the early 1980s. By 1985, cumulative production of the Karamay group of fields had reached 42,000,000 t (metric tonnes) (306,000,000 bbl), with a calculated minimum ultimate recovery of 280,000,000 t (2 billion bbl). Principal production comes from Permian and Triassic strata in continental facies. Apart from marine Mid and Upper Carboniferous strata, source rocks occur mainly in fine-grained lacustrine detrital beds of the Permian, the Triassic, the Jurassic and the Tertiary. Several uplifts and downwarps elsewhere in the Junggar basin remain to be drilled comprehensively. Results from such drilling may enhance the very important position that the Junggar already has attained in the hierarchy of China's onshore basins.

  19. Quaternary Tectonism in a Collision Zone, Northwest Washington

    Science.gov (United States)

    McCrory, P. A.; Wolf, S. C.; Intelmann, S. S.; Danforth, W. W.; Weldon, R. J.; Blair, J. L.

    2004-12-01

    Kinematic, geodetic, and geologic observations define a region with 6-8 mm/y of north-south contraction between the Columbia River and Vancouver Island. We attribute this contraction to differential forearc-block motion within the Cascadia subduction system where the Oregon Coast Range block is moving northward relative to Vancouver Island. The contraction is accommodated by a combination of distributed uplift in the Olympic Mountains, and faulting along the margins of the Coast Range and Vancouver Island blocks. The tide gauge at Neah Bay, which records one of the highest rates of uplift anywhere along the Cascadia subduction margin, suggests that a significant portion of this north-south contraction occurs between the northern Olympic Peninsula and Vancouver Island. The northwest-trending Calawah fault, extending from Makah Bay eastward to near Lake Crescent, appears to mark the modern boundary between the Olympic Mountains block and the Vancouver Island block in northwestern Washington. Onshore, the 80+ km-long Calawah fault displaces late Quaternary glacial sediments and geodetic uplift rates increase abruptly across the fault zone. Offshore in Makah Bay, new multibeam, sidescan-sonar, and high-resolution seismic reflection data image a complex, multi-strand fault zone that offsets the seafloor and moves Cape Flattery rocks seaward. Two parallel, northwest-trending fault strands bound a down-dropped block that in turn terminates along a northward-trending anticlinal fold and thrust fault. These data suggest that the Calawah fault zone currently accommodates contraction both by uplift and by seaward translation of rocks north of the forearc-block boundary. Our geologic mapping in the Cape Flattery area indicates that differential block motion is accommodated by a combination of crustal uplift, folding, and left-lateral, strike-slip faulting.

  20. Epidermal studies of three species of Vernonia Schreb. in Southern Nigeria

    Directory of Open Access Journals (Sweden)

    CATHERINE IJEOMA KEMKA-EVANS

    2014-10-01

    Full Text Available Kemka-Evans CI, Okoli B, Nwachukwu CU. 2014. Epidermal studies of three species of Vernonia Schreber in Southern Nigeria. Biodiversitas 15: 137-141.The leaf epidermal studies of three species of Vernonia namely V. cinerea (L Less, V. amygdalina Delile. (bitter leaf and non-bitter leaf variety and V. conferta Benth. were undertaken with the aim of revealing their foliar characters which will enhance their identification and determination of their taxonomic relationship. Matured leaves were soaked in Sodium Oxochlorate II for 24hours to separate the epidermal surfaces. Data from the measurement of stomata and epidermal cells were analyzed. The presence of diagnostic characters such as contiguous stomata and sinuous anticlinal walls on the abaxial leaf surface of non-bitter variety of V. amygdalina and on both leaf surfaces (adaxial and abaxial of V. cinerea are of taxonomic importance. The irregular T-shaped trichomes on the leaf surfaces of V. amygdalina (bitter leaf and the cuticular striations on the adaxial surface of the same taxa could be used to delimit the taxa from the other species. The distribution of the stomata show hypoamphistomatic in all the three species studied. Anomocytic stomata occurred on all the taxa studied. Anisocytic stomata were found on the abaxial surface of V. conferta. These characters examined revealed interspecies relationship among the three species and also suggest that V. amygdalina (non bitter leaf is a variety of V. amygdalina (bitter leaf and should not be regard as another species of Vernonia. The epidermal leaf characters of V. amygdalina (non-bitter leaf is also been reported for the first time.

  1. Hydrocarbon Accumulation and Distribution Characteristics of the Silurian in the Tazhong Uplift of Tarim Basin

    Science.gov (United States)

    LÜ, Xiuxiang; BAI, Zhongkai; ZHAO, Fengyun

    Hydrocarbon accumulation of the Silurian in the Tazhong uplift of Tarim basin is characterized by "two sources and three stages". "Two sources" means that the hydrocarbons are derived from two source rocks of the Cambrian and Middle-Upper Ordovician. "Three stages" means that asphalt and movable oil undergoes three hydrocarbon accumulation stages, i.e., Late Caledonian, Late Hercynian, and Yanshanian-Himalayan. The formation of asphalt resulted from the destruction of the hydrocarbons accumulated and migrated in the early stages. The present movable oil, mostly derived from Middle-Upper Ordovician source rock, resulted from the hydrocarbons accumulated in the late stage. There are three types of reservoirs, i.e., anticline structural, stratigraphic lithological, and lava shield reservoirs in the Tazhong uplift. Hydrocarbon accumulation of the Silurian in the Tazhong uplift is controlled by the three factors. (1) The background of uplift structure. Around the ancient uplift, the compounding of many types makes up the composite hydrocarbon accumulation areas. (2) Effective cover. The show of oil gas including asphalt, heavy crude oil, and normal oil is quite active in the Silurian. Asphalt and heavy crude oil are distributed under the red mudstone member and movable oil is distributed under the gray mudstone member. (3) High quality reservoir bed. Sandstone is distributed widely in the Tazhong area. Reservoir pore space can be divided into three types: a) secondary origin-primary origin pore space; b) primary origin-secondary origin pore space, and c) micropore space. Porosity is 3.3-17.4%, and permeability is (0.1-667.97) × 10 -3 μm 2.

  2. Timing of the deposition of uppermost Cretaceous and Paleocene coal-bearing deposits in the Greater Glendive area, Montana and North Dakota

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-02-01

    With the aid of a grant from the National Geographic Society, a cooperative agreement with the State University of New York at Stony Brook, and contract with the U.S. Department of Energy, Late Cretaceous and Paleocene geologic and paleontologic field studies were undertaken in Makoshika, State Park and vicinity, Dawson County, Montana. This region was chosen as a study area because of its potential for yielding new fossil localities and extensive exposures both above and below the K/T boundary, as suggested by previous research by David W. Krause and Joseph H. Hartman. Related field studies were also undertaken in areas adjacent to the Cedar Creek Anticline in North Dakota. This work was part of ongoing research to document change in the composition of mammalian and molluscan faunas during the Late Cretaceous and Paleocene and to relate observed patterns to floral and invertebrate changes in composition. This study focuses on the record of mammals and mollusks in the Makoshika stratigraphic section and places old and new observations into a paleomagnetic and palynomorph framework. Of particular interest is the appearance and diversification of archaic ungulate mammals. Simultaneous dinosaur extinction with ungulate radiation has been invoked in gradual, as opposed to catastrophic, models of faunal change at the K/T boundary. However, supposed Cretaceous localities bearing archaic ungulates and other mammals of {open_quotes}Paleocene aspect{close_quotes} may be the product of faunal reworking. Elsewhere in the Williston Basin (e.g., Garfield and McCone Counties, Montana), the molluscan record of uppermost Cretaceous and Paleocene strata indicates the extinction of all of the highly sculptured unionid bivalves just prior to the onset of coal swamps and subsequent coal formation.

  3. 3D Geometry of Salt Controlled Normal Faults on Friesland Platform - NW Netherlands

    Science.gov (United States)

    Yucel, Kivanc; Kaymakci, Nuretdin; Arda Ozacar, A.

    2010-05-01

    A detailed 3D structural modeling was carried out using the available 3D seismic reflection and borehole data, in order to reveal the structures and deformation history, associated with the dynamic evolution of the Middle-Late Permian age Zechstein salt layer in Northern Friesland - Netherlands. The model includes major structures and seismostratigraphic units of Permian to recent, revealing salt and salt induced structures, formed during the periods of active salt movement in the study area. The model indicates a thick salt layer formed on N-S oriented grabens and half grabens of South Permian Basin that acted as the primary control for the location of salt diapirs and reflected the basement deformation pattern to the cover. A major salt movement was initiated in Triassic, during E-W Mesozoic rifting i.e breaking up of Pangea, evidenced by rim-synclines on Triassic mini-basins. Structurally conformable layers of Cretaceous and Early Cenozoic units overlie Triassic units unconformably by base Cretaceous unconformity, deposited during a tectonic quiescence when salt movement was ceased. A second phase of salt movement took place during the Early Cenozoic that was triggered possily due to the compressional tectonism related to Late Cretaceous - Early Tertiary Alpine Orogeny. A final and still ongoing phase is observed in the slightly deformed Neogene and Quaternary units. The model represents a N-S oriented salt cored anticline and a convergent transfer zone between a pair of segmented normal growth faults, controlled by the salt movement. Major faults associated with the transfer zone have assymetrical half graben geometry away from the transfer zone and symmetrical graben structure with small scale synthetic and antithetic faults at the center of the transfer zone. Detailed study of the structural model in 3D with the aid of cross sections, allows the establishment of the architecture of the transfer zone and its relation with the salt deformation process.

  4. Reply to the "Comment on "The May 1 20 (MW 6.1) and 29 (MW 6.0), 2012, Emilia (Po Plain, northern Italy) earthquakes: New seismotectonic implications from subsurface geology and high-quality hypocenter location" by Carannante et al., 2015" by Bonini L., et al.

    Science.gov (United States)

    Argnani, Andrea; Carannante, Simona; Massa, Marco; Lovati, Sara; D'Alema, Ezio

    2016-12-01

    In their comments Bonini et al. argue that our seismotectonic interpretation of the Emilia 2012 seismic sequence does not agree with observations, and follow three lines of arguments to support their statement. These concern the structural interpretation of seismic reflection profiles, the relationship between seismogenic sources and seismicity patterns, and the fit of inferred fault geometry to InSAR observations. These lines of arguments are mostly repeating what has been previously presented by the same authors, and none of them, as discussed in detail in our reply, presents a strong case against our structural interpretation, that, we are convinced, does not conflict with the available data. The two adjacent rupture surfaces outlined by accurately relocated aftershocks are an indication of the presence of two different active fault planes. Interpretation of seismic profiles supports seismological observation and indicates the occurrence of relevant along-strike changes in structural style. These pieces of information have been integrated to build a new seismotectonic interpretation for the area of the Emilia 2012 seismic sequence. Analysis of geodetic data from the area of the Emilia earthquakes has produced very different models of the fault planes; unlike what has been stated by Bonini et al., who see a difficult fit to InSAR data for the fault planes we have identified, the most recent results are consistent with our interpretation that see a steep fault in the upper 8-10 km under the Mirandola anticline. We point out that the geological structures in the subsurface of the Ferrara Arc do change along strike, and the attempt of Bonini et al. to explain both the May 20 and May 29 sequences using a single cross section is not appropriate.

  5. Decadal-Scale Decoupling of the Japan Trench Prior to the 2011 Tohoku-Oki Earthquake from Geodetic and Repeating-Earthquake Observations

    Science.gov (United States)

    McCaffrey, R.; King, R. W.; Lancaster, M.; Miller, M. M.; Wells, R. E.

    2014-12-01

    Geodetic, geologic and paleomagnetic data reveal that Oregon and parts of California, Nevada and Idaho rotate clockwise at 0.3 to 1.0 deg/Ma (relative to North America) about an axis near the Idaho-Oregon-Washington border, while northeast Washington is relatively fixed to North America. This rotation has been going on for at least 15 Ma. The spatial termination of the rotation requires shortening between Oregon and Washington. The Yakima fold and thrust belt (YFTB) lies along the boundary between northern Oregon and central Washington where convergence of the clockwise-rotating Oregon block is apparently accommodated. Shortening across the YFTB is thought to occur in a fan-like manner, increasing to the west. We obtained high-accuracy, high-density geodetic GPS measurements in 2012 and 2013 that are used with earlier measurements to characterize YFTB kinematics. Deformation associated with the YFTB starts in the south at the Blue Mountains Anticline in northern Oregon and extends northward to Frenchman Hills in Washington. To the east, the faulting and earthquake activity of the YFTB are truncated by a NNW-trending, narrow zone of deformation that runs along the Pasco Basin and Moses Lake region. It accommodates about 0.5 to 1.0 mm/yr of east to northeast shortening along the eastern boundary of the Department of Energy Hanford Site. The deforming zone aligns with recent seismicity in the Ice Harbor dike swarm, a relatively young ~ 8.5 Ma vent complex. West of the Cascade arc, shortening is accommodated by a series of east-trending faults, starting at the Doty fault in central coastal Washington and extending through Seattle up to the Canadian border. South of the Doty fault, other faults may take up some motion but may be too slow to resolve with GPS.

  6. Rotation of the Pacific Northwest and Deformation Across the Yakima Fold and Thrust Belt Estimated with GPS

    Science.gov (United States)

    McCaffrey, R.; King, R. W.; Lancaster, M.; Miller, M. M.; Wells, R. E.

    2015-12-01

    Geodetic, geologic and paleomagnetic data reveal that Oregon and parts of California, Nevada and Idaho rotate clockwise at 0.3 to 1.0 deg/Ma (relative to North America) about an axis near the Idaho-Oregon-Washington border, while northeast Washington is relatively fixed to North America. This rotation has been going on for at least 15 Ma. The spatial termination of the rotation requires shortening between Oregon and Washington. The Yakima fold and thrust belt (YFTB) lies along the boundary between northern Oregon and central Washington where convergence of the clockwise-rotating Oregon block is apparently accommodated. Shortening across the YFTB is thought to occur in a fan-like manner, increasing to the west. We obtained high-accuracy, high-density geodetic GPS measurements in 2012 and 2013 that are used with earlier measurements to characterize YFTB kinematics. Deformation associated with the YFTB starts in the south at the Blue Mountains Anticline in northern Oregon and extends northward to Frenchman Hills in Washington. To the east, the faulting and earthquake activity of the YFTB are truncated by a NNW-trending, narrow zone of deformation that runs along the Pasco Basin and Moses Lake region. It accommodates about 0.5 to 1.0 mm/yr of east to northeast shortening along the eastern boundary of the Department of Energy Hanford Site. The deforming zone aligns with recent seismicity in the Ice Harbor dike swarm, a relatively young ~ 8.5 Ma vent complex. West of the Cascade arc, shortening is accommodated by a series of east-trending faults, starting at the Doty fault in central coastal Washington and extending through Seattle up to the Canadian border. South of the Doty fault, other faults may take up some motion but may be too slow to resolve with GPS.

  7. Structural style and reservoir development in the west Netherlands oil province

    Energy Technology Data Exchange (ETDEWEB)

    Racero-Baena, A. (Nederlandse Aardolie Maatschappij, Assen (Netherlands)); Drake, S. (Nederlandse Aardolie Maatschappij, Schiedam (Netherlands))

    1993-09-01

    The area of the Rijswijk concession largely coincides with the onshore extent of the west Netherlands basin. To date, oil has been produced from a total of 15 fields within the Rijswijk concession, which have a total STOIIP of about 210 x 10[sup 6]m[sup 3] (1.3 x 10[sup 9] bbl). Reservoirs generally comprise continental and shallow marine clastics of the Upper Jurassic of Lower Cretaceous deposited in synrift and postrift settings. The west netherlands basin was created during a phase of Late Jurassic and Early Cretaceous rifting, characterized by divergent oblique-slip faulting. This resulted in a northwest-southeast-trending block-faulted depression between the London-Brabant Massif to the south, and the Zandvoort Ridge to the north. In the subsequent postrift stage, shallow marine clastics and marls were deposited in a wide basin, with only mild synsedimentary faulting. At the end of the Cretaceous, regional uplift and convergent oblique-slip faulting resulted in basin inversion and the reverse reactivation of preexisting normal faults. Due to the transpressional nature of the basin inversion, narrow asymmetric anticlines were formed, often bounded by upward diverging reverse faults, in the hanging-wall blocks of the former normal faults. These type of structures constitute the general trap geometry of the Cretaceous oil fields in this basin. The acquisition of three-dimensional seismic data has resulted in significantly enhanced structural definition and has lead to the development of new structural and depositional models, which improve the prediction of reservoir distribution and risk assessment.

  8. Active faulting within a megacity: the geometry and slip rate of the Pardisan thrust in central Tehran, Iran

    Science.gov (United States)

    Talebian, M.; Copley, A. C.; Fattahi, M.; Ghorashi, M.; Jackson, J. A.; Nazari, H.; Sloan, R. A.; Walker, R. T.

    2016-12-01

    Tehran, the capital city of Iran with a population of over 12 million, is one of the largest urban centres within the seismically active Alpine-Himalayan orogenic belt. Although several historic earthquakes have affected Tehran, their relation to individual faults is ambiguous for most. This ambiguity is partly due to a lack of knowledge about the locations, geometries and seismic potential of structures that have been obscured by dramatic urban growth over the past three decades, and which have covered most of the young geomorphic markers and natural exposures. Here we use aerial photographs from 1956, combined with an ˜1 m DEM derived from stereo Pleiades satellite imagery to investigate the geomorphology of a growing anticline above a thrust fault-the Pardisan thrust-within central Tehran. The topography across the ridge is consistent with a steep ramp extending from close to the surface to a depth of ˜2 km, where it presumably connects with a shallow-dipping detachment. No primary fault is visible at the surface, and it is possible that the faulting dissipates in the near surface as distributed shearing. We use optically stimulated luminescence to date remnants of uplifted and warped alluvial deposits that are offset vertically across the Pardisan fault, providing minimum uplift and slip-rates of at least 1 mm yr-1. Our study shows that the faults within the Tehran urban region have relatively rapid rates of slip, are important in the regional tectonics, and have a great impact on earthquake hazard assessment of the city and surrounding region.

  9. Geostatistical Approach to Estimating the Gold Ore Characteristics and Gold Reserves: A Case Study Daksa Area, Quang Nam Province, Viet Nam

    Science.gov (United States)

    Luan Truong, Xuan; Luong Le, Van; Quang Truong, Xuan

    2015-04-01

    Daksa gold deposit is the biggest gold deposits in Vietnam. The Daksa geological structure complicated, distributed mainly metamorphosed sedimentary NuiVu formation (PR3-?1nv2). The sulfide gold ore bodies distributed in quartz schist, quartz - biotite related to faut and distribution wing anticline. The gold ore bodies form circuits, network circuits, circuits lenses; fill the cup surface layer of the developing northeast - southwest; is the less than or west longitude north - SE. The results show that, Au and accompanying elements (Ag, Pb and Zn) have correlated pretty closely. All of its consistent with the logarithmic distribution standard, in accordance with the law of distribution of content mineral rare. The structure functions have nugget effect and spherical models with show that Au and accompanying elements special variation are changes. Au contents shown local anisotropy, no clearly anisotropy (K=1,17) and weakly anisotropy (K=1,4). Intensity mineralization of the ore bodies are quite high with demand spherical conversion coefficient ranging from 0.49 to 0.75 and from 0.66 to 0.97 (for other body). With nugget effects, ore bodies shown that it is consistent with mineralization in the ore bodies study, ore erasable, micro vein, infilling fractures in quartz vein. All of variogram presents local anisotropy, indicated gold mineralization at study area has least two-mineralization stages, consistent with the analysis of mineralography samples. By the results of the structure function study, the authors present the system optimization for exploration deposit and used to evaluate gold reserves by Ordinary Kriging. High accuracy of Kriging estimation results are expressed in the minimum Kriging variance, by compare the results calculated by some other methods (such as distance inverse weighting method, ..) and specially compare to the results of a some blocks have been exploited. Key words: Geostat and gold deposits VN. Daksa and gold mineralization. Geostat

  10. Structural characteristics of the Lake Van Basin, eastern Turkey, from high-resolution seismic reflection profiles and multibeam echosounder data: geologic and tectonic implications

    Science.gov (United States)

    Cukur, Deniz; Krastel, Sebastian; Tomonaga, Yama; Schmincke, Hans-Ulrich; Sumita, Mari; Meydan, Ayşegül Feray; Çağatay, M. Namık; Toker, Mustafa; Kim, Seong-Pil; Kong, Gee-Soo; Horozal, Senay

    2016-03-01

    The structural evolution of Lake Van Basin, eastern Turkey, was reconstructed based on seismic reflection profiles through the sedimentary fill as well as from newly acquired multibeam echosounder data. The major sub-basins (Tatvan Basin and Northern Basin) of Lake Van, bound by NE-trending faults with normal components, formed during the past ~600 ka probably due to extensional tectonics resulting from lithospheric thinning and mantle upwelling related to the westward escape of Anatolia. Rapid extension and subsidence during early lake formation led to the opening of the two sub-basins. Two major, still active volcanoes (Nemrut and Süphan) grew close to the lake basins approximately synchronously, their explosive deposits making up >20 % of the drilled upper 220 m of the ca. 550-m-thick sedimentary fill. During basin development, extension and subsidence alternated with compressional periods, particularly between ~340 and 290 ka and sometime before ~14 ka, when normal fault movements reversed and gentle anticlines formed as a result of inversion. The ~14 ka event was accompanied by widespread uplift and erosion along the northeastern margin of the lake, and substantial erosion took place on the crests of the folds. A series of closely spaced eruptions of Süphan volcano occurred synchronously suggesting a causal relationship. Compression is still prevalent inside and around Lake Van as evidenced by recent faults offsetting the lake floor and by recent devastating earthquakes along their onshore continuations. New, high-resolution bathymetry data from Lake Van reveal the morphology of the Northern Ridge and provide strong evidence for ongoing transpression on a dextral strike-slip fault as documented by the occurrence of several pop-up structures along the ridge.

  11. The Katmandu and Gosainkund nappes, central Nepal Himalaya (cartography, structure, metamorphism, geochemistry and radio-chronology); Les nappes de Katmandou et du Gosainkund, Himalaya du Nepal central (Etude cartographique, structurale, metamorphique, geochimique et radiochronologique)

    Energy Technology Data Exchange (ETDEWEB)

    Rai, S.M

    1998-10-01

    In central Nepal, a multidisciplinary study has been carried out to characterize and distinguish the crystalline nappes of Katmandu and Gosainkund from the Midland formations. Two principal deformations are recorded: one ductile, syn-metamorphic, marked by microstructures (stretching lineation, S-C structures, etc. ), another, post-metamorphic, recorded by an anticline, roughly EW -directed, and by NNE-SSW -directed folds. The syn-metamorphic P-T conditions show differences between Katmandu Crystalline Nappe (900-720 MPa; 700-480 deg C) and Gosainkund Crystalline Nappe (890-580 MPa; 750-590 deg C). They exhibit well preserved inverted metamorphism between the Upper Midland Formations (750 Mpa; 560 deg C) and the Gosainkund Nappe. In central Nepal, the augen gneisses and the 'Lesser Himalayan' Cambro-Ordovician granites bear similar petrographic and geochemical characteristics which suggest a common origin. However, the geological setting and age of the Proterozoic Ulleri augen gneiss rule out correlation with these formations. {sup 40}Ar/{sup 39}Ar analyses of muscovite, indicate cooling ages younger from south to north: 22 to 13 Ma in the Katmandu Nappe, 16 to 5 Ma in the Gosainkund Nappe, and 12 to 6 Ma in the Midland Formation. The principal points summarized by this study are the following: clear distinction between two nappes marked by their litho-stratigraphy and metamorphism; the ductile movement of MCT in the north of Katmandu is blocked since approximately 25 Ma; the late emplacement and late or common post metamorphic history of the two nappes; but earlier cooling history of the Katmandu nappe; the present uplift of the Katmandu region, underlined by the intense micro-seismicity, concerns indifferently the two nappes that form a single tectonic block at present; the combined uplift of the two nappes is due to the displacement on a ramp of major decollement surface. (author)

  12. Hydrodynamic trapping in Mission Canyon Formation (Mississippian) reservoirs: Elkhorn Ranch field, North Dakota

    Energy Technology Data Exchange (ETDEWEB)

    Demis, W.D. (Marathon Oil Co., Houston, TX (United States))

    1991-03-01

    Hydrocarbons in Mission Canyon dolomite reservoirs in the Elkhorn Ranch field are trapped by downdip flow of formation water to the northeast. Elkhorn Ranch field is located on a north-plunging anticline with only 10 ft (3 m) of crestal closure. The Mission Canyon is a regressive, shallowing upward sequence of subtidal dolomitized mudstones and wackestones grading upward into sebkha-salina evaporites. Mission Canyon oil production is localized on the north and northeast side of the structure. Maps of porosity pinch-outs and permeability barriers defined from core data, superimposed upon the Mission Canyon structure, show that most of the oil cannot be trapped by stratigraphic facies change. Southwest-trending, updip porosity pinch-outs cross the north-plunging structural axis at an angle so low that hydrocarbons would leak out to the southwest under hydrostatic conditions. Downdip hydrodynamic flow to the northeast provides the critical trapping component. Regional maps of apparent formation water resistivity and water salinity show a region of fresher water south and southwest of the field. A regional potentiometric map constructed using Horner-plot extrapolated shut-in pressure data indicates a head gradient of about 20 ft/mi (4 m/km) to the northeast at Elkhorn Ranch field. This gradient corresponds to a calculated water-oil tilt of about 50 ft/mi (20 m/km). Observed tilt of the oil accumulation is actually about 25 ft/mi (5 m/km) to the northeast. This discrepancy might be the result of the field having not yet reached equilibrium with the invading water.

  13. Geothermal investigations in Idaho. Part 3. An evaluation of thermal water in the Weiser area, Idaho

    Energy Technology Data Exchange (ETDEWEB)

    Young, H.W.; Whitehead, R.L.

    1974-01-01

    The Weiser area encompasses about 200 square miles in southwest Idaho and contains two thermal water areas: (1) the Crane Creek subarea, which is 12 miles east of Weiser, Idaho, and (2) the Weiser Hot Springs subarea, which is 5 miles northwest of Weiser. Volcanic and sedimentary rocks of Miocene to Pleistocene age have been faulted and folded to form the northwest-trending anticlines present in much of the area. Basalt of the Columbia River Group or underlying rocks are believed to constitute the reservoir for the hot water. Gravity and magnetic anomalies are present in both subareas. A preliminary audio-magnetotelluric survey indicates that a shallow conductive zone is associated with each thermal site. Above-normal ground temperatures measured at a depth of 1 metre below the land surface in the Weiser Hot Springs subarea correlate with relatively high concentrations of boron in underlying ground waters, which, in turn, are usually associated with thermal waters in the study area. Sampled thermal waters are of a sodium chloride sulfate or sodium sulfate type, having dissolved-solids concentrations that range from 225 to 1,140 milligrams per litre. Temperatures of sampled waters ranged from 13/sup 0/ to 92.0/sup 0/C. Minimum aquifer temperatures calculated from chemical analysis of water, using geochemical thermometers, were 170/sup 0/ and 150/sup 0/C in the Crane Creek and Weiser Hot Springs subareas, respectively. Estimated maximum temperatures ranged from 212/sup 0/ to 270/sup 0/C and 200/sup 0/ to 242/sup 0/C, respectively, in these subareas. The probable heat sources for both subareas are (1) young magmatic intrusive rocks underlying the basalt or (2) above-normal temperatures resulting from thinning of the earth's crust. Maps are included.

  14. The Donets Basin (Ukraine/Russia). Coalification and thermal history

    Energy Technology Data Exchange (ETDEWEB)

    Sachsenhofer, R.F.; Rainer, T.; Shymanovskyy, V.A. [Institut fuer Geowissenschaften, Montanuniversitaet Leoben, Peter-Tunner-Strasse 5, A-8700 Leoben (Austria); Privalov, V.A. [Donetsk State Technical University, Artem str., UA-84000 Donetsk (Ukraine); Zhykalyak, M.V. [Donetsk State Regional Geological Survey, Sybirtseva str. 17, UA-84500 Artemovsk (Ukraine); Bueker, C. [Institute of Geology, and Geochemistry of Petroleum and Coal, Aachen (Germany); Panova, E.A. [UkrNIMI, Tchelyuskintsev str. 291, UA-83121 Donetsk (Ukraine); Stephenson, R. [Research School of Sedimentary Geology, Vrije Universiteit, De Boelelaan 1085, 1081 HV Amsterdam (Netherlands)

    2002-02-01

    The Donets Basin (Donbas) is one of the major late Paleozoic coal basins in the world. The Donbas Foldbelt is an inverted part of the Donets Basin characterized by WNW-ESE-trending folds and faults. The age of basin inversion is under discussion. Large parts of the Donets Basin host anthracite and meta-anthracite. Low-rank coals are restricted to the western and northern basin margins. Vitrinite reflectance patterns along the Gorlovka Anticline indicate syn-deformational coalification. Vitrinite reflectance isolines are displaced along thrusts, clear evidence that main coalification predates late faulting. 1-D and 2-D numerical models were applied to elucidate the factors that control coalification in the western Donets Basin (Krasnoarmeisk Monocline, Kalmius-Torets Depression, South Syncline). The models indicate that the depth of the seams and the heat flow during maximum (Permian) burial are the most important parameters. The thickness of late Carboniferous and Permian rocks increased from the southwestern basin margin towards the basin center. Permian erosion along the Krasnoarmeisk Monocline and in the Kalmius-Torets Depression was on the order of 2-3 km. More rocks were eroded southeast of the Donetsk-Kadievka Fault Zone (4-5 km). Heat flow during maximum burial was in the range of 40-75 mW/m{sup 2}. Heat flow in the Krasnoarmeisk Monocline and the Kalmius-Torets Depression increased in a northeastward direction from 40 to 55 mW/m{sup 2}. Heat flow at the eastern edge of the Kalmius-Torets Depression and in the South Syncline was in the range of 60-75 mW/m{sup 2} and increased towards the southeast. The resulting coalification pattern in this area was overprinted by thermal events in the northern Krasnoarmeisk Monocline and the South Syncline. These are probably related to (Permian?) magmatic intrusions. Coked coal occurs at the contact to presumed Permian sills and dikes southwest of Donetsk.

  15. Geological structure and the history of hydrocarbon exploration in the area of the Luetow and Heringsdorf structures on the island of Usedom; Geologischer Bau und Entwicklung der Erdoelprospektion im Bereich der Strukturen Luetow und Heringsdorf/Usedom

    Energy Technology Data Exchange (ETDEWEB)

    Beer, H. [Landesamt fuer Geowissenschaften und Rohstoffe Brandenburg, Kleinmachnow (Germany); Muenzberger, E. [Geologisches Inst., Greifswald Univ. (Germany); Sommer, S. [Erdoel-Erdgas Gommern GmbH, Gommern (Germany)

    1993-12-31

    Economic oil and gas accumulations were discovered in the marginal facies of the Stassfurt carbonate as a result of exploration work for oil and gas on the northeastern margin of the German Zechstein Basin. The accumulations are associated with anticlinal structures on the shelf margin, the carbonate-sand barrier zone. Carbonate sands (grainstone, in some cases packstone) form the reservoirs; in most of them the true porosity is accompanied by a minor joint porosity, and often the top of the reservoir is cemented by anhydrite. All deposits are filled with hydrocarbons up to the spill point; the traps are inferred to have been filled during Late Kimmerian to Laramian, some of them post Laramian. An account is given of the exploration methods, the geological structure, the development of the trap structure, the nature of the reservoir, and data on the type of deposit and production methods used. (orig.) [Deutsch] Prospektionsarbeiten auf Erdoel-Erdgasvorkommen am NE-Rand des Germanischen Zechsteinbeckens haben in der randnahen Fazies des Stassfurtkarbonats wirtschaftlich fuendige Oel- und Gas-Lagerstaetten erschlossen. Die Vorkommen sind an antiklinalartige Strukturen des Plattformrandes, and die Karbonatsand-Barrenzone gebunden. Speicher sind Karbonatsande (grainstone, z.T. packstone), ausgebildet als Porenspeicher, meist mit Kluftspeicheranteilen, gegen das Hangende haeufig anhydritzementiert. Alle Lager sind bis zum spill-point KW-gefuellt; die Fallenfuellung wird spaetkimmerisch bis laramisch, teils postlaramisch angesetzt. Dargestellt werden die Aufschlussmethodik, der geologische Aufbau und die Entwicklung der Struktur/Falle, die Speicherbeschaffenheit bis hin zu speziellen Daten des Lagerstaettencharakters und des Lagerstaettenabbaus. (orig.)

  16. The simulation model of growth and cell divisions for the root apex with an apical cell in application to Azolla pinnata.

    Science.gov (United States)

    Piekarska-Stachowiak, Anna; Nakielski, Jerzy

    2013-12-01

    In contrast to seed plants, the roots of most ferns have a single apical cell which is the ultimate source of all cells in the root. The apical cell has a tetrahedral shape and divides asymmetrically. The root cap derives from the distal division face, while merophytes derived from three proximal division faces contribute to the root proper. The merophytes are produced sequentially forming three sectors along a helix around the root axis. During development, they divide and differentiate in a predictable pattern. Such growth causes cell pattern of the root apex to be remarkably regular and self-perpetuating. The nature of this regularity remains unknown. This paper shows the 2D simulation model for growth of the root apex with the apical cell in application to Azolla pinnata. The field of growth rates of the organ, prescribed by the model, is of a tensor type (symplastic growth) and cells divide taking principal growth directions into account. The simulations show how the cell pattern in a longitudinal section of the apex develops in time. The virtual root apex grows realistically and its cell pattern is similar to that observed in anatomical sections. The simulations indicate that the cell pattern regularity results from cell divisions which are oriented with respect to principal growth directions. Such divisions are essential for maintenance of peri-anticlinal arrangement of cell walls and coordinated growth of merophytes during the development. The highly specific division program that takes place in merophytes prior to differentiation seems to be regulated at the cellular level.

  17. Remote sensing and field analysis of the Palaeozoic structural style in NW Libya: The Qarqaf arch a paleo-transfer fault zone between the Ghadamis and Murzuq basins

    Science.gov (United States)

    Chorowicz, Jean; Benissa, Mahmoud

    2016-11-01

    The N75°E-trending Qarqaf arch in NW Libya separates the Ghadamis and Murzuq basins. We have updated existing geological maps by remote sensing analysis and fieldwork in order to describe the tectonic style of the Palaeozoic units. We have evidenced a Bir Aishah anticline, a Wadi Ash Shabiyat graben and arrays of sedimentary and/or vein quartz dykes that relate to extension fractures or open faults some of them being filled up by on-going sedimentation. We show that continuous brittle syn-depositional deformation occurred throughout the Palaeozoic and progressively with time focused into major faults. The Qarqaf arch is a Palaeozoic right-lateral fault zone comprising main conjugate dextral N60°E and sinistral N90°E fault families. It also comprises ∼ N-striking extensional faults with related drag or fault-propagation folds. The Palaeozoic tectonic style is that of rift basins connected by a major transfer fault zone. The arch is as a consequence of strike-slip mechanism. In order to account for distinct folds affecting the Carboniferous strata we argue that partly consolidated silty Devonian and Carboniferous deposits slid in mass by places at the end of their deposition over tilting Devonian layers. Our model is alternative to the currently considered concept of major Variscan compressional orogen in this area. The regional so called 'Variscan' age disconformity actually is the Triassic early Neo-Tethyan event. These general concepts have potential impact on basin modelling of subsidence, uplift, thermal history and hydrocarbon migration. Any new structural geology study in this area is important for oil exploration.

  18. Pb-induced avoidance-like chloroplast movements in fronds of Lemna trisulca L.

    Directory of Open Access Journals (Sweden)

    Sławomir Samardakiewicz

    Full Text Available Lead ions are particularly dangerous to the photosynthetic apparatus, but little is known about the effects of trace metals, including Pb, on regulation of chloroplast redistribution. In this study a new effect of lead on chloroplast distribution patterns and movements was demonstrated in mesophyll cells of a small-sized aquatic angiosperm Lemna trisulca L. (star duckweed. An analysis of confocal microscopy images of L. trisulca fronds treated with lead (15 μM Pb2+, 24 h in darkness or in weak white light revealed an enhanced accumulation of chloroplasts in the profile position along the anticlinal cell walls, in comparison to untreated plants. The rearrangement of chloroplasts in their response to lead ions in darkness was similar to the avoidance response of chloroplasts in plants treated with strong white light. Transmission electron microscopy X-ray microanalysis showed that intracellular chloroplast arrangement was independent of the location of Pb deposits, suggesting that lead causes redistribution of chloroplasts, which looks like a light-induced avoidance response, but is not a real avoidance response to the metal. Furthermore, a similar redistribution of chloroplasts in L. trisulca cells in darkness was observed also under the influence of exogenously applied hydrogen peroxide (H2O2. In addition, we detected an enhanced accumulation of endogenous H2O2 after treatment of plants with lead. Interestingly, H2O2-specific scavenger catalase partly abolished the Pb-induced chloroplast response. These results suggest that H2O2 can be involved in the avoidance-like movement of chloroplasts induced by lead. Analysis of photometric measurements revealed also strong inhibition (but not complete of blue-light-induced chloroplast movements by lead. This inhibition may result from disturbances in the actin cytoskeleton, as we observed fragmentation and disappearance of actin filaments around chloroplasts. Results of this study show that the

  19. Geometría y cinemática de las estructuras que involucran al basamento en la zona del arroyo Tordillo, faja corrida y plegada de Malargüe, Mendoza

    Directory of Open Access Journals (Sweden)

    M.M. Turienzo

    2005-12-01

    Full Text Available El estudio detallado realizado en la zona de los arroyos Tordillo y Blanco, en la faja corrida y plegada de Malargüe, permitió reconocer una gran variedad de estructuras tectónicas que afectan tanto al basamento como a la cubierta sedimentaria. Con los datos estructurales relevados e información de subsuelo, confeccionamos una sección estructural retrodeformable de las estructuras aflorantes y su continuidad en profundidad, e interpretamos su evolución cinemática. Dos pares anticlinal-sinclinal, que posiblemente involucran al basamento, tienen lugar en el sector más occidental del área de estudio. Estos son transportados sobre una cuña de basamento, la cual en su avance hacia el antepaís genera un pliegue por propagación de falla en la cubierta sedimentaria. Cuando el desplazamiento hacia el este de la cuña es obstaculizado, en su extremo se generan dos retrocorrimientos. En este intrincado marco estructural, el corrimiento que dio origen a la cuña es reactivado como una falla fuera de secuencia. Finalmente un nuevo corrimiento desarrollado más al este genera otra escama de basamento que eleva a las estructuras previas. La interpretación cinemática permitió calcular los acortamientos tectónicos para cada estadio de la estructuración así como visualizar la estrecha relación existente entre las estructuras.

  20. Geological feature and ore-controlling regulation of Na'neng gold deposit in Fu'ning county, Yunnan%云南省富宁县那能金矿床地质特征及控矿规律

    Institute of Scientific and Technical Information of China (English)

    张继安

    2011-01-01

    Na'neng gold deposit locates in Triassic clasolite after regional weak alteration, and it is a medium or low temperature hydrothermal, micro-fine disseminated gold deposit.The deposit is controlled by both NWW-SEE fault and fold structures.It has obvious rock-controlling characteristics.The core of anticline and its nearby small fractures are the main factors that control the distribution of orebodies.The paper introduces the geological features of Naneng gold deposit and introduces the ore-controlling regulations.It is put forward that there is potential to find primary gold resources in the deep, which is of indication significance for future prospecting.%那能金矿床产于经区域弱变质的三叠系碎屑岩兼中,属中低温热液、微细浸染型金矿床.该矿床主要受NWW-SEE向断裂和褶皱构造的双重控制,同时具有明显岩控特征;背斜核部及其附近的小断裂是控制矿体分布的主要因素.阐述了那能金矿床的地质特征,总结了控矿规律,提出了深部具有寻找原生矿资源的潜力,对指导企业进一步找矿并取得储量的更大突破具有指导意义.

  1. Seismic transpressive basement faults and monocline development in a foreland basin (Eastern Guadalquivir, SE Spain)

    Science.gov (United States)

    Pedrera, A.; Ruiz-Constán, A.; Marín-Lechado, C.; Galindo-Zaldívar, J.; González, A.; Peláez, J. A.

    2013-12-01

    We examine the late Tortonian to present-day deformation of an active seismic sector of the eastern Iberian foreland basement of the Betic Cordillera, in southern Spain. Transpressive faults affecting Paleozoic basement offset up to Triassic rocks. Late Triassic clays and evaporites constitute a décollement level decoupling the basement rocks and a ~100 m thick cover of Jurassic carbonates. Monoclines trending NE-SW to ENE-WSW deform the Jurassic cover driven by the propagation of high-angle transpressive right-lateral basement faults. They favor the migration of clays and evaporites toward the propagated fault tip, i.e., the core of the anticline,