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Sample records for caucasus basin northern

  1. The jurassic events in the Greater Caucasus basin (Northern Neotethys and the Neuquén basin (West Gondwana: a comparison

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    Dmitry A. Ruban

    2008-12-01

    Full Text Available Quite a few common tectonic, palaeoenvironmental, and palaeobiological events have been recognized in the Jurassic evolution of the Greater Caucasus basin (Northern Neotethys and the Neuquén basin (West Gondwana. Both basins were originated by the same planetary-scale tectonic force, i.e., by the activity of the Intrapangaean Shear Zone stretching eastwards along the Eurasian margin as the Northern Tethyan Shear Zone. An oxygen depletion occurred in both studied regions in the Toarcian as a result of global anoxia, which provoked a mass extinction. In both basins, the Callovian was a time for the carbonate platform growth, although in the Greater Caucasus, a carbonate platform appeared only in the Late Callovian. A salinity crisis occurred in the Greater Caucasus during the Kimmeridgian-Tithonian, whereas the same took place twice in the Neuquén basin - in the Middle Callovian and in the late Oxfordian-Kimmeridgian. These events were related to the global epoch of evaporite deposition. Some important differences between the considered basins are also documented. Palaeontological data from the Neuquén basin suggest against the mass extinction at the Jurassic-Cretaceous transition. In contrast, data from the Greater Caucasus basin permit to recognize this global event, although its regional peak occurred in the Berriasian. The Jurassic transgressions and regressions in the Greater Caucasus and western Argentina differed, facts that may be explained by the differences in the regional geodynamics. The only common pattern was a stepwise transgression during the Sinemurian-Pliensbachian.

  2. Source classification in the Northern Caucasus

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    Chernobay, I. P.; Gabsatarova, I. P.

    1999-06-01

    Regional records of-well documented mine blasts in the area of Caucasian Mineral Water (Northern Caucasus, Russia) are analyzed to test the efficiency of the spectrogram method and Pg/Lg spectral ratios as discriminants between small earthquakes (magnitude self-training algorithm, based on the comparison of `demeaned' envelopes, which grouped events by means of hierarchical cluster analysis, P/S discriminant, was implemented to classify a data set of 18 months of routine observations. A total of 366 out of 374 records were successfully classified and separated into 19 groups of events. This algorithm is especially useful when data analyzed are from sparse networks or from a region of complicated crust structure where averaging over the network can lead to systematic error.

  3. Oak ecosystem succession of the Northern Caucasus

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    Chalaya, Elena; Slepykh, Victor; Efimenko, Natalia; Povolotskaya, Nina

    2014-05-01

    English oak (Quercus robur L.) along with its well-known good properties has a high sanitary-hygienic and curative potential. Its volatile metabolites (VM) influence bacteriostatically Staphylococcus aureus 209r, oppressing it in vitro by 85% compared with the control, and Escherichia coli by 45%. There is the least amount of epiphytic microorganisms on the leaves of Q. robur L. compared with some tree species [1]. In addition, VM of Q. robur L. have direct milieu (hypotensive) effects on the organism under its canopy, lowering blood pressure by 20-25 mm Hg [2]. A.P. Kazankin (1993) [4] calculated the prehistoric formula of forest species composition of Caucasian Mineral Waters region (Northern Caucasus): 6Qr3Crp1Fr which was based on the theory of calcium-magnesium absorption complex. According to the theory, underground mineral water, soil, forest litter and the leaves of ground vegetation of the area have the same ratio of the cations Ca and Mg - calcium-magnesium index [3]. Hence oldgrowth in the region consisted of oak (Qr) by 60%, hornbeam (Carpinus-Crp) by 30% and ash (Fraxinus-Fr) only by 10%. Currently, the formula of the forests of the region has been changed by man: 5Fr3Crp2Qr. The proportion of oak forests has decreased to 20%, the proportion of ash has increased by 50%, but the proportion of hornbeam hasn't changed. So it is relevant to restore oak forests of the region in the former ratio to other forest-forming species - ash and hornbeam. Taking into consideration the change of economic formation of society in Russia, it is extremely important to restore natural seed oak forests. Therein the luminance of surface areal is a limiting factor. We have calculated that the natural recovery of oak forests is possible providing observation of optimal moisture standards and soil fertility in combination with solar light within 10-24% from the light of open space. Measures for promotion of oak natural regeneration in mountain resorts of the Northern Caucasus

  4. Thermal history, exhumation, uplift, and long-term landscape evolution of the Eastern Great and Northern Lesser Caucasus, Azerbaijan

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    Spilger, Tatiana; Glasmacher, Ulrich Anton; Mosar, Jon

    2015-04-01

    The Caucasus orogen (Great and Lesser Caucasus) is the highest mountain range between Asia and Europe, whose growth takes place since the beginning of the Cenozoic (Mosar et al. 2010). The orogen has evolved as a result of the active north directed convergence of the Arabian plate (Nikishin et al. 2001). The Great Caucasus (GC) represents a doubly verging fold-and-thrust belt, with a per-and a retro wedge actively propagating into the foreland sedimentary basins to the south and to the north (Sholpo 1993). Thermochronometric techniques (fission-track, (U-Th-Sm)/He, each on apatite and zircon) are used to reconstruct the thermal evolution of the upper crust, the subsidence, as well as the rock and surface uplift of the Eastern GC and Northern Lesser Caucasus and to connect them with the thrust kinematics of the GC. Samples were taken along different transects in Eastern GC and Northern Lesser Caucasus in Azerbaijan. Most samples of Eastern GC are Lower Jurassic age sandstones (deep marine and slope facies). Several sedimentary rock samples of Cretaceous, Miocene, Pliocene and Quaternary age were taken from the outcrops in the Kura basin and along rivers in the Eastern GC. Samples of the Lesser Caucasus are igneous and sedimentary origin and have Lower Jurassic to Holocene age. The first AFT-data in the Eastern Great Caucasus were investigated. All researched samples show recessed AF-ages. Most dated sedimentary samples have several populations of apatite minerals. Apatite minerals have low U-concentration (up to 10 ppm). Most dated samples taken in Aalenian sandstone have very young AFT-ages (up to 10 Ma). Some samples show Oligocene AF-ages of 23-28Ma. The preliminary data confirm orogeny in the Eastern Great Caucasus since Oligocene and propagation of orogeny since middle Miocene (Mosar et al. 2010). References Mosar, J., Kangarli, T., Bochud, M., Glasmacher, U.A., Rast, A., Brunet, M.-F. & Sosson, M. 2010. Cenozoic-Recent tectonics and uplift in the Greater

  5. Active deformation processes of the Northern Caucasus deduced from the GPS observations

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    Milyukov, Vadim; Mironov, Alexey; Rogozhin, Eugeny; Steblov, Grigory; Gabsatarov, Yury

    2015-04-01

    The Northern Caucasus, as a part of the Alpine-Himalayan mobile belt, is a zone of complex tectonics associated with the interaction of the two major tectonic plates, Arabian and Eurasian. The first GPS study of the contemporary geodynamics of the Caucasus mountain system were launched in the early 1990s in the framework of the Russia-US joint project. Since 2005 observations of the modern tectonic motion of the Northern Caucasus are carried out using the continuous GPS network. This network encompasses the territory of three Northern Caucasian Republics of the Russian Federation: Karachay-Cherkessia, Kabardino-Balkaria, and North Ossetia. In the Ossetian part of the Northern Caucasus the network of GPS survey-mode sites has been deployed as well. The GPS velocities confirm weak general compression of the Northern Caucasus with at the rate of about 1-2 mm/year. This horizontal motion at the boundary of the Northern Caucasus with respect to the Eurasian plate causes the higher seismic and tectonic activity of this transition zone. This result confirms that the source of deformation of the Northern Caucasus is the sub-meridional drift of the Arabian plate towards the adjacent boundary of the Eastern European part of the Eurasian lithospheric plate. The concept of such convergence implies that the Caucasian segment of the Alpine-Himalayan mobile belt is under compression, the layers of sedimentary and volcanic rocks are folded, the basement blocks are subject to shifts in various directions, and the upper crust layers are ruptured by reverse faults and thrusts. Weak deviation of observed velocities from the pattern corresponding to homogeneous compression can also be revealed, and numerical modeling of deformations of major regional tectonic structures, such as the Main Caucasus Ridge, can explain this. The deformation tensor deduced from the velocity field also exhibits the sub-meridional direction of the major compressional axes which coincides with the direction of

  6. THE ISLAMIST MOVEMENT IN THE NORTHERN CAUCASUS: TRENDS, POSSIBLE DEVELOPMENTS, AND HOW TO OPPOSE IT

    OpenAIRE

    Dobaev, Igor

    2006-01-01

    Unfolding in the late 1980s and early 1990s, the religious revival that involved all the traditional confessions, including Islam, existing in Russia spread to the Northern Caucasus. In fact, it added a political dimension to the local forms of Islam and, by the same token, made it more radical. Centrifugal factors caused disunity in North Caucasian Islam on the institutional level when seven independent spiritual administrations replaced the single Spiritual Administration of the North Cauca...

  7. Glacier variations in the Northern Caucasus compared to climatic reconstructions over the past millennium

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    Solomina, Olga; Bushueva, Irina; Dolgova, Ekaterina; Jomelli, Vincent; Alexandrin, Mikhail; Mikhalenko, Vladimir; Matskovsky, Vladimir

    2016-05-01

    In the Northern Caucasus, glacier and climatic variations over the past centuries remain insufficiently documented. In this review, we summarized the high-resolution information on glacier and climate fluctuations in the region for the past millennium and provided a synthesis of these two lines of evidence with respect to regional climate change. The key areas considered in the paper are the Elbrus area, the Teberda and Arkhyz valleys in the Western Caucasus and the Cherek Bezengiisky and Tsey valleys in the Eastern Caucasus, where the most paleoclimatic evidence has been retrieved. We focused on the fluctuation records of the ten glaciers that are best documented. To reconstruct changes in glacier length in the past, we used aerial photos, optical space images, repeated photographs and old maps. The ages of moraines were defined with the help of instrumental records, historical images, old maps, and tree-ring dating. Lichenometry was used as a supplementary tool to determine the relative ages of glacial landforms. We reviewed the collection of control points used for the lichenometric curves and determined the time limit of potential use of this method in the Caucasus to be up to one millennium. High-resolution tree-ring-based hydroclimatic reconstructions in the Northern Caucasus are presented based on the reconstruction of June-September temperature (1595-2012 CE), the mass balance reconstruction of the Garabashi Glacier (1800-2008 CE) and the runoff of the Teberda River (low-frequency variations) for May, July and August for 1850-2005 CE. The synthesis of all the available paleoclimatic records revealed several distinct climatic periods. Evidence of a warm interval (traditionally referred to as the "Arkhyz break in glaciation") preceding the Little Ice Age (LIA) in the Caucasus is based on archeological, palynological, geochemical and pedological data. However, the conclusions concerning the duration and magnitude of this warming are still vague due to the low

  8. The New 2-M RCC Telescope in the Northern Caucasus for Modern Astronomical Research

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    Tarady, V. K.; Yatskiv, Ya. S.

    A new 2-m Ritchey-Chretien-Coude (RCC) telescope in the Northern Caucasus (the Kabardin-Balkar Republic, Russian Federation) is nearing being put into operation. It has been developed by the National Academy of Sciences of the Ukraine on the Terskol peak (near Elbrus) which seems to be one of the best sites for astronomical ground observations in terms of its astroclimate. This paper describes the present status of the telescope, its instrumentation and outlines the scientific problems that can be solved using the telescope.

  9. Megalandslide in the Northern Caucasus foredeep (Uspenskoye, Russia): geomorphology, possible mechanism and age constraints

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    Pánek, T.; Hradecký, J.; Šilhán, K..; Strom, A. L.; Smolková, V.; Zerkal, O.

    2012-04-01

    Although worldwide datasets reveal that majority of giant landslides have occurred within the steepest portion of the Earth's landsurface, recent observations have brought evidence that some of the largest landslides originated in the low-relief landscapes and moved upon very gently inclined slip surfaces. Extremely large landslide with volume ~2.8 km3 was detected on the right bank of the Kuban river in the Northern Caucasus foredeep (Russian Federation). Megalandslide with gently inclined (prefer palaeoseismic hypothesis in connection with rupture of some Late Quaternary fault in the vicinity of landslide area. Area of megalandslide is recently subject of intensive denudation marked by activity of numerous shallow landslides, gully erosion and dynamic aggradation (>2 m during last ~300 years) of material within valley floors.

  10. Simulation and reconstruction of parameters of streamflow and glacier mass balance in the Northern Caucasus

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    V. G. Konovalov

    2014-01-01

    Full Text Available The work was aimed at numerical modeling of spatial-temporal variability of the river Terek seasonal (April to September streamflow characteristics and long-term fluctuations of components of annual glacier mass balances in this basin and on the adjacent territories. Mass balance of glaciers Djankuat and Garabashi was calculated. Simulation was performed by means of stochastic modeling and discrete data presenting fields of main meteorological parameters (precipitation, air temperature and humidity having effect on the streamflow. Realization of this approach is complicated by the fact that spatial representativeness of hydrological and meteorological sites are not corresponding one to another. Data on the runoff is clearly related to the total drainage area closed by a gauging station. And for this data we study a relationship with meteorological parameters which are measured at a non-regular observational network whose spatial representativeness is unknown. These stations are generally located beyond the area under investigation (Fig. 2. Similar problem exists when we analyze a relationship between components of the mass balance of individual glaciers (Djankuat and Garabashi and the above climate characteristics measured at some stations located on the whole Caucasus territory. The same takes place when long-term indices of width and density of tree annual rings obtained in upper reaches of the river Kuban’ are used for analysis of variations of the runoff and the glacier mass balance in the river Terek basin located at a distance of 100-150 km from the Kuban’ dendrologic sites.To solve the problem we used a wide number of factors which directly (various information about the climate or indirectly (indices of the climate dryness, wood ring characteristics characterize conditions of formation of annual and seasonal river runoff and components of glacier mass balance in the North Caucasus. Use of all obtained information made possible the

  11. The new 2meter RCC Telescope in the Northern CAucasus (3100m) for Modern Astronomical Research

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    Tarady, V.; Yatskiv, Ya.

    A new 2 meter Ritchey-Chretien-Coude telescope in the Northern Caucasus is expected to be ready for astronomical research in late 1995. The telescope is located on the Terskol peak (near Elbrus) with the altitude of 3100 meter. The low atmospheric water vapour content and the high air transparency in the ultraviolet region allow us to infer that the Terskol peak is one of the best sites in Europe for astronomical ground observation. The mean seeing is about 1 arcsec at the Terskol peak. The main parameters of the optical system are as follows: * equivalent focal length is 16000 mm for the Ritchey-Chretien system and 72000 mm for the Coude system; * diameter of the field free from vignetting is 108' for the Ritchey-Chretien system and 5' for another one; *spot concentration is 80% inside the 0.5" circle. The new telescope will be used in investigating the fundamental problems of the star brightness variability, physics of stars and galaxies, studying the planet and satellite atmosphere dynamics. The precise astrometrical problems can also be solved with this telescope. The telescope will be equiped with the following detectors: -CCD Echelle spectrograph in the Coude focus; - astronomical infrared Fourie spectrometre; -digital panoramic polarimeter; -panoramic spectrophotometer with Fabry-Perot interferometer. This project is realized by the joint efforts of the Main Astronomical Observatory in Kiev (Ukrainian Academy of Sciences) and the International Centre for Astronomical and Medical-Ecological Investigations. Proposals for Scientific observation at the Terskol Observatory are encouraged.

  12. Intracanyon basalt lavas of the Debed River (northern Armenia), part of a Pliocene-Pleistocene continental flood basalt province in the South Caucasus

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    Sheth, Hetu; Meliksetian, Khachatur; Gevorgyan, Hripsime; Israyelyan, Arsen; Navasardyan, Gevorg

    2015-03-01

    Late Pliocene to Early Pleistocene (~ 3.25-2.05 Ma), 200-400 m thick basalt lavas outcrop in the South Caucasus region, including the Kars-Erzurum Plateau (northeastern Turkey), the Javakheti Plateau (Georgia-Armenia), and the Lori Plateau (northern Armenia). These fissure-fed, rapidly erupted fluid lavas filled pre-existing river valleys over many tens of kilometres. The basalts exposed in the Debed River canyon, northern Armenia, are ~ 200 m thick and of three morphological types: (1) basal pillow basalts and hyaloclastites, overlain by (2) columnar-jointed pahoehoe sheet flows, in turn overlain by (3) slabby pahoehoe and rubbly pahoehoe flows. The lower and middle lavas show evidence for damming of river drainage, like many lavas of the Columbia River flood basalt province, Scotland, Ireland, and Iceland. There is also evidence for syn-volcanic faulting of the early lavas. Related basalts also outcrop in the Gegham Uplands and the Hrazdan River basin in Armenia. This 3.25-2.05 Ma South Caucasus basalt province, covering parts of Turkey, Georgia and Armenia, has an estimated areal extent of ~ 15,000 km2 and volume of ~ 2250 km3. Because its main geological features are remarkably like those of many continental flood basalt (CFB) provinces, we consider it a true, albeit small, CFB province. It is the smallest and youngest CFB in the world. An analogue closely similar in major features is the Late Miocene Altos de Jalisco CFB province in the western Trans-Mexican Volcanic Belt. Both provinces formed during lithospheric pull-apart and transtensional faulting. Their broader significance is in showing flood basalt size distribution to be a continuum without natural breaks, with implications for geodynamic models.

  13. Sediment Coring of the Proglacial Lake Donguz-Orun (northern Caucasus, Russia)

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    Alexandrin, Mikhail; Solomina, Olga; Kalugin, Ivan; Darin, Andrey; Nesje, Atle

    2014-05-01

    So far, no high-resolution reconstructions of climate and glacier variations based on lake sediment properties are available in Caucasus Mountains. In other presently glaciated regions this approach is proved to be very useful for this purpose (e.g. Nesje et al., 2001, 2011; Bakke, 2005, Nesje, 2009) In this paper we report the first results of the sediment coring of Donguz-Orun Lake (N 43°13'26", E 42°29'35") situated in the upper reaches of Donguz-Orun-Kyol, a tributary of Baksan river in the Elbrus region of Northern Caucasus, a typical proglacial lake dammed by a lateral moraine deposited by the Donguz-Orun Glacier. It is a drainage lake with several inflowing glacial streams and effluent river Donguz-Orun. The surface area is around 105 000 m2 with a water volume of 465 000m3. The average water depth is around 4.5 m, with a maximum water depth of 14 m. The deepest part is found close to the moraine dam in the narrow northern part of the lake. This is normally consistent with this type of glacial lake systems. An intensive gravitational drift of the moraine material towards the lake is observed. These non-rounded moraine boulders constitute a significant part of the lakebed. Lacustrine sediments are present though. The coring campaign from Institute of Geography, Russian Academy of Sciences (August 2012) used a modified piston corer with a 110 mm-diameter plastic tube (Nesje, 1992) mounted on the inflatable catamaran to obtain lake sediments from Lake Donguz-Orun. A 28-cm long core was retrieved from a water depth of around 7 m. The sediments consist of regularly laminated, fine beige clay, with several interlayers of sand. The coring process appeared to be challenging due to the stiffness of clay, which led to extreme bending of the sediment layers in the basal part of the core. The original thickness of the sediments was obviously higher than observed in the core. In order to clarify the recent history of the Donguz-Orun glacier, we used lichenometry and

  14. Nitrogen transformation in alpine soils of the Northern Caucasus: effect of nitrogen source and low temperatures

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    Makarov, Mikhail; Ermak, Anton; Malysheva, Tatiana; Mulyukova, Olga

    2010-05-01

    The alpine landscape supports a variety of plant communities whose distribution corresponds to their topographic position. Topography controls snow accumulation and hence soil winter temperature, length of growing season and soil water availability. The research was conducted at the Teberda Biosphere Reserve (Northern Caucasus, Russia). The study sites were located at Mt. Malaya Khatipara (43°27'N, 41°42'E) between 2700 and 2750 m a.s.l. The investigated toposequence was representative of the soil and plant community associations in the alpine zone of the Teberda Reserve: the wind-exposed ridges and upper slopes are covered by low-productive alpine lichen heaths; intermediate topographic positions are occupied by the most productive grasslands and meadows; the slope bottom is occupied by low-productive snowbed community. Under intensive snow cover accumulation typical for many alpine ecosystems, the temperature of soil within winter makes nearby 0 °C, while in case of absence or thin snow cover, characteristic for a lichen heath, the temperature can fall to -10 °C. The influence of nitrogen source, low temperatures and soil drying on processes of nitrogen mineralization, nitrification and plant/microbial immobilization was studied in the field and laboratory incubation experiments. 15N labeled ammonium, nitrate, glycine and aspartic acid were injected in situ before growth of aboveground biomass into the soil of lichen heath to investigate how the different nitrogen sources was subsequently utilized and cycled in the ecosystem. We analyzed the distribution of 15N between plants, soil microorganisms and different soil nitrogen compounds during all growing season in order to reveal differences for separate nitrogen sources. We concluded that the soil microorganisms were more efficient than plants in nitrogen uptake (especially amino acids) under natural conditions. In the laboratory, fresh and dry-rewetted soils of different alpine ecosystems were incubated at

  15. Teberda valley runoff variability (AD 1850-2005) based on tree-ring reconstruction (Northern Caucasus, Russia)

    International Nuclear Information System (INIS)

    Seven tree-ring chronologies are used to reconstruct Teberda River (Northern Caucasus, Russia) smoothed runoff for May, July and August. Six chronologies were developed from Pinus sylvestris and one from Abies nordmanniana. Tree growth is significantly, but weakly, correlated with maximum temperatures (negatively) and relative humidity (positively) during summer. All possible combinations of seven predictors were tried to get the best result on the cross-validation. Two of three reconstructions showed high wavelet coherence with instrumental data on decadal timescales and were analysed for spectrum stability. Minima of moving trends at the end of the reconstructions along with weakening of decadal cycles may be a marker of significant change of Teberda River hydrological regime during the second half of the 20th century.

  16. Spectral and informational analysis of seismicity: An application to the 1996-2012 seismicity of the Northern Caucasus-Azerbaijan part of the greater Caucasus-Kopet Dag region

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    Telesca, Luciano; Lovallo, Michele; Babayev, Gulam; Kadirov, Fakhraddin

    2013-12-01

    The time series analysis of seismic sequences needs proper methodologies that allow us to capture the main features of the time dynamics of earthquakes. Among these features, the identification of periodicities along with the quantification of their intensity represents an important task, concerning the detection of regular dynamical behaviours, with clear implications for earthquake prediction. In the present study, we applied three different methods to investigate the time dynamics of the seismic activity of the Northern Caucasus-Azerbaijan part of the Greater Caucasus-Kopet Dag region. We analysed the monthly number of earthquakes which occurred between 1996 and 2012 by means of: (i) the robust estimation of the periodogram, (ii) the singular spectrum analysis (SSA), and (iii) the Fisher-Shannon method. Two main significant periodicities are detected: 102 months and 20 months. The first corresponds actually to the long-term variation of the monthly seismic activity of the area, while the second represents the more intense cyclic component. Periodicities of 7 and 30 months are also identified, but with a lower intensity than the 20-month periodicity. The Fisher-Shannon method has revealed that the long-term variation of the series is also characterized by higher organization and lower degree of disorder. The present study shows how the application of methods from statistical mechanics could contribute to unveil dynamical features in seismicity.

  17. Megafans of the Northern Kalahari Basin

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    Wilkinson, M. J.; Miller, R. McG.; Eckardt, F.; Kreslavsky, M. A.

    2016-01-01

    We identify eleven megafans (partial cones of fluvial sediment, >80 km radius) in the northern Kalahari Basin, using several criteria based on VIS and IR remotely sensed data and SRTM-based surface morphology reconstructions. Two other features meet fewer criteria of the form which we class as possible megafans. The northern Kalahari megafans are located in a 1700 km arc around the southern and eastern flanks of the Angola's Bié Plateau, from northern Namibia through northwest Botswana to western Zambia. Three lie in the Owambo subbasin centered on the Etosha Pan, three in the relatively small Okavango rift depression, and five in the Upper Zambezi basin. The population includes the well-known Okavango megafan (150 km), Namibia's Cubango megafan, the largest megafan in the region (350 km long), and the largest nested group (the five major contiguous megafans on the west slopes of the upper Zambezi Valley). We use new, SRTM-based topographic roughness data to discriminate various depositional surfaces within the flat N. Kalahari landscapes. We introduce the concepts of divide megafans, derived megafans, and fan-margin rivers. Conclusions. (i) Eleven megafan cones total an area of 190,000 sq km. (ii) Different controls on megafan size operate in the three component basins: in the Okavango rift structural controls become the prime constraint on megafan length by controlling basin dimensions. Megafans in the other les constricted basins appear to conform to classic relationships fan area, slope, and feeder-basin area. (iii) Active fans occupy the Okavango rift depression with one in the Owambo basin. The rest of the population are relict but recently active fans (surfaces are relict with respect to activity by the feeder river). (iv) Avulsive behavior of the formative river-axiomatic for the evolution of megafans-has resulted in repeated rearrangements of regional drainage, with likely effects in the study area well back into the Neogene. Divide megafans comprise the

  18. Subducted, detached, and torn slabs during early orogeny: evidence from deep earthquakes under the Greater Caucasus

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    Mumladze, T.; Forte, A. M.; Cowgill, E.; Trexler, C.; Niemi, N. A.; Kellogg, L. H.; Yikilmaz, M.

    2013-12-01

    The Arabia-Eurasian collision is the second-largest active collisional orogen on Earth and provides a rare opportunity to investigate the role that pre-suturing tectonism plays in defining the deformational response of the upper plate to continental collision and suturing. The Greater Caucasus Mountains, which define the northern margin of the Arabia-Eurasia collision zone between the Black and Caspian seas, result from late Cenozoic closure of the Greater Caucasus basin, a Mesozoic back-arc basin that opened during northward subduction of Neotethys beneath the Lesser Caucasus island arc. However, both the extent to which the basin closed by subduction and its original width remain controversial. Many previous estimates suggest that the basin was very narrow and that no subduction occurred during the formation of the Greater Caucasus. However, newly compiled earthquake locations show that the central and eastern Greater Caucasus are underlain by a northeast-dipping subducted slab. We assembled the new catalog of earthquake locations by combining earthquake records from local networks in Georgia, Russia, and Azerbaijan with previously published data. Our dataset includes records from 3820 events with magnitudes M>2. Visualization of the final catalogue in an immersive visualization environment at the UC Davis Keck Center for Active Visualization in the Earth Sciences (KeckCAVES) provides a clear image of a northeast-dipping zone of seismicity beneath the Greater Caucasus, which we interpret as the remnant of a subducted slab. Beneath the central Greater Caucasus (45°E), the zone of seismicity extends to a depth of at least 158 km and dips to the northeast at ~40°. In contrast, beneath the western GC (i.e., west of 45°E) there is a pronounced lack of events below 25 km, which we infer to reflect slab breakoff. We also observe a gap in intermediate-depth seismicity (30 to 60 km) at the western end of the subducted slab beneath the central Greater Caucasus, which we

  19. Uranium deposits: northern Denver Julesburg basin, Colorado

    International Nuclear Information System (INIS)

    The Fox Hills Sandstone and the Laramie Formation (Upper Cretaceous) are the host rocks for uranium deposits in Weld County, northern Denver Julesburg basin, Colorado. The uranium deposits discovered in the Grover and Sand Creek areas occur in well-defined north--south trending channel sandstones of the Laramie Formation whereas the sandstone channel in the upper part of the Fox Hills Sandstone trends east--west. Mineralization was localized where the lithology was favorable for uranium accumulation. Exploration was guided by log interpretation methods similar to those proposed by Bruce Rubin for the Powder River basin, Wyoming, because alteration could not be readily identified in drilling samples. The uranium host rocks consist of medium- to fine-grained carbonaceous, feldspathic fluvial channel sandstones. The uranium deposits consist of simple to stacked roll fronts. Reserve estimates for the deposits are: (1) Grover 1,007,000 lbs with an average grade of 0.14 percent eU3O8,2) Sand Creek 154,000 lbs with an average grade of 0.08 percent eU3O8, and 3) The Pawnee deposit 1,060,000 lbs with an average grade of 0.07 percent eU3O8. The configuration of the geochemical cells in the Grover and Sand Creek sandstones indicate that uraniferous fluids moved northward whereas in the Pawnee sandstone of the Fox Hills uraniferous fluids moved southward. Precipitation of uranium in the frontal zone probably was caused by downdip migration of oxygcnated groundwater high in uranium content moving through a favorable highly carbonaceous and pyritic host sandstone

  20. Colloquium on Caucasus

    International Nuclear Information System (INIS)

    This document is the proceedings of a colloquium organized by the French senate on Caucasus. Caucasus encompasses three countries: Armenia, Azerbaijan and Georgia. In their presentations, the different participants stress on some particular political-economical aspects of this region: present day economic status, role in the development of central Asia, political stability of South Caucasus, influence of foreign countries (Russia, USA), relations with the European Union, the energy, road and rail paths, the stakes of Azerbaijan on the petroleum scene (hydrocarbons production and transit), hydrocarbons exploitation in Azerbaijan (regional cooperation, foreign investments, profits), experience of foreign companies working in Caucasus countries (beverage industry), juridical framework of investments made in Caucasus countries, business reality in these countries. (J.S.)

  1. Aklimaite, Ca4[Si2O5(OH)2](OH)4 · 5H2O, a new natural hydrosilicate from Mount Lakargi, the Northern Caucasus, Russia

    Science.gov (United States)

    Zadov, A. E.; Pekov, I. V.; Zubkova, N. V.; Gazeev, V. M.; Chukanov, N. V.; Yapaskurt, V. O.; Kartasheov, P. M.; Galuskin, E. V.; Galuskina, I. O.; Pertsev, N. N.; Gurbanov, A. G.; Pushcharovsky, D. Yu.

    2013-12-01

    A new mineral aklimaite, Ca4[Si2O5(OH)2](OH)4 · 5H2O, has been found near Mount Lakargi, Upper Chegem caldera, Kabardino-Balkaria, the Northern Caucasus, Russia, in the skarnified limestone xenolith in ignimbrite. This hydrothermal mineral occurs in a cavity of altered larnite skarn and is associated with larnite, calcium humite-group members, hydrogarnets, bultfonteinite, afwillite, and ettringite. Aklimaite forms transparent, colorless (or occasionally with pinkish tint) columnar or lath-shaped crystals up 3 × 0.1 × 0.01 mm in size, flattened on {001} and elongated along {010}; they are combined in spherulites. The luster is vitreous; the cleavage parallel to the {001} is perfect. D calc = 2.274 g/cm3. The Mohs' hardness is 3-4. Aklimaite is optically biaxial, negative, 2 V meas > 70°, 2 V calc = 78°, α = 1.548(2), β = 1.551(3), γ = 1.553(2). The IR and Raman spectra are given. The chemical composition (wt %, electron microprobe) is as follows: 0.06 Na2O, 0.02 K2O, 45.39 CaO, 0.01 MnO, 0.02 FeO, 24.23 SiO2, 0.04 SO3, 3.22 F, 27.40 H2O(calc.), -1.36 -O=F2; the total is 99.03. The empirical formula calculated on the basis of 2Si apfu with O + OH + F = 16 is as follows: (Ca4.02Na0.01)Σ4.03[Si2.00O5.07(OH)1.93][(OH)3.16F0.84] Σ4.00 · 5H2O. The mineral is monoclinic, space group C2/ m, a = 16.907(5), b = 3.6528(8), c = 13.068(4) Å, β = 117.25(4)·, V= 717.5(4) Å3, Z = 2. Aklimaite is representative of the new structural type, the sorosilicate with disilicate groups [Si2O5(OH)2]. The strongest reflections in the X-ray powder patterns [ d, Å ( hkl)] are: 11.64(100)(001), 2.948(32)(310, 203), 3.073(20) (, ), 2.320(12)(005, 510), 2.901 (11)(004), 8.30(10). The type specimen is deposited in the Fersman Mineralogical Museum, Russian Academy of Sciences, Moscow.

  2. Geomorphological characterization of endorheic basins in northern Chile

    Science.gov (United States)

    Dorsaz, J.; Gironas, J. A.; Escauriaza, C. R.; Rinaldo, A.

    2011-12-01

    Quantitative geomorphology regroups a large number of interesting tools to characterize natural basins across scales. The application of these tools to several river basins allows the description and comparison of geomorphological properties at different spatial scales as oppose to more traditional descriptors that are typically applied at a single scale, meaning the catchment scale. Most of the recent research using these quantitative geomorphological tools has focused on open catchments and no specific attention has been given to endorheic basins, and the possibility of having particular features that distinguish them from exorheic catchments. The main objective of our study is to characterize endorheic basins and investigate whether these special geomorphological features can be identified. Because scaling invariance is a widely observed and relatively well quantified property of open basins, it provides a suitable tool to characterize differences between the geomorphology of closed and open basins. Our investigation focuses on three closed basins located in northern Chile which describe well the diversity in the geomorphology and geology of this arid region. Results show that endhoreic basins exhibit different slope-area and flow paths sinuosity regimes compared to those observed in open basins. These differences are in agreement with the particular self-similar behavior across spatial scales of the Euclidean length of subcatchments, as well as the Hack's law and Horton's ratios. These regimes imply different physical processes inside the channel network regardless of the basin area, and they seem to be related to the endorheic character of these basins. The analysis of the probability density functions of contributing areas and lengths to the lower region shows that the hypothesis of self-similarity can also be applied to closed basins. Theoretical expressions for these distributions were derived and validated by the data. Future research will focus on (1

  3. Northern Rivers Basins human health monitoring program : report

    Energy Technology Data Exchange (ETDEWEB)

    Gabos, S. [Alberta Health, Edmonton, AB (Canada). Health Surveillance

    1999-04-01

    The Northern River Basins Human Health Monitoring Program was established in 1994 to investigate the possible relationships between various environmental risk factors and the health of northern residents in the province. This report presents the initial analysis of the health program and examines the differences in health outcomes across the province and compares the Northern Rivers Basin Study (NRBS) area with the other areas of the province. A series of maps and graphs showed the prevalence of certain diseases and disorders within the Peace and Athabasca river basins. The focus of the report was on reproductive health, congenital anomalies, respiratory ailments, circulatory diseases, gastrointestinal disorders, endocrine and metabolic disorders, and neurocognitive disorders. The study showed that compared to other areas of the province, the NRBS area had higher incidences of endometriosis, selected congenital anomalies, bronchitis, pneumonia, peptic ulcers and epilepsy. There were three potential exposure pathways to environmental contaminants. These were through ingestion of water or food, inhalation of air and through dermal exposure. refs., tabs., figs.

  4. Helminth parasites of freshwater fishes, Nazas River basin, northern Mexico

    Directory of Open Access Journals (Sweden)

    León, G. Pérez-Ponce

    2010-01-01

    Full Text Available This paper represents the first study of the helminth parasites of freshwater fishes from the Nazas River basinin northern Mexico. Between July 2005 and December 2008, 906 individual fish were collected and examined for helminthparasites in 23 localities along the river basin. Twenty-three species of fish were examined as a part of this inventory work.In total, 41 helminth species were identified: 19 monogeneans, 10 digeneans, seven cestodes, one acanthocephalan, andfour nematodes. The biogeographical implications of our findings are briefly discussed.

  5. Three-dimensional seismo-tectonics in the Po Valley basin, Northern Italy

    NARCIS (Netherlands)

    Turrini, Claudio; Angeloni, Pamela; Lacombe, Olivier; Ponton, Maurizio; Roure, François

    2015-01-01

    The Po Valley (Northern Italy) is a composite foreland-foredeep basin caught in between the Southern Alps and Northern Apennine mountain belts. By integrating the 3D structural model of the region with the public earthquake dataset, the seismo-tectonics of the basin is shown at different scales of o

  6. The characteristics of ginger-like rock and its geological significance in Northern Zhungeer basin

    International Nuclear Information System (INIS)

    The author studies the characteristics of ginger-like stratum and its genesis in northern Zhungeer basin. There are many ginger-like strata of Tertiary-Quaternary exist in northern Zhungeer basin. It shows a good prospect for the formation of Tertiary sandstone type Uranium deposit which can be leached in-situ

  7. CZARIST NATIONAL-COLONIAL POLICY IN THE CENTRAL CAUCASUS

    OpenAIRE

    Alizade, Zakhida

    2007-01-01

    The author uses a vast amount of factual material to reveal the essence of czarist Russia’s colonial imperial policy toward the Muslims of the Caucasus, and Northern Azerbaijan in particular, when the area was finally conquered in the early 19th century. This discriminatory policy was acutely felt in all spheres of life; the Azeris, in particular, were deprived of many political, civil, and religious rights. Russia’s reforms in the area deprived Northern Azerbaijan of its previous administrat...

  8. Cenozoic foreland-basin evolution in the northern Andes : insights from thermochronology and basin analysis in the Eastern Cordillera, Colombia

    OpenAIRE

    Parra, Mauricio

    2009-01-01

    The modern foreland basin straddling the eastern margin of the Andean orogen is the prime example of a retro-arc foreland basin system adjacent to a subduction orogen. While widely studied in the central and southern Andes, the spatial and temporal evolution of the Cenozoic foreland basin system in the northern Andes has received considerably less attention. This is in part due to the complex geodynamic boundary conditions, such as the oblique subduction and accretion of the Caribbean plates ...

  9. Regional Fluid Flow and Basin Modeling in Northern Alaska

    Science.gov (United States)

    Kelley, Karen D., (Edited By)

    2007-01-01

    INTRODUCTION The foothills of the Brooks Range contain an enormous accumulation of zinc (Zn) in the form of zinc sulfide and barium (Ba) in the form of barite in Carboniferous shale, chert, and mudstone. Most of the resources and reserves of Zn occur in the Red Dog deposit and others in the Red Dog district; these resources and reserves surpass those of most deposits worldwide in terms of size and grade. In addition to zinc and lead sulfides (which contain silver, Ag) and barite, correlative strata host phosphate deposits. Furthermore, prolific hydrocarbon source rocks of Carboniferous and Triassic to Early Jurassic age generated considerable amounts of petroleum that may have contributed to the world-class petroleum resources of the North Slope. Deposits of Zn-Pb-Ag or barite as large as those in the Brooks Range are very rare on a global basis and, accordingly, multiple coincident favorable factors must be invoked to explain their origins. To improve our understanding of these factors and to contribute to more effective assessments of resources in sedimentary basins of northern Alaska and throughout the world, the Mineral Resources Program and the Energy Resources Program of the U.S. Geological Survey (USGS) initiated a project that was aimed at understanding the petroleum maturation and mineralization history of parts of the Brooks Range that were previously poorly characterized. The project, titled ?Regional Fluid Flow and Basin Modeling in Northern Alaska,? was undertaken in collaboration with industry, academia, and other government agencies. This Circular contains papers that describe the results of the recently completed project. The studies that are highlighted in these papers have led to a better understanding of the following: *The complex sedimentary facies relationships and depositional settings and the geochemistry of the sedimentary rocks that host the deposits (sections 2 and 3). *The factors responsible for formation of the barite and zinc deposits

  10. Tectonic evolution of Tethyan tectonic field, formation of Northern Margin basin and explorative perspective of natural gas in Tarim Basin

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Analyzing the characteristics of the Tethyan tectonic field, the authors think that the Tethyan tectonic field underwent three evolutional stages: closing of Paleo-Tethys and rifting of Neo-Tethys from early Permian to late Triassic, subduction of Neo-Tethys and collision between the Indian plate and the Eurasia plate from Jurassic to early of low Tertiary, and collision between the Arab plate and the Eurasia plate and the A-type subduction of Indian plate from late of low Tertiary to the present. Combining the evolution of the Tethyan orogenic belt with the characteristics of the Northern Margin basin, it is suggested that the sedimentary and tectonic characteristics and types of the Northern Mar-gin basin are controlled by the formation and evolution of the Tethyan orogenic belt and the ingression of Tethys. The evolution of Northern Margin basin can be divided into three development stages: back-arc foreland basin from late Permian to Triassic, the back-arc fault subsidence and depression from Jurassic to the early of low Tertiary, and the reactive foreland basin from the late of low Tertiary to the present. The Northern Margin basin in the Tethyan tectonic field is an important region for natural gas accumulation, and the Tarim Basin is a part of this region.

  11. Linking basin evolution to plate tectonic processes in (northern) Africa

    OpenAIRE

    Gravråk, Mariann

    2011-01-01

    Several sedimentary basins in Africa are classified as intracratonic basins, but no conclusive formation mechanism has been identified for these basin types. Tectonic subsidence curves may help in unraveling formation mechanisms or identify tectonic forcing for these basins. This thesis presents and analyses basin subsidence curves for basins in the interior of Africa and near its passive margins. A backstripping program has been written to solve the backstripping equations needed to make the...

  12. Digital assessment of northern and central Appalachian basin coals

    Energy Technology Data Exchange (ETDEWEB)

    Ruppert, L.F.; Tewalt, S.J.; Braff, L.J.; Wallack, R.N. [US Geological Survey National Center, Reston, VA (US)

    1999-10-01

    The US Geological Survey (USGS) is currently conducting a coal resource assessment of the coalbeds and zones that are projected to provide the bulk of the nation's resources for the next few decades. The Pittsburgh and Upper Freeport coals are the first two beds in the northern and central Appalachian basin region to undergo fully digital coal assessments. The bed-specific assessments are being carried out in partnership with the state geologic surveys of West Virginia, Ohio, Pennsylvania and Maryland. Comprehensive stratigraphic and geochemical data-bases have been developed for both of the beds. The extent of the bed with mined areas, structure contour, isopach, and overburden thickness maps for the Pittsburgh coal bed have been realised as USGS open-file reports. The articles includes several detailed maps showing the export of the Pittsburgh coalbed, ash yield, sulphur contents and calorific value of the coal by county, structure contours, overburden thickness and isopac lines. 10 figs., 2 tabs.

  13. Early Mesozoic history of the Black-Sea - Caucasus area

    Energy Technology Data Exchange (ETDEWEB)

    Kazmin, V.G. (Institute of Oceanology, Moscow (USSR))

    1988-08-01

    Marginal basins with ocean crust existed in the Black Sea area in Triassic time behind a volcanic arc built on top of the Hercynian basement of Pontides. The eastern extension of the arc was in the fore-Caucasus. Triassic sediments and volcanics, formed in forearc basins, can be traced from the southern slope of the Great Caucasus (Svanetia) to the Karakaya belt of Turkey. These sediments were deformed at the end of the Triassic when terranes derived from Gondwana collided with the active margin of Paleotethys. In Svanetia a succession of middle Paleozoic clastics (the Dizi series) deposited at the base of the north-facing continental slope, presumably on the passive margin of Gondwana. The Dizi series is either an independent terrane or forms a western extension of Iran, which collided with Eurasia at the same time. Displacement of the subduction zone to the south of the accreted terranes was accompanied by a major episode of extension on the active margin in Early Jurassic time; the marginal sea of the Great Caucasus and the intra-Pontide basin in Turkey were opened. In the late Middle Jurassic, Pontides collided with Crimea, closing the Triassic proto-Black Sea. Immediately after collision, continental rifting commenced, once again separating Pontides from Eurasia and manifesting the birth of the Black Sea basin. Oceanic crust began to grow in the latter in Senonian time.

  14. Caucasus Geopolitics: Modern Trends Conflicts and Development

    Directory of Open Access Journals (Sweden)

    Svetlana V. Petrova

    2011-11-01

    Full Text Available The article studies major trends of Caucasus geopolitical situation development in terms of modern global politics, indicates major parties, settling conflicts in the region and their immediate interests in the Caucasus.

  15. Fluid flow in the northern Broad Fourteens Basin during Late Cretaceous inversion

    NARCIS (Netherlands)

    Oude Essink, Gualbert

    2003-01-01

    A basin-scale hydrogeological study of the inverted northern Broad Fourteens Basin, Netherlands offshore, has resulted in a reconstruction of geological evolution, an estimate of Late Cretaceous topography and model scenarios of syn-inversion meteoric water infiltration. This study was performed in

  16. Deep crustal structure of the Adare and Northern Basins, Ross Sea, Antarctica, from sonobuoy data

    Science.gov (United States)

    Selvans, M. M.; Stock, J. M.; Clayton, R. W.; Cande, S.; Granot, R.

    2014-11-01

    Extension associated with ultraslow seafloor spreading within the Adare Basin, in oceanic crust just north of the continental shelf in the Ross Sea, Antarctica, extended south into the Northern Basin. Magnetic and gravity anomaly data suggest continuity of crustal structure across the continental shelf break that separates the Adare and Northern Basins. We use sonobuoy refraction data and multi-channel seismic (MCS) reflection data collected during research cruise NBP0701, including 71 new sonobuoy records, to provide constraints on crustal structure in the Adare and Northern Basins. Adjacent 1D sonobuoy profiles along several MCS lines reveal deep crustal structure in the vicinity of the continental shelf break, and agree with additional sonobuoy data that document fast crustal velocities (6000-8000 m/s) at shallow depths (1-6 km below sea level) from the Adare Basin to the continental shelf, a structure consistent with that of other ultraslow-spread crust. Our determination of crustal structure in the Northern Basin only extends through sedimentary rock to the basement rock, and so cannot help to distinguish between different hypotheses for formation of the basin.

  17. Paleogene palaeogeography and basin evolution of the Western Carpathians, Northern Pannonian domain and adjoining areas

    Science.gov (United States)

    Kováč, Michal; Plašienka, Dušan; Soták, Ján; Vojtko, Rastislav; Oszczypko, Nestor; Less, György; Ćosović, Vlasta; Fügenschuh, Bernhard; Králiková, Silvia

    2016-05-01

    The data about the Paleogene basin evolution, palaeogeography, and geodynamics of the Western Carpathian and Northern Pannonian domains are summarized, re-evaluated, supplemented, and newly interpreted. The presented concept is illustrated by a series of palinspastic and palaeotopographic maps. The Paleogene development of external Carpathian zones reflects gradual subduction of several oceanic realms (Vahic, Iňačovce-Kričevo, Szolnok, Magura, and Silesian-Krosno) and growth of the orogenic accretionary wedge (Pieniny Klippen Belt, Iňačovce-Kričevo Unit, Szolnok Belt, and Outer Carpathian Flysch Belt). Evolution of the Central Western Carpathians is characterized by the Paleocene-Early Eocene opening of several wedge-top basins at the accretionary wedge tip, controlled by changing compressional, strike-slip, and extensional tectonic regimes. During the Lutetian, the diverging translations of the northward moving Eastern Alpine and north-east to eastward shifted Western Carpathian segment generated crustal stretching at the Alpine-Carpathian junction with foundation of relatively deep basins. These basins enabled a marine connection between the Magura oceanic realm and the Northern Pannonian domain, and later also with the Dinaridic foredeep. Afterwards, the Late Eocene compression brought about uplift and exhumation of the basement complexes at the Alpine-Carpathian junction. Simultaneously, the eastern margin of the stretched Central Western Carpathians underwent disintegration, followed by opening of a fore-arc basin - the Central Carpathian Paleogene Basin. In the Northern Hungarian Paleogene retro-arc basin, turbidites covered a carbonate platform in the same time. During the Early Oligocene, the rock uplift of the Alpine-Carpathian junction area continued and the Mesozoic sequences of the Danube Basin basement were removed, along with a large part of the Eocene Hungarian Paleogene Basin fill, while the retro-arc basin depocentres migrated toward the east

  18. Cenozoic evolution of the northwestern Salar de Atacama Basin, northern Chile

    Science.gov (United States)

    Pananont, P.; Mpodozis, C.; Blanco, N.; Jordan, T. E.; Brown, L. D.

    2004-12-01

    Since 90 Ma, the nonmarine Salar de Atacama Basin has been the largest, deepest, and most persistent sedimentary basin of northern Chile. Integration of 200 km of two-dimensional seismic reflection data with surface geological data clarifies Oligocene and Neogene evolution of the northern part of the basin. A normal fault with 6 ± 1 km of vertical separation controlled the western boundary of the basin during the accumulation of the Oligocene-lower Miocene Paciencia Group. The combination of this structure, a similar one in the Calama Basin, and regional structural data suggests that localized extension played an important role within a tectonic environment dominated by margin-perpendicular compression and margin-parallel strike-slip deformation. Seismic data substantiate the surface interpretation that much of the Cordillera de la Sal ridge resulted from diapiric flow of the Paciencia Group. Diapiric flow initiated during the late early Miocene or middle Miocene, associated with a deep reverse fault.

  19. Meso-Cenozoic basin evolution in northern Korean Peninsula

    Institute of Scientific and Technical Information of China (English)

    PAK Hyon Uk; LYANG To Jun; LIU Yongjiang; HYON Yun Su; KIM Gyong Chol

    2009-01-01

    In the Korean Peninsula the Meso-Cenozoic basins were mainly formed due to fault block and block movement. The Mesozoic fracture structures correspond basically to modern large rivers in direction. Such faults were usually developed to rift and formed lake-type tectonic basin, such as the Amrokgang-, Taedonggang-, Ryesonggang-, Hochongang-, Jangphari-, Susongchon-, Pujon-, and Nampho basins. The Mesozoic strata are considered to be divided into the Lower Jurassic Taedong System, Upper Jurassic Jasong System, Upper Jurassic- -early Lower Cretaceous Taebo System, and the Upper Cretaceous- -Paleocene (Chonjaebong, Hongwon, Jaedok Series). The Cenozoic block movement succeeded the Mesozoic fault block movement. The Kilju-Myongchon Graben and Tumangang Basin, etc, are the basins related to the fault zones developed from the Oligocene to Miocene. In addition, the Tertiary basins were formed in many areas in the Miocene (e.g. Sinhung, Oro, Hamhung, Yonghung, Anbyon, Cholwon, etc). The Cenozoic sedimentation occurred mainly from the late Oligocene to Miocene. The Kilju-Myongchon Graben was the fore deep connected to the sea and the basins inclined in the Chugaryong Fault Zone are intramountain basins. Therefore, coal-bearing beds and clastic rocks in the intramountain basins and rare marine strata and terrigenous clastic rocks are main sedimentary sequences in the Cenozoic.

  20. Decoupling of modern shortening rates, climate, and topography in the Caucasus

    Science.gov (United States)

    Forte, Adam M.; Whipple, Kelin X.; Bookhagen, Bodo; Rossi, Matthew W.

    2016-09-01

    The Greater and Lesser Caucasus mountains and their associated foreland basins contain similar rock types, experience a similar two-fold, along-strike variation in mean annual precipitation, and were affected by extreme base-level drops of the neighboring Caspian Sea. However, the two Caucasus ranges are characterized by decidedly different tectonic regimes and rates of deformation that are subject to moderate (less than an order of magnitude) gradients in climate, and thus allow for a unique opportunity to isolate the effects of climate and tectonics in the evolution of topography within active orogens. There is an apparent disconnect between modern climate, shortening rates, and topography of both the Greater Caucasus and Lesser Caucasus which exhibit remarkably similar topography along-strike despite the gradients in forcing. By combining multiple datasets, we examine plausible causes for this disconnect by presenting a detailed analysis of the topography of both ranges utilizing established relationships between catchment-mean erosion rates and topography (local relief, hillslope gradients, and channel steepness) and combining it with a synthesis of previously published low-temperature thermochronologic data. Modern climate of the Caucasus region is assessed through an analysis of remotely-sensed data (TRMM and MODIS) and historical streamflow data. Because along-strike variation in either erosional efficiency or thickness of accreted material fail to explain our observations, we suggest that the topography of both the western Lesser and Greater Caucasus are partially supported by different geodynamic forces. In the western Lesser Caucasus, high relief portions of the landscape likely reflect uplift related to ongoing mantle lithosphere delamination beneath the neighboring East Anatolian Plateau. In the Greater Caucasus, maintenance of high topography in the western portion of the range despite extremely low (structure of either range.

  1. Multiple Refuge Bat Inventory: Great Basin & Great Northern LCC

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This was a cooperative project between the Upper Columbia Basin Network (UCBN) of the National Park Service I&M Program, USFWS Region 1 I&M Program (R1...

  2. Petroleum potential of the northern Sinu-San Jacinto Basin, Colombia: an integrated petroleum system and basin modeling approach

    Energy Technology Data Exchange (ETDEWEB)

    Nino, Christian H.; Goncalves, Felix T.T.; Bedregal, Ricardo P. [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Coordenacao dos Programas de Pos-graduacao de Engenharia (COPPE). Lab. de Modelagem de Bacias (LAB2M); Azevedo, Debora A. [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Inst. de Quimica; Landau, Luis [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Coordenacao dos Programas de Pos-graduacao de Engenharia (COPPE). Lab. de Metodos Computacionais em Engenharia (LAMCE)

    2004-07-01

    The northern Sinu-San Jacinto basin, located in the northwestern corner of South America (Colombia), belongs to the accretionary prism that resulted from the collision and subduction of the Caribbean plate under the South America plate. Despite all the previous exploratory efforts, solely a few small sub-commercial oil and gas accumulation have been found up to now. The geological and geochemical information acquired by different companies during the lasts decades was integrated with new geochemical analysis and basin modeling to characterize the petroleum systems, to reconstruct the hydrocarbon charge history in the study area and to better assess the exploratory risk. (author)

  3. Deep seismic structure of the Atacama basin, northern Chile

    Science.gov (United States)

    Schurr, B.; Rietbrock, A.

    2004-06-01

    The Atacama basin is a prominent morphological anomaly in the Central Andean forearc. 3D seismic structure beneath the depression and its surroundings has been determined from local earthquake tomography. Depth maps of P-wave velocity and attenuation (1/Qp) through the lithosphere reveal a rheologically strong (high Qp and vp) lithospheric block beneath the basin, surrounded by weak regions (low Qp and vp) beneath Pre- and Western Cordilleras. The anomalous lithospheric structure appears to bar hot asthenospheric mantle from penetrating trenchward, and hence causes the volcanic front to be deflected by the Salar de Atacama basin. The cold block may also influence the thermal structure of the subducted slab causing reduced Benioff seismicity and less hydration of mantle rocks evident from reduced vp/vs ratios. Seismic data are hard to reconcile with extension and lithospheric thinning as a mechanism for subsidence of the basin. Instead, high strength of the Atacama lithospheric block may contribute to basin formation by focussing deformation and uplift along the block's weak edges.

  4. Low palaeoelevation of the northern Lhasa terrane during late Eocene: Fossil foraminifera and stable isotope evidence from the Gerze Basin

    OpenAIRE

    Yi Wei; Kexin Zhang; Garzione, Carmala N.; Yadong Xu; Bowen Song; Junliang Ji

    2016-01-01

    The Lhasa terrane is a key region for understanding the paleoelevation of the southern Tibetan Plateau after India-Asia collision. The Gerze Basin, located in the northern part of the Lhasa terrane, is a shortening-related basin. We discovered Lagena laevis (Bandy) fossils in upper Eocene strata of the Gerze Basin. This type of foraminifera is associated with lagoon and estuarine environments, indicating that the northern part of the Lhasa terrane was near sea level during the late Eocene. We...

  5. Discussion on the characteristics of Meso-Cenozoic U-productive basins in northern China and their prospecting direction

    International Nuclear Information System (INIS)

    Based on the study of sedimentary evolution characteristics of main sedimentary basins and combined with characteristics of known uranium-productive basins in northern China, and the analysis on airborne geophysical survey data, the principles for selecting prospecting and target area have been set up. And the prospecting direction for uranium in Meso-Cenozoic basins of northern China has been proposed through a preliminary analysis. (authors)

  6. Potential Inundation Hazards in the Taipei Basin Induced by Reactivation of the Shanchiao Fault in Northern Taiwan

    OpenAIRE

    Jihn-Sung Lai; Chun-Ying Chiu; Hsiang-Kuan Chang; Jyr-Ching Hu; and Yih-Chi Tan

    2010-01-01

    The Shanchiao fault, located to the west of the Taipei Basin in northern Taiwan, is a highly active normal fault that has a left-slip component and fault length of over 40 km. We suggest that the Shanchiao fault still has the ability to induce coseismic subsidence in the Taipei Basin under present extensional regime of northern Taiwan. In order to characterize the coseismic ground deformation and assess the potential inundation hazards in Taipei Basin, we estimate surface displacements using ...

  7. The U.S. Geological Survey`s National Coal Resource Assessment: The Northern and Central Appalachian Basin

    Energy Technology Data Exchange (ETDEWEB)

    Ruppert, L.; Bragg, L.; Tewalt, S. [Geological Survey, Reston, VA (United States)

    1996-09-01

    The US Geological Survey (USGS) Energy Resource Surveys Program is currently conducting a five-year National Coal Resource Assessment project. Primary focus is on the quality and quantity of top-producing coal beds and coal zones in five of the nine major coal producing regions in the US. These regions include the (1) Northern and Central Appalachian Basin, (2) Gulf Coastal Plain, (3) Illinois Basin, (4) Colorado Plateau, and (5) Powder River Basin and Northern Great Plains.

  8. Tectonoestratigraphic and Thermal Models of the Tiburon and Wagner Basins, northern Gulf of California Rift System

    Science.gov (United States)

    Contreras, J.; Ramirez Zerpa, N. A.; Negrete-Aranda, R.

    2014-12-01

    The northern Gulf of California Rift System consist sofa series faults that accommodate both normal and strike-slip motion. The faults formed a series of half-greens filled with more than 7 km of siliciclastic suc­cessions. Here, we present tectonostratigraphic and heat flow models for the Tiburón basin, in the southern part of the system, and the Wag­ner basin in the north. The models are constrained by two-dimensional seis­mic lines and by two deep boreholes drilled by PEMEX­-PEP. Analysis of the seismic lines and models' results show that: (i) subsidence of the basins is controlled by high-angle normal faults and by flow of the lower crust, (ii) basins share a common history, and (iii) there are significant differences in the way brittle strain was partitioned in the basins, a feature frequently observed in rift basins. On one hand, the bounding faults of the Tiburón basin have a nested geometry and became active following a west-to-east sequence of activation. The Tiburon half-graben was formed by two pulses of fault activity. One took place during the protogulf extensional phase in the Miocene and the other during the opening of Gulf of California in the Pleistocene. On the other hand, the Wagner basin is the result of two fault generations. During the late-to middle Miocene, the west-dipping Cerro Prieto and San Felipe faults formed a domino array. Then, during the Pleistocene the Consag and Wagner faults dissected the hanging-wall of the Cerro Prieto fault forming the modern Wagner basin. Thermal modeling of the deep borehole temperatures suggests that the heat flow in these basins in the order of 110 mW/m2 which is in agreement with superficial heat flow measurements in the northern Gulf of California Rift System.

  9. Adaptation tot changing water resources in the Ganges basin, northern India

    NARCIS (Netherlands)

    Moors, E.J.; Groot, A.M.E.; Biemans, H.; Terwisscha van Scheltinga, C.T.H.M.; Siderius, C.; Stoffel, M.

    2011-01-01

    An ensemble of regional climate model (RCM) runs from the EU HighNoon project are used to project future air temperatures and precipitation on a 25 km grid for the Ganges basin in northern India, with a view to assessing impact of climate change on water resources and determining what multi-sector a

  10. The mechanics of continental extension in Qiongdongnan Basin, northern South China Sea

    Science.gov (United States)

    Zhao, Zhongxian; Sun, Zhen; Wang, Zhenfeng; Sun, Zhipeng

    2015-09-01

    Located in the intersection of NE-trended rifted margin of South China Sea (SCS) and NW-oriented Ailao Shan-Red River Shear Zone (RRSZ), Qiongdongnan Basin shows significant differences in geological features from west to east, indicating different mechanics of continental extension. Based on the dense and updated multichannel seismic profiles, we disclose the characteristics of the remnant crystalline crust. Besides, we analyze the basin structures, calculate the stretching factors of upper and whole crust, and compute the syn-rift and post-rift unloaded tectonic subsidence along three selected transects in the west, middle and east of Qiongdongnan Basin. The crust thickness is 22 km on the northern and southern parts of Qiongdongnan Basin and thins gradually towards the central depression with two extremely thinned domains (factors of crust are 1.5-2 on both sides and increase remarkably towards the central depression (β > 2) with two extremely stretched domains (β > 9), of which one is in Ledong Sag in the west and another is in Baodao and Changchang Sags in the east. However, the mechanics of continental extension vary significantly from west to east. The simple shear dominates in the west, the pure shear dominates in the east, and it is intermediate between the two end members of simple shear and pure shear in the middle of Qiongdongnan Basin. The simple shear in the west of Qiongdongnan Basin is probably controlled by the left-lateral movement of RRSZ. The pure shear in the east is probably related to the Cenozoic rifting along the northern continental margin of SCS. The transitional zone in the middle of Qiongdongnan Basin is possibly the combined results of the left-lateral movement of RRSZ and the Cenozoic rifting along the northern continental margin of SCS.

  11. A decision support tool for basin irrigation in northern Nigeria

    Directory of Open Access Journals (Sweden)

    Olumuyiwa S. Asaolu

    2009-07-01

    Full Text Available Inadequate rainfall, water resources scarcity and attendant food security-related problems have made irrigation technology a necessity. This work presents the development of a decision support system for solving surface irrigation design problems in northern Nigeria. The arid northern states affected by desert encroachment constitute a good candidate and their climatological data was obtained from the Nigerian Metrological Agency. The interactive system was defined in terms of inputs and outputs. The inputs were properties of soil, surface irrigation method and climate. The outputs were mainly the quantity of water application, scheduling pattern, possible design configuration, advance time, cut-off time, application rate, and water use efficiency. The FAO Penman-Monteith equation was used to estimate evapotranspiration values of major crops grown in Nigeria. Mathematical models outlined by Walker and Skogerboe were adapted, and heuristics applied in determining the best configuration that achieves optimum water application efficiency. We encoded the knowledge base using Matlab® software. The application was successfully used for the modification of a farm irrigation scheme in Kaduna state. This indicates that the adoption of new technologies for irrigation design issues could enhance agricultural productivity in northern Nigeria.

  12. Colloquium on Caucasus; Colloque sur le Caucase

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2005-07-01

    This document is the proceedings of a colloquium organized by the French senate on Caucasus. Caucasus encompasses three countries: Armenia, Azerbaijan and Georgia. In their presentations, the different participants stress on some particular political-economical aspects of this region: present day economic status, role in the development of central Asia, political stability of South Caucasus, influence of foreign countries (Russia, USA), relations with the European Union, the energy, road and rail paths, the stakes of Azerbaijan on the petroleum scene (hydrocarbons production and transit), hydrocarbons exploitation in Azerbaijan (regional cooperation, foreign investments, profits), experience of foreign companies working in Caucasus countries (beverage industry), juridical framework of investments made in Caucasus countries, business reality in these countries. (J.S.)

  13. Evidence for bloc rotation tectonics in the seismic Cheliff basin (northern Algeria) from paleomagnetic investigations

    Science.gov (United States)

    El-M. Derder, Mohamed; Henry, Bernard; Amenna, Mohamed; Bayou, Boualem; Maouche, Said; Besse, Jean; Ayache, Mohamed; Abtout, Abdeslam

    2010-05-01

    The seismic activity in the Western Mediterranean area is mainly concentrated in northern Africa, particularly in northern Algeria, as it was shown by the 21 May 2003 Boumerdes and the 10 October 1980 El Asnam earthquakes (of moment magnitudes Mw =6.9, and Ms= 7.3 respectively), which were among the strongest recent ones recorded in the western Mediterranean area. This seismicity is due to the convergence between Africa and Eurasia plates since at least the Oligocene. This convergence involves a transpression tectonic with N-S to NNW-SSE direction of shortening, which is expressed by active deformations along the boundary of these two plates. In Algeria, the seismicity is focused in a coastal zone (the Tell Atlas) in the northern part of the country. Active structures define there NE-SW trending folds and NE-SW sinistral transpressive faults, which affect the intermountain and coastal basins of Neogene to Quaternary age (e.g. " Cheliff "basin, " Mitidja "basin). These reverse faults are coupled with NW-SE to E-W trending strike-slip deep faults. The active deformation in northern Algeria could thus be explained by a kinematic model of bloc rotation: the transpression tectonics with NNW-SSE direction of convergence defines NE-SW oriented blocs, which have been possibly subjected to clockwise rotation. The aim of this study is to look for such blocks rotation in the "Cheliff" basin (northern Algeria), by using the paleomagnetic tool. A paleomagnetic study has been thus conducted on the midlle Miocene, Tortonian, Messinian and Pliocene sedimentary rocks cropping out on the eastern part of this basin. The study is still in progress, but despite the very weak intensity of the Natural Remanent Magnetization (NRM) measured on the samples, and the frequently observed magnetization instability during the thermal demagnetization, the preliminary results show that clockwise rotations have affected different sites of the studied area. The magnitude of these rotations varies

  14. Structure and seismic stratigraphy of deep Tertiary basins in the northern Aegean Sea

    Science.gov (United States)

    Beniest, Anouk; Brun, Jean-Pierre; Smit, Jeroen; Deschamps, Rémy; Hamon, Youri; Crombez, Vincent; Gorini, Christian

    2015-04-01

    Whereas active basin formation in the Aegean Sea is illustrated by seafloor bathymetry, the sedimentary and tectonic history of Tertiary basins is poorly known as existing offshore industrial seismic and well-log data are not easily accessible. We studied the evolution of the northern Aegean Sea with a focus on the North Aegean Trough and the Northern Skyros Basin, which are amongst the deepest basins of the northern Aegean domain. Structural and seismic stratigraphic interpretation of a 2D seismic dataset retrieved in the 1970's is combined with the well-investigated records of the onshore deep basins of northern Greece and Western Turkey. A general seismic signature chart was established using onshore basin stratigraphy and poorly-constrained well data. The studied domain shows two sharp unconformities that correspond to the Eocene-Oligocene transition and the Miocene-Pliocene shift, respectively. These transitions were then used as pillars for a more detailed structural and seismic stratigraphic interpretation. A NW-SE trending seismic line that cross-cuts the southern part of the NE-SW-trending North Aegean Through displays the main features that are observed in the area: 1) an overall basin geometry that is rather symmetrical; 2) pre-Pliocene units affected by steep normal faults; 3) a rather constant thickness of Oligocene sediments that define a depocenter with an apparent NW-SE orientation; 4) an ablation of Miocene sediments by erosion, likely related to the Messinian Salinity Crises (MSC); (5) thick deltaic/turbiditic deposits in the NE-SW oriented central through of Neogene age; 6) trans-tensional growth patterns in Pliocene and Quaternary sediments that combine NE-SW steeply dipping fault zones, more likely corresponding to strike-slip corridors, and E-W-trending normal faults. The evidence listed above suggest that, in the northern Aegean Sea, (1) extension started at the latest during the Late Eocene/Early Oligocene (data quality does not allow for a

  15. Estimating flows in ungauged river basins in northern Mozambique

    Science.gov (United States)

    Minihane, M.

    2011-12-01

    In many regions across the globe, there are limited streamflow observations and therefore limited knowledge of availability of surface water resources. In many cases, these rivers lie in countries that would benefit from economic development and improved access to water and sanitation services, both of which are linked to water resources. Additional information about streamflow in these watersheds is critical to water resources planning and economic development strategies. In southeastern Africa, the remote Rovuma River lies on the border between Mozambique and Tanzania. There are limited historic measurements in the main tributary and no recent observations. Improved knowledge of the water resource availability and inter-annual variability of the Rovuma River will enhance transboundary river basin management discussions for this river basin. While major rivers farther south in the country are more closely monitored, those in the north have gauging stations with only scattered observations and have not been active since the early 1980's. Reliable estimates of historic conditions are fundamental to water resources planning. This work aims to provide estimates in these rivers and to quantify uncertainty and bounds on those estimates. A combination of methods is used to estimate historic flows: simple index gauge methods such as the drainage area ratio method and mean flow ratio method, a statistical regression method, a combination of an index gauge method and global gridded runoff data, and a hydrological model. These results are compared to in-situ streamflow estimates based on stage measurements and rating curves for the basins and time frames for which data is available. The evaluation of the methods is based on an efficiency ratio, bias, and representation of seasonality and inter-annual variability. Use of gridded global datasets, either with the mean flow ratio method or a hydrological model, appears to provide improved estimates over use of local observations

  16. Hydrogeochemical exploration for uranium within the Athabasca Basin, northern Saskatchewan

    International Nuclear Information System (INIS)

    As part of exploration programs for unconformity-related uranium deposits, the chemistry of deep ground waters has been studied from throughout the Athabasca Basin. Samples have been collected from routine, small-diameter, exploration diamond drillholes, and considerable emphasis has been placed on ensuring that they represent true ground waters. The authors have measured both major and minor constituents, including various uranium daughter products. Ground-water samples collected from the vicinity of uranium mineralization have consistently high levels of uranium, radium, radon and helium. Although they have not been able to establish the maximum extent of the hydrogeochemical anomalies in this environment, they have detected anomalies at distances of up to tens of meters from known mineralization. (orig.)

  17. Astronomy in the Ancient Caucasus

    Science.gov (United States)

    Simonia, Irakli; Jijelava, Badri

    This chapter discusses the role of recurrent heavenly phenomena in the formation of ancient cultural traditions. Artifacts bearing witness to astronomical and calendrical practices in the ancient Caucasus are described and we analyze the significance of the "boats of the sun" petroglyphs at Gobustan in Azerbaijan, the solar station at Abuli in Georgia, and the "sky dial" at Carahunge in Armenia. Similarities and differences between the ancient cultures of the region are discussed. Finally, we present the results of the latest field research and new facts and hypotheses.

  18. Tectonics, recent geodynamics and seismicity of Azerbaijan part of the Greater Caucasus

    Science.gov (United States)

    Aliyev, Fuad; Kangarli, Talat; Rahimov, Fuad; Murtuzov, Zaur; Aliyev, Ziya

    2016-04-01

    Transition area of the Eastern Caucasus - Caspian Megadepression corresponds to a periclinal submergence zone of the mountain folded structure of the Greater Caucasus under Pliocene-Holocenic sedimentary complex of Caspian megabasin. Being a part of Alpine-Himalayan folded belt, Greater Caucasus has formed during alpine stage of tectogenesis under geodynamic conditions of convergent interactions between Northern and Southern Caucasus continental microplates. This process has been accompanied by pseudosubduction of the first plate under the second with formation of allochtonous accretion prism above underthrust zone. Modern folding and napping structure of the orogeny has formed as a result of the horizontal movements of different phases and subphases of alpine tectogenesis, that are presented represented by Late Cimmerian - Wallachian tectonic phases within Azerbaijan territory. Limited by meridional fault-slip zones, Caspian megadepression present itself as a young structure that layered on sublatitudinal convergent zone and developed during Late Miocene (10 million years ago) as a flexure zone between two indenters which actively move northward provoking their separation from the African continent and Arabian plate in the west and secession from Central Iranian plate of the Lut block in the east. The acting movement of Arabian plate to the north results in accumulation of the horizontal stress at the current stage of tectogenesis. Current process reveals itself both in the fragmentation of Southern and Northern Caucasus continental microplates into various-size blocks along the general and anti-Caucasus trended faults, and in consideration horizontal and vertical movements within the convergence zone. All these factors define the complexity of geodynamic condition revealed here, in which seismic activity of a transition zone become apparent. There exist the seismic zones here that are confined both to a convergence line and to the fault zones that confine Caspian

  19. Cenozoic subsurface stratigraphy and structure of the Salar de Atacama Basin, northern Chile

    Science.gov (United States)

    Jordan, T. E.; Mpodozis, C.; Muñoz, N.; Blanco, N.; Pananont, P.; Gardeweg, M.

    2007-02-01

    Sequence mapping of industry seismic lines and their correlation to exposed stratigraphic formations enable a description of the evolution of the nonmarine Salar de Atacama Basin. This major tectonic basin, located in the present-day forearc of the northern Chilean Andes, was first defined topographically by late Cretaceous inversion of the Jurassic-early Cretaceous extensional Tarapacá backarc Basin. Inversion led to both the uplift of the Cordillera de Domeyko and subsidence of the Salar de Atacama Basin along its eastern flank. The basin evolved from a continental backarc in the Cretaceous and Paleogene to a forearc tectonic setting during the Neogene. The principal causes of basin-scale tectonic subsidence include late Cretaceous and earliest Paleocene shortening and Oligocene-early Miocene localized extension. The basin was not completely filled by late Cretaceous (Purilactis Group, sequence G) and Paleocene (sequence H) strata, and its empty space persisted through the Cenozoic. Eocene deformation caused long-wavelength rotation of a deeply weathered surface, generating an erosional unconformity across which coarse clastic strata accumulated (sequence J). Oligocene-early Miocene normal faulting, perhaps in a transtensional environment, repositioned the western basin margin and localized hangingwall subsidence, leading to the accumulation of thousands of meters of evaporitic strata (sequence K, Paciencia Group). By the close of the early Miocene, shortening resumed, first uplifting the intrabasinal Cordillera de la Sal and later generating Pliocene blind reverse faults within the topographically lowest part of the basin. Unequal deposition and tilting across the nascent Cordillera de la Sal induced diapirism of the Paciencia Group halite. In combination, inherited accommodation space and new tectonic subsidence, plus local salt-withdrawal subsidence, shaped the distribution of Upper Miocene-Recent ignimbrites, evaporites, and clastics (sequence M and Vilama

  20. Diversity of Bacteroidetes in high altitude saline evaporitic basins in northern Chile

    OpenAIRE

    Dorador, Cristina; Meneses, D.; Urtuvia, V.; Demergasso, C.; Vila, I; Witzel, K.-P.; Imhoff, Johannes F.

    2009-01-01

    The phylum Bacteroidetes represents one of the most abundant bacterial groups of marine and freshwater bacterioplankton. We investigated the diversity of Bacteroidetes in water and sediment samples from three evaporitic basins located in the highlands of northern Chile. We used both 16S rRNA gene clone libraries created with targeted Bacteroidetes-specific primers and separation of specifically amplified gene fragments by denaturing gradient gel electrophoresis (DGGE). DGGE analysis revealed ...

  1. Sustainable Transformations of Water Supply Regimes. The Cuvelai-Etosha Basin in Central Northern Namibia.

    OpenAIRE

    Zimmermann, Martin

    2013-01-01

    In this thesis, an interdisciplinary modelling approach for water resources management and its application is presented that is able to deal with socio-technical systems that are characterised by a multiplicity of variables, interdependencies, and actors. The case study area is the Cuvelai-Etosha Basin, which is located in central northern Namibia. Approximately 850,000 people or 40 % of the Namibian population live in this area, which comprises only about 14 % of the country’s area. The regi...

  2. Competition, Cooperation, and the Emergence of Regional Centers in the Northern Lake Titicaca Basin, Peru

    OpenAIRE

    Levine, Abigail Ruth

    2012-01-01

    Regional centers with dense populations developed in the Titicaca Basin during the late Middle (ca. 1300-500 BC) and early Upper Formative (ca. 500 BC- AD 400) Periods. These aggregated settlements have long been considered the hallmark of intermediate societies. This dissertation focuses on the transition from small village societies to ones with pronounced social, political, and economic hierarchies. In the northern Titicaca region, only two sites--Taraco and Pukara--became powerful cent...

  3. Analysis on Structural Control of Coal Distribution in the Northern Qaidam Basin, NW China

    Institute of Scientific and Technical Information of China (English)

    LIU Tianji; WANG Tong; ZHAN Wenfeng

    2008-01-01

    The distribution of the Jurassic coal measures in the northern Qaidam Basin is obviously controlled by the regional structures. Based on the existing data of coalfield exploration and combined with the analysis of coalfield basement structures, features of the main faults, and the distribution of coal measures, this paper brings forward a scheme of coalfield tectonic divisional units and the definition of the coal-controlling structural styles in the northern Qaidam Basin. The structure control of the distribution of coal measures is further discussed. Several stages of regional tectonic activities since the Indosinian has led to the distribution of coal measures into the characteristics of zonation from the north to south and block from east to west. The results indicate that the structural deformations are the most intense in the front of the three uplifted belts, which are characterized by the combination of thrusts. The coal measures are uplifted to the shallow formations, and are easy to be exploited, but the scale of mines is small because of serious damages by the coal distribution. On the contrary, the stress and strain are weak in the three depressions, with the coal-controlling structural styles being mainly the thrust-fold and thrust-monocline combinations. The distribution of coals in the depressions is relatively stable. The shallower part of the depression will become the key areas for exploration and development of coal resources in the northern Qaidam Basin.

  4. Tectonic control on the Late Quaternary hydrography of the Upper Tiber Basin (Northern Apennines, Italy)

    Science.gov (United States)

    Benvenuti, Marco; Bonini, Marco; Moroni, Adriana

    2016-09-01

    We examine the intramontane Upper Tiber Basin in the Northern Apennines (central Italy), where sub-orthogonal fault systems forced river deviation and the abandonment of alluvial fans since the late Middle Pleistocene. Archaeological material, spanning the Middle Palaeolithic-Iron Age, was collected mostly from the surface of the Late Quaternary alluvial landforms and related deposits (MUP and HOL units). This information contributed to the partial dating of seven major stages of drainage development. Normal faults parallel and transverse to the basin trend were active at different times and conditioned the valley pattern of the Middle (MUP1-2)-Late (MUP3) Pleistocene Tiber, Singerna, Sovara and Tignana rivers, which still flow today into the basin. The MUP1 and the MUP3 fans were beheaded by the displacement of their feeder valleys along the basin-transverse Carmine and Montedoglio faults. In some cases, the former feeder rivers underwent stream piracy but their courses mostly deviated in response of the topographic gradient created by faulting, as well as through the incision of new valleys that exploited the lithological contrast along the fault lines. The MUP3 Tignana fan was abandoned mostly due to the activity of the basin-parallel, dip-slip Sansepolcro fault. Subsidence driven by the basin-parallel Anghiari and Sansepolcro fault systems also provided the accommodation space for the MUP3 and HOl1-2 Afra fans between Late Pleistocene and early-mid Holocene. This study exemplifies the interplay between longitudinal and transverse fault systems, and the Late Quaternary hydrographic evolution of an extensional basin settled in the axial zone of an active fold-and-thrust belt. Although the faulting has interacted with the forcing exerted by the Late Quaternary climate fluctuations on the basin drainage systems, the tectonic rates are sufficiently high to represent the prime controller on base-level change and drainage routing patterns.

  5. Reactive Transport of Nitrate in Northern California Groundwater basins: An Integrated Characterization and Modeling Approach

    Science.gov (United States)

    Esser, B. K.; Moran, J. E.; Hudson, G. B.; Carle, S. F.; McNab, W.; Tompson, A. F.; Moore, K.; Beller, H.; Kane, S.; Eaton, G.

    2003-12-01

    More than 1/3 of active public drinking water supply wells in California produce water with nitrate-N levels indicative of anthropogenic inputs (> 4 mg/L). Understanding how the distribution of nitrate in California groundwater basins will evolve is vital to water supply and infrastructure planning. To address this need, we are studying the basin-scale reactive transport of nitrate in the Livermore and Llagas basins of Northern California. Both basins have increasingly urban populations heavily reliant on groundwater. A distinct nitrate "plume" exists in the Livermore Basin (Alameda County) whereas pervasive nitrate contamination exists in shallow groundwaters of the Llagas Basin (Santa Clara County). The sources and timing of nitrate contamination in these basins are not definitively known; septic systems, irrigated agriculture and livestock operations exist or have existed in both areas. The role of denitrification in controlling nitrate distribution is also unknown; dissolved oxygen levels are sufficiently low in portions of each basin as to indicate the potential for denitrification. We have collected water from 60 wells, and are determining both groundwater age (by the 3H/3He method) and the extent of denitrification (by the excess N2 method). Excess nitrogen is being determined by both membrane-inlet and noble gas mass spectrometry, using Ar and Ne content to account for atmospheric N2. We are also analyzing for stable istotopes of nitrate and water, nitrate co-contaminants, and general water quality parameters. Preliminary analysis of archival water district data from both basins suggests positive correlations of nitrate with Ca+2, Mg+2 and bicarbonate and negative correlation with pH. In the Llagas Basin, a negative correlation also exists between nitrate and temperature. Flow path-oriented reactive transport modeling is being explored as a tool to aid in the identification of both the sources of nitrate and evidence for denitrification in both basins

  6. Tectonic Subsidence Analysis of the Pearl River Mouth Basin, Northern South China Sea

    Science.gov (United States)

    Tang, X.; Huang, S. S. X. E. C.; Zhuang, W.; LIU, Z.; Duan, W.; Hu, S.

    2015-12-01

    The Pearl River Mouth Basin (PRMB hereafter) in the northern margin of the South China Sea has attracted great attention not only because of its special tectonic location but also for its abundant hydrocarbon resources. Tectonic evolution controls the petroleum geological condition of hydrocarbon-bearing basins. Efforts have been made to understand the tectonic evolution of this basin. However, many issues about the tectonic features and the evolution process of this basin, such as the age of the breakup unconformities and the anomalously accelerated subsidence during the post-rifting stage, remain controversial. Here we employ tectonic subsidence analysis of sedimentary basins, a technique of removing isostatic loading and compaction effects by back-stripping, to investigate the tectonic controls on the basin formation of the PRMB. We performed the analysis on 4 drill wells and 43 synthetic wells constructed based on recently acquired seismic profiles. The result shows that tectonic subsidence in the eastern sags of the PRMB began to decrease at ~30Ma while in the western sags the onset was ~23.8Ma. This suggests that the break-up time i.e. the end of rifting in the PRMB is earlier in the eastern sags than in the western sags. Abnormally accelerated tectonic subsidence occurred between 17.5-16.4Ma during the post-rifting stage, at an average subsidence rate as high as 301.9m/Ma. This phenomenon discriminates the PRMB from the category of classical Atlantic passive continental marginal basins, of which the tectonic subsidence during the post-rifting stage decays exponentially. The main objective of this paper is to provide insights into the geological and geodynamic evolution of the PRMB. The result bears significance to hydrocarbon exploration in this region.

  7. Miocene woods from the Qaidam Basin on northern Qinghai-Tibet Plateau with implications for paleoenvironmental change

    Science.gov (United States)

    Cheng, Ye-Ming; Yang, Xiao-Nan

    2016-02-01

    The Qaidam Basin with the most complete Cenozoic sedimentary preservation in northern Qinghai-Tibet Plateau is a key area for studying uplift and environmental change of the plateau. Three types of woods, Ulmus (Ulmaceae), Leguminosae (?) (angiosperm) and Cupressaceae (gymnosperm) were recognized from the large-scale preservation of fossil woods in late Miocene Shang Youshashan Formation in northern Qaidam Basin on the Qinghai-Tibet Plateau. Both investigations of their Nearest Living Relatives (NLRs) and previous grassland mammal evidences suggest that there have been temperate deciduous broad-leaved forest and needle-leaved forest with grass in northern Qaidam Basin during the late Miocene in contrast to the desert vegetation found there nowadays. The presence of the ancient forest steppe further implies that the southern part of the plateau used to be adequately low, so that the Indian and East Asian monsoons could approach the northern area and to accommodate the vegetation in late Miocene.

  8. Hydrogeochemistry of high-fluoride groundwater at Yuncheng Basin, northern China

    International Nuclear Information System (INIS)

    Hydrogeochemical and environmental isotope methods were integrated to delineate the spatial distribution and enrichment of fluoride in groundwater at Yuncheng Basin in northern China. One hundred groundwater samples and 10 Quaternary sediment samples were collected from the Basin. Over 69% of the shallow groundwater (with a F− concentration of up to 14.1 mg/L), 44% of groundwater samples from the intermediate and 31% from the deep aquifers had F− concentrations above the WHO provisional drinking water guideline of 1.5 mg/L. Groundwater with high F− concentrations displayed a distinctive major ion chemistry: Na-rich and Ca-poor with a high pH value and high HCO3− content. Hydrochemical diagrams and profiles and hydrogen and oxygen isotope compositions indicate that variations in the major ion chemistry and pH are controlled by mineral dissolution, cation exchange and evaporation in the aquifer systems, which are important for F− mobilization as well. Leakage of shallow groundwater and/or evaporite (gypsum and mirabilite) dissolution may be the major sources for F− in groundwater of the intermediate and deep aquifers. - Highlights: • High-F− groundwater widely occurs in Yuncheng Basin of northern China. • High-F− groundwater is Na and HCO3-rich and Ca-poor, with high pH. • Major hydrogeochemical processes are mineral dissolution, ion exchange and evaporation. • Shallow groundwater leakage/evaporite dissolution may cause F enrichment in lower aquifers

  9. Prospect analysis for sandstone-type uranium mineralization in the northern margin of Qaidam basin

    International Nuclear Information System (INIS)

    Affected by the regional geological structural evolution, a set of sedimentary structure, i.e. the construction of coal-bearing classic rocks which is in favor of the sandstone-type uranium mineralization has deposited in the northern margin of Qaidam Basin since Meso-Cenozoic. A NWW thrust nappe tectonic belt, i.e. the ancient tectonic belt which is the basis for the development of ancient interlayer oxidation zone formed by the tectonic reverse in late Jurassic and Cretaceous. The Mid and late Jurassic layer was buried by the weak extension in Paleogene and the depression in early Neogene. The extrusion reversal from late Neogene to Quaternary made the basin into the development era of the modern interlayer oxidation zone. It can be concluded that the layer of the northern margin of Qaidam Basin has the premise for the formation of sandstone-type uranium ore. Based on the analysis of the characteristics of the thrust belt, the structure of the purpose layer, the sand body, the hydrogeology, the interlayer oxidation zone and uranium mineralization, the results indicated that the ancient interlayer oxidation zone is the prospecting type of sandstone-type uranium ore. Beidatan and the east of Yuqia are the favorable prospective area of sandstone-type uranium mineralization. (authors)

  10. Characteristics and genesis of clay minerals in the northern margin of the Qaidam Basin

    Institute of Scientific and Technical Information of China (English)

    Wang Linlin; Jiang Bo; Peng Dehua; Yin Chengming; Zeng Chunlin

    2011-01-01

    In order to develop appropriate reservoir protection measures in the northern margin of the Qaidam Basin and improve its oil and gas recovery efficiency, characteristics of clay minerals from eleven clay rock samples from the northern margin of the Qaidam Basin were investigated using X-ray diffraction analysis, the Scanning Electron Microscope (SEM) and energy spectrum analysis. Clay mineral composition and distribution characteristics of the main hydrocarbon reservoirs, I.e., from the Jurassic and Paleogene-Neogene, were explored. We analyzed the main factors which affected these attributes. The results show that the major clay minerals in the northern margin are chlorite, kaolinite, illite, smectite and illite/smectite inter-stratified minerals, Illite is the most widely spread clay mineral in this area.Chlorite is mainly found in the entire Neogene and in shallow horizons of the Paleogene. Smectite is enriched in the shallow Paleogene-Neogene. There are large amounts of kaolinite and illite/smectite inter-stratified minerals in the Jurassic. The major factors affecting the different development of clay minerals in the region are properties of parent rocks, paleoclimate and paleowater media conditions,diagenesis transformation, tectonic and terrain conditions.

  11. Evidence for a broadly distributed Samoan-plume signature in the northern Lau and North Fiji Basins

    Science.gov (United States)

    Price, Allison A.; Jackson, Matthew G.; Blichert-Toft, Janne; Hall, Paul S.; Sinton, John M.; Kurz, Mark D.; Blusztajn, Jerzy

    2014-04-01

    enrichment of lavas in the northern Lau Basin may reflect the influx of Samoan-plume mantle into the region. We report major and trace element abundances and He-Sr-Nd-Hf-Pb-isotopic measurements for 23 submarine volcanic glasses covering 10 locations in the northern Lau and North Fiji Basins, and for three samples from Wallis Island, which lies between Samoa and the Lau Basin. These data extend the western limit of geochemical observations in the Basins and improve the resolution of North-South variations in isotopic ratios. The Samoan hot spot track runs along the length of the northern trace of the Lau and North Fiji Basins. We find evidence for a Samoan-plume component in lavas as far West as South Pandora Ridge (SPR), North Fiji Basin. Isotopic signatures in SPR samples are similar to those found in Samoan Upolu shield lavas, but show a slight shift toward MORB-like compositions. We explain the origin of the enriched signatures by a model in which Samoan-plume material and ambient depleted mantle undergo decompression melting during upwelling after transiting from beneath the thick Pacific lithosphere to beneath the thin lithosphere in the northern Lau and North Fiji Basins. Other lavas found in the region with highly depleted isotopic signatures may represent isolated pockets of depleted mantle in the basins that evaded this enrichment process. We further find that mixing between the two components in our model, a variably degassed high-3He/4He Samoan component and depleted MORB, can explain the diversity among geochemical data from the northern Lau Basin.

  12. Structural style and Basin Formation in Deep-water Area of Northern South China Sea

    Science.gov (United States)

    di, Z.; Zhen, S.; Xiong, P.; Min, C. C.

    2007-12-01

    In the deep-water area of northern South China Sea (SCS) developed a series of sedimentary basins. Active exploration for deep-water hydrocarbon has begun in these areas since this century. The well LW3-1-1 at water depth of 1480m in the BaiYun Sag (BYS) of the Pearl River Mouth Basin in 2006 discovered 56m layer of pure gas, demonstrated the good hydrocarbon potential of the area. Wide-angle seismic profiling has verified the transitional type of crust in the slope areas. The Moho surface shoals step-by-step from 30-29km under the shelf, ~15 km under the slope, and ~12km under the abyssal plain. Moho also rises beneath depocenters, mirroring the shape of sedimentary basement. The crustal thickness at the center of the BYS is Pacific Ocean towards the East Eurasian margin. The stress field in the East Eurasian margin changed abruptly in Late Cretaceous. Rifting started in the entire margin and eventually led to the opening of the SCS in late Early Oligocene. Large sedimentary basins developed in the margins of the SCS. Paleogene lacustrine sediments contain hydrocarbon sources, while traps are mostly found in Neogene marine strata. The structure of the northern SCS shows clear W-E variation, divided into NE-, NEE-, and NE-trending segments by two major NW-SE transfer faults. The Southern Depression of the Qiongdongnan Basin to the west is characterized by NE-trending half grabens. The BYS at the central segment is characterized by NEE-trending composite grabens and down warps with relatively small offset of boundary faults. To the east the Chaoshan Depression is composed of Mesozoic strata under very thin (deep-water basins is different from that of shallow-water basins. A study is ongoing to explore the basin formation mechanism, taking into account of the factors of abnormal lithosphere rheology, active mantle underplating and magmatic heating, lower crust flow, as well as the superposition of later extensional events. The study is supported by NSFC grants

  13. Federally owned coal and Federal lands in the northern and central Appalachian Basin coal regions

    Energy Technology Data Exchange (ETDEWEB)

    Susan J. Tewalt

    2002-02-01

    The US Geological Survey (USGS) assessed five coals beds or coal zones in the northern and central Appalachian Basin coal regions for the National Coal Resource Assessment: the Pittsburgh coal bed, the Upper Freeport coal bed, the Fire Clay coal zone, the Pond Creek coal zone, and the Pocahontas No. 3 coal bed. The assessment produced stratigraphic and geochemical databases and digital coal maps, or models, which characterized the coal beds and coal zones. Using the assessment models, the USGS estimated original and remaining (unmined) resources for these coal beds or zones. The Appalachian Basin assessment was conducted in collaboration with the State geological surveys of West Virginia, Pennsylvania, Ohio, Maryland, Kentucky, and Virginia. 3 refs., 7 figs.

  14. Coal resources of selected coal beds and zones in the northern and central Appalachian Basin

    Energy Technology Data Exchange (ETDEWEB)

    Leslie Ruppert; Susan Tewalt; Linda Bragg

    2002-02-01

    The U.S. Geological Survey (USGS) is completing a National Coal Resource Assessment of five coal-producing regions of the United States, including the Appalachian Basin. The USGS, in cooperation with the State geological surveys of Kentucky, Maryland, Ohio, Pennsylvania, Virginia, and West Virginia, has completed a digital coal resource assessment of five of the top-producing coal beds and coal zones in the northern and central Appalachian Basin coal regions -- the Pittsburgh coal bed, the Upper Freeport coal bed, the Fire Clay and Pond Creek coal zones, and the Pocahontas No. 3 coal bed. Of the 93 billion short tons of original coal in these units, about 66 billion short tons remain. 2 refs., 5 figs., 2 tabs.

  15. Visan miospore biostratigraphy and correlation of the Poti Formation (Parnaba Basin, northern Brazil).

    Science.gov (United States)

    Melo; Loboziak

    2000-10-01

    The Poti Formation, which consists mainly of sandstones with minor proportions of carbonaceous shales and other siliciclastic lithologies, represents all the Viséan strata thus far recorded in the Parnaíba Basin, northern Brazil.Well-preserved miospores featuring species with both Southern Euramerican and Gondwanan affinities have been recovered from this formation in four well sections. The most characteristic species are listed in this paper, and brief systematic descriptions are presented for the most significant species, along with comments on their biostratigraphy. A new generic combination is proposed: Cordylosporites magnidictyus (Playford and Helby) Loboziak and Melo comb. nov. Comparisons with miospores illustrated from the Grand Erg Occidental, Algerian Sahara, are tentatively proposed.In terms of the Western European Carboniferous palynozonation, miospore assemblages from the Poti Formation are assignable to the Perotrilites tessellatus-Schulzospora campyloptera (TC)-Raistrickia nigra-Triquitrites marginatus (NM) zonal range. This corresponds to the upper part of the Holkerian and the whole Asbian, which are British regional stages for the lower to middle parts of the upper Viséan. The Viséan age formerly attributed to biostratigraphic interval XII of Petrobras' regional palynostratigraphic scheme is therefore confirmed. As already noted in our recent investigations of the Faro Formation in the Amazon Basin and equivalent strata of the Solimões Basin, latest Tournaisian and early to middle Viséan sections are either absent or barren of characteristic miospores in the Parnaíba Basin as well. PMID:11042330

  16. Latest Miocene to Quaternary deformation in the southern Chaiwopu Basin, northern Chinese Tian Shan foreland

    Science.gov (United States)

    Lu, Honghua; Wang, Zhen; Zhang, Tianqi; Zhao, Junxiang; Zheng, Xiangmin; Li, Youli

    2015-12-01

    Basinward propagation of fold and thrust belts is a crucial geological process accommodating Cenozoic crustal shortening within the India-Eurasia collision zone. Anticlinal growth strata in the southern Chaiwopu Basin (a piggyback basin) of the northern Chinese Tian Shan foreland record basinward encroachment of the Tian Shan along the Junggar Frontal Thrust Fault. A new magnetostratigraphic section constrains the onset of syntectonic growth strata at circa 6.4 Ma and suggests synchronous basinward thrusting and propagation of the Tian Shan. The intense alluviation in the southern Chaiwopu Basin ceased at circa 0.55 Ma due to significant anticlinal growth and its resultant river incision. More recent anticlinal growth and deformation during the late Quaternary are revealed by folded river terraces developing across the anticline. The terrace height profile indicates that terrace T1H has been vertically offset about 0.6 m by thrust faulting since its formation at about 7 Ka. The stratigraphic and geomorphic data presented in this work are helpful to understand the initiation of thrust-related folding, as well as aggradation and subsequent incision, in foreland basins of the Tian Shan in relation to the India-Asia collision.

  17. Geophysical observations on northern part of Georges Bank and adjacent basins of Gulf of Maine

    Science.gov (United States)

    Oldale, R.N.; Hathaway, J.C.; Dillon, William P.; Hendricks, J.D.; Robb, James M.

    1974-01-01

    Continuous-seismic-reflection and magnetic-intensity profiles provide data for inferences about the geology of the northern part of Georges Bank and the basins of the Gulf of Maine adjacent to the bank. Basement is inferred to be mostly sedimentary and volcanic rocks of Paleozoic age that were metamorphosed and intruded locally by felsic and mafic plutons near the end of the Paleozoic Era. During Late Triassic time, large fault basins formed within the Gulf of Maine and probably beneath Georges Bank. The fault basins and a possible major northeast-trending fault zone beneath the northern part of the bank probably formed as a result of the opening Atlantic during the Mesozoic. Nonmarine sediments, associated with mafic flows and intrusive rocks, were deposited in the fault basins as they formed. The upper surface of the Triassic and pre-Triassic rocks that comprise basement is an unconformity that makes up much of the bottom of the Gulf of Maine. Depth to the basement surface beneath the gulf differ greatly because of fluvial erosion in Tertiary time and glacial erosion in Pleistocene time. Beneath the northern part of Georges Bank the basement surface is smoother and slopes southward. Prominent valleys, cut before Late Cretaceous time, are present beneath this part of the bank. Cretaceous, Tertiary, and possibly Jurassic times were characterized by episodes of coastal-plain deposition and fluvial erosion. During this time a very thick wedge of sediment, mostly of Jurassic(?) and Cretaceous ages, was deposited on the shelf. Major periods of erosion took place at the close of the Cretaceous and during the Pliocene. Fluvial erosion during the Pliocene removed much of the coastal-plain sedimentary wedge and formed the Gulf of Maine. Pleistocene glaciers eroded all but a few remnants of the coastal-plain sediments within the gulf and deposited a thick section of drift against the north slope of Georges Bank and a thin veneer of outwash on the bank. Marine sediments were

  18. HIGH-RESOLUTION SEISMIC VELOCITY AND ATTENUATION MODELS OF THE CAUCASUS-CASPIAN REGION

    Energy Technology Data Exchange (ETDEWEB)

    Mellors, R; Gok, R; Pasyanos, M; Skobeltsyn, G; Teoman, U; Godoladze, T; Sandvol, E

    2008-07-01

    The southwest edge of Eurasia is a tectonically and structurally complex region that includes the Caspian and Black Sea basins, the Caucasus Mountains, and the high plateaus south of the Caucasus. Using data from 25 broadband stations located in the region, new estimates of crustal and upper mantle thickness, velocity structure, and attenuation are being developed. Receiver functions have been determined for all stations. Depth to Moho is estimated using slant stacking of the receiver functions, forward modeling, and inversion. Moho depths along the Caspian and in the Kura Depression are in general poorly constrained using only receiver functions due to thick sedimentary basin sediments. The best fitting models suggest a low velocity upper crust with Moho depths ranging from 30 to 40 km. Crustal thicknesses increase in the Greater Caucasus with Moho depths of 40 to 50 km. Pronounced variations with azimuth of source are observed indicating 3D structural complexity and upper crustal velocities are higher than in the Kura Depression to the south. In the Lesser Caucasus, south and west of the Kura Depression, the crust is thicker (40 to 50 km) and upper crustal velocities are higher. Work is underway to refine these models with the event based surface wave dispersion and ambient noise correlation measurements from continuous data. Regional phase (Lg and Pg) attenuation models as well as blockage maps for Pn and Sn are being developed. Two methods are used to estimate Q: the two-station method to estimate inter-station Q and the reversed, two-station, two event method. The results are then inverted to create Lg and Pg Q maps. Initial results suggest substantial variations in both Pg and Lg Q in the region. A zone of higher Pg Q extends west from the Caspian between the Lesser and Greater Caucasus and a narrow area of higher Lg Q is observed.

  19. Recognition of relict Mesozoic Dongsha Basin in the northern margin, South China Sea and its implication

    Science.gov (United States)

    Yan, Pin; Wang, Yanlin

    2015-04-01

    The Pearl River Mouth Basin (PRMB) is dominated by NE-trending rift architecture produced mainly during Cenozoic Era. It comprises a series of grabens built up with thick Paleogene and thick Neogene sediments, up to 12000 m, and dividing basement highs composing Yanshanian granitic rocks. Though previously considered as one constituent part of PRMB in the southeast, Dongsha Basin displays major differences in sedimentary architecture and tectonic framework. Firstly, Dongsha Basin is characterized by a prominent angular unconformity, interpreted as a spectacular planation or rough erosion surface which separates the sediment column into two distinct parts. It is interpreted with accumulating seismic and drill data that the underlying strata comprise Early Cretaceous terrestrial, Jurassic marine and possibly Triassic sedimentary rocks totaling to 4~9 km thick, whereas the overlying strata are very thin (usually 0.5~1 km in whole) composing mainly Neogene sediments. The major sedimentary hiatus between them corresponds to the Late Cretaceous to mid-Miocene Epoch, well during the rifting to spreading process when the PRMB developed. Secondly, unlike the PRMB, the Dongsha Basin has suffered considerably less extension except its boundary areas, and actually remained as a relatively stable block though Cenozoic Era. Moreover, there are a few compressive open fold structures within the buried Mesozoic strata over the central Dongsha Basin. These folds trend in NNE and are characterized mostly by few minor growing upthrust faults with offsets in the order of few tens to hundreds meter. The upthrust faults dipped mostly southeastward against the northwestward subduction of paleo-Pacific plate as postulated in other previous study. The blind folds featured more like back-thrust growth tectonics, formed a broad NNE-SSW trending belt, obviously oblique to the trend of northern margin of the South China Sea and the PRMB as well. In a few recent models, the most prominent

  20. Lithospheric Velocity Structure of the Anatolain plateau-Caucasus-Caspian Regions

    Energy Technology Data Exchange (ETDEWEB)

    Gok, R; Mellors, R J; Sandvol, E; Pasyanos, M; Hauk, T; Yetirmishli, G; Teoman, U; Turkelli, N; Godoladze, T; Javakishvirli, Z

    2009-04-15

    Anatolian Plateau-Caucasus-Caspian region is an area of complex structure accompanied by large variations in seismic wave velocities. Despite the complexity of the region little is known about the detailed lithospheric structure. Using data from 29 new broadband seismic stations in the region, a unified velocity structure is developed using teleseismic receiver functions and surface waves. Love and Rayleigh surface waves dispersion curves have been derived from event-based analysis and ambient-noise correlation. We jointly inverted the receiver functions with the surface wave dispersion curves to determine absolute shear wave velocity and important discontinuities such as sedimentary layer, Moho, lithospheric-asthenospheric boundary. We combined these new station results with Eastern Turkey Seismic Experiment results (29 stations). Caspian Sea and Kura basin underlained by one of the thickest sediments in the world. Therefore, short-period surface waves are observed to be very slow. The strong crustal multiples in receiver functions and the slow velocities in upper crust indicate the presence of thick sedimentary unit (up to 20 km). Crustal thickness varies from 34 to 52 km in the region. The thickest crust is in Lesser Caucasus and the thinnest is in the Arabian Plate. The lithospheric mantle in the Greater Caucasus and the Kura depression is faster than the Anatolian Plateau and Lesser Caucasus. This possibly indicates the presence of cold lithosphere. The lower crust is slowest in the northeastern part of the Anatolian Plateau where Holocene volcanoes are located.

  1. Diversity of Bacteroidetes in high-altitude saline evaporitic basins in northern Chile

    Science.gov (United States)

    Dorador, Cristina; Meneses, Daniela; Urtuvia, Viviana; Demergasso, Cecilia; Vila, Irma; Witzel, Karl-Paul; Imhoff, Johannes F.

    2009-06-01

    The phylum Bacteroidetes represents one of the most abundant bacterial groups of marine and freshwater bacterioplankton. We investigated the diversity of Bacteroidetes in water and sediment samples from three evaporitic basins located in the highlands of northern Chile. We used both 16S rRNA gene clone libraries created with targeted Bacteroidetes-specific primers and separation of specifically amplified gene fragments by denaturing gradient gel electrophoresis (DGGE). DGGE analysis revealed a reduced richness of these organisms in samples from Salar de Huasco (two to four DGGE bands) increasing in Salar de Ascotán (two to seven DGGE bands) and Laguna Tebenquiche at Salar de Atacama (four to eight DGGE bands). Cluster analysis (WPGMA) of DGGE bands showed that bands from Salar de Huasco and Salar de Ascotán grouped together and samples from Salar de Atacama formed separate clusters in water and sediment samples, reflecting different Bacteroidetes communities between sites. Most of the sequences analyzed belonged to the family Flavobacteriaceae and clustered with the genera Psychroflexus, Gillisia, Maribacter, Muricauda, Flavobacterium, and Salegentibacter. The most abundant phylotype was highly related to Psychroflexus spp. and was recovered from all three study sites. The similarity of the analyzed sequences with their closest relatives in GenBank was typically Culture efforts will be necessary to get a better description of the diversity of this group in saline evaporitic basins of northern Chile.

  2. Extraordinarily thick-boned fish linked to the aridification of the Qaidam Basin (northern Tibetan Plateau).

    Science.gov (United States)

    Chang, Meemann; Wang, Xiaoming; Liu, Huanzhang; Miao, Desui; Zhao, Quanhong; Wu, Guoxuan; Liu, Juan; Li, Qiang; Sun, Zhencheng; Wang, Ning

    2008-09-01

    Scattered with numerous salt lakes and approximately 2,700-3,200 m above sea level, the giant Qaidam inland basin on the northern Tibetan Plateau has experienced continuing aridification since the beginning of the Late Cenozoic as a result of the India-Asia plate collision and associated uplift of the Tibetan Plateau. Previous evidence of aridification comes mainly from evaporite deposits and salinity-tolerant invertebrate fossils. Vertebrate fossils were rare until recent discoveries of abundant fish. Here, we report an unusual cyprinid fish, Hsianwenia wui, gen. et sp. nov., from Pliocene lake deposits of the Qaidam Basin, characterized by an extraordinarily thick skeleton that occupied almost the entire body. Such enormous skeletal thickening, apparently leaving little room for muscles, is unknown among extant fish. However, an almost identical condition occurs in the much smaller cyprinodontid Aphanius crassicaudus (Cyprinodonyiformes), collected from evaporites exposed along the northern margins of the Mediterranean Sea during the Messinian desiccation period. H. wui and A. crassicaudus both occur in similar deposits rich in carbonates (CaCO(3)) and sulfates (CaSO(4)), indicating that both were adapted to the extreme conditions resulting from the aridification in the two areas. The overall skeletal thickening was most likely formed through deposition of the oversaturated calcium and was apparently a normal feature of the biology and growth of these fish. PMID:18757732

  3. Hydrogeochemistry of high-fluoride groundwater at Yuncheng Basin, northern China

    Energy Technology Data Exchange (ETDEWEB)

    Li, Chengcheng [State Key Laboratory of Biogeology and Environmental Geology and School of Environmental Studies, China University of Geosciences, Wuhan 430074 (China); Gao, Xubo, E-mail: xubo.gao.cug@gmail.com [State Key Laboratory of Biogeology and Environmental Geology and School of Environmental Studies, China University of Geosciences, Wuhan 430074 (China); University of Texas at Austin, Austin, TX, 78705 (United States); Wang, Yanxin, E-mail: yx.wang@cug.edu.cn [State Key Laboratory of Biogeology and Environmental Geology and School of Environmental Studies, China University of Geosciences, Wuhan 430074 (China)

    2015-03-01

    Hydrogeochemical and environmental isotope methods were integrated to delineate the spatial distribution and enrichment of fluoride in groundwater at Yuncheng Basin in northern China. One hundred groundwater samples and 10 Quaternary sediment samples were collected from the Basin. Over 69% of the shallow groundwater (with a F{sup −} concentration of up to 14.1 mg/L), 44% of groundwater samples from the intermediate and 31% from the deep aquifers had F{sup −} concentrations above the WHO provisional drinking water guideline of 1.5 mg/L. Groundwater with high F{sup −} concentrations displayed a distinctive major ion chemistry: Na-rich and Ca-poor with a high pH value and high HCO{sub 3}{sup −} content. Hydrochemical diagrams and profiles and hydrogen and oxygen isotope compositions indicate that variations in the major ion chemistry and pH are controlled by mineral dissolution, cation exchange and evaporation in the aquifer systems, which are important for F{sup −} mobilization as well. Leakage of shallow groundwater and/or evaporite (gypsum and mirabilite) dissolution may be the major sources for F{sup −} in groundwater of the intermediate and deep aquifers. - Highlights: • High-F{sup −} groundwater widely occurs in Yuncheng Basin of northern China. • High-F{sup −} groundwater is Na and HCO{sub 3}-rich and Ca-poor, with high pH. • Major hydrogeochemical processes are mineral dissolution, ion exchange and evaporation. • Shallow groundwater leakage/evaporite dissolution may cause F enrichment in lower aquifers.

  4. Towards large scale modelling of wetland water dynamics in northern basins.

    Science.gov (United States)

    Pedinotti, V.; Sapriza, G.; Stone, L.; Davison, B.; Pietroniro, A.; Quinton, W. L.; Spence, C.; Wheater, H. S.

    2015-12-01

    Understanding the hydrological behaviour of low topography, wetland-dominated sub-arctic areas is one major issue needed for the improvement of large scale hydrological models. These wet organic soils cover a large extent of Northern America and have a considerable impact on the rainfall-runoff response of a catchment. Moreover their strong interactions with the lower atmosphere and the carbon cycle make of these areas a noteworthy component of the regional climate system. In the framework of the Changing Cold Regions Network (CCRN), this study aims at providing a model for wetland water dynamics that can be used for large scale applications in cold regions. The modelling system has two main components : a) the simulation of surface runoff using the Modélisation Environmentale Communautaire - Surface and Hydrology (MESH) land surface model driven with several gridded atmospheric datasets and b) the routing of surface runoff using the WATROUTE channel scheme. As a preliminary study, we focus on two small representative study basins in Northern Canada : Scotty Creek in the lower Liard River valley of the Northwest Territories and Baker Creek, located a few kilometers north of Yellowknife. Both areas present characteristic landscapes dominated by a series of peat plateaus, channel fens, small lakes and bogs. Moreover, they constitute important fieldwork sites with detailed data to support our modelling study. The challenge of our new wetland model is to represent the hydrological functioning of the various landscape units encountered in those watersheds and their interactions using simple numerical formulations that can be later extended to larger basins such as the Mackenzie river basin. Using observed datasets, the performance of the model to simulate the temporal evolution of hydrological variables such as the water table depth, frost table depth and discharge is assessed.

  5. Ellipticity of Rayleigh waves in basin and hard-rock sites in Northern Italy

    Science.gov (United States)

    Berbellini, Andrea; Morelli, Andrea; Ferreira, Ana M. G.

    2016-07-01

    We measure ellipticity of teleseismic Rayleigh waves at 95 seismic stations in Northern Italy, for wave period between 10 and 110 s, using an automatic technique and a large volume of high-quality seismic recordings from over 500 global earthquakes that occurred in 2008-2014. Northern Italy includes a wide range of crustal structures, from the wide and deep Po Plain sedimentary basin to outcropping sedimentary and crystalline rocks in the Northern Apennines and Alps. It thus provides an excellent case for studying the influence of shallow earth structure on polarization of surface waves. The ellipticity measurements show excellent spatial correlation with geological features in the region, such as high ellipticity associated with regions of low seismic velocity in the Po Plain and low ellipticity values in faster, hard rock regions in the Alps and Apennine mountains. Moreover, the observed ellipticity values also relate to the thickness of the basement, as highlighted by observed differences beneath the Alps and the Apennines. Comparison between observations and predicted ellipticity from a reference crustal model of the region show substantial fit, particularly for T ˜ 38 s data. Discrepancy for shorter wave period suggests that slight modifications of the model are needed, and that the ellipticity measurements could help to better constrain the shallow crustal structure of the region. Predictions for the Po Plain are larger than the observations by a factor of four or more and transition from retrograde to prograde Rayleigh wave motion at the surface for periods of T ˜ 10-13 s is predicted for seismic stations in the plain. Analysis of corresponding real data indicates a possible detection of teleseismic prograde particle motion, but the weak teleseismic earthquake signals are mixed with ambient noise signals at the predicted, short, transition periods. Detection of the period of polarity inversion from the joint analysis of earthquake and ambient noise

  6. Ellipticity of Rayleigh waves in basin and hard-rock sites in Northern Italy

    Science.gov (United States)

    Berbellini, Andrea; Morelli, Andrea; Ferreira, Ana M. G.

    2016-04-01

    We measure ellipticity of teleseismic Rayleigh waves at 95 seismic stations in Northern Italy, for wave period between 10 s and 110 s, using an automatic technique and a large volume of high-quality seismic recordings from over 500 global earthquakes that occurred in 2008-2014. Northern Italy includes a wide range of crustal structures, from the wide and deep Po Plain sedimentary basin to outcropping sedimentary and cristalline rocks in the Northern Apennines and Alps. It thus provides an excellent case for studying the influence of shallow earth structure on polarisation of surface waves. The ellipticity measurements show excellent spatial correlation with geological features in the region, such as high ellipticity associated with regions of low seismic velocity in the Po Plain and low ellipticity values in faster, hard rock regions in the Alps and Apennine mountains. Moreover, the observed ellipticity values also relate to the thickness of the basement, as highlighted by observed differences beneath the Alps and the Apennines. Comparison between observations and predicted ellipticity from a reference crustal model of the region show substantial fit, particularly for T ˜ 38 s data. Discrepancy for shorter wave period suggests that slight modifications of the model are needed, and that the ellipticity measurements could help to better constrain the shallow crustal structure of the region. Predictions for the Po Plain are larger than the observations by a factor of four or more and transition from retrograde to prograde Rayleigh wave motion at the surface for periods of T ˜ 10-13 s is predicted for seismic stations in the Plain. Analysis of corresponding real data indicates a possible detection of teleseismic prograde particle motion, but the weak teleseismic earthquake signals are mixed with ambient noise signals at the predicted, short, transition periods. Detection of the period of polarity inversion from the joint analysis of earthquake and ambient noise

  7. The Millstone Grit Group (Pennsylvanian) of the Northumberland-Solway Basin and Alston Block of northern England

    OpenAIRE

    Waters, C.N; Millward, D.; C. W. Thomas

    2014-01-01

    In the Northumberland–Solway Basin and Alston Block of northern England, some aspects of the stratigraphical and sedimentological relationships between the Millstone Grit Group, the Stainmore Formation (Namurian part of the Yoredale Group) and the Westphalian Pennine Coal Measures Group are uncertain. Also, confusion has resulted from discontinuation of Millstone Grit as a formal lithostratigraphical term north of the Stainmore Basin. This paper presents the evidence for, and describes the na...

  8. A long lacustrine record from the Piànico-Sèllere Basin (Middle-Late Pleistocene, Northern Italy)

    OpenAIRE

    A. Moscariello; Ravazzi, C.; Achim Brauer; C. Mangili; Chiesa, S.; Rossi, S.; J.-L. de Beaulieu; M. Reille

    2000-01-01

    The stratigraphical succession of the Piànico-Sèllere Basin (Northern Italy) represents an exceptionally well preserved sedimentary assemblage which formed in a closed lake basin during the Middle–Upper Pleistocene. These deposits are grouped into the hereby proposed "Piànico Formation". This includes four lacustrine, fine-grained, laminated lithostratigraphical units containing a 10.5 m thick interval of well preserved varved carbonates. The lacustrine units are coeval, and laterally heterop...

  9. Helium Isotope Variations in the Northern Lau and North Fiji Basins

    Science.gov (United States)

    Lupton, J. E.; Arculus, R. J.; Jenner, F. E.; Evans, L.; Greene, R.

    2012-12-01

    Recent measurements of submarine basalts from the Northern Lau Basin exhibit a fascinating pattern in the helium isotopes. In particular, basalts along the NW Lau Spreading Center and the Rochambeau Rifts (NWLSC-RR) all have elevated 3He/4He ratios ranging from 11 to 28 Ra, much higher than the MORB-like values of 7 - 9 Ra that might be expected for a typical back-arc spreading center (Lupton et al, GRL 2009) (R = 3He/4He and Ra = Rair = 1.39E-6). This has been interpreted as indicating the presence of a mantle plume component, possibly from the Samoan hotspot, which has somehow intruded into the northern Lau Basin. Furthermore, neon isotopes analyzed in this same suite of basalts exhibit enrichments in 21Ne/22Ne and 20Ne/22Ne distinct from MORB neon and similar to neon isotopes measured in Samoan lavas (Lupton et al., GRL, 2012), further evidence for intrusion of a Samoan plume component. Surprisingly, this hotspot component is only evident along the NWLSC-RR, while samples from seafloor basalts and submarine hydrothermal fluids in the NE Lau Basin have MORB-like values or lower, varying from 6.5 to 8.5 Ra. However, very few samples have been collected to the west of the NWLSC-RR, and the question thus remains as to the origin and extent of this 3He-rich component in the northern Lau Basin. Recently, expedition SS2012 of the R/V Southern Surveyor collected submarine rock samples from the volcanic zones in the northwestern Lau Basin and North Fiji Basin. These samples have 3He/4He ratios ranging from 9.0 up to 14.6 Ra, above the range for normal MORBs. Of particular interest is the zone immediately to the west of the Rochambeau Rifts. Samples from the SE Futuna Volcanic Zone and from the Futuna Spreading Center have 3He/4He varying from 9.2 to 10.6 Ra. Farther west, samples from the West Cikobia Volcanic Zone due north of the Fiji Islands have helium with 9.3 up to 12.2 Ra. Still farther west in the Fiji Basin at 17S, 174E, samples dredged from the NE Fiji Triple

  10. Water masses of the northern part of the Iceland Basin in the late Pleistocene

    Science.gov (United States)

    Lukashina, N. P.

    2013-02-01

    A core of bottom sediments AMK-4438 with a length of 320 cm was taken in the North-Eastern part of the Iceland Basin from the depth of 2240 m. The continuous sampling (every 2 cm) made it possible to study the core using the principle of high-resolving paleoceanology. For the stratigraphic partition of the core, we applied the paleotemperature analysis by planktonic foraminifera and carbonate analysis; the distribution of the iceberg rafted debris (IRD) was studied. As a result, nine isotopic stages were distinguished. The change in the complexes of benthic foraminifera indicates that the present-day deepwater circulation in the North-Eastern part of the Iceland Basin had no analogs in earlier glacial periods, including the MIS 5 age. During almost 300 ka, there were relatively warm, rich in nutrients, and poor in oxygen water masses. The formation of the modern Northern-Eastern deep water in the Iceland Basin began in the Bolling-Allerod 14 ka B.P.

  11. Formation Laws of Inorganic Gas Pools in the Northern Jiangsu Basin

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    In the Northern Jiangsu basin there are high pure CO2 gas pools, low condensed oil-containing CO2 gas pools, high condensed oil-containing CO2 gas pools and He-containing natural gas pools, with the d 13Cco2 (PDB) values ranging from - 2.87to - 6.50 3He/4He 3.71×10- 6 to 6.42×10- 6, R/Ra 2.64 to 4.5, 40Ar/36Ar 705 to 734, belonging to typical mantle source inorganic gas pools which are related to young magmatic activity. The gas layers occur in two major reservoir-caprock systems, the terrestrial Meso-Cenozoic clastic rock system and the marine Meso-Palaeozoic carbonate rock-clastic rock system. Controlled by the difference in the scale of traps in the two reservoir-caprock systems, large and medium-scale inorganic gas pools are formed in the marine Meso-Palaeozoic Group and only small ones are formed in the terrestrial Meso-Cenozoic strata. Inorganic gas pools in this basin are distributed along the two deep lithospheric faults on the west and south boundaries of the basin. Gas pools are developed at the intersected part of the ENE-trending faults that control the half graben and the E-W tenso-shear faults, mainly distributed near the Es1, Ny1 and Ny2-Q basalt eruption centres.

  12. An isotope hydrochemical approach to understand fluoride release into groundwaters of the Datong Basin, Northern China.

    Science.gov (United States)

    Su, Chunli; Wang, Yanxin; Xie, Xianjun; Zhu, Yapeng

    2015-04-01

    The hydrogeochemical and isotopic investigations of high fluoride (up to 8.26 mg L(-1)) groundwater in the Datong Basin, Northern China were carried out in order to evaluate the geochemical controls on fluoride enrichment. The groundwater fluoride concentration tends to increase along with the regional groundwater flow path away from the basin margins, towards the central parts of the basin. Groundwater with high F concentrations has a distinctive major ion chemistry, being generally HCO3(-)-rich, Na-rich, Ca-poor, and having weak alkaline pH values (7.2 to 8.2) and Na-HCO3 waters. These data indicate that variations in the groundwater major ion chemistry and possibly pH, which are controlled by water-rock interaction processes in the aquifer, are important in mobilizing F. Positive correlations between fluoride with lithogenic sodium (LNa) and HCO3(-) in groundwater show that the high fluoride content and alkaline sodic characteristics of groundwater result from dissolution of fluorine-bearing minerals. The occurrence and behavior of fluorine in groundwater are mainly controlled by fluorite precipitation as a function of Ca(2+) concentration. A positive correlation between fluoride and δ(18)O, low F(-)/Cl(-) ratios, and the low tritium level in the fluoride-rich groundwater indicate the effects of long-term water-rock interactions and intensive evapotranspiration. PMID:25743227

  13. Tree-ring based reconstruction of spring hydroclimate variability in the Caucasus

    Science.gov (United States)

    Martin-Benito, Dario; Köse, Nesibe; Güner, Tuncay; Pederson, Neil

    2015-04-01

    The Caucasus region has been identified as one of the most prominent biodiversity hotspots in the world. The region experiences recurrent droughts that not only affect natural vegetation but also the agriculturally-based economies in the Caucasus. Across northeastern Turkey and the Caucasus region, instrumental records providing information on climate variability are generally scarce. Thus the magnitude and frequency of past droughts in this biologically important region are less known. Additionally, despite the increase of climate reconstructions in the past decades for many parts of Europe and Asia, relatively little work has been done to understand hydroclimate variability in the Caucasus region. Nearly all efforts in the region have focused on the Mediterranean part of Turkey and the Middle East region. We developed new tree-ring width chronologies from different elevation sites in northeastern Turkey with the goal to reconstruct annually-resolved estimates of temperature and hydroclimate across the region. We developed the first reconstruction of spring hydroclimate variability for the Caucasus and the southeastern Black Sea Region since 1750 CE using a nested procedure. Despite the high mean annual precipitation in the region, our reconstruction accounted for over 45% of May-June precipitation variability from 1925 to 2006. We observed no evidence of a decrease in spring precipitation during the recent decades. However, we do see a decrease in precipitation variability over the last 75 years with respect to previous periods that, at this time, does not appear to be related to sample replication. Although our reconstructed precipitation shows important similarities with previous work from Mediterranean and northern Turkey, we find distinct drought periods are also evident suggesting a wider range of climate dynamics in the broader Black Sea region than what has been previously identified. Distinct episodes of drought at the larger scales could have important

  14. Adaptation to changing water resources in the Ganges basin, northern India

    International Nuclear Information System (INIS)

    An ensemble of regional climate model (RCM) runs from the EU HighNoon project are used to project future air temperatures and precipitation on a 25 km grid for the Ganges basin in northern India, with a view to assessing impact of climate change on water resources and determining what multi-sector adaptation measures and policies might be adopted at different spatial scales. The RCM results suggest an increase in mean annual temperature, averaged over the Ganges basin, in the range 1-4 oC over the period from 2000 to 2050, using the SRES A1B forcing scenario. Projections of precipitation indicate that natural variability dominates the climate change signal and there is considerable uncertainty concerning change in regional annual mean precipitation by 2050. The RCMs do suggest an increase in annual mean precipitation in this region to 2050, but lack significant trend. Glaciers in headwater tributary basins of the Ganges appear to be continuing to decline but it is not clear whether meltwater runoff continues to increase. The predicted changes in precipitation and temperature will probably not lead to significant increase in water availability to 2050, but the timing of runoff from snowmelt will likely occur earlier in spring and summer. Water availability is subject to decadal variability, with much uncertainty in the contribution from climate change. Although global social-economic scenarios show trends to urbanization, locally these trends are less evident and in some districts rural population is increasing. Falling groundwater levels in the Ganges plain may prevent expansion of irrigated areas for food supply. Changes in socio-economic development in combination with projected changes in timing of runoff outside the monsoon period will make difficult choices for water managers. Because of the uncertainty in future water availability trends, decreasing vulnerability by augmenting resilience is the preferred way to adapt to climate change. Adaptive policies are

  15. Early life history of the northern pikeminnow in the lower Columbia River basin

    Science.gov (United States)

    Gadomski, D.M.; Barfoot, C.A.; Bayer, J.M.; Poe, T.P.

    2001-01-01

    The northern pikeminnow Ptychocheilus oregonensis is a large, native cyprinid in the Columbia River basin that has persisted in spite of substantial habitat alterations. During the months of June to September 1993-1996, we investigated the temporal and spatial patterns of northern pikeminnow spawning, along with describing larval drift and characterizing larval and early juvenile rearing habitats in the lower Columbia River (the John Day and Dalles reservoirs and the free-flowing section downstream of Bonneville Dam) as well as in the lower sections of two major tributaries (the John Day and Deschutes rivers). The density of newly emerged drifting larvae was higher in dam tailraces (a mean of 7.7 larvae/100 m3 in surface tows) than in the lower reservoirs (0.3 larvae/100 m3), indicating that tailraces were areas of more intense spawning. Density was particularly high in the Bonneville Dam tailrace (15.1 larvae/100 m3), perhaps because adult northern pikeminnow are abundant below Bonneville Dam and this is the first tailrace and suitable main-stem spawning habitat encountered during upriver spawning migrations. Spawning also occurred in both of the tributaries sampled but not in a backwater. Spawning in the Columbia River primarily took place during the month of June in 1993 and 1994, when the water temperature rose from 14??C to 18??C, but occurred about 2 weeks later in 1995 and 1996, possibly because of cooler June water temperature (14-15??C) in these years. The period of drift was brief (about 1-3 d), with larvae recruiting to shallow, low-velocity shorelines of main-channel and backwater areas to rear. Larvae reared in greatest densities at sites with fine sediment or sand substrates and moderate- to high-density vegetation (a mean density of 92.1 larvae/10 m3). The success of northern pikeminnow in the Columbia River basin may be partly attributable to their ability to locate adequate spawning and rearing conditions in a variety of main-stem and tributary

  16. PLIOCENE ALLUVIAL TO MARINE DEPOSITS OF THE VAL D’ORCIA BASIN (NORTHERN APENNINES, ITALY): SEQUENCE STRATIGRAPHY AND BASIN ANALYSIS

    OpenAIRE

    MASSIMILIANO GHINASSI

    2007-01-01

    Since the Middle-Late Miocene, the Apennine chain was characterised by the development of several basins. These basins have been alternatively explained as extensional post-orogenic basins or syn-orogenic compressional basins. In this framework, the Pliocene depositional history of the Val d'Orcia Basin (Southern Tuscany) is described, based on a sequence stratigraphic approach. Three depositional sequences (Vd3a-c) have been recognized. The Vd3a sequence records marine ingression and subsequ...

  17. Tectonic stratification and seismicity of the accretionary prism of the Azerbaijani part of Greater Caucasus

    Science.gov (United States)

    Alizade, Akif; Kangarli, Talat; Aliyev, Fuad

    2013-04-01

    The Greater Caucasus has formed during last stage of the tectogenesis in a geodynamic condition of the lateral compression, peculiar to the zone pseudo-subduction interaction zone between Northern and Southern Caucasian continental microplates. Its present day structure formed as a result of horizontal movements of the different phases and sub-phases of Alpine tectogenesis (from late Cimmerian to Valakhian), and is generally regarded as zone where, along Zangi deformation, the insular arc formations of the Northern edge of South Caucasian microplate thrust under the Meso-Cenozoic substantial complex contained in the facials of marginal sea of Greater Caucasus. The last, in its turn, has been pushed beneath the North-Caucasus continental margin of the Scythian plate along Main Caucasus Thrust fault. Data collected from the territory of Azerbaijan and its' sector of the Caspian area stands for pseudo-subduction interaction of microplates which resulted in the tectonic stratification of the continental slope of Alpine formations, marginal sea and insular arc into different scale plates of south vergent combined into napping complexes. In the orogeny's present structure, tectonically stratified Alpine substantial complex of the marginal sea of Greater Caucasus bordered by Main Caucasus and Zangi thrusts, is represented by allochthonous south vergent accretionary prism in the front of first deformation with its' root buried under the southern border of Scythian plate. Allocated beneath mentioned prism, the autochthonous bedding is presented by Meso-Cenosoic complex of the Northern flank of the South-Caucasian miroplate, which is in its' turn crushed and lensed into southward shifted tectonic microplates gently overlapping the northern flank of Kura flexure along Ganykh-Ayrichay-Alyat thrust. Data of real-time GPS measurement of regional geodynamics indicates that pseudo-subduction of South Caucasian microplate under the North Caucasian microplate still continues during

  18. Polyphase tectonic subsidence evolution of the Vienna Basin inferred from quantitative subsidence analysis of the northern and central parts

    Science.gov (United States)

    Lee, Eun Young; Wagreich, Michael

    2016-04-01

    The Vienna Basin is a tectonically complex Neogene basin situated at the Alpine-Carpathian transition. This study analyzes a detailed quantification of subsidence in the northern and central parts of the Vienna Basin to understand its tectonic subsidence evolution. About 200 wells were used to arrange stratigraphic setting, and wells reaching the pre-Neogene basement were analyzed for subsidence. To enhance the understanding of the regional subsidences, the wells were sorted into ten groups based on their position on major fault blocks. In the Early Miocene, subsidence was slow and along E-W to NE-SW trending axis, indicating the development of thrust-controlled piggyback basins. During the late Early Miocene data show abruptly increasing subsidence, making the initiation of the Vienna pull-apart basin system. From the Middle Miocene, the tectonic subsidence curves show regionally different patterns. The tectonic subsidence during the Middle Miocene varies laterally across the Vienna Basin, and the differential subsidence can be related to the changing tensional regime of weakening transtension and strengthening extension toward the late Middle Miocene. From the late Middle Miocene to the Late Miocene, the tectonic subsidence occurred dominantly along the regional active faults, and corresponds to the axis of E-W trending extension of the western parts of the Pannonian Basin system. In the Quaternary the Vienna Basin has been reactivated, and resulted in subsidence along the NE-SW trending Vienna Basin transfer fault system.

  19. A Very Large Population of Likely Buried Impact Basins in the Northern Lowlands of Mars Revealed by MOLA Data

    Science.gov (United States)

    Frey, H. V.; Shockey, K. M.; Frey, E. L.; Roark, J. H.; Sakimoto, S. E. H.

    2001-01-01

    High resolution Mars Orbiter Laser Altimeter (MOLA) data have revealed a large number of subdued quasi-circular depressions (QCDs) >50 km diameter in the northern lowlands of Mars which are generally not visible in Viking imagery and which may be buried ancient impact basins. Additional information is contained in the original extended abstract.

  20. Facies-controlled volcanic reservoirs of northern Songliao Basin, NE China

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    Volcanic rocks of the late Mesozoic are very important reservoirs for the commercial natural gases including hydrocarbon, carbon dioxide and rare gases in the northern Songliao Basin. The reservoir volcanic rocks include rhyolite,andesite, trachyte, basalt and tuff. Facies of the volcanic rocks can be classified into 5 categories and 15 special types.Porosity and permeability of the volcanic reservoirs are facies-controlled. Commercial reservoirs were commonly found among the following volcanic subfacies: volcanic neck (Ⅰ1), underground-explosive breccia (Ⅰ3), pyroclastic-bearing lava flow (Ⅱ3), upper effusive (Ⅲ3) and inner extrusive ones (Ⅳ1). The best volcanic reservoirs are generally evolved in the interbedded explosive and effusive volcanics. Rhyolites show in general better reservoir features than other types of rocks do.

  1. New GMP Models for Caucasus Region

    Science.gov (United States)

    Jorjiashvili, N.; Godoladze, T.; Tvaradze, N.; Tumanova, N.

    2014-12-01

    The Caucasus is a region of numerous natural hazards and ensuing disasters. Analysis of the losses due to past disasters indicates those most catastrophic in the region have historically been due to strong earthquakes. Estimation of expected ground motion is a fundamental earthquake hazard assessment. The most commonly used parameter for attenuation relation is peak ground acceleration because this parameter gives useful information for Seismic Hazard Assessment. Thus, many peak ground acceleration attenuation relations have been developed by different authors. However, a few attenuation relations were developed for Caucasus region: Ambraseys et al. (1996,2005) which were based on entire European region and they were not focused locally on Caucasus Region, Smit et.al.(2000) that was based on a small amount of acceleration data that really is not enough. Since 2003 construction of Georgian Digital Seismic Network has started with the help of number of International organizations, Projects and Private companies. In this study new GMP models are obtained based on new data from Georgian seismic network and also from neighboring countries. Estimation of models is obtained by classical, statistical way, regression analysis. Also site ground conditions are considered because the same earthquake recorded at the same distance may cause different damage according to ground conditions. Thus, this parameter is emphasized in the present study. Here it must be mentioned that in previous model which only one was done for Caucasus Region (Smit et. al., 2000) local conditions were not considered. Thus, it is an advantage of models from this study.

  2. Hydrogeochemistry of high-fluoride groundwater at Yuncheng Basin, northern China.

    Science.gov (United States)

    Li, Chengcheng; Gao, Xubo; Wang, Yanxin

    2015-03-01

    Hydrogeochemical and environmental isotope methods were integrated to delineate the spatial distribution and enrichment of fluoride in groundwater at Yuncheng Basin in northern China. One hundred groundwater samples and 10 Quaternary sediment samples were collected from the Basin. Over 69% of the shallow groundwater (with a F(-) concentration of up to 14.1mg/L), 44% of groundwater samples from the intermediate and 31% from the deep aquifers had F(-) concentrations above the WHO provisional drinking water guideline of 1.5mg/L. Groundwater with high F(-) concentrations displayed a distinctive major ion chemistry: Na-rich and Ca-poor with a high pH value and high HCO3(-) content. Hydrochemical diagrams and profiles and hydrogen and oxygen isotope compositions indicate that variations in the major ion chemistry and pH are controlled by mineral dissolution, cation exchange and evaporation in the aquifer systems, which are important for F(-) mobilization as well. Leakage of shallow groundwater and/or evaporite (gypsum and mirabilite) dissolution may be the major sources for F(-) in groundwater of the intermediate and deep aquifers. PMID:25478652

  3. Arsenic release by indigenous bacteria Bacillus cereus from aquifer sediments at Datong Basin, northern China

    Science.gov (United States)

    Xie, Zuoming; Wang, Yanxin; Duan, Mengyu; Xie, Xianjun; Su, Chunli

    2011-03-01

    Endemic arsenic poisoning due to long-term drinking of high arsenic groundwater has been reported in Datong Basin, northern China. To investigate the effects of microbial activities on arsenic mobilization in contaminated aquifers, Bacillus cereus ( B. cereus) isolated from high arsenic aquifer sediments of the basin was used in our microcosm experiments. The arsenic concentration in the treatment with both bacteria and sodium citrate or glucose had a rapid increase in the first 18 d, and then, it declined. Supplemented with bacteria only, the concentration could increase on the second day. By contrast, the arsenic concentration in the treatment supplemented with sodium citrate or glucose was kept very low. These results indicate that bacterial activities promoted the release of arsenic in the sediments. Bacterial activities also influenced other geochemical parameters of the aqueous phase, such as pH, Eh, and the concentrations of dissolved Fe, Mn, and Al that are important controls on arsenic release. The removal of Fe, Mn, and Al from sediment samples was observed with the presence of B. cereus. The effects of microbial activities on Fe, Mn, and Al release were nearly the same as those on As mobilization. The pH values of the treatments inoculated with bacteria were lower than those without bacteria, still at alkaline levels. With the decrease of Eh values in treatments inoculated with bacteria, the microcosms became more reducing and are thus favorable for arsenic release.

  4. Using Diverse Data Types to Calibrate a Watershed Model of the Trout Lake Basin, Northern Wisconsin

    Science.gov (United States)

    Hunt, R. J.; Feinstein, D. T.; Pint, C. D.; Anderson, M. P.

    2004-12-01

    As part of the USGS Water, Energy, and Biogeochemical Budgets project and NSF Long-Term Ecological Research work, a parameter estimation code was used to calibrate a deterministic groundwater flow model of the Trout Lake Basin in northern Wisconsin. Observations included traditional calibration targets (head, lake stage, and baseflow observations) as well as unconventional targets such as groundwater flows to and from lakes, depth of a lake plume, and time of travel. The unconventional data types were important for parameter estimation convergence and allowed the development of a more parameterized model. Independent estimates of groundwater inflow to lakes were most important for constraining lakebed leakance, and the depth of the lake plume was important for determining hydraulic conductivity and conceptual aquifer layering. The most important target, however, was a conventional regional baseflow target that was important for correctly distributing flow between sub-basins and the regional system. The use of parameter estimation: 1) facilitated the calibration process by providing a quantitative assessment of the model's ability to match disparate observed data types; and 2) provided a best fit for the particular model conceptualization. The model calibration required the use of a "universal" parameter estimation code in order to include all types of observations in the objective function. The methods described here help address issues of watershed complexity and non-uniqueness common to deterministic watershed models.

  5. Crustal Structure Improvement for the Caucasus Region

    Science.gov (United States)

    Tumanova, N.; Godoladze, T.; Gok, R.; Dreger, D. S.

    2012-12-01

    The Caucasus is a tectonically active and structurally complex region. The crustal and upper mantle velocities show great heterogeneity and the regional phases display significant variability in both amplitude and travel time. Existing regional velocity and attenuation models fail to capture the complexity of the region, and the extent of the variability is not well quantified. In the last eight years, a large number of digital stations, both broad-band and short-period have been installed in this region. The southern Caucasus countries (Armenia, Azerbaijan and Georgia) have a strongcollaboration to share the data from their national networks through onlinedata exchange. Each country has access to all the available waveform data for use it in scientific research. Utilizing the newly available digital data we have developed an improved seismic velocity model and crustal of the Caucasus. The data from national seismic networks of Georgia, Azerbaijan, and Armenia were analyzed and the velocity model was developed using joint inversion of teleseismic receiver functions and surface waves. We then calculated a forward waveform model of the seismic sources of the Caucasus, calibrating the existing velocity models, and improving the understanding of regional phase propagation in this complex region. Love and Rayleigh wave surface waves group and phase dispersion curves were derived from regional and teleseismic events. The stacked receiver functions and surface wave dispersion curves were jointly inverted to yield the absolute shear wave velocity to a depth of 100-120 km at each station. The depth of major discontinuities (sediment/basement, crust/mantle, and lithosphere/aesthenosphere) were inferred from the velocity/depth profiles at each station. In addition, we performed a local tomography study, based on data from several strong events recorded on temporal networks deployed throughout the southern Caucasus during the last few years ( Racha 2009. Javakheti 2010

  6. Land cover changes associated with recent energy development in the Williston Basin; Northern Great Plains, USA.

    Science.gov (United States)

    Preston, Todd M; Kim, Kevin

    2016-10-01

    The Williston Basin in the Northern Great Plains has experienced rapid energy development since 2000. To evaluate the land cover changes resulting from recent (2000-2015) development, the area and previous land cover of all well pads (pads) constructed during this time were determined, the amount of disturbed and reclaimed land adjacent to pads was estimated, land cover changes were analyzed over time for three different well types, and the effects from future development were predicted. The previous land cover of the 12,990ha converted to pads was predominately agricultural (49.5%) or prairie (47.4%) with lesser amounts of developed (2.3%), aquatic (0.5%), and forest (0.4%). Additionally, 12,121ha has likely been disturbed and reclaimed. The area required per gas well remained constant through time while the land required per oil well increased initially and then decreased as development first shifted from conventional to unconventional drilling and then to multi-bore pads. For non-oil-and-gas wells (i.e. stratigraphic test wells, water wells, and injection wells), the area per well increased through time likely due to increased produced water disposal requirements. Future land cover change is expected to be 2.7 times greater than recent development with much of the development occurring in five counties in the core Bakken development area. Direct land cover change and disturbance from recent and expected development are predicted to affect 0.4% of the landscape across the basin; however, in the core Bakken development area, 2.3% of the landscape will be affected including 2.1% of the remaining grassland. Although future development will result in significant land cover change, evolving industry practices and proactive siting decisions, such as development along energy corridors and placing pads in areas previously altered by human activity, have the potential to reduce the ecological effects of future energy development in the Williston Basin. PMID:27318516

  7. Source identification of fine-grained suspended sediment in the Kharaa River basin, northern Mongolia

    International Nuclear Information System (INIS)

    Fine sediment inputs into river systems can be a major source of nutrients and heavy metals and have a strong impact on water quality and ecosystem functions of rivers and lakes, including those in semiarid regions. However, little is known to date about the spatial distribution of sediment sources in most large scale river basins in Central Asia. Accordingly, a sediment source fingerprinting technique was used to assess the spatial sources of fine-grained (< 10 μm) sediment in the 15 000 km2 Kharaa River basin in northern Mongolia. Variation in geochemical composition (e.g. in Ti, Sn, Mo, Mn, As, Sr, B, U, Ca and Sb) was used for sediment source discrimination with geochemical composite fingerprints based on Genetic Algorithm (GA)-driven Discriminant Function Analysis, the Kruskal–Wallis H-test and Principal Component Analysis. All composite fingerprints yielded a satisfactory GOF (> 0.97) and were subsequently used for numerical mass balance modelling with uncertainty analysis. The contributions of the individual sub-catchment spatial sediment sources varied from 6.4% (the headwater sub-catchment of Sugnugur Gol) to 36.2% (the Kharaa II sub-catchment in the middle reaches of the study basin), generally showing higher contributions from the sub-catchments in the middle, rather than the upstream, portions of the study area. The importance of river bank erosion is shown to increase from upstream to midstream tributaries. The source tracing procedure provides results in reasonable accordance with previous findings in the study region and demonstrates the applicability and associated uncertainties of the approach for fine-grained sediment source investigation in large scale semi-arid catchments. - Highlights: • Applied statistical approach for selecting composite fingerprints in Mongolia. • Geochemical fingerprinting for the definition of source areas in semiarid catchment. • Test of applicability of sediment sourcing in large scale semi-arid catchments.

  8. Source identification of fine-grained suspended sediment in the Kharaa River basin, northern Mongolia

    Energy Technology Data Exchange (ETDEWEB)

    Theuring, Philipp [Department of Aquatic Ecosystem Analysis and Management — ASAM, Helmholtz Centre for Environmental Research — UFZ, Brückstrasse 3a, D-39114 Magdeburg (Germany); Collins, Adrian L. [Sustainable Soils and Grassland Systems Department, Rothamsted Research, North Wyke, Okehampton, Devon EX20 2SB (United Kingdom); Rode, Michael [Department of Aquatic Ecosystem Analysis and Management — ASAM, Helmholtz Centre for Environmental Research — UFZ, Brückstrasse 3a, D-39114 Magdeburg (Germany)

    2015-09-01

    Fine sediment inputs into river systems can be a major source of nutrients and heavy metals and have a strong impact on water quality and ecosystem functions of rivers and lakes, including those in semiarid regions. However, little is known to date about the spatial distribution of sediment sources in most large scale river basins in Central Asia. Accordingly, a sediment source fingerprinting technique was used to assess the spatial sources of fine-grained (< 10 μm) sediment in the 15 000 km{sup 2} Kharaa River basin in northern Mongolia. Variation in geochemical composition (e.g. in Ti, Sn, Mo, Mn, As, Sr, B, U, Ca and Sb) was used for sediment source discrimination with geochemical composite fingerprints based on Genetic Algorithm (GA)-driven Discriminant Function Analysis, the Kruskal–Wallis H-test and Principal Component Analysis. All composite fingerprints yielded a satisfactory GOF (> 0.97) and were subsequently used for numerical mass balance modelling with uncertainty analysis. The contributions of the individual sub-catchment spatial sediment sources varied from 6.4% (the headwater sub-catchment of Sugnugur Gol) to 36.2% (the Kharaa II sub-catchment in the middle reaches of the study basin), generally showing higher contributions from the sub-catchments in the middle, rather than the upstream, portions of the study area. The importance of river bank erosion is shown to increase from upstream to midstream tributaries. The source tracing procedure provides results in reasonable accordance with previous findings in the study region and demonstrates the applicability and associated uncertainties of the approach for fine-grained sediment source investigation in large scale semi-arid catchments. - Highlights: • Applied statistical approach for selecting composite fingerprints in Mongolia. • Geochemical fingerprinting for the definition of source areas in semiarid catchment. • Test of applicability of sediment sourcing in large scale semi-arid catchments

  9. Crustal structure beneath the Northern Transantarctic Mountains and Wilkes Subglacial Basin: Implications for tectonic origins

    Science.gov (United States)

    Hansen, Samantha E.; Kenyon, Lindsey M.; Graw, Jordan H.; Park, Yongcheol; Nyblade, Andrew A.

    2016-02-01

    The Transantarctic Mountains (TAMs) are the largest noncollisional mountain range on Earth. Their origin, as well as the origin of the Wilkes Subglacial Basin (WSB) along the inland side of the TAMs, has been widely debated, and a key constraint to distinguish between competing models is the underlying crustal structure. Previous investigations have examined this structure but have primarily focused on a small region of the central TAMs near Ross Island, providing little along-strike constraint. In this study, we use data from the new Transantarctic Mountains Northern Network and from five stations operated by the Korea Polar Research Institute to investigate the crustal structure beneath a previously unexplored portion of the TAMs. Using S wave receiver functions and Rayleigh wave phase velocities, crustal thickness and average crustal shear velocity (V>¯s) are resolved within ±4 km and ±0.1 km/s, respectively. The crust thickens from ~20 km near the Ross Sea coast to ~46 km beneath the northern TAMs, which is somewhat thicker than that imaged in previous studies beneath the central TAMs. The crust thins to ~41 km beneath the WSB. V>¯s ranges from ~3.1-3.9 km/s, with slower velocities near the coast. Our findings are consistent with a flexural origin for the TAMs and WSB, where these features result from broad flexure of the East Antarctic lithosphere and uplift along its western edge due to thermal conduction from hotter mantle beneath West Antarctica. Locally, thicker crust may explain the ~1 km of additional topography in the northern TAMs compared to the central TAMs.

  10. The eastern Black Sea-Caucasus region during the Cretaceous: New evidence to constrain its tectonic evolution

    Science.gov (United States)

    Sosson, Marc; Stephenson, Randell; Sheremet, Yevgeniya; Rolland, Yann; Adamia, Shota; Melkonian, Rafael; Kangarli, Talat; Yegorova, Tamara; Avagyan, Ara; Galoyan, Ghazar; Danelian, Taniel; Hässig, Marc; Meijers, Maud; Müller, Carla; Sahakyan, Lilit; Sadradze, Nino; Alania, Victor; Enukidze, Onice; Mosar, Jon

    2016-01-01

    We report new observations in the eastern Black Sea-Caucasus region that allow reconstructing the evolution of the Neotethys in the Cretaceous. At that time, the Neotethys oceanic plate was subducting northward below the continental Eurasia plate. Based on the analysis of the obducted ophiolites that crop out throughout Lesser Caucasus and East Anatolides, we show that a spreading center (AESA basin) existed within the Neotethys, between Middle Jurassic and Early Cretaceous. Later, the spreading center was carried into the subduction with the Neotethys plate. We argue that the subduction of the spreading center opened a slab window that allowed asthenospheric material to move upward, in effect thermally and mechanically weakening the otherwise strong Eurasia upper plate. The local weakness zone favored the opening of the Black Sea back-arc basins. Later, in the Late Cretaceous, the AESA basin obducted onto the Taurides-Anatolides-South Armenia Microplate (TASAM), which then collided with Eurasia along a single suture zone (AESA suture).

  11. Hydrothermal recrystallization of the Lower Ordovician dolomite and its significance to reservoir in northern Tarim Basin

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Discovered in S15 and some other wells, the Lower Ordovician in the northern Tarim Basin consists mainly of brown gray-dark gray very fine-fine crystalline dolomite, with a minor portion of locally light gray-white medium-coarse crystalline dolomite. Silicification can be observed in the medium-coarse dolomite, and some euhedral drusy quartz can also be found in pores and fractures of the dolomite. The homogenization temperature of the fluid inclusions in the medium-coarse dolomite is between 110 and 200°C with maximum between 140 and 190°C, and the salinity is between 10.7 and 18.5 wt.% NaCl Eq. The homogenization temperature and salinity of the fluid inclusions in the medium-coarse dolomite are similar to those in the drusy quartz. Compared with the very fine-fine dolomite, the medium-coarse phase contains relatively high Fe and Mn. The average concentration of FeO and MnO in the medium-coarse dolomite is 1.917% and 0.323%, respectively. The medium-coarse dolomite has a remarkable negative Eu anomaly, consistent with the REE pattern of the intermediate-felsic igneous rocks in the Tarim Basin. The oxygen isotopic composition of the medium-coarse dolomite is relatively lighter than that of the very fine-fine dolomite. The δ18OPDB values of the medium-coarse dolomite are between -10.35‰ and -7.31‰. The δ18OSMOW values of the fluid associated with the medium-coarse dolomite can be calculated according to homogenization temperature and oxygen isotope fractionation factor between dolomite and fluid, and the calculated values are between +4‰ and +10‰, consistent with those of the hydrothermal fluid. The medium-coarse dolomite has relatively high 87Sr/86Sr ratios as well, indi- cating an origin associated with intermediate-felsic igneous rock. The homogenization temperature, element composition, REE pattern, oxygen and strontium isotopes demonstrate that the medium-coarse dolomite is the result of recrystallization of very fine-fine dolomite under

  12. Low palaeoelevation of the northern Lhasa terrane during late Eocene: Fossil foraminifera and stable isotope evidence from the Gerze Basin

    Science.gov (United States)

    Wei, Yi; Zhang, Kexin; Garzione, Carmala N.; Xu, Yadong; Song, Bowen; Ji, Junliang

    2016-01-01

    The Lhasa terrane is a key region for understanding the paleoelevation of the southern Tibetan Plateau after India-Asia collision. The Gerze Basin, located in the northern part of the Lhasa terrane, is a shortening-related basin. We discovered Lagena laevis (Bandy) fossils in upper Eocene strata of the Gerze Basin. This type of foraminifera is associated with lagoon and estuarine environments, indicating that the northern part of the Lhasa terrane was near sea level during the late Eocene. We speculate that these foraminifera were transported inland by storm surges to low elevation freshwater lakes during times of marine transgressions. This inference is consistent with the relatively positive δ18O values in carbonate from the same deposits that indicate low palaeoelevations close to sea level. Considering the palaeoelevation results from the nearby Oligocene basins at a similar latitude and the volcanic history of the Lhasa terrane, we infer that large-magnitude surface uplift of the northern Lhasa terrane occurred between late Eocene and late Oligocene time. PMID:27272610

  13. Radionuclide levels in fish from Lake Athabasca February 1993. Northern River Basins Study project report no.26

    International Nuclear Information System (INIS)

    The Northern River Basins Study was initiated through the 'Canada-Alberta-Northwest Territories Agreement Respecting the Peace-Athabasca-Slave River Basin Study, Phase II - Technical Studies' which was signed September 27, 1991. The purpose of the study is to understand and characterize the cumulative effects of development on the water and aquatic environment of the Study Area by coordinating with existing programs and undertaking appropriate new technical studies. This publication reports the method and findings of particular work conducted as part of the Northern River Basins Study. As such, the work was governed by a specific terms of reference and is expected to contribute information about the Study Area within the context of the overall study as described by the Study Final Report. This report has been reviewed by the Study Science Advisory Committee in regards to scientific content and has been approved by the Study Board of Directors for public release. It is explicit in the objectives of the Study to report the results of technical work regularly to the public. This objective is served by distributing project reports to an extensive network of libraries, agencies, organizations and interested individuals and by granting universal permission to reproduce the material. This report contains referenced data obtained from external to the Northern River Basins Study. Individuals interested in using external data must obtain permission to do so from the donor agency. (author). 47 refs., 9 tabs., 2 figs

  14. Seismic sequence and depositional evolution of slope basins in mid-northern margin of the South China Sea

    Institute of Scientific and Technical Information of China (English)

    LI Mingbi; JIN Xianglong; LI Jiabiao; DING Weiwei; FANG Yinxia; LIU Jianhua; TANG Yong

    2011-01-01

    As one of the biggest marginal seas in the western Pacific margin,the South China Sea (SCS) experienced continental riffing and seafloor spreading during the Cenozoic.The northern continental margin of the SCS is classified as a passive continental margin.However,its depositional and structural evolution remains controversial,especially in the deep slope area.The lack of data hindered the correlation between continental shelf and oceanic basin,and prevented the establishment of sequence stratigraphic frame of the whole margin.The slope basins in the mid-northern margin of SCS developed in the Cenozoic;the sediments and basin infill recorded the geological history of the continental margin and the SCS spreading.Using multi-channel seismic dataset acquired in three survey cruises during 1987 to 2004,combined with the data of ODP Leg 184 core and industrial wells,we carried out the sequence stratigraphic division and correlation of the Cenozoic in the middle-northern margin of SCS with seismic profiles and sedimentary facies.We interpreted the seismic reflection properties including continuity,amplitude,frequency,reflection terminals,and 15 sequence boundaries of the Cenozoic in the study area,and correlated the well data in geological age.The depositional environment changed from river and lake,shallow bay to open-deep sea,in correspondence to tectonic events of syn-rifting,early drifting,and late drifting stages of basin evolution.

  15. Low palaeoelevation of the northern Lhasa terrane during late Eocene: Fossil foraminifera and stable isotope evidence from the Gerze Basin

    Science.gov (United States)

    Wei, Yi; Zhang, Kexin; Garzione, Carmala N.; Xu, Yadong; Song, Bowen; Ji, Junliang

    2016-06-01

    The Lhasa terrane is a key region for understanding the paleoelevation of the southern Tibetan Plateau after India-Asia collision. The Gerze Basin, located in the northern part of the Lhasa terrane, is a shortening-related basin. We discovered Lagena laevis (Bandy) fossils in upper Eocene strata of the Gerze Basin. This type of foraminifera is associated with lagoon and estuarine environments, indicating that the northern part of the Lhasa terrane was near sea level during the late Eocene. We speculate that these foraminifera were transported inland by storm surges to low elevation freshwater lakes during times of marine transgressions. This inference is consistent with the relatively positive δ18O values in carbonate from the same deposits that indicate low palaeoelevations close to sea level. Considering the palaeoelevation results from the nearby Oligocene basins at a similar latitude and the volcanic history of the Lhasa terrane, we infer that large-magnitude surface uplift of the northern Lhasa terrane occurred between late Eocene and late Oligocene time.

  16. Oligocene-Miocene deformational and depositional history of the Andean hinterland basin in the northern Altiplano plateau, southern Peru

    Science.gov (United States)

    Perez, Nicholas D.; Horton, Brian K.

    2014-09-01

    Cenozoic basin fill of the northern Altiplano plateau records the tectonic development of the flanking Western Cordillera magmatic arc and Eastern Cordillera fold-thrust belt. The Ayaviri hinterland basin of southern Peru contains a ~2300 m thick succession of fluvial sandstones and overbank siltstones (upper Oligocene Puno Group and lower Miocene lower Tinajani Formation) capped by ~400 m of alluvial fan conglomerates (middle Miocene upper Tinajani Formation). New U-Pb zircon chronostratigraphic constraints from ~30 to 15 Ma yield sediment accumulation rates of 110-660 m/Myr. Newly dated growth strata highlight the genetic role played by thrust displacement in basin evolution. A several phase accumulation history derived from chronostratigraphic, provenance, and structural data reveals Oligocene basin filling by fluvial sand and mud that changes provenance from Western Cordillera Mesozoic-Cenozoic volcanic rocks to Paleozoic-Mesozoic Eastern Cordillera sedimentary rocks driven by deformation along the southwest directed, northeastern basin margin Ayaviri thrust at 28-26 Ma. Continued early Miocene fluvial deposition was sourced solely from the Eastern Cordillera. An abrupt middle Miocene shift to coarse alluvial fan deposition sourced from the Western Cordillera was driven by out-of-sequence deformation along the northeast directed, southwestern basin margin Pasani thrust at 18-16 Ma. This northern Altiplano out-of-sequence deformation was coincident with increased Eastern and Western Cordillera exhumation and thrusting and may be symptomatic of changes in critical wedge dynamics. The overall record of basin sedimentation and syndepositional fold-thrust deformation emphasizes the role of regional shortening in governing crustal thickening and basin evolution in the central Andes during the Oligocene to Miocene.

  17. New seismo-stratigraphic data of the Volturno Basin (northern Campania, Tyrrhenian margin, southern Italy: implications for tectono-stratigraphy of the Campania and Latium sedimentary basins

    Directory of Open Access Journals (Sweden)

    Ennio Marsella

    2011-07-01

    Full Text Available A geological section of the Volturno Basin (northern Campania, continental margin, Italy has been constructed based on new multi-channel seismic data, to show the stratigraphic relationships between the filling in the Quaternary basin and the Meso-Cenozoic acoustic basement. The new seismic sections presented here outline the underlying structures of the basin and their relationships to the filling in the Quaternary basin. Deep exploration wells in Campania and Latium on the Tyrrhenian margin have gathered litho-stratigraphic and commercial multi-channel seismic data that can be used for better integration of the geological data for the area under study. The trending of the seismic units is controlled by the Massico Structural High, which forms the boundary of the Volturno Basin towards the north-west. This produces a geometry that is characteristic of a fan complex, with NE-SW trending. This qualitative calibration of the seismic sequences that fill the sedimentary basin was carried out through the litho-stratigraphic data of the «Castelvolturno 2» well, which highlights the pyroclastic layers and conglomeratic strata of the lagoon and delta environments as they evolve upwards towards marine sediments. Seismo-stratigraphic analysis shows the complex depositional geometries of the filling in the Volturno Basin, which overlie the Meso-Cenozoic carbonatic basement and the related flysch deposits. Coupled with regional geological evidence, the data interpretation here suggests that the Volturno Basin represents a half-graben structure that is characterized by down-thrown blocks along normal faults.

  18. ITCZ-monsoonal association during the last glacial (Cariaco Basin, Northern Arabian Sea)

    Science.gov (United States)

    Deplazes, G.; Haug, G. H.; Lueckge, A.

    2010-12-01

    The anoxic Cariaco Basin on the northern shelf of Venezuela preserves detailed records of past tropical climate variability. The sediment formation in this basin is controlled by the migration of the Atlantic Intertropical Convergence Zone (ITCZ) and the corresponding rain belt and trade winds. In the oxygen minimum zone off Pakistan in the northeastern Arabian Sea sediment archives of low-latitude monsoonal climate are preserved. In this study sediments from the two settings that cover the last 80,- to 110,000 years were analysed. Sediment color analysis resulted in reflectance records with a down to annual resolution. An age model was set up by correlation of these records to the δ18O record of Greenland ice (NGRIP). The major element chemistry of the sediments was analysed with X-ray fluorescence scanning. The new high resolution proxy records indicate an unbroken association between warm climate conditions over Greenland, a northerly position of the Atlantic Intertropical Convergence Zone, and a strong Indian summer monsoon since the last glacial. The tight coupling is explained by a dominant role of the North Atlantic that is communicated largely through the atmosphere. New insights of dynamical mechanisms arise from comparison of individual Dansgaard-Oeschger events. The tropical records and the Greenland δ18O record show both an abrupt change at the beginning of an interstadial. The δ18O of Greenland ice peaks early in the interstadials and then decreases more or less constantly toward stadial values. However, the tropical records have a tendency to maintain dark interstadial color on a similar level over several centuries. The following centennial-scale lightening toward the next stadial appears to be delayed compared to the δ18O ice record. This “resistance” of the tropics to the interstadial-stadial transitions suggests a threshold response of the tropics to North Atlantic cooling.

  19. Development of Overpressure in the Tertiary Damintun Depression, Liaohe Basin, Northern China

    Institute of Scientific and Technical Information of China (English)

    YE Jiaren; HAO Fang; CHEN Jianyu

    2003-01-01

    The Damintun depression is one of the four depressions in the Liaohe basin in northern China, and is a rift basin developed in the Paleogene. This paper discusses in detail the characteristics of pressure and fluid potential of the Damintun depression based on a synthesis of the data from boreholes, well tests and seismic surveys. Data from sonic logs, well tests and seismic velocity measurements are used to study the pressure characteristics of the areas. From the sonic log data, shales can be characterized as normally pressured, slightly overpressured or highly overpressured; from the well test data, the pressure-depth gradient in oil-producing intervals implies hydrostatic pressure in general. Most seismic profiles in the Damintun depression are of sufficiently high quality for seismic velocities to be measured. The fluid pressures, excess pressures and pressure coefficients in 47 representative seismic profiles are predicted using formula calculation methods, and further transformed to fluid potentials. The resultant pressure profiles show normal pressure, moderate overpressure and intense overpressure increasing with depth. The pressure evolution can be divided into three stages as initial generation, partial dissipation and re-accumulation. Fluid potential is the principal factor controlling hydrocarbon migration in a reservoir. Its distribution varies with depth; above the T4 interface a gravity-flow dominates, whereas beneath it a compaction flow dominates. The development of overpressure in the Damintun depression has a crucial influence on the distribution of fluid potentials, which agrees with that of overpressure in general. The results of the fluid potential analysis indicate that the areas of Dongshenpu-Xinglongpu and the southwestern part of the depression are most favorable for hydrocarbon migration and accumulation.

  20. Effects of precipitation and potential evaporation on actual evapotranspiration over the Laohahe basin, northern China

    Science.gov (United States)

    Liu, Y.; Ren, L.; Yang, X.; Ma, M.; Yuan, F.; Jiang, S.

    2015-06-01

    Problems associated with water scarcity are facing new challenges under the climate change. As one of main consumptions in water cycle on the Earth, evapotranspiration plays a crucial role in regional water budget. In this paper, we employ two methods, i.e. hydrological sensitivity analysis and hydrological model simulation, to investigate the effect of climate variability and climatic change on actual evapotranspiration (Ea) within the Laohahe basin during 1964-2009. Calibrations of the two methods are firstly conducted during the baseline period (1964-1979), then with the two benchmarked models, simulations in climatic change duration (1980-2009) are further conducted and quantitative assessments on climatic change-induced variation of Ea are analysed accordingly. The results show that affected by combined impacts of decreased precipitation and potential evapotranspiration, variation of annual Ea in most sub-catchments suffer a downward trend during 1980-2009, with a higher descending rate in northern catchments. At decadal scale, Ea shows significant oscillation in accordance with precipitation patterns. Northern catchments generally suffer more decadal Ea changes than southern catchments, implying the impact of climatic change on decadal Ea is more intense in semi-arid areas than that in semi-humid regions. For whole changed durations, a general 0-20 mm reduction of Ea is found in most parts of studied region. For this water-limited region, Ea shows higher sensitivity to precipitation than to potential evaporation, which confirms the significant role of precipitation in controlling Ea patterns, whereas the impact of potential evapotranspiration variation would be negligible.

  1. High resolution sequence stratigraphic analysis of the Late Miocene Abu Madi Formation, Northern Nile Delta Basin

    Science.gov (United States)

    Sarhan, Mohammad Abdelfattah

    2015-12-01

    Abu Madi Formation represents the Upper Miocene Messinian age in the Nile Delta basin. It consists mainly of sandstones and shale intercalations and because of its richness in hydrocarbon, it has been subdivided by the petroleum companies into Level-I, Level-II and Level-III, respectively according to the increase in the sandstone to the shale ratio. The Miocene cycle in the northern subsurface section of the Nile Delta encompasses three main formations namely from the base; Sidi Salim formation, Qawasim Formation and Abu Madi Formation at the top. The high resolution sequence stratigraphic analysis, using gamma ray responses, has been done for the Late Miocene formation in the northern part of the Nile delta subsurface section. For this purpose, the gamma-ray logs of ten deep wells, arranged in four cross-sections trending in almost north-south direction throughout the northern region of the Nile Delta, were analyzed. The analysis has revealed that the interpreted 4th order depositional cycles within Abu Madi Formation display great variations in both number and gamma ray responses in each investigated well, and cannot be traced laterally, even in the nearest well. These variations in the interpreted 4th order depositional sequences could be attributed to the presence of normal faults buried in the inter-area laying between the investigated wells. This finding matches with the conclusion of that Abu Madi Formation represents a part of the Upper Miocene Nile Delta syn-rift megasequence, developed during the Upper Miocene rift phase of the Red Sea - Gulf of Suez province in Egypt. Accordingly, in the sequence stratigraphic approach, the depositional history of Abu Madi Formation was strongly overprinted by the tectonic controls rather than the relative sea-level changes which are assumed to be of a secondary influence. Regarding the hydrocarbon aspects of the Abu Madi Formation, the present work recommends to direct the drilling efforts into the stratigraphic traps

  2. Peat accumulation in drained thermokarst lake basins in continuous, ice-rich permafrost, northern Seward Peninsula, Alaska

    Science.gov (United States)

    Jones, Miriam C.; Grosse, Guido; Jones, Benjamin M.; Anthony, Katey Walter

    2012-01-01

    Thermokarst lakes and peat-accumulating drained lake basins cover a substantial portion of Arctic lowland landscapes, yet the role of thermokarst lake drainage and ensuing peat formation in landscape-scale carbon (C) budgets remains understudied. Here we use measurements of terrestrial peat thickness, bulk density, organic matter content, and basal radiocarbon age from permafrost cores, soil pits, and exposures in vegetated, drained lake basins to characterize regional lake drainage chronology, C accumulation rates, and the role of thermokarst-lake cycling in carbon dynamics throughout the Holocene on the northern Seward Peninsula, Alaska. Most detectable lake drainage events occurred within the last 4,000 years with the highest drainage frequency during the medieval climate anomaly. Peat accumulation rates were highest in young (50–500 years) drained lake basins (35.2 g C m−2 yr−1) and decreased exponentially with time since drainage to 9 g C m−2 yr−1 in the oldest basins. Spatial analyses of terrestrial peat depth, basal peat radiocarbon ages, basin geomorphology, and satellite-derived land surface properties (Normalized Difference Vegetation Index (NDVI); Minimum Noise Fraction (MNF)) from Landsat satellite data revealed significant relationships between peat thickness and mean basin NDVI or MNF. By upscaling observed relationships, we infer that drained thermokarst lake basins, covering 391 km2 (76%) of the 515 km2 study region, store 6.4–6.6 Tg organic C in drained lake basin terrestrial peat. Peat accumulation in drained lake basins likely serves to offset greenhouse gas release from thermokarst-impacted landscapes and should be incorporated in landscape-scale C budgets.

  3. Determination of faults parameters controlling the Petroleum Systems Elements in the northern North Sea by using 3D basin Modelling

    OpenAIRE

    Andriamihaja, Spariharijaona

    2011-01-01

    3D basin modelling of the northern North Sea region covering 4886km2 is performed in order to understand the petroleum system elements within the area. The approach used to obtain the most likely model is to analyze and determine quantitatively the faults properties controlling the hydrocarbons accumulations in the Gullfaks, Visund, Kvitebjørn, and Huldra fields. This approach is made by varying the faults properties defined by shale gauge ratio until the reserves in place in the four fields ...

  4. Growth Normal Faulting at the Western Edge of the Metropolitan Taipei Basin since the Last Glacial Maximum, Northern Taiwan

    OpenAIRE

    Chih-Tung Chen; Jian-Cheng Lee; Yu-Chang Chan; and Chia-Yu Lu

    2010-01-01

    Growth strata analysis is an useful tool in understanding kinematics and the evolution of active faults as well as the close relationship between sedimentation and tectonics. Here we present the Shanchiao Fault as a case study which is an active normal fault responsible for the formation of the 700-m-thick late Quaternary deposits in Taipei Basin at the northern tip of the Taiwan mountain belt. We compiled a sedimentary record, particularly the depositional facies and their dated ages, at thr...

  5. Analysis of geological characteristics of uranium mineralization of Na Linggou in Husiliang located in the northern of Ordos basin

    International Nuclear Information System (INIS)

    In this paper, rock facies, the development of interlayer oxidation zone and the control factors and characteristics of uranium mineralization in northern Ordos basin in terms of beam areas call Adams Ridge sulcus satisfied lots Zhiluo uranium mineralization characteristics do lower concluded that the location uranium mineralization controlled by the interlayer oxidation zone of uranium deposits located in the developed parts of the faults. (author)

  6. Trace fossils associated to the end-Messinian unconformity in the northern border of the Bajo Segura Basin (SE Spain)

    OpenAIRE

    Caracuel, Jesús Esteban; Corbí, Hugo; Estévez, Antonio; Giannetti, Alice; Monaco, Paolo; Pina, José Antonio; Soria, Jesús M.; Tent Manclús, José Enrique; Yébenes, Alfonso

    2009-01-01

    A detailed analysis of the Upper Messinian-Lower Pliocene at the northern border of the Bajo Segura Basin (BSB) has been carried out. Trace fossils of firm- and rockground were collected, aiding in the recognition of three ichnofacies: Glossifungites (types A and B), Entobia and Gnathichnus. The ichnological data provide evidence that the Pliocene flooding of the BSB, after the Messinian Salinity Crisis, was developed in two pulses. In the first one, the ingression penetrated only along the p...

  7. PLIOCENE ALLUVIAL TO MARINE DEPOSITS OF THE VAL D’ORCIA BASIN (NORTHERN APENNINES, ITALY: SEQUENCE STRATIGRAPHY AND BASIN ANALYSIS

    Directory of Open Access Journals (Sweden)

    MASSIMILIANO GHINASSI

    2007-11-01

    Full Text Available Since the Middle-Late Miocene, the Apennine chain was characterised by the development of several basins. These basins have been alternatively explained as extensional post-orogenic basins or syn-orogenic compressional basins. In this framework, the Pliocene depositional history of the Val d'Orcia Basin (Southern Tuscany is described, based on a sequence stratigraphic approach. Three depositional sequences (Vd3a-c have been recognized. The Vd3a sequence records marine ingression and subsequent relative sea-level highstand in a narrow W-E trending depression. Subsequent relative sea-level fluctuations led to a progressive basin widening and deposition of Vd3b and Vd3c sequences. Basin scale sedimentation was mainly controlled by relative sea-level changes, although accumulation of bioclastic deposits of the Vd3c sequence could have been influenced by climatic factors. Based on its wide bowl-shaped geometry, the Pliocene Val d'Orcia Basin has been interpreted as an inherited depression. This depression is thought to be originated by erosion at the Late Miocene-Early Pliocene transition. 

  8. Calculated Porosity of Volcanic Reservoir in Wangjiatun of the Northern Songliao Basin, NE China

    Institute of Scientific and Technical Information of China (English)

    Xuanlong Shan; Chuanbiao Wa; Rihui Cheng; Wanzhu Liu

    2003-01-01

    In Wangjiatun area of the Northern Songliao Basin, reservoir space can be divided into three types: primary pore, secondary pore and fissure according to their origins,which can be subdivided into eight subtypes: macro-vesicule,shrank primary vesicule, alteration pore, groundmass corrosive pore, normal structural crack, corrosive structural crack,filled structural crack and groundmass shrank crack according to texture and origin of the pore space. It has characteristic of double pore medium. Volcanic porosities of small diameter samples (with diameter of ca. 2.5 cm) and large diameter samples (with diameter of ca. 21.5 cm) were tested in accordance with the characteristic of volcanic reservoir space. Volcanic porosities for small diameter samples correspond with matrix porosities and those of large diameter samples correspond with total porosities including matrix and fractured porosities. Models of the calculated porosity by acoustic wave or density of volcanic reservoir are established in view of those measured data. Comparison of calculated and measuredporosities shows that precision of calculated porosities is lower for rhyolite and tuffites, and higher for basaltand andesite.Relative errors of calculated porosities by model of large diameter samples are lower than those of small diameter samples, i. e. precision of the former is higher than that of the later.

  9. Cross-fault pressure depletion, Zechstein carbonate reservoir, Weser-Ems area, Northern German Gas Basin

    Energy Technology Data Exchange (ETDEWEB)

    Corona, F.V.; Brauckmann, F.; Beckmann, H.; Gobi, A.; Grassmann, S.; Neble, J.; Roettgen, K. [ExxonMobil Production Deutschland GmbH (EMPG), Hannover (Germany)

    2013-08-01

    A cross-fault pressure depletion study in Upper Permian Zechstein Ca2 carbonate reservoir was undertaken in the Weser-Ems area of the Northern German Gas Basin. The primary objectives are to develop a practical workflow to define cross-fault pressures scenarios for Zechstein Ca2 reservoir drillwells, to determine the key factors of cross-fault pressure behavior in this platform carbonate reservoir, and to translate the observed cross-fault pressure depletion to fault transmissibility for reservoir simulation models. Analysis of Zechstein Ca2 cross-fault pressures indicates that most Zechstein-cutting faults appear to act as fluid-flow baffles with some local occurrences of fault seal. Moreover, there appears to be distinct cross-fault baffling or pressure depletion trends that may be related to the extent of the separating fault or fault system, degree of reservoir flow-path tortuosity, and quality of reservoir juxtaposition. Based on the above observations, a three-part workflow was developed consisting of (1) careful interpretation and mapping of faults and fault networks, (2) analysis of reservoir juxtaposition and reservoir juxtaposition quality, and (3) application of the observed cross-fault pressure depletion trends. This approach is field-analog based, is practical, and is being used currently to provide reliable and supportable pressure prediction scenarios for subsequent Zechstein fault-bounded drill-well opportunities.

  10. Biostratigraphy, sedimentology and paleoenvironments of the northern Danube Basin: Ratkovce 1 well case study

    Directory of Open Access Journals (Sweden)

    Rybár Samuel

    2015-02-01

    Full Text Available The Ratkovce 1 well, drilled in the Blatné depocenter of the northern Danube Basin penetrated the Miocene sedimentary record with a total thickness of 2000 m. Biostratigraphically, the NN4, NN5 and NN6 Zones of calcareous nannoplankton were documented; CPN7 and CPN8 foraminifer Zones (N9, 10, 11 of the global foraminiferal zonation; and MMi4a; MMi5 and MMi6 of the Mediterranean foraminiferal zonation were recognized. Sedimentology was based on description of well core material, and together with SP and RT logs, used to characterize paleoenvironmental conditions of the deposition. Five sedimentary facies were reconstructed: (1 fan-delta to onshore environment which developed during the Lower Badenian; (2 followed by the Lower Badenian proximal slope gravity currents sediments; (3 distal slope turbidites were deposited in the Lower and Upper Badenian; (4 at the very end of the Upper Badenian and during the Sarmatian a coastal plain of normal marine to brackish environment developed; (5 sedimentation finished with the Pannonian-Pliocene shallow lacustrine to alluvial plain deposits. The provenance analysis records that the sediment of the well-cores was derived from crystalline basement granitoides and gneisses and from the Permian to Lower Cretaceous sedimentary cover and nappe units of the Western Carpathians and the Eastern Alps. Moreover, the Lower Badenian volcanism was an important source of sediments in the lower part of the sequence.

  11. Strategic groundwater resources in the Tagliamento River basin (northern Italy): hydrogeological investigation integrated with geophysical exploration

    Science.gov (United States)

    Rapti-Caputo, Dimitra; Bratus, Antonio; Santarato, Giovanni

    2009-09-01

    The western sector of the Tagliamento River basin (Friuli Venezia-Giulia Region; northern Italy) is characterized by important water resources, both superficial and underground. In particular, in the Quaternary deposits of the plain, up to a depth of 500 m, six artesian aquifer systems exist. A large amount of lithological, geomorphological, and hydrogeological data is presented, allowing for definition of (a) the principal aquifer system of the area to a depth of about 500 m; (b) geometrical characteristics of the aquifers (thickness, lateral extension, etc); (c) the hydraulic parameters (hydraulic conductivity, transmissivity); (d) chemico-physical characteristics of the water; and (e) vulnerability to pollution of the aquifer systems. In a test area, where many boreholes were drilled for fresh water supply, the conceptual hydrogeological model was integrated by a detailed and repeated three-dimensional (3D) resistivity survey using combined electrical resistivity tomography (ERT) and time-domain electromagnetic (TDEM) soundings. ERT investigation was mainly used to get detailed information about geometry and porosity of the overburden and to calibrate the shallowest TDEM information.

  12. Digital resource modeling of the northern and central Appalachian Basin coal regions: Top producing coals

    Energy Technology Data Exchange (ETDEWEB)

    Ruppert, L.; Tewalt, S.; Bragg, L.; Wallack, R.; Jenkins, J.; Tully, J. [Geological Survey, Reston, VA (United States)

    1998-12-31

    The US Geological Survey is currently conducting a coal resource assessment of the coal beds and zones that are expected to provide the bulk of the Nation`s coal resources for the next few decades. In partnership with the state geologic surveys of Kentucky, Tennessee, West Virginia, Virginia, Pennsylvania, Ohio, and Maryland, six coal beds will be digitally assessed in the northern and central Appalachian Basin coal region. In ascending stratigraphic order, the beds which range from the Lower Pennsylvanian Pocahontas Formation to the Upper Pennsylvanian Monongahela Group are the Pocahontas No. 3, Pond Creek, Fire Clay, Lower Kittanning, Upper Freeport, and Pittsburgh coals. Comprehensive stratigraphic and geochemical databases have been developed for the coal beds. Maps that show the extent and mined areas of the beds, structure contour, isopach, and overburden thickness have been compiled for the Pittsburgh coal bed and are in preparation for the other coal beds. The resource model for the Pittsburgh coal bed indicates that of the original 33.6 billion short tons (30.5 billion tonnes) of Pittsburgh coal, approximately 15.9 billion short tons (14.4 billion tonnes) remain. The remaining coal is, however, higher in ash and sulfur, and generally thinner and under thicker overburden cover.

  13. New palynological data from Karoo sediments, Mana Pools basin, northern Zimbabwe

    Science.gov (United States)

    d'Engelbronner, E. R.

    1996-07-01

    The palynological associations of 16 Karoo samples, collected in the Mana Pools basin, Northern Zimbabwe, were studied, and four zonal assemblages can be recognized. Assemblage I (Kondo Pools Formation) is dominated by monosaccate pollen grains and diverse alete bisaccate pollen grains occur frequently. Important but rare marker genera include Limitisporites, Vittatina and Weylandites. These indicate a middle to late Early Permian age (e.g. Late Sakmarian to Early Artinskian). The palynological assemblage, derived from the Massive Sandstone Member, Angwa Sandstone Formation, is characterized by a small number of smooth and apiculate spores, but is lacking any age significant marker taxa. Assemblages II and III, both from the Alternations Member (Angwa Sandstone Formation), and Assemblage IV (Pebbly Arkose Formation) are dominated by alete bisaccate and multitaeniate pollen grains. The rare occurrence of Vittatina, Weylandites lucifer and Guttulapollenites hannonicus indicates a Late Permian to Early Triassic age for Assemblage II. Based on sedimentological data and literature, a preliminary age of Early Triassic (Induan) can be given. A range from latest Fassanian (Ladinian) to Lacian (Norian) for Assemblage III is indicated by the occurrence of Asseretospora gyrata, Cadargasporites senectus, Eucommiidites, Infernopollenites, Minutosaccus crenulatus, Retisulcites perforatus and Samaropollenites speciosus. Small amounts of Asseretospora gyrata, Cadargasporites senectus, Cycadopites, Microcachryidites and Minutosaccus crenulatus indicate a slightly larger age range for Assemblage IV (e.g. Carnien to Rhaetian).

  14. Geology and coal-bed methane resources of the northern San Juan Basin, Colorado and New Mexico

    International Nuclear Information System (INIS)

    This guidebook is the first of its kind: A focused look at coal-bed methane in a large Rocky Mountain Laramide basin. The papers in this volume cover every aspect of coal-bed methane in the San Juan Basin, including: The geology, environments of deposition, and geometry of the coal beds that contain the resource; the origin and migration history of the gas; basin-wide resource estimates; the engineering aspects of getting the gas out of the ground; the marketing and economics of producing coal-bed methane in the San Juan Basin; the legal ownership of the gas; state regulations governing well spacing and field rules; disposal of produced water; and land and mineral ownership patterns in the northern part of the basin. Also included are detailed papers on all of the major coal-bed methane fields in the basin, and in a paper on the history of Fruitland gas production, a discussion of most of the not-so-major fields. A small section of the book deals with geophysical methods, as yet still experimental, for surface detection of underground hydrocarbon resources. Individual papers have been processed separately for inclusion on the data base

  15. Precipitation thresholds for triggering floods in Corgo hydrographic basin (Northern Portugal)

    Science.gov (United States)

    Santos, Monica; Fragoso, Marcelo

    2016-04-01

    The precipitation is a major cause of natural hazards and is therefore related to the flood events (Borga et al., 2011; Gaál et al., 2014; Wilhelmi & Morss, 2013). The severity of a precipitation event and their potential damage is dependent on the total amount of rain but also on the intensity and duration event (Gaál et al., 2014). In this work, it was established thresholds based on critical combinations: amount / duration of flood events with daily rainfall data for Corgo hydrographic basin, in northern Portugal. In Corgo basin are recorded 31 floods events between 1865 and 2011 (Santos et al., 2015; Zêzere et al., 2014). We determined the minimum, maximum and pre-warning thresholds that define the boundaries so that an event may occur. Additionally, we applied these thresholds to different flood events occurred in the past in the study basin. The results show that the ratio between the flood events and precipitation events that occur above the minimum threshold has relatively low probability of a flood happen. These results may be related to the reduced number of floods events (only those that caused damage reported by the media and produced some type of damage). The maximum threshold is not useful for floods forecasting, since the majority of true positives are below this limit. The retrospective analysis of the thresholds defined suggests that the minimum and pre warning thresholds are well adjusted. The application of rainfall thresholds contribute to minimize possible situations of pre-crisis or immediate crisis, reducing the consequences and the resources involved in emergency response of flood events. References Borga, M., Anagnostou, E. N., Blöschl, G., & Creutin, J. D. (2011). Flash flood forecasting, warning and risk management: the HYDRATE project. Environmental Science & Policy, 14(7), 834-844. doi: 10.1016/j.envsci.2011.05.017 Gaál, L., Molnar, P., & Szolgay, J. (2014). Selection of intense rainfall events based on intensity thresholds and

  16. The Post-Permian evolution of the Northern Part of the North German Basin

    Science.gov (United States)

    Hansen, M. B.; Huebscher, C.; Lykke-Andersen, H.; Gajewski, D.; Dehghani, A.; Reicherter, K.

    2004-12-01

    In the frame of the Priority Program 1135 of the German Research Foundation (DFG) "Dynamics of sedimentary systems under varying stress conditions by example of the Central European Basin System", the scientific goal of the NeoBaltic project is to describe the post-Permian to recent geological evolution of the entire western Baltic Sea region, with a special emphasis on neotectonic activity and it relation to salt dynamics. The western Baltic Sea comprises the northern part of the North German Basin (NGB), a part of the Central European Basin System (CEBS), and the transitional zone between the NGB and the Baltic Shield. In order to investigate these scientific goals the Universities of Aarhus (Denmark) and Hamburg (Germany) has since 1998 completed seven marine campaigns in the western Baltic Sea, collecting 2D high resolution seismic (HRS), gravity and magnetic data in the entire region during different projects. Since 2003 all these data has been available for the NeoBaltic project. All together the data pool have more than 7000 km HRS, 5000 km gravity and 4000 km magnetic data. Until now the project work has been focused on the completion of the data processing and the digital interpretation of important Mesozoic and Cenozoic markers on the seismic sections from the Bays of Kiel and Mecklenburg. Furthermore, several maps have been completed from the potential field data (gravity and magnetic). As a result of the digital interpretation of the HRS data, the overall geological evolution of the northern part of the NGB can be subdivided into four distinct periods. During the Triassic and the Early Jurassic, E-W extension and the deposition of clastic sediments initiated the movement of the underlying Zechstein evaporites. This is seen by the presence of several salt pillows in the region. The deposition ceased during the Middle Jurassic, when the entire area was uplifted, due to the Mid North Sea Doming. The uplift resulted in a pronounced erosion of Upper Triassic

  17. Concerts of earthquakes and transverse dislocations in the Caucasus

    Science.gov (United States)

    Pirouzian, S. A.

    1992-02-01

    The geologic-geophysical phenomenon of simultaneous fairly strong tremors or "concerts" of earthquakes in the territory of the Caucasus is considered. The tectonic interpretation of the phenomenon is proposed from the viewpoint of simultaneous activity of different parts of a seismogenic fault or the system of correlated disjunctive dislocations and especially, the transverse dislocations in the Caucasus.

  18. Depositional and provenance record of the Paleogene transition from foreland to hinterland basin evolution during Andean orogenesis, northern Middle Magdalena Valley Basin, Colombia

    Science.gov (United States)

    Moreno, Christopher J.; Horton, Brian K.; Caballero, Victor; Mora, Andrés; Parra, Mauricio; Sierra, Jair

    2011-10-01

    The Central Cordillera and Eastern Cordillera of the northern Andes form the topographic flanks of the north-trending Magdalena Valley Basin. Constraining the growth of these ranges and intervening basin has implications for Andean shortening and the transformation from a foreland to hinterland basin configuration. We present sedimentological, paleocurrent, and sandstone petrographic results from Cenozoic type localities to provide insights into the tectonic history of the northern Middle Magdalena Valley Basin of Colombia. In the Nuevo Mundo Syncline, the mid-Paleocene transition from marine to nonmarine deposystems of the Lisama Formation corresponds with a paleocurrent shift from northward to eastward transport. These changes match detrital geochronological evidence for a contemporaneous shift from cratonic (Amazonian) to orogenic (Andean) provenance, suggesting initial shortening-related uplift of the Central Cordillera and foreland basin generation in the Magdalena Valley by mid-Paleocene time. Subsequent establishment of a meandering fluvial system is recorded in lower-middle Eocene strata of the lower La Paz Formation. Eastward paleocurrents in mid-Paleocene through uppermost Eocene fluvial deposits indicate a continuous influence of western sediment source areas. However, at the upper middle Eocene (˜40 Ma) boundary between the lower and upper La Paz Formation, sandstone compositions show a drastic decrease in lithic content, particularly lithic volcanic fragments. This change is accompanied by a facies shift from mixed channel and overbank facies to thick, amalgamated braided fluvial deposits of possible fluvial megafans, reflecting changes in both the composition and proximity of western sediment sources. We attribute these modifications to the growing influence of exhumed La Cira-Infantas paleohighs in the axial Magdalena Valley, features presently buried beneath upper Eocene-Quaternary basin fill along the western flank of the Nuevo Mundo Syncline. In

  19. The architecture of an incipient oceanic basin: a tentative reconstruction of the Jurassic Liguria-Piemonte basin along the Northern Apennines-Alpine Corsica transect

    Science.gov (United States)

    Marroni, Michele; Pandolfi, Luca

    2007-11-01

    In this paper, a scenario for the early evolution of the Jurassic oceanic Liguria-Piemonte basin is sketched. For this purpose, four selected examples of ophiolite sequences from the Northern Apennines and Corsica are described and analyzed. In the External Ligurian units (Northern Apennines), the ocean-continent transition of the Adria plate was characterized by a basement made up of subcontinental mantle and lower continental crust, covered by extensional allochthons of upper crust. Both, the basement rocks and the extensional allochthons are cut by basaltic dikes and covered by basalts and pelagic deposits. The conjugate ocean-continent transition of the Corsica margin, represented by the Balagne nappe (Corsica), was composed of mantle peridotites and gabbros covered by basaltic flows and minor breccias, that in addition include continent-derived clasts. By contrast, the innermost (i.e., closest to the ocean) preserved area observed in the Internal Ligurian (Northern Apennines) and Inzecca (Corsica) units consists of former morphological highs of mantle peridotites and gabbros, bordered by small basins where the basement is covered by a volcano-sedimentary complex, characterized by ophiolitic breccias and cherts interlayered with basaltic flows. The overall picture resulting from our reconstructions suggests an asymmetric architecture for the Liguria-Piemonte basin with a central area bounded by two different transition zones toward the continental margins. This architecture can be interpreted as the result of a rifting process whose development includes a final stage characterized by passive, asymmetric extension of the lithosphere along an east-dipping detachment fault system.

  20. Palaeoclimatic oscillations in the Pliensbachian (Early Jurassic) of the Asturian Basin (Northern Spain)

    Science.gov (United States)

    Gómez, Juan J.; Comas-Rengifo, María J.; Goy, Antonio

    2016-05-01

    One of the main controversial themes in palaeoclimatology involves elucidating whether climate during the Jurassic was warmer than the present day and if it was the same over Pangaea, with no major latitudinal gradients. There has been an abundance of evidence of oscillations in seawater temperature throughout the Jurassic. The Pliensbachian (Early Jurassic) constitutes a distinctive time interval for which several seawater temperature oscillations, including an exceptional cooling event, have been documented. To constrain the timing and magnitude of these climate changes, the Rodiles section of the Asturian Basin (Northern Spain), a well exposed succession of the uppermost Sinemurian, Pliensbachian and Lower Toarcian deposits, has been studied. A total of 562 beds were measured and sampled for ammonites, for biochronostratigraphical purposes, and for belemnites, to determine the palaeoclimatic evolution through stable isotope studies. Comparison of the recorded latest Sinemurian, Pliensbachian and Early Toarcian changes in seawater palaeotemperature with other European sections allows characterization of several climatic changes that are likely of a global extent. A warming interval partly coinciding with a δ13Cbel negative excursion was recorded at the Late Sinemurian. After a "normal" temperature interval, with temperatures close to average values of the Late Sinemurian-Early Toarcian period, a new warming interval containing a short-lived positive δ13Cbel peak, developed during the Early-Late Pliensbachian transition. The Late Pliensbachian represents an outstanding cooling interval containing a δ13Cbel positive excursion interrupted by a small negative δ13Cbel peak. Finally, the Early Toarcian represented an exceptional warming period, which has been pointed out as being responsible for the prominent Early Toarcian mass extinction.

  1. Long-term geochemical connections between the Samoan hotspot and the northern Lau and North Fiji Basins

    Science.gov (United States)

    Price, A. A.; Jackson, M. G.; Blichert-Toft, J.; Hall, P. S.; Sinton, J. M.; Kurz, M. D.; Blusztajn, J.

    2013-12-01

    The Lau and North Fiji Basins provide a unique environment for the study of upper mantle flow around a subducting slab due to the juxtaposition of the Tonga Trench and the Samoan hotspot (Hart et al., 2004). Both geochemical and geophysical data suggest that material from the Samoan hotspot is leaking southward into the adjacent Lau Basin, but the direction and rate of mantle flow are difficult to constrain.Spatial variations in the isotope geochemistry of igneous rocks from the Lau Basin can provide a useful window on flow in the upper mantle. For example, some lavas from the Samoan hotspot exhibit high 3He/4He, and the observation of elevated 3He/4He at Rochambeau Bank in the nearby northern Lau Basin has been interpreted as the result of a 'finger-like' intrusion of Samoan-plume mantle into the region. However, high 3He/4He is rare even in Samoan lavas, so other geochemical signatures including radiogenic 87Sr/86Sr and Pb-isotopic compositions unique to the Samoan hotspot are useful for characterizing the spatial distribution of the Samoan component within the northern Lau and North Fiji Basins. We present analyses of a combination of geochemical tracers (He-Hf-Nd-Sr-Pb isotopes, major, and trace elements) measured on glasses from the northern Lau Basin and the North Fiji Basin. The samples have 3He/4He ratios that vary between 6 and 10.5 times atmospheric. The samples also show arange in isotopic values from extremely depleted (87Sr/86Sr=0.702892, 143Nd/144Nd=0.513218 and 176Hf/177Hf=0.283510 on a ridge 100km North of Fiji) to moderately enriched (87Sr/86Sr=0.703598, 143Nd/144Nd=0.512884 and 176Hf/177Hf=0.283082 in lavas fromPandora Ridge). Notably, moderately enriched isotopic compositions in Pandora Ridge lavas plot near Samoa's Upolu Island in isotope space, but are slightly shifted isotopically towards a depleted MORB mantle component. The new data suggestthat the western extent of the Samoan plume's influence in the region extends into both the

  2. A review of tectonics and sedimentation in a forearc setting: Hellenic Thrace Basin, North Aegean Sea and Northern Greece

    Science.gov (United States)

    Maravelis, A. G.; Boutelier, D.; Catuneanu, O.; Seymour, K. St.; Zelilidis, A.

    2016-04-01

    Exposure of the forearc region of the North Aegean Sea, Greece, offers insight into evolving convergent margins. The sedimentary fill of the Thrace Basin during the Late Eocene to Oligocene time provides a record of subduction-driven processes, such as growth of magmatic arcs and construction of accretionary complexes. This large sediment repository received sediment from two sources. The southern (outboard) basin margin reflects the active influence of the exhumed accretionary prism (e.g. Pindic Cordillera or Biga peninsula), while the northern (inboard) margin records the effect of the magmatic arc in the Rhodope region. The forearc basin sedimentary fills shoal upward into shallow-marine strata but are dominated mainly by deep-marine facies. The depositional trend and stacking pattern are dominated by progradational patterns. This trend, which is observed in both basin margins, is related to tectonic deformation rather than sea-level fluctuations. Additional evidence for this tectonic uplift comes from the backstripping analysis. The accretionary complex provided material into the forearc basin. This material was transported northeast and formed a sand-rich turbidity system that evolved upslope into shallow-marine deposits. Stratigraphic data indicate that this turbidity system exhibits a successive landward (inboard) migration of the depocenter. Provenance data utilizing sandstone petrography, conglomerate clast composition, and bulk-rock geochemistry suggest that this system reflects an increased influx of mafic material into the basin. Volcanic arc-derived material was transported south and east and accumulated in deep-marine settings. Both stratigraphic and provenance data indicate a seaward (outboard) migration of the basin depocenter and a significant increase in felsic detritus into the forearc.

  3. Stress state variations among the clay and limestone formations of the molasse basin of Northern Switzerland

    International Nuclear Information System (INIS)

    Document available in extended abstract form only. Full text of publication follows: The design of geological repositories for radioactive waste responds to the requirements of technical feasibility and long-term safety in the context of a specific geological setting. An important aspect of the geological setting is the primary stress field. To a large extent the stress state controls repository induced effects such as the excavation damage zone and the associated potential changes in the waste isolation properties of the host rock. Therefore the measurement of the stress state receives some attention where the site selection for geological repositories focuses onto relatively weak host rocks such as clay-stones and marly shales that tend to develop a significant excavation damage zone. Measurements of the minimum stress magnitudes in a recently drilled geothermal well in the Molasse Basin of northern Switzerland have yielded a stress profile reaching from 592 m to 1455 m depth. It straddles several rock units and includes the top of the crystalline basement. The sedimentary sequence consists of Marine limestones, shales and marls unconformably covered by Tertiary rocks of the Molasse. In other parts of the basin the evaporitic rocks of the Triassic Muschelkalk formation at the base of the sedimentary layer served as a regional detachment and enabled thin skinned thrusting and the formation of the Jura Fold and Thrust Belt in the Late Miocene. The stress measurements have been performed in the open hole by Mini-frac tests. The method uses a double packer system to isolate a one meter long interval of the borehole that is then pressurized at high injection rates up to the breakdown of the formation. Repeated pressurization of the interval allows to determine the stress that acts on the newly created fracture. The total injected volume during such a test is in the range of a few litres and the size of the fracture that extends from the borehole normal to the minimum

  4. Thermal-rheological structure of lithosphere beneath the northern flank of Tarim Basin, western China:Implications for geodynamics

    Institute of Scientific and Technical Information of China (English)

    LIU; Shaowen; WANG; Liangshu; LI; Cheng; LI; Hua; HAN; Yong

    2004-01-01

    Based on the data of geo-temperature and thermophysical parameters of rocks in the Kuqa Depression and the Tabei Uplift, northern flank of the Tarim Basin, in terms of the analytical solution of 1-D heat transfer equation, the thermal structure of the lithosphere under this region is determined. Our results show that the average surface heat flow of the northern flank of the Tarim Basin is 45 mW/m2, and the mantle heat flow is between 20 and 23 mW/m2; the temperature at crust-mantle boundary (Moho) ranges from 514℃ to 603℃ and the thermal lithosphere where the heat conduction dominates is 138-182 km thick. Furthermore, in combination with the P wave velocity structure resulting from the deep seismic sounding profile across this region and rheological modeling, we have studied the local composition of the lithosphere and its rheological profile, as well as the strength distribution. We find that the rheological stratification of the lithosphere in this region is apparent. The lowermost of the lower crust is ductile; however,the uppermost of the mantle and the upper and middle parts of the crust are both brittle layers,which is typically the so-called sandwich-like structure. Lithospheric strength is also characterized by the lateral variation, and the uplift region is stronger than the depression region. The lithospheric strength of the northem flank of the Tarim Basin decreases gradually from south to north; the Kuqa Depression has the lowest strength and the south of the Tabei Uplift is strongest.The total lithospheric strength of this region is 4.77× 1012-5.03 × 1013 N/m under extension, and 6.5 × 1012-9.4× 1013 N/m under compression. The lithospheric brittle-ductile transition depth is between 20 km and 33 km. In conclusion, the lithosphere of the northern flank of the Tarim Basin is relatively cold with higher strength, so it behaves rigidly and deforms as a whole, which is also supported by the seismic activity in this region. This rigidity of the

  5. FACIES ANALYSIS, STRATIGRAPHY AND PALAEONTOLOGY (MOLLUSCS AND VERTEBRATES IN THE UPPER PLIOCENE SANDY FLOOD-BASIN DEPOSITS OF THE UPPER VALDARNO BASIN (NORTHERN APENNINES

    Directory of Open Access Journals (Sweden)

    MASSIMILIANO GHINASSI

    2005-11-01

    Full Text Available The Upper Valdarno Basin, one of the most investigated Neogene–Quaternary basins of the Northern Apennines, developed during three main phases, as testified by the occurrence of three unconformity-bounded stratigraphic units (UBSUs in the basin infill. Despite numerous studies having been carried out, biochronological, paleoecological and stratigraphical issues in the lower portion of the Montevarchi Synthem (second phase have yet to be understood. Sandy deposits (Montecarlo Sand and Silt Unit, stratigraphically located in this portion of the Montevarchi Synthem, are the focus of this multidisciplinary study. These deposits conformably overlie sandy fluvio-eolian sediments and are, in turn, capped by fluvio-palustrine deposits through a progressive unconformity. Facies analysis suggest a sandy flood-basin environment for these deposits, characterised by variations in water discharge and flood event energy. Mollusc and fish remains, pointing to quiet or slow-moving shallow waters, have been affected by transport processes before final burial in overbank areas. Fish remains of the primary marine family Mugilids highlight a connection between the basin and the sea that was previously only supposed. Small mammal remains, referred to the rodent Mimomys polonicus, are coherent with a water-rich environment. Cyclic variations in shell content and sedimentological characteristics testify to the occurrence of short-term climatic oscillations during this warming phase. This study fits with paleomagnetic and radiometric datings and mammal biochronology, in indicating that the Montecarlo Sand and Silt Unit belongs to a time interval preceding the Reunion paleomagnetic event. The depositional evolution of the Montecarlo Unit was driven by climatic change from arid to humid conditions, related to a global increase in temperature that occurred between 2.4 and 2.2 Ma.

  6. Cheatgrass percent cover change: Comparing recent estimates to climate change − Driven predictions in the Northern Great Basin

    Science.gov (United States)

    Boyte, Stephen P.; Wylie, Bruce K.; Major, Donald J.

    2016-01-01

    Cheatgrass (Bromus tectorum L.) is a highly invasive species in the Northern Great Basin that helps decrease fire return intervals. Fire fragments the shrub steppe and reduces its capacity to provide forage for livestock and wildlife and habitat critical to sagebrush obligates. Of particular interest is the greater sage grouse (Centrocercus urophasianus), an obligate whose populations have declined so severely due, in part, to increases in cheatgrass and fires that it was considered for inclusion as an endangered species. Remote sensing technologies and satellite archives help scientists monitor terrestrial vegetation globally, including cheatgrass in the Northern Great Basin. Along with geospatial analysis and advanced spatial modeling, these data and technologies can identify areas susceptible to increased cheatgrass cover and compare these with greater sage grouse priority areas for conservation (PAC). Future climate models forecast a warmer and wetter climate for the Northern Great Basin, which likely will force changing cheatgrass dynamics. Therefore, we examine potential climate-caused changes to cheatgrass. Our results indicate that future cheatgrass percent cover will remain stable over more than 80% of the study area when compared with recent estimates, and higher overall cheatgrass cover will occur with slightly more spatial variability. The land area projected to increase or decrease in cheatgrass cover equals 18% and 1%, respectively, making an increase in fire disturbances in greater sage grouse habitat likely. Relative susceptibility measures, created by integrating cheatgrass percent cover and temporal standard deviation datasets, show that potential increases in future cheatgrass cover match future projections. This discovery indicates that some greater sage grouse PACs for conservation could be at heightened risk of fire disturbance. Multiple factors will affect future cheatgrass cover including changes in precipitation timing and totals and

  7. Past, present and future formation of groundwater resources in northern part of Baltic Artesian Basin

    Science.gov (United States)

    Marandi, A.; Vallner, L.; Vaikmae, R.; Raidla, V.

    2012-04-01

    Cambrian-Vendian Aquifer System (CVAS) is the deepest confined aquifer system used for water consumption in northern part of Baltic Artesian Basin (BAB). A regional groundwater flow and transport model (Visual Modflow) was used to investigate the paleohydrogeological scientific and contemporary management problems of CVAS. The model covers the territory of Estonia and its close surrounding, all together 88,000 km2 and includes all main aquifers and aquitards from ground surface to as low as the impermeable part of the crystalline basement. Three-dimensional distribution of groundwater heads, flow directions, velocities, and rates as well as transport and budget characteristics were simulated by the model. Water composition was changed significantly during the last glaciations.Strongly depleted O and H stable isotope composition, absence of 3H and low radiocarbon concentration are the main indicators of glacial origin of groundwater in the Cambrian-Vendian aquifer in northern Estonia. The noble gas analyses allowed concluding, that palaeorecharge took place at temperatures around the freezing point. While in North Estonia, most of water was changed by glacial melt water, high salinity water is till preserved in Southern part of Estonia.First results of modeling suggest that during the intrusion period lasting 7.3-9.3 ka the front of glacial thaw water movement had southeast direction and reachedto 180-220 kmfrom CVAS outcrop in Baltic Sea. Confining layer of CVAS is cut through by deep buried valleys in several places in North Estonia making possible for modern precipitation to infiltrate into aquifer system in present day. In case of natural conditions, the water pressure of CVAS is few meters above sea level and most of valleys act as discharge areas for aquifers system. Two regional depression ones have formed in North Estonia as a result of groundwater use from CVAS. Water consumption changes the natural groundwater gradient, flow direction and thereforerecharge

  8. Review of the Upper Jurassic-Lower Cretaceous stratigraphy in Western Cameros basin, Northern Spain

    DEFF Research Database (Denmark)

    Vidal, Maria del Pilar Clemente

    2010-01-01

    The Upper Jurassic-Lower Cretaceous stratigraphy of the Cameros basin has been reviewed. In Western Cameros the stratigraphic sections are condensed but they have a parallel development with the basin depocentre and the same groups have been identified. The Tera Group consists of two formations...

  9. Structure of the Wagner Basin in the Northern Gulf of California From Interpretation of Seismic Reflexion Data

    Science.gov (United States)

    Gonzalez, M.; Aguilar, C.; Martin, A.

    2007-05-01

    The northern Gulf of California straddles the transition in the style of deformation along the Pacific-North America plate boundary, from distributed deformation in the Upper Delfin and Wagner basins to localized dextral shear along the Cerro Prieto transform fault. Processing and interpretation of industry seismic data adquired by Petroleos Mexicanos (PEMEX) allow us to map the main fault structures and depocenters in the Wagner basin and to unravel the way strain is transferred northward into the Cerro Prieto fault system. Seismic data records from 0.5 to 5 TWTT. Data stacking and time-migration were performed using semblance coefficient method. Subsidence in the Wagner basin is controlled by two large N-S trending sub-parallel faults that intersect the NNW-trending Cerro Prieto transform fault. The Wagner fault bounds the eastern margin of the basin for more than 75 km. This fault dips ~50° to the west (up to 2 seconds) with distinctive reflectors displaced more than 1 km across the fault zone. The strata define a fanning pattern towards the Wagner fault. Northward the Wagner fault intersects the Cerro Prieto fault at 130° on map view and one depocenter of the Wagner basin bends to the NW adjacent to the Cerro Prieto fault zone. The eastern boundary of the modern depocenter is the Consag fault, which extends over 100 km in a N-S direction with an average dip of ~50° (up to 2s) to the east. The northern segment of the Consag fault bends 25° and intersects the Cerro Prieto fault zone at an angle of 110° on map view. The acoustic basement was not imaged in the northwest, but the stratigraphic succession increases its thickness towards the depocenter of the Wagner basin. Another important structure is El Chinero fault, which runs parallel to the Consag fault along 60 km and possibly intersects the Cerro Prieto fault to the north beneath the delta of the Colorado River. El Chinero fault dips at low-angle (~30°) to the east and has a vertical offset of about 0

  10. Evolution of the Neogene Andean foreland basins of the Southern Pampas and Northern Patagonia (34°-41°S), Argentina

    Science.gov (United States)

    Folguera, Alicia; Zárate, Marcelo; Tedesco, Ana; Dávila, Federico; Ramos, Victor A.

    2015-12-01

    The Pampas plain (30°-41°S) has historically been considered as a sector that evolved independently from the adjacent Andean ranges. Nevertheless, the study of the Pampas showed that it is reasonable to expect an important influence from the Andes into the extraandean area. The Pampas plain can be divided into two sectors: the northern portion, adjacent to the Pampean Ranges, has been studied by Davila (2005, 2007, 2010). The southern sector (34°-41°S) is the objective of the present work. The study of this area allowed to characterize two separate foreland basins: the Southern Pampa basin and the Northern Patagonian basin. The infill is composed of Late Miocene and Pliocene units, interpreted as distal synorogenic sequences associated with the late Cenozoic Andean uplift at this latitudinal range. These foreland basins have been defined based on facies changes, distinct depositional styles, along with the analysis of sedimentary and isopach maps. The basins geometries are proposed following De Celles and Gilles (1996) taking into account the infill geometry, distribution and grain size. In both cases, these depocenters are located remarkably far away from the Andean tectonics loads. Therefore they cannot be explained with short-wave subsidence patterns. Elastic models explain the tectonic subsidence in the proximal depocenters but fail to replicate the complete distal basins. These characteristics show that dynamic subsidence is controlling the subsidence in the Southern Pampas and Northern Patagonian basins.

  11. Hydrogeochemistry and stable isotopes of ground and surface waters from two adjacent closed basins, Atacama Desert, northern Chile

    Science.gov (United States)

    Alpers, C.N.; Whittemore, D.O.

    1990-01-01

    The geochemistry and stable isotopes of groundwaters, surface waters, and precipitation indicate different sources of some dissolved constituents, but a common source of recharge and other constituents in two adjacent closed basins in the Atacama Desert region of northern Chile (24??15???-24??45???S). Waters from artesian wells, trenches, and ephemeral streams in the Punta Negra Basin are characterized by concentrations of Na>Ca>Mg and Cl ???SO4, with TDS Mg ??? Ca and SO4 > Cl, with TDS also Mg ??? Ca and SO4 > Cl, but with TDS up to 40 g/l. The deep mine waters have pH between 3.2 and 3.9, and are high in dissolved CO2 (??13 C = -4.8%PDB), indicating probable interaction with oxidizing sulfides. The deep mine waters have ??18O values of ???-1.8%.compared with values < -3.5??? for other Hamburgo Basin waters; thus the mine waters may represent a mixture of meteoric waters with deeper "metamorphic" waters, which had interacted with rocks and exchanged oxygen isotopes at elevated temperatures. Alternatively, the deep mine waters may represent fossil meteoric waters which evolved isotopically along an evaporative trend starting from values quite depleted in ??18O and ??Dd relative to either precipitation or shallow groundwaters. High I/Br ratios in the Hamburgo Basin waters and La Escondida mine waters are consistent with regionally high I in surficial deposits in the Atacama Desert region and may represent dissolution of a wind-blown evaporite component. Rain and snow collected during June 1984, indicate systematic ??18O and ??D fractionation with increasing elevation between 3150 and 4180 m a.s.l. (-0.21??.??18O and -1.7??.??D per 100 m). Excluding the deep mine waters from La Escondida, the waters from the Hamburgo and Punta Negra Basins have similar ??D and ??18O values and together show a distinct evaporative trend (??D = 5.0 ??18O - 20.2). Snowmelt from the central Andes Cordillera to the east is the most likely source of recharge to both basins. Some of the

  12. Hydrological application of the INCA model with varying spatial resolution and nitrogen dynamics in a northern river basin

    Directory of Open Access Journals (Sweden)

    K. Rankinen

    2002-01-01

    Full Text Available As a first step in applying the Integrated Nitrogen model for CAtchments (INCA to the Simojoki river basin (3160 km2, this paper focuses on calibration of the hydrological part of the model and nitrogen (N dynamics in the river during the 1980s and 1990s. The model application utilised the GIS land-use and forest classification of Finland together with a recent forest inventory based on remote sensing. In the INCA model, the Hydrologically Effective Rainfall (HER is used to drive the water flow and N fluxes through the catchment system. HER was derived from the Watershed Simulation and Forecast System (WSFS. The basic component of the WSFS is a conceptual hydrological model which simulates runoff using precipitation, potential evapotranspiration and temperature data as inputs. Spatially uniform, lumped input data were calculated for the whole river basin and spatially semi-distributed input data were calculated for each of the nine sub-basins. When comparing discharges simulated by the INCA model with observed values, a better fit was obtained with the semi-distributed data than with the spatially uniform data (R2 0.78 v. 0.70 at Hosionkoski and 0.88 v. 0.78 at the river outlet. The timing of flow peaks was simulated rather well with both approaches, although the semi-distributed input data gave a more realistic simulation of low flow periods and the magnitude of spring flow peaks. The river basin has a relatively closed N cycle with low input and output fluxes of inorganic N. During 1982-2000, the average total N flux to the sea was 715 tonnes yr–1, of which 6% was NH4-N, 14% NO3-N, and 80% organic N. Annual variation in river flow and the concentrations of major N fractions in river water, and factors affecting this variation are discussed. Keywords: northern river basin, nitrogen, forest management, hydrology, dynamic modelling, semi-distributed modelling

  13. Paleoenvironmental and source rock assessment of black shales of Pennsylvanian Age, Powder River and northern Denver basins

    Energy Technology Data Exchange (ETDEWEB)

    Clayton, J.L.; King, J.D.; Lubeck, C.M.; Leventhal, J.S.; Daws, T.A.

    1988-07-01

    Thin Middle Pennsylvanian (Desmoinesian) organic-rich black shales (cumulative thickness < 50 ft) underlie much of the northern Denver basin and southeastern Powder River basin. In the Powder River basin, these shales are part of the middle member of the Minnelusa Formation. During Desmoinesian time, the present area of the southeastern Powder River basin and Nebraska was a shallow, at times highly saline, restricted sea. In contrast, in the present area of northeastern Colorado, black shales were deposited in a marine environment with normal salinity that was probably continuous with the Mid-Continent Pennsylvanian sea. Assessment of the paleoenvironment has been carried out using organic geochemical parameters. Shales deposited in the restricted basin setting contain abundant porphyrins (25,000-30,000 ppm relative to total extractable organic matter) and significant quantities of aryl isoprenoids. The aryl isoprenoid compounds (1) are evidence for the presence of the sulfur bacteria families Chlorobiaceae and possibly Chromatiaceae and (2) indicate that euxinic conditions existed in the water column. High ratios of sulfur to carbon in the shales support this interpretation. In contrast, extracts from black shale in the normal sea to the south contain lower porphyrin concentrations (generally less than 1000 ppm) and aryl isoprenoids are minor constituents or are absent. Sulfur/carbon ratios in these latter shales are similar to those observed for normal marine shales (that is, not euxinic conditions). Other paleoenvironmental indicators (sterane composition, alkane distribution) are consistent with these observations. Bulk organic matter in the black shales from both environments is type II and has good source potential for generation of liquid hydrocarbons during catagenesis. Pyrolysis yields of 50 kg/MT (50,000 ppm) are common, and in some shales, yield is 100 kg/MT (100,000 ppm).

  14. GLOBALIZATION MYTH AND TRADITIONAL CULTURE IN GEORGIA AND THE CAUCASUS

    OpenAIRE

    Yakobishvili-piralishvili, Lela

    2008-01-01

    The geocultural orientation of the Caucasus, and Georgia as its part, is growing more and more important in the age of globalization. This process has already offered Caucasian geoculture new possibilities; the Caucasus has been given the chance of becoming the only cultural transit region where many different cultures meet. Cultural diffusion will not be its only function: it stands a good chance of becoming a topos of the dialogue of cultures. As part of the topos of the Georgian geoculture...

  15. THE NORTHERN CAUCASUS FROM THE PERSPECTIVE OF CULTURAL GLOBALIZATION

    OpenAIRE

    Hanahu, Ruslan

    2008-01-01

    Globalization is undoubtedly a complex and contradictory sociocultural phenomenon affecting both numerically large and small nationalities, but its consequences can differ. The cultures of numerically small ethnic groups experience the consequences of globalization under the same conditions as large nationalities. But whereas large ethnic groups are in relatively little danger of losing their language and culture, the threat to the culture and uniqueness of numerically small Caucasian nationa...

  16. Gas hydrate formation and accumulation potential in the Qiangtang Basin, northern Tibet, China

    International Nuclear Information System (INIS)

    Highlights: • Qiangtang Basin is the biggest residual petroleum-bearing basin in Tibet Plateau. • The Late Triassic Tumen Gela Formation is the most important gas source rock. • Seventy-one potential anticline structural traps have been found. • A favorable geothermal condition for gas hydrate formation. • A large number of mud volcanoes were discovered in the basin. - Abstract: The Qiangtang Basin is the biggest residual petroleum-bearing basin in the Qinghai–Tibet Plateau, and is also an area of continuous permafrost in southwest China with strong similarities to other known gas-hydrate-bearing regions. Permafrost thickness is typically 60–180 m; average surface temperature ranges from −0.2 to −4.0 °C, and the geothermal gradient is about 2.64 °C/100 m. In the basin, the Late Triassic Tumen Gela Formation is the most important gas source rock for gas, and there are 34.3 × 108 t of gas resources in the Tumen Gela Formation hydrocarbon system. Seventy-one potential anticline structural traps have been found nowadays covering an area of more than 30 km2 for each individual one, five of them are connected with the gas source by faults. Recently, a large number of mud volcanoes were discovered in the central Qiangtang Basin, which could be indicative of the formation of potential gas hydrate. The North Qiangtang depression should be delineated as the main targets for the purpose of gas hydrate exploration

  17. Radioecological monitoring of south Caucasus - main results

    International Nuclear Information System (INIS)

    Basing in surrounding ambience at present radioactive on its origin possible to split into two main groups: artificial and natural radioactive. How is obvious from the most names, natural based in the nature nearly with first days of its shaping and are its by the component. Artificial - not existed or not saved in the nature - having radioactive characteristics isotopes 'appeared' as a result artificial doing atoms. Getting into surrounding ambience as a result person activity artificial (systematically or episodic detectable there) possible conditionally split into three subgroups. Artificial radioactive isotopes, got into surrounding natural ambience as a result anthropogenic activity, in principal (ecological) are distinguished from the natural radioactive isotopes by fetters and particularities to migration on ecological chains, but, consequently, and nature 'influence'. Sufficiently remind that if in biosphere practically no ecological niches, in which goes an accumulation natural, capable to give significant dozing effect; for the artificial (isotopes of iodine, isotopes a strontium, caesium) exactly ability be accumulated in separate 'niches' ecological chain or in separate organs or weaving an organism (thyroid gland for the iodine) do artificial radioisotopes hygienic extremely dangerous. Location of Caucasus in the area of approximate location of firing ranges of test, (after the series 1961-1962 conducted by USSR in the North hemisphere this were test China) and damages on Chernobyl, in the area of most intensity stratosphere - troposphere exchange, manifests themselves: 1. Early approach spring-year maximum; 2. More clear maximum in the seasonal move; 3. The Greater fallout levels in contrast with other regions of country; 4. The Greater 'sensitivity' to 'fresh' products. Structure of global fallout on the under investigation region is stipulated: 1. Decreasing the fallout levels from the north on the south. 2. Vertical fallout levels (growth with the

  18. The Eurasian Otter in the South Caucasus

    Directory of Open Access Journals (Sweden)

    Gorgadze G.

    2004-07-01

    Full Text Available Seven species of Mustelidae are to be found in the south Caucasus (Armenia, Azerbaijan and Georgia: Lutra lutra, Martes martes, Martes foina, Meles meles, Mustela vison, Mustela nivalis and Vormela peregusna. The rarest of these species are the Eurasian otter (Lutra lutra and the marbled polecat (Vormela peregusna. The Eurasian otter, one of most endangered species of the south caucasian fauna, is still suffering under the influence of poaching, habitat loss, disturbance and pollution. No fundamental research has been undertaken on otters in any of the south Caucasian countries and, therefore, data provided in the literature are scarce. Further, no DNA analysis has been undertaken in this part of the world and, therefore, the actual number of subspecies is not clear.

  19. Seismo-stratigraphic evolution of the northern Austral Basin and its possible relation to the Andean tectonics, onshore Argentina.

    Science.gov (United States)

    Sachse, Victoria; Anka, Zahie; Pagan, Facundo; Kohler, Guillermina; Cagnolatti, Marcelo; di Primio, Rolando; Rodriguez, Jorge

    2013-04-01

    The Austral Basin is situated in a formerly and recently high active tectonic zone in southern Argentina. The opening of the South Atlantic to the east, the opening of the Drake Passage in the south, and the subduction related to the rise of the Andes to the west, had major influence on the study area. To identify the impact of the tectonic events on basin geometry, sediment thickness and depocenter migration through time, 2D seismic interpretation was performed for an area of approx. 180.000 km² covering the onshore northern Austral Basin. A total of 10 seismic horizons were mapped and tied to the stratigraphy from well reports, representing 9 syn- and post- rift sequences. The main units are: Basement (U1), Jurassic Tobifera Formation (U2), Early Cretaceous (U3), Late Cretaceous (U4), sub-unit Campanian (U4A), Paleocene (U5), Eocene (U6), Oligocene (U7), Miocene (U8), and Plio-Pleistocene (U9). Main tectonic events are identified representing the break-up phase forming graben systems and the evolution from the ancient backarc Rocas Verdes Basin to the foreland Austral Basin. Inversion and changes in the tectonic regime are concomitant with onlapping and thinning of the base of the Upper Cretaceous to Campanian sediments, while the Top of the Upper Cretaceous represents a Maastrichtian unconformity. Units depth maps show a triangular geometry since the Jurassic, tracing the north-eastern basement high and deepening to the south. Since the Campanian the former geometry of basin fill changed and deepening to the south stopped. Beginning of the foreland phase is assigned to this time as well as changes in the stress regime. Paleogene times are marked by a relatively high sedimentation rate coupled with enduring thermal subsidence, on-going rise of the Andes and changes in the convergence rates of the Nazca relative to the South American plate. Onset of sediment supply from the Andes (Incaic phase) resulted in enhanced sedimentation rates during the Paleocene

  20. Raft tectonics in northern Campos Basin; Tectonica de jangada (raft tectonics) na area norte da Bacia de Campos

    Energy Technology Data Exchange (ETDEWEB)

    Castro, Marilia R. de [Universidade Estadual do Norte Fluminense (UENF), Campos dos Goytacases, RJ (Brazil)]|[PETROBRAS, Macae, RJ (Brazil). Unidade de Negocio da Bacia de Campos; Fugita, Adhemar M. [Universidade do Estado, Rio de Janeiro, RJ (Brazil). Programa de Recursos Humanos da ANP

    2004-07-01

    In the northern area of Campos Basin salt gliding/spreading processes promoted the break-up and transport of Cretaceous and Tertiary rocks overlying the evaporites. This process is known as raft tectonics, and it represents the most extreme form of thin-skinned extension above the salt decollement surface. Three distinct geotectonic domains were recognized that formed in response to the raft tectonics. The first one, confined to the shallower shelf portion of the basin, is characterized by minor extension (pre-raft domain), probably because of small salt thickness and low gradient. In the second domain (or disorganized rafts domain), located in distal platformal and slope areas, seismic sections show the occurrence of blocks or rafts with angular shapes, sometimes imbricated and frequently discontinuous. In the third domain, or domain of organized rafts, located in bacinal region, seismic sections show a more continuous raft pattern, often folded because of salt compression in the distal portions of the basin. The main purposes of this work is to characterize these three tectonic domains distinguished by raft tectonics, as well as their importance in hydrocarbon accumulations in calcarenites. (author)

  1. Geologic implications of large-scale trends in well-log response, northern Green River Basin, Wyoming

    International Nuclear Information System (INIS)

    Well-log response in lower Tertiary and Upper Cretaceous rocks in the northern Green River basin, Wyoming, is examined. Digitally recorded well-log data for selected wells located throughout the basin were processed by computer and displayed as highly compressed depth-scale plots for examining large-scale geologic trends. Stratigraphic units, formed under similar depositional conditions, are distinguishable by differing patterns on these plots. In particular, a strong lithologic contrast between Tertiary and underlying Upper Cretaceous non-marine clastic rocks is revealed and correlated through the study area. Laboratory analysis combined with gamma-ray spectrometry log data show that potassium feldspars in the arkosic Tertiary sandstones cause the contrast. The nature and extent of overpressuring has been examined. Data shift on shale conductivity and shale acoustic transit-time plots, previously ascribed to changes in pore pressure, correspond to stratigraphic changes and not necessarily with changes in pore pressure as indicated by drilling-mud weights. Gulf Coast well-log techniques for detecting overpressuring are unreliable and ineffectual in this basin, which has experienced significantly different geologic depositional and tectonic conditions

  2. The linkage between longitudinal sediment routing systems and basin types in the northern South China Sea in perspective of source-to-sink

    Science.gov (United States)

    Su, Ming; Hsiung, Kan-Hsi; Zhang, Cuimei; Xie, Xinong; Yu, Ho-Shing; Wang, Zhenfeng

    2015-11-01

    Using bathymetric and seismic data, this study describes the morpho-sedimentary features in Qiongdongnan basin and southwest Taiwan collision basin, northern South China Sea and reveals the linkages between sediment routing system and basin types. The modern Central Canyon in the Qiongdongnan basin is located along the rift margin, and subparallel to the shelf-break southeast of Hainan Island. The modern Central Canyon develops along the basin axis (i.e., Xisha Trough) and longitudinally transports sediments eastward which are mainly supplied by northern continental slope. The Penghu Canyon in the southwest Taiwan collision basin is located along the collision boundary parallel to the strike of the adjacent uplifted Taiwan orogen. The Penghu Canyon develops along the tilting basin axis transporting sediments longitudinally southward to the deep-sea basin and Manila Trench. The Penghu Canyon is supplied with sediments from both flank Kaoping and South China Sea slopes where tributary canyons and channels transport sediments down-slope and feed the axial canyon. The certain basin types may be occupied by particular styles of sediment routing system. By comparing the morpho-sedimentary features and basin characteristics associated with the modern Central Canyon to that of the Valencia Channel in NW Mediterranean Sea, the longitudinal sediment routing system in rift basin type can be determined. In contrast, the longitudinal sediment routing systems in collision setting can be represented by the comparable examples of Penghu Canyon in southwest Taiwan collision basin and Markham Canyon in western Solomon Sea. The rift type sediment routing system is characterized by an axial canyon with a single sediment supply from land drainage margin. In contrast, sediment routing system in collision type basins consists of an axial canyon and dual sediment supplies from flank adjacent slopes. The axial canyons in collision basins are more active than that of the rift basin due to

  3. Neotectonic aspects of the northern margin of the Adana–Cilicia submarine basin, NE Mediterranean

    Indian Academy of Sciences (India)

    E Ozel; A Ulug; B Pekcetinoz

    2007-04-01

    The sedimentary basins that dominate the north-eastern Mediterranean (Adana–Cilicia basins in the west and Iskenderun basin in the east) are located on the flanks of a partly submerged positive structure (a part of the Africa–Eurasia convergence zone) along which strike-slip faults are evident. This study summarizes the findings of two seismic surveys carried out in the Alanya– Mersin offshore region. Some 850 km of geophysical survey lines were compiled on these cruises. Based on the results determined from these surveys, the north and central part of Adana–Cilicia basin can be subdivided into eastern, central and western structural sub-basins separated by the Ecemiş fault complex in the east and the Anamur–Kormakiti structural high in the west at the same time. Results of this study also indicate that Ecemiş and Anamur–Kormakiti faults are active. Late Miocene regional compression was responsible for the compartmentation of this complex into the present arrangement and has initiated the rotational regime which has governed subsequent tectonic developments, notably the extensional behaviour of the NE–SW trending Ecemiş and Anamur–Kormakiti faults and the transpressive behaviour of the NNE–SSW trending border fault complex.

  4. Paleogeographic significance of Upper Triassic basinal succession of the Tamar Valley, northern Julian Alps (Slovenia

    Directory of Open Access Journals (Sweden)

    Gale Luka

    2015-08-01

    Full Text Available The Julian Alps (western Slovenia structurally belong to the eastern Southern Alps. The Upper Triassic succession mostly consists of shallow water platform carbonates of the Dolomia Principale-Dachstein Limestone system and a deep water succession of the Slovenian Basin outcropping in the southern foothills of the Julian Alps. In addition to the Slovenian Basin, a few other intraplatform basins were present, but they remain poorly researched and virtually ignored in the existing paleogeographic reconstructions of the eastern Southern Alps. Herein, we describe a deepening-upward succession from the Tamar Valley (north-western Slovenia, belonging to the Upper Triassic Tarvisio Basin. The lower, Julian-Tuvalian part of the section comprises peritidal to shallow subtidal carbonates (Conzen Dolomite and Portella Dolomite, and an intermediate carbonate-siliciclastic unit, reflecting increased terrigenous input and storm-influenced deposition (Julian-lowermost Tuvalian shallow-water marlstone and marly limestone of the Tor Formation. Above the drowning unconformity at the top of the Portella Dolomite, Tuvalian well-bedded dolomite with claystone intercalations follows (Carnitza Formation. The latter gradually passes into the uppermost Tuvalian–lowermost Rhaetian bedded dolomite with chert and slump breccias, deposited on a slope and/or at the toe-of-slope (Bača Dolomite. Finally, basinal thin-bedded bituminous limestone and marlstone of Rhaetian age follow (Frauenkogel Formation. The upper part of the Frauenkogel Formation contains meter-scale platform-derived limestone blocks, which are signs of platform progradation. The Tarvisio Basin may have extended as far as the present Santo Stefano di Cadore area, representing a notable paleogeographic unit at the western Neotethys margin.

  5. Hydrochemistry (major and trace elements of Lake Malawi (Nyasa, Tanzanian Northern Basin: local versus global considerations

    Directory of Open Access Journals (Sweden)

    P. Branchu

    2010-07-01

    Full Text Available This paper presents the first inventory of dissolved minor and trace element (F, Al, Fe, Mn, Ba, Cd, Cr, Cu, Pb, Mo, Bi, Sr, Zn concentrations in Lake Malawi, the second largest African lake. Sampling was carried out during 1993 dry season in the northern part of the lake. Trace metal concentrations were measured, together with Ca, Mg, Na, K, Cl, SO4, Alkalinity and Si, along three profiles in the lake northern extremity, in five tributaries and two on-land hydrothermal springs. Water profiles show similar elemental distributions and concentrations that are influenced by lake physical-chemical stratification. Stratification, assessed using temperature, conductivity, Si and Mn profiles, is characterised by two boundaries: the thermocline (70–90 m and the oxicline (150–190 m. Elemental water concentrations are discussed using simple covariance analyse. Epilimnetic concentrations and distribution are also influenced by atmospheric deposition and river diving. Comparison of dissolved concentrations for potentially polluting elements with World Health Organisation Guidelines and those reported for other East African lakes shows that this reservoir is uncontaminated despite an increasing human stress. Major element behaviour is assessed through a 3 boxes model. In this model Cl and K are conservative elements whereas Si is removed from the solution by diatom productivity and sedimentation. Ca, Na, Mg and alkalinity show low reactivity. Evaporation is one of the controlling factors of lake element concentration that superimposes on the watershed control. Hydrothermal activity, not evidenced in the lake, controls the chemistry of one of the main northern tributary. Chemical comparison between Northern rivers and other tributaries characterises the geographical and geological specificity of studied northern watershed. Moreover the lake annual chemical budget shows that northern watershed generates the main elemental input to the lake

  6. HIGH-RESOLUTION SEISMIC VELOCITY AND ATTENUATION MODELS OF THE CAUCASUS-CASPIAN REGION

    Energy Technology Data Exchange (ETDEWEB)

    Mellors, R; Gok, R; Sandvol, E

    2007-07-10

    The southwest edge of Eurasia is a tectonically and structurally complex region that includes the Caspian and Black Sea basins, the Caucasus Mountains, and the high plateaus south of the Caucasus. Crustal and upper mantle velocities show great heterogeneity in this region and regional phases display variations in both amplitudes and travel time. Furthermore, due to a lack of quality data, the region has largely been unexplored in terms of the detailed lithospheric seismic structure. A unified high-resolution 3D velocity and attenuation model of the crust and upper mantle will be developed and calibrated. This model will use new data from 23 new broadband stations in the region analyzed with a comprehensive set of techniques. Velocity models of the crust and upper mantle will be developed using a joint inversion of receiver functions and surface waves. The surface wave modeling will use both event-based methods and ambient noise tomography. Regional phase (Pg, Pn, Sn, and Lg) Q model(s) will be constructed using the new data in combination with existing data sets. The results of the analysis (both attenuation and velocity modeling) will be validated using modeling of regional phases, calibration with selected events, and comparison with previous work. Preliminary analyses of receiver functions show considerable variability across the region. All results will be integrated into the KnowledgeBase.

  7. National Account Energy Alliance Final Report for the Basin Electric Project at Northern Border Pipeline Company's Compressor Station #7, North Dakota

    Energy Technology Data Exchange (ETDEWEB)

    Sweetzer, Richard [Exergy Partners Corp.; Leslie, Neil [Gas Technology Institute

    2008-02-01

    A field research test and verification project was conducted at the recovered energy generation plant at Northern Border Pipeline Company Compressor Station #7 (CS#7) near St. Anthony. Recovered energy generation plant equipment was supplied and installed by ORMAT Technologies, Inc. Basin Electric is purchasing the electricity under a purchase power agreement with an ORMAT subsidiary, which owns and operates the plant.

  8. Recent area and volume changes of Marukh glacier in western Caucasus

    Science.gov (United States)

    Kutuzov, S.; Lavrentiev, I. I.; Petrakov, D. A.; Macheret, Yu. Ya.

    2012-04-01

    Field studies have been carried out at Marukh glacier located in western part of the Northern Caucasus in summer 2011. Studies included ground-based radio-echo sounding measurements at a frequency of 20 MHz and glacier surface elevation survey using a dual frequency differential GPS receiver. Marukh Glacier is most western valley type glacier in the Russian Greater Caucasus. It is located 60 km from the Black Sea and was selected as most maritime glacier in the Soviet Union for direct measurements of ice, water and energy balances during IHD (International Hydrologycal Decade) in 1966-67-1981-82 when mass balance measurements were accompanied by meteorological observations and several topographic map were completed in scale of 1:10000. Detailed volume and surface area changes of the glacier for the period 1945-2011 were obtained using aerial photo, satellite images and topographic maps analysis. Annual glacier accumulation, ablation and mass balance have been estimated for the period of 1967 to 2011 using direct measurements (1967-1982) and mass balance reconstruction based on meteorological data. It is founded that Marukh glacier is retreating and has reduced its surface area by 17% over the past 66 years. Glacier volume is 0,276 km3 in 2011 and has decreased by 0,06 km3 since 1967.

  9. The northern and central Appalachian basin coal region -- The Upper Freeport and Pond Creek coal bed assessments

    Energy Technology Data Exchange (ETDEWEB)

    Ruppert, L.; Tewalt, S.; Bragg, L.; Wallack, R.; Freeman, P.; Tully, J.

    1999-07-01

    The Upper Freeport and Pond Creek coal beds are two of six coal beds being assessed by the US Geological Survey (USGS) in the northern and central Appalachian basin coal region. The coal resource assessments were designed to provide up-to-date, concise data on the location, quantity, and quality of US coals for Federal agencies, the public, industry and academia. Assessment products are fully digital and include original and remaining resource estimates; maps depicting areal extent, mined areas, geologic structure contour, isopach, overburden thickness, ash yield, sulfur content, calorific value, and selected trace-element contents; and public domain geochemical and stratigraphic databases. The assessment methodology and a few results are presented.

  10. Existing concepts of the formation of the Northern Czech lignite basin

    Energy Technology Data Exchange (ETDEWEB)

    Nurnik, S.

    1982-01-01

    In the Myocene period, the area of sediment accumulation occupied three times more area than the region of the basin's denudation. The Krushnyye Mountains and Czech Midland did not yet exist as orographic units. These morphostructures arose in the Pleistocene epoch. Both morphostructures are currently considered to be an integral part of the large fold.

  11. Fluvio-lacustrine sedimentation and volcanism in a Late Carboniferous tensional intra-arc basin, northern Chile

    Science.gov (United States)

    Breitkreuz, Christoph

    1991-11-01

    Extensive outcrops of Late Carboniferous to Triassic volcanoplutonic magnetic-arc complexes occur in the Andes of northern Chile. In the Salar de Atacama area, terrestrial volcanosedimentary successions include a 200-600 m thick fluvio-lacustrine sequence ("Miembro Medio"). The terrestrial basin which accommodated this sequence formed during the latest Carboniferous on top of the deposits of the pre-existing Carboniferous composite volcanoes. The lower part of the Miembro Medio consists of green limnic and multicoloured alluvial fan deposits; the upper part is made up of red fluvial sedimentary rocks. Basic volcanic rocks occur locally throughout the sequence. The climate is inferred to have been warm and humid. The limnic (freshwater) environment had a minimum extension of 300 × 100 km. Limnic facies is inferred from the existence of fine-parallel-bedded sediments, ooliths and a limnic benthic fauna. Lake-shore deposits prevail in the outcrops. In some sections, the green limnic sequence is followed by red fine-grained floodplain or alluvial plain, and fluvial channel deposits. The framework composition of the Miembro Medio is dominated by volcanogenic detritus presumably eroded from the successions of the previous Late Carboniferous volcanic arc. Another volcanogenic clast type was provided by syndepositional basalto-andesitic phreatomagmatic activity, which also produced peperitic sills, dykes and lavas. The limnic-alluvial fan facies association, the predominance of volcanogenic detritus, and the accompanying intrabasinal basic calc-alkaline volcanism together with the considerable size of the basin point to a ?NW-SE trending half-graben setting controlled by (trans-)tensional arc tectonics. With regard to the Late Carboniferous-Triassic volcanosedimentary successions of northern Chile, this Latest Carboniferous tensional setting is the only feature in this area supporting those models, which inferred an extensional magmatic arc for the entire Central and

  12. Late Quaternary faulting on the Manas and Hutubi reverse faults in the northern foreland basin of Tian Shan, China

    Science.gov (United States)

    Gong, Zhijun; Li, Sheng-Hua; Li, Bo

    2015-08-01

    The Tian Shan Range lies in the actively deforming part of the India-Asia collision zone. In the northern foreland basin of Tian Shan, the strata were intensively deformed by Cenozoic folding and faulting. Slip rate studies along these faults are important for understanding the dynamics of crustal deformation and evaluating the seismic hazards in the region. Two reverse faults (the Manas and Hutubi faults) in the northern foreland basin were investigated. Due to past faulting events along these faults, the terrace treads along the Manas River were ruptured, forming fault scarps several meters in height. Loess deposits were trapped and preserved at the surface ruptures along these scarps. The thickness of the trapped loess is dependent on the size of the ruptures. The minimum and maximum ages of these scarps are constrained by dating the loess preserved at the surface ruptures and the terrace treads, respectively, using the quartz optically stimulated luminescence (OSL) dating technique. Our dating results suggest that the loess trapped at the ruptures was deposited from the early to mid-Holocene at the Hutubi Fault, and from the mid- to late-Holocene at the Manas Fault. The vertical displacements of the faults were evaluated by measuring the topographic profiles across the investigated fault scarps using the differential global position system (DGPS). Our results suggest that, during the late Quaternary in the studied region, the vertical slip rates of the Manas Fault were between ˜ 0.74 mm /yr and ˜ 1.6 mm /yr, while the Hutubi Fault had a much lower vertical slip rate between ˜ 0.34 mm /yr and ˜ 0.40 mm /yr. The tectonic implications of our results are discussed.

  13. What drives basin scale spatial variability of snowpack properties in northern Colorado?

    Science.gov (United States)

    Sexstone, G. A.; Fassnacht, S. R.

    2014-03-01

    This study uses a combination of field measurements and Natural Resource Conservation Service (NRCS) operational snow data to understand the drivers of snow density and snow water equivalent (SWE) variability at the basin scale (100s to 1000s km2). Historic snow course snowpack density observations were analyzed within a multiple linear regression snow density model to estimate SWE directly from snow depth measurements. Snow surveys were completed on or about 1 April 2011 and 2012 and combined with NRCS operational measurements to investigate the spatial variability of SWE near peak snow accumulation. Bivariate relations and multiple linear regression models were developed to understand the relation of snow density and SWE with terrain variables (derived using a geographic information system (GIS)). Snow density variability was best explained by day of year, snow depth, UTM Easting, and elevation. Calculation of SWE directly from snow depth measurement using the snow density model has strong statistical performance, and model validation suggests the model is transferable to independent data within the bounds of the original data set. This pathway of estimating SWE directly from snow depth measurement is useful when evaluating snowpack properties at the basin scale, where many time-consuming measurements of SWE are often not feasible. A comparison with a previously developed snow density model shows that calibrating a snow density model to a specific basin can provide improvement of SWE estimation at this scale, and should be considered for future basin scale analyses. During both water year (WY) 2011 and 2012, elevation and location (UTM Easting and/or UTM Northing) were the most important SWE model variables, suggesting that orographic precipitation and storm track patterns are likely driving basin scale SWE variability. Terrain curvature was also shown to be an important variable, but to a lesser extent at the scale of interest.

  14. Characteristics of high arsenic groundwater in Hetao Basin, Inner Mongolia, northern China

    Institute of Scientific and Technical Information of China (English)

    YangChun Zhu; XueYong Zhao; Min Chen; YongQing Luo; Xin Zhou

    2015-01-01

    It is well known that the Hetao Basin is one of the most seriously arsenic-affected groundwater areas in China. In order to understand the characteristics of high arsenic (As) groundwater in the Basin, a brief overview of arsenic in groundwater follows. High arsenic in the Basin commonly occurs in shallow groundwater and the total arsenic concentrations range from 0.58 to 572 µg/L (average 99.73 µg/L), exceeding the maximum mandated value of 10 µg/L for drinking water in China;As(Ш) is the predominant species. The regional distribution pattern of arsenic in the groundwater increases from south/southeast to north/northwest. Hangjinhouqi and Wuyuan counties are considered as the most seriously affected areas, with high incidences of endemic arsenicosic diseases in the Hetao Basin. High groundwater arsenic correlates with the increase of well depth. Previous studies proposed that groundwater arsenic in the Basin is mainly originated from desorption of some natural solid materials in the sediments, under reducing condition. Generally, reducing condition is believed to be the primary factor for arsenic releasing from the sediment to groundwater in the region. Under inorganic or bacterial processes, Fe2O3 changes to FeS and arsenic adsorbed to Fe(OH)3 dissolves into groundwater, and As(V) is re-duced to As(Ш). Besides, reducing environments, groundwater hydraulic gradients, organic matter, pH, evapotranspiration, and soil texture are presumed to be the predominant factors that control arsenic mobilization.

  15. Unroofing around Qaidam Basin of northern Tibet at 30 Ma:constraints from 40Ar/39Ar and FT thermochronology on granitoids

    Institute of Scientific and Technical Information of China (English)

    王非; 罗清华; 李齐; 万京林; 郑德文; 王二七

    2002-01-01

    An 40Ar/39Ar and fission track thermochronological study has been carried out on three suites of granitoids collected along the northern and southern edges of the Qaidam Basin to better constrain the mechanisms accommodating the India-Asia collision around the Qaidam Basin (northern Tibet), in order to understand the evolution of the entire deformation area. Mica and K-feldspar have been analyzed and the cooling histories of the latter have been modeled. The cooling histories based upon K-feldspar modeling and fission track ages show that samples simultaneously recorded an important cooling event (7.5-10.7℃/Ma) around 30 Ma, which is thought to reflect an increase of denudation rate related to the tectonic activity in this area associated with uplift suggesting significant crustal thickening starting around 30 Ma in this area. The estimated sedimentation rate in the Qaidam Basin, the propagation rate along the Altyn Tagh fault and field observations support this deduction.

  16. The importance of diverse data types to calibrate a watershed model of the Trout Lake Basin, Northern Wisconsin, USA

    Science.gov (United States)

    Hunt, Randall J.; Feinstein, Daniel T.; Pint, Christine D.; Anderson, Mary P.

    2006-04-01

    As part of the USGS Water, Energy, and Biogeochemical Budgets project and the NSF Long-Term Ecological Research work, a parameter estimation code was used to calibrate a deterministic groundwater flow model of the Trout Lake Basin in northern Wisconsin. Observations included traditional calibration targets (head, lake stage, and baseflow observations) as well as unconventional targets such as groundwater flows to and from lakes, depth of a lake water plume, and time of travel. The unconventional data types were important for parameter estimation convergence and allowed the development of a more detailed parameterization capable of resolving model objectives with well-constrained parameter values. Independent estimates of groundwater inflow to lakes were most important for constraining lakebed leakance and the depth of the lake water plume was important for determining hydraulic conductivity and conceptual aquifer layering. The most important target overall, however, was a conventional regional baseflow target that led to correct distribution of flow between sub-basins and the regional system during model calibration. The use of an automated parameter estimation code: (1) facilitated the calibration process by providing a quantitative assessment of the model's ability to match disparate observed data types; and (2) allowed assessment of the influence of observed targets on the calibration process. The model calibration required the use of a 'universal' parameter estimation code in order to include all types of observations in the objective function. The methods described in this paper help address issues of watershed complexity and non-uniqueness common to deterministic watershed models.

  17. Seismic imaging and analysis of source and migration within an integrated hydrocarbon system study: Northern Gulf of Mexico Basin

    Energy Technology Data Exchange (ETDEWEB)

    Gross, Oliver P.; Hood, Kenneth C.; Harrison, Stanley C. [Exxon Exploration Co., Houston, TX (United States); Wenger, Lloyd M. [Exxon Production Research Co., Houston, TX (United States)

    1995-12-31

    The sources for hydrocarbons in young Tertiary reservoirs of the offshore Gulf of Mexico have been enigmatic in the past due to the lack of source rock penetration in offshore drilling. Exxon formed a multidisciplinary team to address source, maturation, and migration in the northern Gulf of Mexico. The study was initiated in a pilot area east of the Mississippi River Delta where the complete hydrocarbon system can be seismically imaged, then expanded to the west across much of the shelf and slope. Hydrocarbons from seeps and reservoirs were geochemically characterized across the entire northern Gulf of Mexico Basin, and direct oil to source rock correlations were made both offshore (in pilot area) and onshore. Modern 2-D and 3-D seismic was used to develop a geologic framework and to map potential offshore source intervals. The major sources identified offshore are centered on the Eocene, Turonian, Tithonian, and Oxfordian, and correspond to second-order sequence stratigraphic transgressions. (author). 1 fig., 1 tab

  18. FOREIGN POLICY ON THE SLOPES OF CAUCASUS

    Directory of Open Access Journals (Sweden)

    Attila IAKOB

    2015-10-01

    Full Text Available The past years showed to the world and to the European Union that classical approaches are not enough to be a power breaker in the Caucasian region, where the overlap of history, myth, and cultures creates a unique geopolitical context marked by century old grudges and imaginary or real socio-economical issues. It is clear that concepts like “ring of friends” or Eastern Partnership need a rebranding and an upgrade due to contemporary context changes. Russian expansion, Turkish political shifts, Ukrainian crisis, Iranian ambitions, Kurd issues, energy policies and socio-economical convulsions are defining the new shape of the geographical areas on both side of the Caucasus Mountain. In this context the European leadership needs to rethink the foreign policy approach to the region and to create a new set of actions in this context. This difficult task is needed not only from the perspective of Europe’s energetic security but from the point of regional stability, because Europe and its global development depend on its involvement in the neighboring regions. From this perspective our paper would like to analyze and create a realistic image on the dynamic of the relations of EU with the countries in this region and the perspectives in the contemporary context where the overlapping geopolitical interests are making this region a key one for several future issues.

  19. Interactions between basement and cover during the evolution of the Salar de Atacama Basin, northern Chile

    OpenAIRE

    Nelson Muñoz; Reynaldo Charrier; Teresa Jordan

    2002-01-01

    ABSTRACT A reinterpretation of the structural style on the eastern Cordillera Domeyko and the adjacent Salar de Atacama Basin reveals the existence of west-dipping, high-angle, thrust-faults extending below the Cordillera Domeyko and Cordón de Lila, resulting from inversion of Cretaceous extensional faults, that transferred west-ward their displacement into the cover, generating fault-propagation and detachment folds. The most conspicuous of these structures is the Cordillera de la Sal. Contr...

  20. CLIMATE CHANGE IN NORTHERN AFRICA: TOWARDS A RETURN OF RAINFALL ON THE SOUTHERN MEDITERRANEAN BASIN

    OpenAIRE

    NOUACEUR ZEINEDDINE; Laignel, B.; TURKI IMEN; JEMAI HIBA

    2014-01-01

    To determine to what extent climate change affects the rainfall recorded on the southern Mediterranean basin, a trend analysis is proposed. This study is based on the chronological graphic method of processing information (MGCTI) of type "Matrice Bertin". Results show an extreme variability of the precipitations and a severe drought, especially for Morocco, observed since 1970s. Finally, a gradual return to humid conditions is observed from the beginning of the 2000s in Algeria and Tunisia an...

  1. Effects of precipitation and potential evaporation on actual evapotranspiration over the Laohahe basin, northern China

    OpenAIRE

    Y. LIU; L Ren; X. Yang; M. Ma; Yuan, F.; Jiang, S.

    2015-01-01

    Problems associated with water scarcity are facing new challenges under the climate change. As one of main consumptions in water cycle on the Earth, evapotranspiration plays a crucial role in regional water budget. In this paper, we employ two methods, i.e. hydrological sensitivity analysis and hydrological model simulation, to investigate the effect of climate variability and climatic change on actual evapotranspiration (Ea) within the Laohahe basin during 1964–2009. Calibr...

  2. Chronostatigraphic basin framework for Palaeoproterozoic rocks (1730-1575 Ma) in northern Australia and implications of base-metal mineralisation

    International Nuclear Information System (INIS)

    The new chronostratigraphic subdivision for Palaeoproterozoic rocks of northern Australia provides an improved framework for future resource exploration. The nine supersequence boundaries identified in the ca 1730-1575Ma Calvert and Isa Superbasins enable the timing of major tectonic events and their stratigraphic response to be better understood. Third- and 4th-order sequence boundaries facilitate the determination of stratigraphic architecture, ultimately providing the necessary information for constraining the flow of fluids in these basins. SHRIMP zircon ages are essential for determining the magnitude of depositional hiatuses at supersequence and some sequence boundaries, and together with palaeomagnetic data provide independent age constraints for the sequence interpretations. Pb/Pb model ages for the world class Broken Hill, Mt Isa, McArthur River and Century Zn Pb Ag deposits coincide with tectonic events recorded at the Gun, Loretta, River Supersequence boundaries and the superbasin boundary formed during closure of the Isa Superbasin during D2 at Mt Isa. The coincidence of a Pb/Pb model age for Broken Hill with an apparent polar wander path inflection at the Gun Supersequence boundary indicates that the regional chronostratigraphic basin framework developed for northern Australia is applicable to rocks of similar age elsewhere in Australia. Furthermore, if the ultimate cause of these inflections is interplate stress, the basin framework should be globally applicable. Hand-held spectrometers provide an efficient and cost-effective method for collecting gamma-ray data from outcrops. The resulting gamma-ray curves permit more accurate correlation with subsurface stratigraphies and together with facies information facilitate the identification of stratigraphic sequences and their bounding stratal surfaces, the essential building blocks of regional chronostratigraphic correlations. Contrary to general belief most of the sections measured in this study preserve

  3. [FLEAS (SIPHONAPTERA) OF MAMMALS AND BIRDS IN THE GREAT CAUCASUS].

    Science.gov (United States)

    Kotti, B K

    2015-01-01

    There are 116 species of fleas in the territory of the Great Caucasus. 21 species are parasites of birds, others are the fleas of mammals. Among 41 genera of Caucasus' fauna only Caenopsylla, Phaenopsylla and Araeopsylla are absent in the Great Caucasus. There are 11 endemic species. Fleas of 66 species are distributed along all mountain system. Parasites of some birds and carnivorous mammals, insectivores and rodents live from lowlands till highlands. Some species are living at the forest altitudinal belt, others prefer the foothills and the mid-height areas; they are absent atthe highlands. Their hosts may live at all longitudinal belts; the distribution of other species is limited to lowlands in accordance with distribution of their main hosts. PMID:26827488

  4. Thermochronological evolution of the Eastern Pontides and the Eastern Anatolian Plateau and NW Lesser Caucasus (Turkey, Georgia, Armenia)

    OpenAIRE

    Albino, Irene

    2013-01-01

    The analysis of apatite fission tracks is applied to the study of the syn- and post-collisional thermochronological evolution of a vast area that includes the Eastern Pontides, their continuation in the Lesser Caucasus of Georgia (Adjara-Trialeti zone) and northern Armenia, and the eastern Anatolian Plateau. The resulting database is then integrated with the data presented by Okay et al. (2010) for the Bitlis Pütürge Massif, i.e. the western portion of the Bitlis-Zagros collision zone between...

  5. Caucasus and the petroleum stakes of Caspian Sea

    International Nuclear Information System (INIS)

    The splitting of the former USSR block in 1991 has generated a shock wave in the Caucasus area with the will of all ex-soviet republics to reach their complete independence. Because of the historical and geographical complexity of Caucasus, both geopolitical and human, this disorder has generated even more hazardous results, enhanced by the coveted oil and gas reserves of the Caspian Sea. This article analyses the petroleum stakes as factors of rivalry and instability (sovereignty of oil and gas fields, rivalries about the exploitation and transport of hydrocarbons), but also as factors of cooperation and re-composition. (J.S.)

  6. CLIMATE CHANGE IN NORTHERN AFRICA: TOWARDS A RETURN OF RAINFALL ON THE SOUTHERN MEDITERRANEAN BASIN

    Directory of Open Access Journals (Sweden)

    NOUACEUR ZEINEDDINE

    2014-03-01

    Full Text Available To determine to what extent climate change affects the rainfall recorded on the southern Mediterranean basin, a trend analysis is proposed. This study is based on the chronological graphic method of processing information (MGCTI of type "Matrice Bertin". Results show an extreme variability of the precipitations and a severe drought, especially for Morocco, observed since 1970s. Finally, a gradual return to humid conditions is observed from the beginning of the 2000s in Algeria and Tunisia and since 2008 in Morocco. This new trend is also confirmed by recent results provided by agricultural data of 2011/2012 and 2012/2013.

  7. Hydrogeochemistry of high iodine groundwater: a case study at the Datong Basin, northern China.

    Science.gov (United States)

    Li, Junxia; Wang, Yanxin; Xie, Xianjun; Zhang, Liping; Guo, Wei

    2013-04-01

    High iodine concentrations in groundwater have seldom been reported and there have been few systematic studies on high iodine groundwater worldwide. To better understand the sources and processes responsible for iodine enrichment in the groundwater of the Datong Basin, the hydrochemical characteristics of groundwater and geochemical features of aquifer sediments were studied. High iodine groundwater mainly occurs in the center of the Datong Basin with iodine concentrations ranging between 3.31 and 1890 μg L(-1). Most samples with iodine concentrations higher than 500 μg L(-1) are from wells with depths between 75 and 120 m. High pH and a reducing environment are favorable for iodine enrichment in the groundwater, with iodide as the dominant species that accounts for 63.2-99.3% of the total iodine. Sediment samples from a borehole specifically drilled for this study contain 0.18-1.46 mg kg(-1) iodine that is moderately correlated with total organic carbon (TOC). The results of sequential extraction experiments show that iodine is mostly bound to iron oxyhydroxides and organic matter in the sediments. The mobilization processes of iodine are proposed to include reductive dissolution of iron oxyhydroxides and transformations among iodide, iodate and organic iodine driven by microbial activities under alkaline and reducing conditions. PMID:23478640

  8. Snow cover dynamics and hydrological regime of the Hunza River basin, Karakoram Range, Northern Pakistan

    Directory of Open Access Journals (Sweden)

    A. A. Tahir

    2011-07-01

    Full Text Available A major proportion of flow in the Indus River is contributed by its snow- and glacier-fed river catchments situated in the Himalaya, Karakoram and Hindukush ranges. It is therefore essential to understand the cryosphere dynamics in this area for water resource management. The MODIS MOD10A2 remote-sensing database of snow cover products from March 2000 to December 2009 was selected to analyse the snow cover changes in the Hunza River basin (the snow- and glacier-fed sub-catchment of the Indus River. A database of daily flows for the Hunza River at Dainyor Bridge over a period of 40 yr and climate data (precipitation and temperature for 10 yr from three meteorological stations within the catchment was made available to investigate the hydrological regime in the area. Analysis of remotely sensed cryosphere (snow and ice cover data during the last decade (2000–2009 suggest a rather slight expansion of cryosphere in the area in contrast to most of the regions in the world where glaciers are melting rapidly. This increase in snow cover may be the result of an increase in winter precipitation caused by westerly circulation. The impact of global warming is not effective because a large part of the basin area lies under high altitudes where the temperature remains negative throughout most of the year.

  9. INNOVATIVE METHODOLOGY FOR DETECTION OF FRACTURE-CONTROLLED SWEET SPOTS IN THE NORTHERN APPALACHIAN BASIN

    Energy Technology Data Exchange (ETDEWEB)

    Robert Jacobi; John Fountain

    2001-02-28

    In the structure task, we completed a N-S transect east of Seneca Lake that indicated a N-striking fault near the southeastern shore of Seneca Lake, and also indicated NE and ENE-trending FIDs and faults north of Valois. The orientation and existence of the NE-striking FIDs and faults are thought to be controlled by basement faults, rather than thrust ramps above the Salina salt controlled only by a far-field Alleghanian stress field. Structure contour maps based on well log analyses have been constructed but not interpreted. Soil gas data displayed a number of ethane-charged soil gas ''spikes'' on a N-S transect from Ovid south to near Valois. The soil gas team found a larger number of spikes in the northern half of the survey, suggesting more open fractures (and faults) in the northern half of the survey. Seismic data has been purchased and reprocessed. Several grabens observed in the Trenton reflector are consistent with surface structure, soil gas, and aeromagnetic anomalies. The aeromagnetic survey is completed and the data is processed. Prominent magnetic anomalies suggest that faults in the Precambrian basement are located beneath regions where grabens in the Trenton are located.

  10. Interactions between basement and cover during the evolution of the Salar de Atacama Basin, northern Chile

    Directory of Open Access Journals (Sweden)

    Nelson Muñoz

    2002-07-01

    Full Text Available ABSTRACT A reinterpretation of the structural style on the eastern Cordillera Domeyko and the adjacent Salar de Atacama Basin reveals the existence of west-dipping, high-angle, thrust-faults extending below the Cordillera Domeyko and Cordón de Lila, resulting from inversion of Cretaceous extensional faults, that transferred west-ward their displacement into the cover, generating fault-propagation and detachment folds. The most conspicuous of these structures is the Cordillera de la Sal. Contractional structures in the Cordillera Domeyko involved a Paleozoic crystalline, volcanic, and sedimentary, uplifted basement. Seismic reflection sections and available surface geology allows to study the interactions between development of the thick-skinned basement structures, sedimentation within the basin, and the thin-skinned deformation in the sedimentary cover. Geometry of the units in the basin continuously modified. Anticline growth above basement thrust-faults locally controlled syn-thrusting sequences, and generated progressive unconformities. Stratigraphic architecture in the basin seems to have been mainly controlled by tectonic activity. Tectonism generated accommodation space, altered base levels, and controlled source areas. The stratigraphy and geometry of the basin deposits resulted mainly from the succession of the following events: local extensional subsidence during the Early to Late Cretaceous, uplift of the Cordillera Domeyko during the latest Cretaceous to Miocene, uplift of the Puna, and subsidence probably caused by flexural response of the lithosphere during thrust-sheet loading, and sediment accumulationRESUMEN Interacciones entre el basamento y la cobertura durante la evolución de la Cuenca del Salar de Atacama, norte de Chile. La reinterpretación del estilo estructural del borde oriental de la Cordillera Domeyko y de la adyacente cuenca del Salar de Atacama, basada en el análisis de la geología de superficie y de perfiles s

  11. Tectonics and paleogeography of the Marajó Basin, northern Brazil

    Directory of Open Access Journals (Sweden)

    JOÃO B. S. COSTA

    2002-09-01

    Full Text Available The Marajó Basin area presents geologic and geomorphologic features chiefly due to the Mesozoic extension and post-Miocene neotectonics. The extension event with an Early and a Late Cretaceous phases originated four sub-basins that constitutes the Marajó Basin, with a thick continental clastic sequence showing marine influence. NW and NNW normal faults and NE and ENE strike-slip faults controlled the basin geometry. The extension, related to the Equatorial Atlantic opening, propagated into the continent along crustal weakness zones of the Precambrian Tumucumaque, Amapá and Araguaia orogenic belts. The neotectonic event is a strike-slip regime which developed transtensional basins filled in by Upper Tertiary shallow marine (Pirabas Formation and transitional sequences (Barreiras Group, followed by Quaternary fluvial deposits and transitional sequences derived from the Amazon and Tocantins rivers and the Marajoara estuary. The current landscape has a typical estuarine morphology. The coast morphology presents sea-cliffs on transitional Upper Tertiary sequences, while inwards dominate hills sustained by Mid-Pleistocene lateritic crust, with a flat erosive surface at 70 m. In the eastern Marajó Island several generations of paleochannels associated with fluvial-estuarine sequences are recognized, while a fluvial-marine plain is widespread on its western side.A área da Bacia do Marajó apresenta feições geológicas e geomorfológicas devidas principamente à distensão Mesozóica e à neotectônica pós-miocênica. O evento de distensão, com fases do Cretáceo Inferior e Superior, originou quatro sub-bacias que contituem a Bacia do Marajó, com uma espessa seqüência clástica continental mostrando influência marinha. Falhas normais NW e NNW e direcionais NE e ENE controlaram a geometria da bacia. A distensão, relacionada com a abertura do Atlântico Equatorial, propagou-se continente adentro ao longo de zonas de fraqueza crustal dos

  12. Spatio-temporal snow cover change and hydrological characteristics of the Astore, Gilgit and Hunza river basins (western Himalayas, Hindukush and Karakoram region) - Northern Pakistan

    Science.gov (United States)

    Tahir, Adnan Ahmad; Chevallier, Pierre; Arnaud, Yves; Lane, Stuart; Terzago, Silvia; Adamowski, Jan Franklin

    2015-04-01

    A large proportion of Pakistan's irrigation water supply is drawn from the Upper Indus River Basin (UIB) situated in the Himalaya-Karakoram-Hindukush (HKH) ranges. More than half of the annual flow in the UIB is contributed by five of its high-altitude snow and glacier-fed sub-basins including the Astore (Western Himalaya - southern part of the UIB), Gilgit (Hindukush - western part of the UIB) and Hunza (Central Karakoram - northern part of the UIB) River basins. Studying the snow cover, its spatio-temporal evolution and the hydrological response of these sub-basins is important so as to better manage water resources. This study compares data from the Astore, Gilgit and Hunza River basins (mean catchment elevation, 4100, 4250 and 4650 m ASL, respectively), obtained using MODIS satellite snow cover images. The hydrological regime of these sub-catchments was analyzed using hydrological and climate data available at different altitudes from the basin areas. The results suggest that the UIB is a region undergoing a stable or slightly increasing trend of snow cover in the southern (Western Himalayas), western (Hindukush) and northern (Central Karakoram) parts. Discharge from the UIB is a combination of snow and glacier melt with rainfall-runoff in the southern part, but snow and glacier melt is dominant in the northern and western parts of the catchment. Despite similar snow cover trends (stable or slightly increasing), different river flow trends (increasing in Astore and Gilgit, decreasing in Hunza) suggest that a sub-catchment level study of the UIB is needed to understand thoroughly its hydrological behavior for better flood forecasting and water resources management and to quantify how the system is being forced by changing climate.

  13. Sedimentological and geochronological evidences of anthropogenic impacts on river basins in the Northern Latium coastal area (Italy)

    Science.gov (United States)

    Piazzolla, Daniele; Paladini de Mendoza, Francesco; Scanu, Sergio; Marcelli, Marco

    2015-04-01

    In this work we aimed to compare sedimentological and geochronological data from three sediment core samples (MIG50, MRT50, and GRT50) taken in the Northern Latium (Italy) coastal area, at -50 m depth, to data regarding rainfall, river flows and the land use in the three most important hydrographic basins (Mignone, Marta and Fiora) and in the coastal area. Different trends of sediment mass accumulation rate (MAR) are detected in the three cores: a strongly increasing trend was identified in MIG50 and MRT50 cores while GRT50 doesn't show significant variation. Data from the sedimentological analysis of GRT50 core identify a progressive decrease in the sandy component, which declined from about 30% to the current level of 7% over the last 36 years, while MRT50 and MIG50 cores (mainly composed by pelitic fraction > 95%) showed slight variations of textural ratio between silt and clay. According to the general decrease of pluviometric trend observed in Italy, related to teleconnection pattern tendency (NAO), the statistical analysis of rain identified significative decrease only in the Fiora river basin, whereas in the other two locations the decrease was not as significant. Regarding the Fiora river flow, a significative decreasing trend of average flow is detected, while the flood regime remained unaffected over the past 30 years. The analysis of the land use shows that the human activities are increased of 6-10% over the available time steps (1990 - 2006) in Fiora and Mignone river basins, while the Marta river basin has a strong human impact since 1990 highligting more than 80% of artificial soil covering. The largest variation is observed on the Fiora basin (10%) where the antrhopic activities have expanded to an area of about 85 Km2. Moreover, in the last ten years a large beach nourishment in 2004 (570000 m3) and dredging activities in the early second half of 2000s (1000000 m3 moved) were performed in Marina di Tarquinia beach and in front of the Torrevaldaliga

  14. Two new species of Pseudancistrus (Siluriformes, Loricariidae from the Amazon basin, northern Brazil

    Directory of Open Access Journals (Sweden)

    Gabriel da Costa e Silva

    2015-02-01

    Full Text Available Two new species of Pseudancistrus, a genus diagnosed by non-evertible cheek plates and hypertrophied odontodes along the snout margin, are described from two drainages of the Brazilian Shield: P. kayabi from the rio Teles Pires (rio Tapajós basin and P. asurini from the rio Xingu. The new species are distinguished from congeners (P. barbatus, P. corantijniensis, P. depressus, P. nigrescens, P. reus, and P. zawadzkii by the coloration pattern. Pseudancistrus kayabi has dark bars on the dorsal and caudal fins which are similar to that of P. reus from the Caroní River, Venezuela. Pseudancistrus asurini is unique among Pseudancistrus in having whitish tips of the dorsal and caudal fins in juveniles to medium-sized adults.

  15. Shelf-edge sedimentary systems off Rio de Janeiro State, northern Santos basin-Brazil

    Science.gov (United States)

    Maia, R. M. C.; Dos Reis, A. T.; Gorini, C.; Silva, C. G.; Rabineau, M.; Granjeon, D.

    2012-04-01

    elements provide a hint at a prevailing subsidence regime and effective sediment supply into the basin that clearly contrast with the conveyed idea of a sediment-starved and tectonic stable shelf. They naturally raise questions about the nature and origin of sediment supply, since no significant point siliciclastic fluvial source flows directly into the shelf. Stemming from that, we are forced to speculate about: (A) the role of neotectonic movements involving the Serra do Mar coastal mountain ranges to potentially source clastic influx into the basin during the Quaternary, or about the real importance of secondary drainage basins debouching today; and (B) the mechanical nature of a supposed subsidence during the Pliocene and the Quaternary time span (overloading ? sediment compaction ? thermal cooling ?). The interpretation of industrial seismic lines can provide the answers of many of these questions. The next step of this work is to make a stratigraphy model of the sedimentary systems of Santos basin to understand how the ancient creation of accommodation space can influence the recent sedimentary architecture and how is the change in sedimentary influx and the sedimentary records of different orders of cyclicity.

  16. Organic geochemical characterisation of shallow marine Cretaceous formations from Yola Sub-basin, Northern Benue Trough, NE Nigeria

    Science.gov (United States)

    Sarki Yandoka, Babangida M.; Abdullah, Wan Hasiah; Abubakar, M. B.; Hakimi, Mohammed Hail; Jauro, Aliyu; Adegoke, Adebanji Kayode

    2016-05-01

    The shallow marine shales of the Cretaceous formations namely Yolde, Dukul, Jessu, Sekuliye and Numanha ranging in age from Cenomanian to Coniacian within the Yola Sub-basin in the Northern Benue Trough, northeastern Nigeria were analysed to provide an overview on their hydrocarbon generation potential. This study is based on pyrolysis analysis, total organic carbon content (TOC), extractable organic matter (EOM), biomarker distributions and measured vitrinite reflectance. The present-day TOC contents range between 0.24 and 0.71 wt. % and Hydrogen Index (HI) values between 8.7 and 113 mg HC/g TOC with Type III/IV kerogens. Based on the present-day kerogen typing, the shale sediments are expected to generate mainly gas. Biomarker compositions indicates deposition in a marine environment under suboxic conditions with prevalent contribution of aquatic organic matter and a significant amount of terrigenous organic matter input. Organic matter that is dominated by marine components contains kerogens of Type II and Type II-III. This study shows that the organic matter has been affected by volcanic intrusion and consequently, have reached post-mature stage of oil generation. These higher thermal maturities levels are consistent with the vitrinite reflectance ranging from 0.85 to 2.35 Ro % and high Tmax (440-508 °C) values as supported by biomarker maturity ratios. Based on this study, a high prospect for major gas and minor oil generation potential is anticipated from the shallow marine Cretaceous formations from Yola Sub-basin.

  17. Late Pleistocene shortening rate on the northern margin of the Yanqi Basin, southeastern Tian Shan, NW China

    Science.gov (United States)

    Huang, Wei-liang; Yang, Xiao-ping; Li, An; Pierce, Ian K. D.; Thompson, Jessica A.; Angster, Stephen J.; Zhang, Ling

    2015-11-01

    How strain is distributed and partitioned on individual faults and folds on the margins of intermontane basins remains poorly understood. The Haermodun (Ha) anticline, located along the northern margin of the intermontane Yanqi Basin on the southeastern flank of the Tian Shan, preserves flights of passively deformed alluvial terraces. These terraces cross the active anticline and can be used to constrain local crustal shortening and uplift rates. Geologic and geomorphic mapping, in conjunction with high-resolution dGPS topographic surveys, reveal that the terrace surfaces are perpendicular to the fold's strike, and display increased rotation with age, implying that the anticline has grown by progressive limb rotation. Combined with the open sinusoidal curve model and excess area method, we calculated uplift and shortening values for each terrace since abandonment. Using the published exposure ages of each terrace, we found the vertical uplift rate gradually decreased from ∼0.43 to ∼0.11 mm/a, whereas the shortening rate remained constant at ∼0.3 mm/a since the anticline began to grow. A fresh fault scarp, 0.4 ± 0.1 m high, is visible along the southern portion of the Ha anticline, and is interpreted to be the most recent evidence of seismic activity. Using an estimated rupture area and the length of the fresh offset created by this earthquake, we estimate that the main thrust underlying the Ha anticline has generated moderate (M < 7) earthquakes in the past. The shortening rates of the Ha anticline from geomorphology agree with current GPS measurements cover-over the fold, and highlight the importance of determining slip rates for individual faults in order to resolve patterns of strain distribution across intermontane belts.

  18. Occurrence, behavior and distribution of high levels of uranium in shallow groundwater at Datong basin, northern China

    International Nuclear Information System (INIS)

    Geochemical investigations of uranium (U) occurrence in the environments were conducted at Datong basin of northern China. The results suggest that U contents were generally 22+) species is dominant and strongly adsorbed onto iron (hydro)xides, while it would be preferentially complexed with carbonate in the alkaline groundwater, forming highly soluble uranyl-carbonate complexes at Datong. Under reducing conditions, uranous (U(IV)) species is ready to precipitate or bind to organic matter, therefore having a low mobility. At the study area, high U groundwater (> 30 μg/L) occurs at the alluvial plains due to intermediate redox and enhanced alkaline conditions. The abnormally high levels of U in groundwater (> 100 μg/L) are locally found at the west alluvial plains. By contrast, U co-precipitation with secondary carbonate minerals like Ca2UO2(CO3)3 in the dominant Ca–Mg–Na–HCO3 type groundwater may prevail at the east alluvial plains. Besides, bedrocks such as Carboniferous and Permian sedimentary rocks, especially the coal-bearing strata which have higher U contents at the west mountain areas may also account for the abnormally high levels of U in groundwater. - Highlights: • High U groundwater occurs at the alluvial plains of Datong basin. • Redox state, complexation and adsorption are responsible for U enrichment. • Carboniferous and Permian sedimentary rocks have higher U contents at Datong. • Uranyl is preferentially complexed with carbonate in groundwater. • U in the aquifer sediments may be primarily associated with carnotite

  19. ATTENUATION OF SEISMIC WAVES IN THE LITHOSPHERE OF THE NORTHERN PART OF THE BASIN AND RANGE PROVINCE

    Directory of Open Access Journals (Sweden)

    А. А. Dobrynina

    2015-09-01

    Full Text Available This paper presents results of the study of attenuation of seismic waves in the lithosphere and upper mantle of the northern part of the Basin and Range Province (BRP (Fig. 1. In this study, the coda-wave method [Aki, Chouet, 1975] is applied to process data collected in the seismic experiment conducted in 1988–1989, PASSCAL Basin and Range Passive Seismic Experiment [Owens, Randall, 1989], including records of 66 earthquakes and explosions (Mb=1.1–5.0 which occurred in BRP (Fig. 2.The effective seismic quality factor by the coda is calculated using the single-backscattering model [Aki, Chouet, 1975]. The QC values are calculated for 18 values of the lapse time window W from 10 to 95 sec with the step of 5 sec at six (6 central frequencies (0.3, 0.75, 1.5, 3.0, 6.0, and 12.0 Hz. In total, 7776 individual measurements of QC were done. It is observed that the quality factor QC is strongly dependent on the frequency and the lapse time window W: QC increases from 12±6 to 359±17 for the central frequencies of 0.3 and 12.0 Hz when the lapse time window is W=10 sec and from 87±6 to 1177±87 for the same frequencies when W=95 sec (Fig. 6. On the basis of the QС values obtained for all the lapse time windows W empirical relationships of quality factors and frequencies are calculated according to [Mitchell, 1981], and values of quality factor Q0 at reference frequency f0 (f0=1 Hz and frequency parameter n (which is close to 1 and varies depending on the heterogeneity of the medium [Aki, 1981] are obtained. In this study, Q0 varies from 60±8 to 222±17, the frequency parameter ranges from 0.57±0.04 to 0.84±0.05, and the attenuation coefficient δ varies from 0.015 to 0.004 km–1, depending on W (Fig. 8; similar values of attenuation parameters are typical of regions with high tectonic activity [Mak et al., 2004].In the single-backscattering model, the dependence of the attenuation parameters from the lapse time window can be explained in terms

  20. Military co-operation with South Caucasus countries / Rafal Seniuch

    Index Scriptorium Estoniae

    Seniuch, Rafal

    2003-01-01

    Ettekanne Poola ja Lõuna-Kaukaasia vabariikide vahelisest sõjalis-poliitilisest koostööst 22.-23. septembrini 2003 Vilniuses toimunud seminaril "South Caucasus: making the best use of external assistance for stability building and for co-operation with NATO"

  1. THE OSSETS IN THE SOUTHERN CAUCASUS: NATIVES OR NEWCOMERS?

    OpenAIRE

    Bubenok, Oleg

    2007-01-01

    This article takes a look at the formation of the Ossetian ethnos in the Southern Caucasus. The author attempts to analyze the different approaches to this issue, particularly those relating to the ethnogenesis and identification of the Ossets, and to coordinate these processes with possible ways to settle the South Osset-Georgian ethnopolitical conflict.

  2. Seismic reflection-based evidence of a transfer zone between the Wagner and Consag basins: implications for defining the structural geometry of the northern Gulf of California

    Science.gov (United States)

    González-Escobar, Mario; Suárez-Vidal, Francisco; Hernández-Pérez, José Antonio; Martín-Barajas, Arturo

    2010-12-01

    This study examines the structural characteristics of the northern Gulf of California by processing and interpreting ca. 415 km of two-dimensional multi-channel seismic reflection lines (data property of Petróleos Mexicanos PEMEX) collected in the vicinity of the border between the Wagner and Consag basins. The two basins appear to be a link between the Delfín Superior Basin to the south, and the Cerro Prieto Basin to the north in the Mexicali-Imperial Valley along the Pacific-North America plate boundary. The seismic data are consistent with existing knowledge of four main structures (master faults) in the region, i.e., the Percebo, Santa María, Consag Sur, and Wagner Sur faults. The Wagner and Consag basins are delimited to the east by the Wagner Sur Fault, and to the west by the Consag Sur Fault. The Percebo Fault borders the western margin of the modern Wagner Basin depocenter, and is oriented N10°W, dipping (on average) ˜40° to the northeast. The trace of the Santa María Fault located in the Wagner Basin strikes N19°W, dipping ˜40° to the west. The Consag Sur Fault is oriented N14°W, and dips ˜42° to the east over a distance of 21 km. To the east of the study area, the Wagner Sur Fault almost parallels the Consag Sur Fault over a distance of ˜86 km, and is oriented N10°W with an average dip of 59° to the east. Moreover, the data provide new evidence that the Wagner Fault is discontinuous between the two basins, and that its structure is more complex than previously reported. A structural high separates the northern Consag Basin from the southern Wagner Basin, comprising several secondary faults oriented NE oblique to the main faults of N-S direction. These could represent a zone of accommodation, or transfer zone, where extension could be transferred from the Wagner to the Consag Basin, or vice versa. This area shows no acoustic basement and/or intrusive body, which is consistent with existing gravimetric and magnetic data for the region.

  3. Did Oligocene crustal thickening precede basin development in northern Thailand? A geochronological reassessment of Doi Inthanon and Doi Suthep

    Science.gov (United States)

    Gardiner, Nicholas J.; Roberts, Nick M. W.; Morley, Christopher K.; Searle, Michael P.; Whitehouse, Martin J.

    2016-01-01

    The Doi Inthanon and Doi Suthep metamorphic core complexes in northern Thailand are comprised of amphibolite-grade migmatitic gneisses mantled by lower-grade mylonites and metasedimentary sequences, thought to represent Cordilleran-style core complexes exhumed through the mobilization of a low-angle detachment fault. Previous studies have interpreted two metamorphic events (Late Triassic and Late Cretaceous), followed by ductile extension between the late Eocene and late Oligocene, a model which infers movement on the detachment at ca. 40 Ma, and which culminates in a rapid unroofing of the complexes in the early Miocene. The Chiang Mai Basin, the largest such Cenozoic Basin in the region, lies immediately to the east. Its development is related to the extension observed at Doi Inthanon and Doi Suthep, however it is not definitively dated, and models for its development have difficulty reconciling Miocene cooling ages with Eocene detachment movement. Here we present new in-situ LA-ICP-MS and SIMS U-Pb age data of zircon and monazite grains from gneiss and leucogranite samples taken from Doi Inthanon and Doi Suthep. Our new zircon data exhibit an older age range of 221-210 Ma, with younger ages of ca. 72 Ma, and 32-26 Ma. Our monazite data imply an older age cluster at 83-67 Ma, and a younger age cluster of 34-24 Ma. While our data support the view of Indosinian basement being reworked in the Cretaceous, they also indicate a late Eocene-Oligocene tectonothermal event, resulting in prograde metamorphism and anatexis. We suggest that this later event is related to localized transpressional thickening associated with sinistral movement on the Mae Ping Fault, coupled with thickening at the restraining bend of the Mae Yuan Fault to the immediate west of Doi Inthanon. Further, this upper Oligocene age limit from our zircon and monazite data would imply a younger Miocene constraint on movement of the detachment, which, when combined with the previously recorded Miocene

  4. Benthic macro red alga:A new possible bio-precursor of Jurassic mudstone source rocks in the northern Qaidam Basin,northwestern China

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Whether benthic macroalga can be an important type of bio-precursor of source rocks is a contentious issue in source-rock studies,and has not been well understood.This paper represents a case study of Jurassic mudstone source rocks from the northern Qaidam Basin,northwestern China,in which the benthic macro red algae were recognized for the first time based on combined organic petrological and biomarker works.We found not only cystocarps in the algae,representative of rhodophyta,but also diahopanes,which are diagnostic biomarkers of such algae.Thus,as many reservoired oils in the northern Qaidam Basin contain abundant diahopanes,it may indicate that the red algae have contributed to hydrocarbon accumulation.This was confirmed by integrated geological and geochemical analyses.Hence,this study provides new evidence for macroalga-generated hydrocarbons.

  5. Growth of the Zagros Fold-Thrust Belt and Foreland Basin, Northern Iraq, Kurdistan

    Science.gov (United States)

    Koshnaw, Renas; Horton, Brian; Stockli, Daniel; Barber, Douglas; Ghalib, Hafidh; Dara, Rebwar

    2016-04-01

    The Zagros orogenic belt in the Middle Eastern segment of the Alpine-Himalayan system is among the youngest seismically active continental collision zones on Earth. However, due to diachronous and incremental collision, the precise ages and kinematics of shortening and deposition remain poorly understood. The Kurdistan region of the Zagros fold-thrust belt and foreland basin contains well-preserved Neogene wedge-top and foredeep deposits that include clastic nonmarine fill of the Upper Fars, Lower Bakhtiari, and Upper Bakhtiari Formations. These deposits record significant information about orogenic growth, fold-thrust dynamics, and advance of the deformation front. Thermochronologic and geochronologic data from thrust sheets and stratigraphic archives combined with local earthquake data provide a unique opportunity to address the linkages between surface and subsurface geologic relationships. This research seeks to constrain the timing and geometry of exhumation and deformation by addressing two key questions: (1) Did the northwestern Zagros fold-thrust belt evolve from initial thin-skinned shortening to later thick-skinned deformation or vice-versa? (2) Did the fold-thrust belt advance steadily under critical/supercritical wedge conditions involving in-sequence thrusting or propagate intermittently under subcritical conditions with out-of-sequence deformation? From north to south, apatite (U-Th)/He ages from the Main Zagros Thrust, the Mountain Front Flexure (MFF), and additional frontal thrusts suggest rapid exhumation by ~10 Ma, ~5 Ma, and ~8 Ma respectively. Field observations and seismic sections indicate progressive tilting and development of growth strata within the Lower Bakhtiari Formation adjacent to the frontal thrusts and within the Upper Bakhtiari Formation near the MFF. In the Kurdistan region of Iraq, a regional balanced cross section constrained by new thermochronometric results, proprietary seismic reflection profiles, and earthquake hypocenters

  6. Quantification of effects of climate variations and human activities on runoff by a monthly water balance model: A case study of the Chaobai River basin in northern China

    OpenAIRE

    Wang, G; Xia, J.; J. Che

    2009-01-01

    The Chaobai River basin in northern China consists of two major tributaries, the Chao River and Bai River. Monthly observations of precipitation, streamfiow, and panevaporation data are available for 35 years (1961-1966 and 1973-2001). Using the annual time series of the observed streamfiow, one break point at 1979 is detected and is adopted to divide the data set into two study periods, the "before" and "after" periods marking the onset of significant anthropogenic alteration of the flow (re...

  7. Middle to late Cenozoic basin evolution in the western Alborz Mountains: Implications for the onset of collisional deformation in northern Iran

    OpenAIRE

    Guest, Bernard; Horton, Brian K.; Axen, Gary J.; Hassanzadeh, Jamshid; MCINTOSH, William C.

    2007-01-01

    Oligocene-Miocene strata preserved in synclinal outcrop belts of the western Alborz Mountains record the onset of Arabia-Eurasia collision-related deformation in northern Iran. Two stratigraphic intervals, informally named the Gand Ab and Narijan units, represent a former basin system that existed in the Alborz. The Gand Ab unit is composed of marine lagoonal mudstones, fluvial and alluvial-fan clastic rocks, fossiliferous Rupelian to Burdigalian marine carbonates, and basalt flows yielding ^...

  8. An investigation of the genus Mesacanthus (Chordata: Acanthodii) from the Orcadian Basin and Midland Valley areas of Northern and Central Scotland using traditional morphometrics

    OpenAIRE

    Baron, Matthew G.

    2015-01-01

    Mesacanthus is a common and speciose genus of acanthodian fish from Lower Old Red Sandstone and Middle Old Red Sandstone assemblages (representing the Lower Devonian and Middle Devonian respectively) and is well represented in many palaeoichthyology collections in the UK. Based upon descriptions given during the 19th century, specimens of the genus Mesacanthus from the Orcadian Basin and Midland Valley areas of Northern and Central Scotland have historically been referred to a number of diffe...

  9. Hydrogeochemistry of co-occurring geogenic arsenic, fluoride and iodine in groundwater at Datong Basin, northern China.

    Science.gov (United States)

    Pi, Kunfu; Wang, Yanxin; Xie, Xianjun; Su, Chunli; Ma, Teng; Li, Junxia; Liu, Yaqing

    2015-12-30

    Abnormal levels of co-occurring arsenic (As), fluorine (F) and iodine (I) in groundwater at Datong Basin, northern China are geochemically unique. Hydrochemical, (18)O and (2)H characteristics of groundwater were analyzed to elucidate their mobilization processes. Aqueous As, F and I ranged from 5.6 to 2680 μg/L, 0.40 to 3.32 mg/L and 10.1 to 186 μg/L, respectively. High As, F and I groundwater was characterized by moderately alkaline, high HCO3(-), Fe(II), HS(-) and DOC concentrations with H3AsO3, F(-) and I(-) as the dominant species. The plots of δ(18)O values and Cl/Br ratios versus Cl(-) concentration demonstrate build-up of more oxidizing conditions and precipitation of carbonate minerals induced by vertical recharge and intensive evaporation facilitate As retention to Fe (hydr) oxides, but enhance F and I mobilization from host minerals. Under reducing conditions, As and I can be simultaneously released via reductive dissolution of Fe (hydr) oxides and reduction of As(V) and I(V) while F migration may be retarded due to effects of dissolution-precipitation equilibria between carbonate minerals and fluorite. With the prevalence of sulfate-reducing condition and lowering of HCO3(-) concentration, As and I may be sequestered by Fe(II) sulfides and F is retained to fluorite and on clay mineral surfaces. PMID:26282220

  10. Simulation experiment on hydrocarbon generating potential of various source rocks on the northern margin of the Qaidam Basin, Qinghai, China

    Institute of Scientific and Technical Information of China (English)

    LI Xin; WANG Dongliang; LIU Baoquan; REN Chunling; GUO Jianying; SU Xuefeng; WANG Jian

    2008-01-01

    The northern margin of the Qaidam Basin is one of the main oil-gas exploration areas in western China, where source rocks are composed mostly of Middle and Lower Jurassic dark mud shale, carbargillite and coal. A large number of subsurface and outcrop samples differing in lithology with different types of organic matter were selected for resource evaluation, research and calculation. And among them, 13 samples were used for simulation experiment on hydrocarbon generating potential of various source rocks. At first, two kinds of heating modes were compared through simulation experiment, including single temperature-step heating and continual heating. Perhaps, the process of hydrocarbon generation and expulsion occurred naturally between a close system and an open system. In addition, the first heating mode was convenient, and all its reaction products were involved in the whole thermal evolution, and the final simulation experimental results were basically in consistency with the natural evolution trend. Therefore, the first heating mode was adopted and the hydrocarbon yield of every sample was worked out. According to the type and lithology of organic matter and the hydrocarbon yield of samples for simulation experiment, hydrocarbon generation and expulsion mode with three kinds of lithology and five types of source rock has been established to provide the basis for hydrocarbon generation evaluation, research and resource calculation.

  11. Quantification and multivariate analysis of water erosion in the Mediterranean region. A case study of the Isser basin. northern Algeria

    Science.gov (United States)

    Zeggane, Houari; Boutoutaou, Djamel

    2016-07-01

    In the Mediterranean region, the specifisity of erosion stems from a particularly contrasted climate, drought, and from summer and autumn severe thunderstorms. The process of erosion generates substantial loss of soil and affects any kind of crop. The adopted approach aims to establish regression models in order to highlight the relationship between solid and liquid flows at four measurement stations in the Isser catchement area, northern Ageria. The Power Model seems to explain this relationship. The quantification and temporal analysis of solid matter transport showed that the rates of erosion are high along the study area. The annual mean solid matter transport for the whole basin is about 2 200 t/km2.year, of which the main part is recorded in autumn during peak flows. The different factors involved in the process of water erosion are determined in advance in order to establish a model between the predictand variable, which is the specific erosion, and other predictors. Besides, a functional relationship has been highlighted between water erosion and the mean slope, the drainage density and the lithology index.

  12. Seismicity in the Raton Basin of Southern Colorado and Northern New Mexico, USA, as Recorded by a Local Array

    Science.gov (United States)

    Macartney, H.

    2013-12-01

    Microseismic events (Basin of southern Colorado and northern New Mexico, USA, over a period of 18 months following the occurrence of a 5.3 magnitude event near Trinidad CO in August, 2011. Micro-seismicity was observed in the region, concentrated in six clusters at depths of 6-12 km below the surface, deep in the basement, and 4-10 km below zones used for fluid disposal from an overlying coalbed methane natural gas field. Clusters are separated from disposal zones by large aseismic intervals. The clusters are mixed in character; both planar and elongate amorphous swarms, some continually active and some as short-lived bursts, with larger initial events tending to occur deeper and smaller after-shocks propagating upward and away from the nucleating events. Magnitudes range between 0 and 3, with the vast majority being less than 1.5M. Most of the clusters have no disposal wells above and no seismic activity was correlated with changes in fluid disposal. No seismicity was detected from hydraulic fracturing operations.

  13. Stable isotope record of Eemian seasonal temperature from MIS 5e tufa stromatolite; Somme Basin, Northern France

    Directory of Open Access Journals (Sweden)

    J. Dabkowski

    2013-03-01

    Full Text Available In many modern to sub-fossil deposits tufa formations, very well crystallised deposits called stromatolites are preserved. These are often strongly laminated deposits, the laminae linked to seasonal climatic and environmental variations. Where found in fossil tufas such deposits have huge potential as high resolution archives of Pleistocene climate. One of the first investigations of this type has been performed on a 2.5 cm-radius stromatolite from the Eemian sequence of Caours (Somme Basin, Northern France, where precise observations in thin section have been combined with intra-lamina δ18O and δ13C analyses. Independent interpretations of petrographical and geochemical data are strongly coherent and demonstrate a clear seasonal signal. Moreover, as δ18O is temperature dependent, we have quantified likely maximum water temperature variations between summer and winter at Caours. A small mismatch between the δ18O derived temperature values and the typical modern range is observed, which may reflect a real difference between modern and Eemian temperature seasonality. This study supports previous investigations performed on a laminated tufa from central Greece and clearly confirms the potential of tufa stromatolites as records of seasonal climatic information and for the quantification of riverine water temperature variations.

  14. Thick-skinned Contractional Salt Structures in the Kuqa Depression, the Northern Tarim Basin: Constraints from Physical Experiments

    Institute of Scientific and Technical Information of China (English)

    YU Yixin; TANG Liangjie; YANG Wenjing; JIN Wenzheng; PENG Gengxin; LEI Ganglin

    2008-01-01

    Thick-skinned contractional salt structures are widely developed in the western Kuqa depression, northern Tarim basin. To understand the mechanisms that govern the development of these structures, physical experiments are conducted and the results show that they are largely governed by the activities of basement faults and the forming of paleo-uplifts and basement slopes. The model materials in this study are dry sand, vaseline and plasticene (or hard foam), simulating the suprasalt, salt, and subsalt layers respectively. The experiments show that, due to the activities of basement faults and the forming of the paleo-uplifts, salt bodies usually accumulate and thicken significantly on the middle top of the paleo-uplifts which are constrained by the pre-exiting boundary faults. The development of large-scale thrust faults and salt nappes is favored by the basement slops with larger dips. The experiments also conclude that differential structural deformation could occur between the subsalt and suprasalt layers because of the presence of salt layers. Their geometries and the locations of structural highs are different, despite of the great similarities in the uplifted areas. The pierced salt diapir is not observed in the experiments, which indicates that the contractional shortening does not effectively accelerate the development of the salt diapir.

  15. Structural framework and its evolution in Chasang area of Qiangtang Basin in northern Tibetan

    Institute of Scientific and Technical Information of China (English)

    刘池洋; 杨兴科; 任战利; 赖绍聪; 陈刚; 赵红格; 魏永佩; 郑孟林; 王成善

    2001-01-01

    Through comprehensive research on the various geophysical and geological data acquired recently, we consider that the Chasang area in the western uplift of Qiangtang is a huge south-dipping block which is overlapped by several east-west trending blocks rather than a simple and palaeo-doming existing for a long time. The structural and geophysical features of the area, which only alone limited between Shuanghu and Rongma districts, are of no regional significance. Their development is closely related with the approximately south-north trending transform faults developed during the Mesozoic era on the east and west sides of the area and their later continuous movement. The compressing, overlapping and uplifting of the Chasang area began at the stage of reversing of the Qiangtang Basin during the Lower Cretaceous, which is in direct relation with Bangonghu-Dingqing limited ocean’s closure and the convergence of the neighboring blocks. The compression and overlapping of the area have further developed and re

  16. 26Al/10Be burial dating of Xujiayao-Houjiayao site in Nihewan Basin, northern China.

    Directory of Open Access Journals (Sweden)

    Hua Tu

    Full Text Available The Xujiayao-Houjiayao site in Nihewan Basin is among the most important Paleolithic sites in China for having provided a rich collection of hominin and mammalian fossils and lithic artifacts. Based on biostratigraphical correlation and exploratory results from a variety of dating methods, the site has been widely accepted as early Upper Pleistocene in time. However, more recent paleomagnetic analyses assigned a much older age of ∼500 ka (thousand years. This paper reports the application of 26Al/10Be burial dating as an independent check. Two quartz samples from a lower cultural horizon give a weighted mean age of 0.24 ± 0.05 Ma (million years, 1σ. The site is thus younger than 340 ka at 95% confidence, which is at variance with the previous paleomagnetic results. On the other hand, our result suggests an age of older than 140 ka for the site's lower cultural deposits, which is consistent with recent post-infrared infrared stimulated luminescence (pIR-IRSL dating at 160-220 ka.

  17. Late Quaternary evolution of the Rotoaira Basin, northern Tongariro ring plain, New Zealand

    International Nuclear Information System (INIS)

    The last 100,000 yr record of volcaniclastic sedimentation in the Rotoaira Basin reflects the critical role played by tectonic and eruptive activity that led to: (1) the catastrophic emplacement of Te Whaiau Formation (60-55 ka); (2) major episodes of effusive activity (c. 30 ka and c. 15 ka); and (3) syn- and post-eruptive lahar aggradation on the shores of Lake Rotoaira. Stratigraphic unconformities, fluvial and aeolian reworking, and subsequent volcanogenic sedimentation indicate that climate change driven periods of erosion contributed significantly to the evolution of the landscape during the late Quaternary. Waters that accumulated in a newly expanded graben formed Lake Rotoaira. An attempt to core through the sediments on the lake's floor revealed a >6.5 m thick mantling of Taupo ignimbrite, restricting chronostratigraphic sampling to the last 1.85 ka. Lake Rotoaira pollen profiles record: (1) the destruction of the indigenous forest by the Taupo ignimbrite eruption; (2) the following period of vegetation recovery (c. 300 yr); and (3) periods of human occupation of the lakeshores (bracken spores and Pinus pollen) in the younger sediments. Coarse sand generated by the 1995-96 tephra-producing Ruapehu eruptions also contributed to the recent lake sedimentation. (author). 59 refs., 9 figs., 1 tab

  18. Mesozoic deformation in the Chaoshan Depression of the Pearl River Mouth Basin, northern South China Sea

    Science.gov (United States)

    Zhang, Jiangyang; Sun, Zhen; Zhang, Yunfan; Li, Fucheng

    2016-05-01

    Newly collected, high resolution multi-beam sonar data are combined with previous bathymetry data to produce an improved bathymetric map of Shatsky Rise oceanic plateau. Bathymetry data show that two massifs within Shatsky Rise are immense central volcanoes with gentle flank slopes declining from a central summit. Tamu Massif is a slightly elongated, dome-like volcanic edifice; Ori Massif is square shaped and smaller in area. Several down-to-basin normal faults are observed on the western flank of the massifs but they do not parallel the magnetic lineations, indicating that these faults are probably not related to spreading ridge faulting. Moreover, the faults are observed only on one side of the massifs, which is contrary to expectations from a mechanism of differential subsidence around the massif center. Multi-beam data show many small secondary cones with different shapes and sizes that are widely-distributed on Shatsky Rise massifs, which imply small late-stage magma sources scattered across the surface of the volcanoes in the form of lava flows or explosive volcanism. Erosional channels occur on the flanks of Shatsky Rise volcanoes due to mass wasting and display evidence of down-slope sediment movement. These channels are likely formed by sediments spalling off the edges of summit sediment cap.

  19. Genetic Relationship between Natural Gas Dispersal Zone and Uranium Accumulation in the Northern Ordos Basin, China

    Institute of Scientific and Technical Information of China (English)

    GAN Huajun; XIAO Xianming; LU Yongchao; JIN Yongbin; TIAN Hui; LIU Dehan

    2007-01-01

    The Ordos Basin is well-known for the coexistence of oil, natural gas, coal and uranium. However, there has been little research to discuss the genetic relationship between them. In this paper, a case study of the Zaohuohao area in Dongsheng, Inner Mongolia, China, is conducted to investigate the genetic relationship between the natural gas and the uranium accumulation. Fluid inclusion data from the uranium-bearing sandstone samples indicate that the fluid inclusions formed in a gas-water transition zone. Using the homogeneous temperatures of aqueous inclusions coeval with hydrocarbonbearing inclusions, combined with the buried history and paleo-temperature data, the gas-water transition zone reached the area at about 110 Ma. On the basis of this, the contents of Uranium (U)and Total Organic Carbon (TOC) of the samples were analyzed, and there was no obvious relation between them. With regard to the available data from both publications and this study, it is found that the U mineralization has a spatiotemporal accordance with the gas-water dispersal zone. Thus, it is believed that the natural gas in the gas-water zone is an effective reducer to the U-bearing ground water abundant in oxygen, which is the main factor to U accumulation. This result can be used as the reference to the U mines predicting and prospecting.

  20. Winter and spring mixing depths affect the trophic status and composition of phytoplankton in the northern meromictic basin of Lake Lugano

    Directory of Open Access Journals (Sweden)

    Marco SIMONA

    2003-08-01

    Full Text Available The trophic state of Lake Lugano is still too high to be acceptable, despite extensive recovery measures undertaken in recent decades which have resulted in a reduction of the external phosphorus load to the deepest of the lake's basins (northern basin; Zmax=286 m to fairly acceptable values. Since meromixis was established in the middle of last century, the deep hypolimnion of the northern basin (the layer between ca 100 m and the bottom has contained high quantities of nutrients (especially phosphorus which are a major potential source of internal load. When there are particularly strong winter mixing events, a portion of this phosphorus reserve is redistributed along the upper water column (0-100 m. The impact of meteo-climatic conditions on the plankton biocenosis were analysed using data collected in the northern basin (Gandria station during the three-year period 1998-2000. The phytoplankton composition, which is typical of eutrophicated waters, shows marked interannual variations, also depending on the degree of mixing of the waters at the start of the vegetative period. Though there is no steady pattern of typical dominant species / master species in the lake, there is a seasonal succession characterised by a marked development of diatoms in spring, and a predominance of chlorophyceans and cyanobacteria in summer and autumn. Under present conditions, the mechanisms of internal replenishment of nutrients towards the euphotic layer, due to the phenomena of late winter and spring mixing, constitute a significant source of nutrients for the spring and summer growth of phytoplankton. On the other hand, pronounced mixing phenomena, like those occurring in the two-year period 1999-2000, can reduce the hypolimnetic nutrient reserves and cause a decrease in the trophic potential of the basin, contrasting with an increase in algal biomass in the euphotic zone.

  1. Rayleigh-wave ellipticity and shallow structure in sedimentary basins: the Po Plain (northern Italy)

    Science.gov (United States)

    Berbellini, A.; Morelli, A.; Ferreira, A. M. G.

    2015-12-01

    The amplitude ratio between horizontal and vertical components of Rayleigh waves (also known as ellipticity) is in principle uniquely sensitive to local earth structure beneath each recording station. Rayleigh wave ellipticity is mostly influenced by the shallowest layers, so it can be effectively used to infer the structure of the uppermost crust, with particular relevance for sedimentary environments. We implement an automatic method to measure Rayleigh wave ellipticity, and extensively apply it to teleseismic records from the northern part of Italy, for a period range between 10s and 130s. As expected, no appreciable correlation with epicenter distance or azimuth can be seen, but rather a strong correlation with local structure: generally high horizontal to vertical amplitude ratios are seen in sedimentary settings, with respect to Alpine and Apenninic crystalline-rock terrains. We verify that shortest usable period may be limited by very low shear-wave velocity in shallow sediments, when the assumed retrograde elliptical particle motion polarisation for the fundamental mode breaks off. The highly non-linear sensitivity of frequency-dependent ellipticity curves can then be inverted using a direct search method to infer shear wave velocity profiles below stations. By comparing our results with local a priori geological information we show that robust information can indeed be retrieved.

  2. Preliminary Paleomagnetic Results From Tertiary Rocks of Sedimentary Basins in Northern Vietnam and Tectonic Implications

    Science.gov (United States)

    Zhao, X.; Liu, Z.; Le, K.; Zhao, Y.; Hoang, V.; Phan, D.

    2013-12-01

    The South China Sea (SCS) is a classical representative of western Pacific marginal seas and contains records of Cenozoic tectonic events of SE Asia. The SCS has been at the center stage of many first-order tectonic and paleoclimatic events since the Mesozoic. One clear way to evaluate the relationship between tectonic uplift and climate is to study the resulting changes in marginal sea strata. To this end, we will conduct an integrated paleomagnetic and stratigraphic investigation on Tertiary strata from Phu Tho and Yen Bai provinces, northern Vietnam to help understand the causal linkages among geological and tectonic events and their consequences related to the SCS evolution. We will collect paleomagnetic samples at sections where the most continuous, complete, and best preserved Eocene-Miocene successions. Standard paleomagnetic field tests, such as the fold, reversal, and conglomerate tests will be used to determine the relative age of the magnetization. In addition to detailed thermal and alternating field demagnetization and analysis, selected samples will also be subjected to several rock magnetic analyses to identify magnetic carriers in the rocks. In particular, the hysteresis parameters Jrs/Js and Hcr /Hc ratios will enable us to apply techniques for detecting low-temperature remagnetization of sedimentary rocks. Preliminary finding of this ongoing project will be presented.

  3. Understanding the Hydrogeology of Raya Valley Basin, Northern Ethopia Using Stablee Isotopes of Water

    International Nuclear Information System (INIS)

    The Raya valley is located in the northern part of Ethiopia. The study area is connected to the Ethiopian rift system and bounded by the Ethiopian plateau to the west and Cherecher Mountain to the east. The study area is characterized by its semiarid climate. In order to investigate isotopic characteristics of different water bodies and groundwater recharge, water samples were collected in the summer rainy season and analysed for stable isotopes of oxygen and hydrogen by a laser based liquid water isotope analyser. Most of the groundwater samples are plotted just below the LMWL, which indicates that the origin is meteoric water and affected by secondary evaporation. There are highly depleted water samples in the eastern side of the study area, which could be attributed to the existence of palaeowater. Groundwater is mainly recharged by rain water and intermittent rivers. Open water bodies (the lake Ashenge and Gerjale swamp area) show enrichment due to high rate of evaporation. Isotopically the flood water in the highland aarea is depleted as a result of high rate of rainfall, high humidity and low rate of evaporation. (author)

  4. Structural architecture and tectonic evolution of the Maghara inverted basin, Northern Sinai, Egypt

    Science.gov (United States)

    Moustafa, Adel R.

    2014-05-01

    Large NE-SW oriented asymmetric inversion anticlines bounded on their southeastern sides by reverse faults affect the exposed Mesozoic and Cenozoic sedimentary rocks of the Maghara area (northern Sinai). Seismic data indicate an earlier Jurassic rifting phase and surface structures indicate Late Cretaceous-Early Tertiary inversion phase. The geometry of the early extensional fault system clearly affected the sense of slip of the inverted faults and the geometry of the inversion anticlines. Rift-parallel fault segments were reactivated by reverse slip whereas rift-oblique fault segments were reactivated as oblique-slip faults or lateral/oblique ramps. New syn-inversion faults include two short conjugate strike-slip sets dissecting the forelimbs of inversion anticlines and the inverted faults as well as a set of transverse normal faults dissecting the backlimbs. Small anticline-syncline fold pairs ornamenting the steep flanks of the inversion anticlines are located at the transfer zones between en echelon segments of the inverted faults.

  5. Characterization of submarine canyon bathymetries in northern Ionian Sea, Italy, using sediment geochemical variation induced by transportation distance and basin depth

    Science.gov (United States)

    Francesco, Perri; Tohru, Ohta; Salvatore, Critelli

    2015-07-01

    Geochemical data of marine mud sediments collected from the Esaro, Neto and Corigliano canyons in the northern Ionian Sea (southern Italy) were investigated in order to characterize canyon bathymetry types. Mud sample compositions analyzed by the principal component analysis (PCA) provided useful information for the morphology of the depositional area of the northern Ionian Sea. The use of sediment geochemical data as well as transportation distance and depth as input variables for PCA enabled the extraction of following latent variables: basin depth (PC1), sedimentation rate (PC2) and transportation distance (PC3). Based on these results, we further developed geochemical indices that can estimate basin depth (F1), sedimentation rate (F2) and transportation distance (F3); these functions can be solely calculated from the elemental concentration data of the mud samples. Since these F1, F2 and F3 functions are mathematically independent variables, they facilitate more precise characterization of individual canyon types. That is, the Esaro Canyon is regarded as a sediment-starved deep canyon characterized by a single source area; the Neto Canyon can be seen as a deeply sloped submarine apron system and sediments are mainly supplied by the sediment gravity flows; the Corigliano Canyon is characterized by multiple sources and moderately sloped system, whose sediments disperse mainly by traction currents. These interpretations are concordant with the basin bathymetry of the studied area. Therefore, F1, F2 and F3 functions might be applicable to any oceanic basins.

  6. Assessment of River Habitat Quality in the Hai River Basin, Northern China

    Directory of Open Access Journals (Sweden)

    Yuekui Ding

    2015-09-01

    Full Text Available We applied a river habitat quality (RHQ assessment method to the Hai River Basin (HRB; an important economic centre in China; to obtain baseline information for water quality improvement; river rehabilitation; and watershed management. The results of the assessment showed that the river habitat in the HRB is seriously degraded. Specifically; 42.41% of the sites; accounting for a river length of 3.31 × 104 km; were designated poor and bad. Habitat in the plain areas is seriously deteriorated; and nearly 50% of the sites; accounting for a river length of 1.65 × 104 km; had either poor or bad habitats. River habitat degradation was attributable to the limited width of the riparian zone (≤5 m; lower coverage of riparian vegetation (≤40%; artificial land use patterns (public and industrial land; frequent occurrence of farming on the river banks and high volumes of solid waste (nearly 10 m3; single flow channels; and rare aquatic plants (≤1 category. At the regional scale; intensive artificial land use types caused by urbanization had a significant impact on the RHQ in the HRB. RHQ was significantly and negatively correlated with farmland (r = 1.000; p < 0.01 and urban land (r = 0.998; p < 0.05; and was significantly and positively correlated with grassland and woodland (r = 1.000; p < 0.01. Intensive artificial land use; created through urbanization processes; has led to a loss of the riparian zone and its native vegetation; and has disrupted the lateral connectivity of the rivers. The degradation of the already essentially black rivers is exacerbated by poor longitudinal connectivity (index of connectivity is 2.08–16.56; caused by reservoirs and sluices. For river habitat rehabilitation to be successful; land use patterns need to be changed and reservoirs and sluices will have to be regulated.

  7. Assessment of River Habitat Quality in the Hai River Basin, Northern China.

    Science.gov (United States)

    Ding, Yuekui; Shan, Baoqing; Zhao, Yu

    2015-09-01

    We applied a river habitat quality (RHQ) assessment method to the Hai River Basin (HRB); an important economic centre in China; to obtain baseline information for water quality improvement; river rehabilitation; and watershed management. The results of the assessment showed that the river habitat in the HRB is seriously degraded. Specifically; 42.41% of the sites; accounting for a river length of 3.31 × 10⁴ km; were designated poor and bad. Habitat in the plain areas is seriously deteriorated; and nearly 50% of the sites; accounting for a river length of 1.65 × 10⁴ km; had either poor or bad habitats. River habitat degradation was attributable to the limited width of the riparian zone (≤5 m); lower coverage of riparian vegetation (≤40%); artificial land use patterns (public and industrial land); frequent occurrence of farming on the river banks and high volumes of solid waste (nearly 10 m³); single flow channels; and rare aquatic plants (≤1 category). At the regional scale; intensive artificial land use types caused by urbanization had a significant impact on the RHQ in the HRB. RHQ was significantly and negatively correlated with farmland (r = 1.000; p urban land (r = 0.998; p urbanization processes; has led to a loss of the riparian zone and its native vegetation; and has disrupted the lateral connectivity of the rivers. The degradation of the already essentially black rivers is exacerbated by poor longitudinal connectivity (index of connectivity is 2.08-16.56); caused by reservoirs and sluices. For river habitat rehabilitation to be successful; land use patterns need to be changed and reservoirs and sluices will have to be regulated. PMID:26393628

  8. Subsurface structure and stratigraphy of the northwest end of the Turkana Basin, Northern Kenya Rift, as revealed by magnetotellurics and gravity joint inversion

    Science.gov (United States)

    Abdelfettah, Yassine; Tiercelin, Jean-Jacques; Tarits, Pascal; Hautot, Sophie; Maia, Marcia; Thuo, Peter

    2016-07-01

    In order to understand the subsurface stratigraphy and structure of the northwest end of the Turkana Basin, Northern Kenya Rift, we used 2-D joint inversion of magnetotelluric (MT) and gravity data acquired along 3 profiles perpendicular to the main Murua Rith-Lapur Rift Border Fault. The regional geology is characterized by a basement of Precambrian age overlain by a ≤500-m thick sandstone formation named the Lapur Sandstone of upper Cretaceous-lower Eocene in age, covered by thick rhyolitic and basaltic lavas of late Eocene-middle Miocene age, known as the "Turkana Volcanics". Final interpretation of the resistivity and density models, until 5 km depth, obtained by the joint inversion approach confirms the previous general knowledge about the half-graben geometry of the northern part of the Turkana Basin. The main Murua Rith-Lapur Rift Border Fault is well identified by both gravity and MT. At least, two other important secondary faults without surface expression are also identified. A new small half-graben basin, named the Kachoda Basin, parallel to the main Turkana Basin and filled by 1.5 km of sediments, has been also characterized. This study also highlights strong thickness variations of the three main geological units that could be expected in the subsurface of the Turkana Basin. For example, the sedimentary Nachukui and Kibish Formations reach up to >3 km in thickness at the eastern end of the north and central profiles. Lateral variations of the topography of the Precambrian basement are also evidenced. Conceptual geological models, which result from the combination of the obtained density and resistivity models as well as from geological and reflection seismic data, are proposed. In such an area of intensive and promising oil exploration, these models are essential in terms of identification of reservoirs, source rocks and trapping mechanisms.

  9. Aerosol chemistry above an extended Archipelago of the Eastern Mediterranean basin during strong northern winds

    Directory of Open Access Journals (Sweden)

    E. Athanasopoulou

    2015-03-01

    Full Text Available Detailed aerosol chemical predictions by a carefully designed model system (i.e. PMCAMx, WRF, GEOS-CHEM, along with airborne and ground-based observations, are presented and analyzed over a wide domain covering the Aegean Archipelago. The studied period is ten successive days during the summer of 2011, characterized by the most frequent prevailing wind conditions (Etesian regime. The submicron aerosol load in the lower troposphere above the Archipelago (< 2.2 km altitude is homogenously enriched in sulfate (average modeled and measured submicron sulfate of 5.5 and 5.8 μg m−3, respectively, followed by organics (2.3 and 4.4 μg m−3 and ammonium (1.5 and 1.7 μg m−3. Aerosol concentrations smoothly decline aloft, reaching lower values (< 1 μg m−3 above 4.2 km altitude. Model performance is found good (according the selected evaluation criteria for sulfate, ammonium, chloride, elemental carbon, organic carbon and total PM10 mass concentration, indicating a satisfactory representation of the aerosol chemistry and precursors. Higher model discrepancies are confined to the highest (e.g. peak sulfate values and lowest ends (e.g. nitrate of the airborne aerosol mass size distribution, as well as in airborne organic concentrations (model underestimation around 50%. The latter is most probably related to the intense fire activity upwind the Archipelago (i.e. Balkan area and Black Sea coastline, which is not represented in the current model application. Overall, the model system shows the best agreement with observations under strong northeastern winds over the Archipelago and up to 2.2 km altitude. The activation of the chemical ageing of biogenic particles is suggested to be used for the aerosol chemistry module, when treating organics in a sufficient nitrogen and sulfate-rich environment, such as that over the Aegean basin. More than 70% of the predicted aerosol mass over the Aegean Archipelago during a representative Etesian episode is

  10. RECONNAISSANCE ASSESSMENT OF CO2 SEQUESTRATION POTENTIAL IN THE TRIASSIC AGE RIFT BASIN TREND OF SOUTH CAROLINA, GEORGIA, AND NORTHERN FLORIDA

    Energy Technology Data Exchange (ETDEWEB)

    Blount, G.; Millings, M.

    2011-08-01

    A reconnaissance assessment of the carbon dioxide (CO{sub 2}) sequestration potential within the Triassic age rift trend sediments of South Carolina, Georgia and the northern Florida Rift trend was performed for the Office of Fossil Energy, National Energy Technology Laboratory (NETL). This rift trend also extends into eastern Alabama, and has been termed the South Georgia Rift by previous authors, but is termed the South Carolina, Georgia, northern Florida, and eastern Alabama Rift (SGFAR) trend in this report to better describe the extent of the trend. The objectives of the study were to: (1) integrate all pertinent geologic information (literature reviews, drilling logs, seismic data, etc.) to create an understanding of the structural aspects of the basin trend (basin trend location and configuration, and the thickness of the sedimentary rock fill), (2) estimate the rough CO{sub 2} storage capacity (using conservative inputs), and (3) assess the general viability of the basins as sites of large-scale CO{sub 2} sequestration (determine if additional studies are appropriate). The CO{sub 2} estimates for the trend include South Carolina, Georgia, and northern Florida only. The study determined that the basins within the SGFAR trend have sufficient sedimentary fill to have a large potential storage capacity for CO{sub 2}. The deeper basins appear to have sedimentary fill of over 15,000 feet. Much of this fill is likely to be alluvial and fluvial sedimentary rock with higher porosity and permeability. This report estimates an order of magnitude potential capacity of approximately 137 billion metric tons for supercritical CO{sub 2}. The pore space within the basins represent hundreds of years of potential storage for supercritical CO{sub 2} and CO{sub 2} stored in aqueous form. There are many sources of CO{sub 2} within the region that could use the trend for geologic storage. Thirty one coal fired power plants are located within 100 miles of the deepest portions of

  11. Structure and Stratigraphy of the Rift Basins in the Northern Gulf of California: Results from Analysis of Seismic Reflection and Borehole Data.

    Science.gov (United States)

    Martín, A.; González, M.; Helenes, J.; García, J.; Aragón, M.; Carreño, A.

    2008-12-01

    The northern Gulf of California contains two parallel, north-south trending rift basin systems separated by a basement-high. The interpretation of several exploration wells, and ~4500 km of seismic reflection data from PEMEX (Mexican national oil company) indicate that the tectonically active basins to the west (Wagner- Consag and Upper Delfin basins) may have initiated synchronously with the now abandoned Tiburón- Tepoca-Altar basins to the east in the Sonora margin. In both basin systems the lower sequence (A) is marine mudstone-siltstone, has parallel reflectors and a largely uniform thickness that reaches up to1.5 km, and gradually pinches out toward the lateral margins. This suggests that the unit was deposited prior to their segmentation by transtensional faulting. Marine microfossils from borehole samples from sequence A in the Tiburón and Consag basins indicates middle Miocene (>11.2 Ma) proto-Gulf conditions. Sequence B conformably overlies sequence A, and is characterized by up to 2 km growth strata with a fanning geometry that show a clear genetic relationship to the major transtensional faults that control the segmentation of the two basin systems. Sequence C in the Tiburón and Tepoca basins is comparatively thin (<800 m) and includes several unconformities, but is much less affected by faulting. In contrast, sequence C in the active Wagner, Consag and Upper Delfin basin is a much thicker (up to 2 km) growth sequence with abundant volcanic intrusions. Marked variations in sequence C in the different basin systems clearly demonstrate a major westward shift of deformation and subsidence at this time. The modern depocenter in Wagner-Consag basins is controlled by the Consag and Wagner faults, which trend parallel to the north ~20 km apart, and show opposite normal offset. These two faults merge at an oblique angle (70°-50°, respectively) into the Cerro Prieto transform fault to the north and likely accommodate an important amount of dextral shear. To

  12. Geo-economy of the Caspian basin

    International Nuclear Information System (INIS)

    The Caspian area is essential for the development of the central Asia countries and Caucasus. Excepted the Iran and the Russia, these areas economy is poor. The hydrocarbons exploitation should reinforce the economic weight of these States. The author analyzes the Caspian area economies and shows that the basin economies are confronted with three handicaps, and that even with different economic ways, the soviet economic system is still present in the basin. (A.L.B.)

  13. Determining the source and genetic fingerprint of natural gases using noble gas geochemistry: a northern Appalachian Basin case study

    Science.gov (United States)

    Hunt, Andrew G.; Darrah, Thomas H.; Poreda, Robert J.

    2012-01-01

    Silurian and Devonian natural gas reservoirs present within New York state represent an example of unconventional gas accumulations within the northern Appalachian Basin. These unconventional energy resources, previously thought to be noneconomically viable, have come into play following advances in drilling (i.e., horizontal drilling) and extraction (i.e., hydraulic fracturing) capabilities. Therefore, efforts to understand these and other domestic and global natural gas reserves have recently increased. The suspicion of fugitive mass migration issues within current Appalachian production fields has catalyzed the need to develop a greater understanding of the genetic grouping (source) and migrational history of natural gases in this area. We introduce new noble gas data in the context of published hydrocarbon carbon (C1,C2+) (13C) data to explore the genesis of thermogenic gases in the Appalachian Basin. This study includes natural gases from two distinct genetic groups: group 1, Upper Devonian (Marcellus shale and Canadaway Group) gases generated in situ, characterized by early mature (13C[C1  C2][13C113C2]: –9), isotopically light methane, with low (4He) (average, 1  103 cc/cc) elevated 4He/40Ar and 21Ne/40Ar (where the asterisk denotes excess radiogenic or nucleogenic production beyond the atmospheric ratio), and a variable, atmospherically (air-saturated–water) derived noble gas component; and group 2, a migratory natural gas that emanated from Lower Ordovician source rocks (i.e., most likely, Middle Ordovician Trenton or Black River group) that is currently hosted primarily in Lower Silurian sands (i.e., Medina or Clinton group) characterized by isotopically heavy, mature methane (13C[C1 – C2] [13C113C2]: 3), with high (4He) (average, 1.85  103 cc/cc) 4He/40Ar and 21Ne/40Ar near crustal production levels and elevated crustal noble gas content (enriched 4He,21Ne, 40Ar). Because the release of each crustal noble gas (i.e., He, Ne, Ar

  14. Growth Normal Faulting at the Western Edge of the Metropolitan Taipei Basin since the Last Glacial Maximum, Northern Taiwan

    Directory of Open Access Journals (Sweden)

    Chih-Tung Chen

    2010-01-01

    Full Text Available Growth strata analysis is an useful tool in understanding kinematics and the evolution of active faults as well as the close relationship between sedimentation and tectonics. Here we present the Shanchiao Fault as a case study which is an active normal fault responsible for the formation of the 700-m-thick late Quaternary deposits in Taipei Basin at the northern tip of the Taiwan mountain belt. We compiled a sedimentary record, particularly the depositional facies and their dated ages, at three boreholes (SCF-1, SCF-2 and WK-1, from west to east along the Wuku Profile that traverses the Shanchiao Fault at its central segment. By incorporating the global sea level change curve, we find that thickness changes of sediments and changes of depositional environments in the Wuku area are in a good agreement with a rapid sea level rise since the Last Glacial Maximum (LGM of about 23 ka. Combining depositional facies changes and their ages with their thickness, we are able to introduce a simple back-stripping method to reconstruct the evolution of growing strata across the Shanchiao Fault since the LGM. We then estimate the vertical tectonic slip rate since 23 ka, which exhibits 2.2 mm yr-1 between SCF-2 and WK-1 and 1.1 mm yr-1 between SCF-1 and SCF-2. We also obtain the Holocene tectonic subsidence rate of 2.3 mm yr-1 at WK-1 and 0.9 mm yr-1 at SCF-2 since 8.4 ka. We thus conclude that the fault zone consists of a high-angle main fault to the east between SCF-2 and WK-1 and a western lower-angle branch fault between SCF-1 and SCF-2, resembling a tulip structure developed under sinistral transtensional tectonism. We find that a short period of 600-yr time span in 9 - 8.4 ka shows important tectonic subsidence of 7.4 and 3.3 m for the main and branch fault, respectively, consistent with possible earthquake events proposed by previous studies during that time. A correlation between geomorphology and subsurface geology in the Shanchiao Fault zone shows

  15. Identifying hydro-meteorological events from precipitation extremes indices and other sources over northern Namibia, Cuvelai Basin

    Directory of Open Access Journals (Sweden)

    Frans C. Persendt

    2015-02-01

    Full Text Available Worldwide, more than 40% of all natural hazards and about half of all deaths are the result of flood disasters. In northern Namibia flood disasters have increased dramatically over the past half-century, along with associated economic losses and fatalities. There is a growing concern to identify these extreme precipitation events that result in many hydro-meteorological disasters. This study presents an up to date and broad analysis of the trends of hydrometeorological events using extreme daily precipitation indices, daily precipitation data from the Grootfontein rainfall station (1917–present, regionally averaged climatologies from the gauged gridded Climate Research Unit (CRU product, archived disasters by global disaster databases, published disaster events in literature as well as events listed by Mendelsohn, Jarvis and Robertson (2013 for the data-sparse Cuvelai river basin (CRB. The listed events that have many missing data gaps were used to reference and validate results obtained from other sources in this study. A suite of ten climate change extreme precipitation indices derived from daily precipitation data (Grootfontein rainfall station, were calculated and analysed. The results in this study highlighted years that had major hydro-meteorological events during periods where no data are available. Furthermore, the results underlined decrease in both the annual precipitation as well as the annual total wet days of precipitation, whilst it found increases in the longest annual dry spell indicating more extreme dry seasons. These findings can help to improve flood risk management policies by providing timely information on historic hydro-meteorological hazard events that are essential for early warning and forecasting.

  16. Meltwater palaeohydrology of the Baker River basin (Chile/Argentina) during Late Pleistocene deglaciation of the Northern Patagonia Icefield

    Science.gov (United States)

    Thorndycraft, Varyl; Bendle, Jacob; Benito, Gerardo; Sancho, Carlos; Palmer, Adrian; Rodríguez, Xavier

    2016-04-01

    The Late Pleistocene deglaciation of the Northern Patagonia Icefield (NPI) was characterised by rapid ice sheet thinning and retreat, and the development of large proglacial lake systems characterised by continental scale drainage reversals. In this region, research has focused primarily on the identification of former ice-limits (e.g. moraine ridges) for geochronological analyses, with little attention given to the meltwater palaeohydrology of major river valleys. The Baker River catchment drains the majority of the eastern ice shed of the NPI, with a basin area of 29,000 km2 that includes the large transboundary lakes of General Carrera/Buenos Aires and Cochrane/Puerreydón. The Baker River valley is aligned north to south, crossing the east-west valleys of the main NPI outflow glaciers, and thus represents an important aspect of regional Late Pleistocene palaeogeography. The Baker River valley therefore has the potential to refine regional models of deglaciation through better understanding of relationships between glacier dynamics, ice dammed lakes and meltwater pathways. Here we present geomorphological mapping from the Atlantic-Pacific drainage divide (over 150 km east of the Cordillera) to the lower Baker valley, in order to reconstruct Late Pleistocene palaeohydrology. We provide new mapping of palaeolake shoreline elevations and evidence for glacial lake outburst flood (GLOF) pathways that require a re-evaluation of the currently accepted palaeogeographic models. For example, the palaeohydrological evidence does not support existing models of a unified Buenos Aires/Puerreydón mega-lake at ca. 400m elevation. We propose a relative chronology of palaeohydrological events that help refine the published moraine chronology derived from cosmogenic nuclide exposure dating. Controls on Late Pleistocene meltwater palaeohydrology of the Baker catchment are discussed, including the interplay of glacial processes and regional tectonics, in particular, dynamic

  17. Scenarios for shale gas development and their related land use impacts in the Baltic Basin, Northern Poland

    International Nuclear Information System (INIS)

    Scenarios for potential shale gas development were modelled for the Baltic Basin in Northern Poland for the period 2015–2030 using the land allocation model EUCS100. The main aims were to assess the associated land use requirements, conflicts with existing land use, and the influence of legislation on the environmental impact. The factors involved in estimating the suitability for placement of shale gas well pads were analysed, as well as the potential land and water requirements to define 2 technology-based scenarios, representing the highest and lowest potential environmental impact. 2 different legislative frameworks (current and restrictive) were also assessed, to give 4 combined scenarios altogether. Land consumption and allocation patterns of well pads varied substantially according to the modelled scenario. Potential landscape fragmentation and conflicts with other land users depended mainly on development rate, well pad density, existing land-use patterns, and geology. Highly complex landscapes presented numerous barriers to drilling activities, restricting the potential development patterns. The land used for shale gas development could represent a significant percentage of overall land take within the shale play. The adoption of appropriate legislation, especially the protection of natural areas and water resources, is therefore essential to minimise the related environmental impact. -- Highlights: •A range of scenarios for shale gas development in Poland were modelled. •The impact in terms of land take and competition for land was assessed. •Of land used for industrial purposes, 7–12% was attributed to shale gas extraction. •If unregulated, 24% of well pads were developed within protected areas. •The legislative framework can have a major influence on overall environmental impact

  18. Natural resources and their prospects in the closed basins of rift valley marginal grabens in northern Ethiopia

    Science.gov (United States)

    Meaza, Hailemariam; Frankl, Amaury; Poesen, Jean; Zenebe, Amanuel; Deckers, Jozef; Vaneetvelde, Veerle; Lanckriet, Sil; Nyssen, Jan

    2016-04-01

    With increasing population, producing more food and fibers has led to an expansion of the area under cultivation. For this, much attention is given to low-lying flat areas in search of suitable agricultural lands. The objectives of this paper are therefore: (1) to review the opportunities and challenges of natural resources in the marginal grabens for rural development; (2) to highlight the knowledge gaps and priorities in research and development in the marginal grabens, and (3) to supplement the literature review through repeat transect walks, focus group discussions and interviews across the western rift valley of northern Ethiopia. The paper shows that marginal grabens along the rift valleys are rich both in blue and green water resources due to their topographical and geological characteristics. Spate irrigation has been a growing water management practice to respond to soil moisture deficit. Besides, marginal grabens are fertile plains as a result of alluvial deposition that could be suitable for agricultural development. However, rainfall variability and groundwater withdrawal lead to graben basin closure and salinization. Notably, riverbed incisions and sediment deposition affects drainage systems and water supply in the marginal grabens. As a result, socioeconomic and natural capital of the marginal graben farmers are continuously threatened. Thus, the benefits of natural resources for rural development in the marginal grabens along the rift valley can be optimized if the current bottlenecks are converted into opportunities. A better understanding of the complex marginal graben system via a robust land evaluation framework will improve livelihoods of the communities that live in the (closed) marginal grabens. Keywords: population pressure, marginal grabens, endorheic lakes, salinization, Ethiopia

  19. Formation of hydrothermal deposits at Kings Triple Junction, northern Lau back-arc basin, SW Pacific: The geochemical perspectives

    Science.gov (United States)

    Paropkari, Anil L.; Ray, Durbar; Balaram, V.; Surya Prakash, L.; Mirza, Imran H.; Satyanarayana, M.; Gnaneshwar Rao, T.; Kaisary, Sujata

    2010-04-01

    An inactive hydrothermal field was discovered near Kings Triple Junction (KTJ) in northern Lau back-arc basin during 19th cruise of R/V Akademik Mstislav Keldysh in 1990. The field consisted of a large elongated basal platform 'the pedestal' with several 'small' chimneys on its periphery and one 'main mound' superposed over it. The surrounding region is carpeted with lava pillows having ferromanganese 'precipitate' as infillings. The adjoining second field consisted of small chimney like growths termed as 'Christmas Tree' Field. The basal pedestal, the peripheral chimneys and small 'Christmas Tree' like growths (samples collected by MIR submersibles), though parts of the same hydrothermal field, differ significantly in their mineralogy and elemental composition indicating different history of formation. The pedestal slab consisting of chalcopyrite and pyrite as major minerals and rich in Cu is likely to have formed at higher temperatures than sphalerite dominated peripheral chimney. Extremely low concentration of high field strength elements (e.g. Zr, Hf, Nb and Ta) and enrichment of light REE in these sulfides indicate prominent influence of aqueous arc-magma, rich in subduction components. The oxide growths in the 'Christmas Tree' Field have two distinct layers, Fe rich orange-red basal part which seems to have formed at very low temperature as precipitates from diffused hydrothermal flows from the seafloor whereas Mn rich black surface coating is formed from hydrothermal fluids emanated from the seafloor during another episode of hydrothermal activity. Perhaps this is for the first time such unique hydrothermal oxide growths are being reported in association with hydrothermal system. Here, we discuss the possible processes responsible for the formation of these different hydrothermal deposits based on their mineralogy and geochemistry.

  20. Innovative Methodology for Detection of Fracture-Controlled Sweet Spots in the Northern Appalachian Basin

    Energy Technology Data Exchange (ETDEWEB)

    Robert Jacobi; John Fountain; Stuart Loewenstein; Edward DeRidder; Bruce Hart

    2007-03-31

    For two consecutive years, 2004 and 2005, the largest natural gas well (in terms of gas flow/day) drilled onshore USA targeted the Ordovician Trenton/Black River (T/BR) play in the Appalachian Basin of New York State (NYS). Yet, little data were available concerning the characteristics of the play, or how to recognize and track T/BR prospects across the region. Traditional exploration techniques for entry into a hot play were of limited use here, since existing deep well logs and public domain seismic were almost non-existent. To help mitigate this problem, this research project was conceived with two objectives: (1) to demonstrate that integrative traditional and innovative techniques could be used as a cost-effective reconnaissance exploration methodology in this, and other, areas where existing data in targeted fracture-play horizons are almost non-existent, and (2) determine critical characteristics of the T/BR fields. The research region between Seneca and Cayuga lakes (in the Finger Lakes of NYS) is on strike and east of the discovery fields, and the southern boundary of the field area is about 8 km north of more recently discovered T/BR fields. Phase I, completed in 2004, consisted of integrating detailed outcrop fracture analyses with detailed soil gas analyses, lineaments, stratigraphy, seismic reflection data, well log data, and aeromagnetics. In the Seneca Lake region, Landsat lineaments (EarthSat, 1997) were coincident with fracture intensification domains (FIDs) and minor faults observed in outcrop and inferred from stratigraphy. Soil gas anomalies corresponded to ENE-trending lineaments and FIDs. N- and ENE-trending lineaments were parallel to aeromagnetic anomalies, whereas E-trending lineaments crossed aeromagnetic trends. 2-D seismic reflection data confirmed that the E-trending lineaments and FIDs occur where shallow level Alleghanian salt-cored thrust-faulted anticlines occur. In contrast, the ENE-trending FIDs and lineaments occur where Iapetan

  1. Innovative Methodology for Detection of Fracture-Controlled Sweet Spots in the Northern Appalachian Basin

    Energy Technology Data Exchange (ETDEWEB)

    Robert Jacobi; John Fountain; Stuart Loewenstein; Edward DeRidder; Bruce Hart

    2007-03-31

    For two consecutive years, 2004 and 2005, the largest natural gas well (in terms of gas flow/day) drilled onshore USA targeted the Ordovician Trenton/Black River (T/BR) play in the Appalachian Basin of New York State (NYS). Yet, little data were available concerning the characteristics of the play, or how to recognize and track T/BR prospects across the region. Traditional exploration techniques for entry into a hot play were of limited use here, since existing deep well logs and public domain seismic were almost non-existent. To help mitigate this problem, this research project was conceived with two objectives: (1) to demonstrate that integrative traditional and innovative techniques could be used as a cost-effective reconnaissance exploration methodology in this, and other, areas where existing data in targeted fracture-play horizons are almost non-existent, and (2) determine critical characteristics of the T/BR fields. The research region between Seneca and Cayuga lakes (in the Finger Lakes of NYS) is on strike and east of the discovery fields, and the southern boundary of the field area is about 8 km north of more recently discovered T/BR fields. Phase I, completed in 2004, consisted of integrating detailed outcrop fracture analyses with detailed soil gas analyses, lineaments, stratigraphy, seismic reflection data, well log data, and aeromagnetics. In the Seneca Lake region, Landsat lineaments (EarthSat, 1997) were coincident with fracture intensification domains (FIDs) and minor faults observed in outcrop and inferred from stratigraphy. Soil gas anomalies corresponded to ENE-trending lineaments and FIDs. N- and ENE-trending lineaments were parallel to aeromagnetic anomalies, whereas E-trending lineaments crossed aeromagnetic trends. 2-D seismic reflection data confirmed that the E-trending lineaments and FIDs occur where shallow level Alleghanian salt-cored thrust-faulted anticlines occur. In contrast, the ENE-trending FIDs and lineaments occur where Iapetan

  2. Seismic hazard assessment for the Caucasus test area

    Directory of Open Access Journals (Sweden)

    V. Trifonov

    1999-06-01

    Full Text Available The GSHAP CAUCAS test area was established under the INTAS Ct.94-1644 (Test Area for sismic Hazard Assessment in the Caucasus and NATO ARW Ct.95-1521 (Historical and Prehistorical Earthquakes in the Caucasus, with the initial support of IASPEI, UNESCO and ILP. The high tectonic interest and seismicity rate of the whole area, the availability of abundant multi-disciplinary data and the long established tradition in hazard assessment provide a unique opportunity to test different methodologies in a common test area and attempt to establish some consensus in the scientific community. Starting from the same input data (historical and instrumental seismic catalogue, lineament and homogeneous seismic source models six independent approaches to seismic hazard assessment have been used, ranging from pure historical deterministic to seismotectonic probabilistic and areal assessment methodologies. The results are here compared.

  3. Zircon Hf isotopic constraints on the mantle source of felsic magmatic rocks in the Phan Si Pan uplift and Tu Le basin, northern Vietnam

    Science.gov (United States)

    Usuki, T.; Lan, C.; Tran, T.; Pham, T.; Wang, K.

    2013-12-01

    Permian plume-related rocks, such as picrites, flood basalts and silicic volcanic rocks occur in northern Vietnam. This area was displaced 600 km southeastward along the Ailao Shan-Red River fault during mid-Tertiary in response to the India-Eurasia collision. The original location of the area was situated at the central Emeishan Large Igneous Province (ELIP) in SW China before Tertiary. The picrites and flood basalts in northern Vietnam have been investigated by many authors and are comparable with the ELIP. While, felsic magmatisms in northern Vietnam has been poorly studied. Zircon U-Pb age and Hf isotopic data are useful to compare the felsic magmatism in northern Vietnam with that in the ELIP, because the magmatisms of the ELIP had a characteristic time period (260-250 Ma) and the Hf isotopes show a remarkable mantle signature. Therefore, this study carried out in-situ U-Pb ages and Hf isotopic compositions for 300 zircon grains in eighteen granitoids and rhyolites in Phan Si Pan uplift and Tu Le basin in northern Vietnam. Zircons from the granitoids and rhyolites occasionally show development of {101} pyramid and {100} prism crystal facies, suggesting typical zircons crystallized from high temperature alkaline granite. 206Pb/238U ages of granitoid and rhyolite yield consistently in a narrow range of 260 to 250 Ma, which coincides with those from peralkaline to metaluminous granites in the ELIP. ɛHf(t) values of zircons in rhyolites and granites of this study dominate in the range of +5 to +10, which is consistent with those from the ELIP. U-Pb ages and Hf isotopic compositions of zircons indicate that felsic magmatic rocks in the Phan Si Pan uplift and Tu La basin have been derived from the same mantle source with the ELIP.

  4. Eocene to late Oligocene history of crustal shortening within the Hoh Xil Basin and implications for the uplift history of the northern Tibetan Plateau

    Science.gov (United States)

    Staisch, Lydia M.; Niemi, Nathan A.; Clark, Marin K.; Chang, Hong

    2016-04-01

    The timing and magnitude of deformation across the northern Tibetan Plateau are poorly constrained but feature prominently in geodynamic models of the plateau's evolution. The Fenghuoshan fold and thrust belt, located in the Hoh Xil Basin, provides a valuable record of the Cenozoic deformation history of the northern Tibetan Plateau. Here we integrate fault gouge geochronology, low-temperature thermochronology, geologic mapping, and a balanced cross section to resolve the deformation history of Hoh Xil Basin. Chronologic data suggest that deformation initiated in the mid-Eocene continued until at least 34 Ma and ceased by 27 Ma. The balanced cross section resolves 34 ± 12 km upper crustal shortening (24 ± 9%). We explore whether the observed Cenozoic shortening can account for the modern elevation and lithospheric thickness in the northern Tibetan Plateau. For a range of reasonable preshortening conditions, we conclude that the observed shortening alone cannot achieve modern crustal and mantle lithospheric thicknesses or modern elevation without either the removal of lithospheric mantle, the influx of lower crustal material, or some combination of these processes. Our results, along with previous studies, suggest that crustal shortening propagated into the northern Tibetan Plateau shortly after the onset of the Indo-Asian collision. The small magnitude of shortening and the late Oligocene cessation of deformation in the northern Tibetan Plateau raise questions of how and where the remaining Indo-Asian convergence was accommodated between Eocene to mid-Miocene time, prior to the approximately late Miocene establishment of the deformation patterns observed in the present day.

  5. Middle-Upper Ordovician (Darriwilian-Early Katian) Positive Carbon Isotope Excursions in the Northern Tarim Basin, Northwest China:Implications for Stratigraphic Correlation and Paleoclimate

    Institute of Scientific and Technical Information of China (English)

    Cunge Liu; Guorong Li; Dawei Wang; Yongli Liu; Mingxia Luo; Xiaoming Shao

    2016-01-01

    ABSTRACT:Three positive carbon isotope excursions are reported from Middle–Upper Ordovician in Tahe oil-gas field, northern Tarim Basin. Based on conodont biostratigraphy, the Middle Darriwilian Isotope Carbon Excursion (MDICE) and the Guttenberg Carbon Isotope Excursion (GICE) are identified from Darriwilian to Early Katian by the aid of whole-rock carbon isotope data from two well cores. Positive excursion within conodont Pygodus anserinus zone is developed in Early Sandbian, and the fluctuation range is no less than MDICE. Because the range of this excursion in the generalized global carbon isotope curve is short, previous studies paid little attention to it, and named Early Sandbian Isotope Carbon Excursion (ESICE) in this paper. Furthermore, these positive excursions are not directly related to sea level fluctuations and the MDICE and GICE identified in northern Tarim can be globally correlated to that in southern China, North America, South America, and Europe. The Saergan Fm. source rocks of Middle-Upper Ordovician in Kalpin Dawangou outcrop are in accord with the geologic time of MDICE and ESICE, and GICE have strong ties to the source rock of Lianglitag Fm. in basin. Abundant organic carbon burial is an important factor in genesis of positive isotope carbon excursions. Positive oxygen isotope excursion, conodont fauna turnover, decreased conodont total diversity, and the change of sedimentary facies indicated that dramatic changes of paleoceanographic environment of Early-Middle Ordovician in Tarim Basin started from the end of Darriwillian, and an obvious icehouse climate of Late Ordovician occurred in ESICE.

  6. Fission track analysis and evolution of mesozoic-paleozoic hydrocarbon resource-rocks headed in Northern Jiangsu-South Yellow sea basin

    International Nuclear Information System (INIS)

    Fission track data of different geologic epoches from Binhai salient, Yancheng sag, Haian sag, Baiju sag, Gaoyou sag, Hongze sag and Jinhu sag of northern Jiangsu basin and seismic data from Laoshan uplift in South Yellow Sea basin and evolution of Paleozoic hydrocarbon resource-rocks headed in the Northern Jiangsu-South Yellow Sea basin were studied. Results indicate that Binhai salient uplifted in 38-15 Ma, forming 'structure uplifting model', Paleozoic hydrocarbon resource-rocks have the appearance of 'different layers but identical mature, different layers but identical temperature' with Laoshan uplift. All sags have the characters of 'long time heating model', and sedimentations in Cenozoic were exploited by 2 km. Mesozoic-Paleozoic hydrocarbon resource- rocks of Laoshan uplift get ahead of 10 km. Structure evolution was compared with Binhai salient. According to the modeling results of secondary hydrocarbon generation, Mesozoic-Paleozoic hydrocarbon resource-rocks of Laoshan uplift have the good reservoir potentiality and probably become an important new window for sea oil and gas exploration. (authors)

  7. A regional view of urban sedimentary basins in Northern California based on oil industry compressional-wave velocity and density logs

    Science.gov (United States)

    Brocher, T.M.

    2005-01-01

    Compressional-wave (sonic) and density logs from 119 oil test wells provide knowledge of the physical properties and impedance contrasts within urban sedimentary basins in northern California, which is needed to better understand basin amplification. These wire-line logs provide estimates of sonic velocities and densities for primarily Upper Cretaceous to Pliocene clastic rocks between 0.1 - and 5.6-km depth to an average depth of 1.8 km. Regional differences in the sonic velocities and densities in these basins largely 1reflect variations in the lithology, depth of burial, porosity, and grain size of the strata, but not necessarily formation age. For example, Miocene basin filling strata west of the Calaveras Fault exhibit higher sonic velocities and densities than older but finer-grained and/or higher-porosity rocks of the Upper Cretaceous Great Valley Sequence. As another example, hard Eocene sandstones west of the San Andreas Fault have much higher impedances than Eocene strata, mainly higher-porosity sandstones and shales, located to the east of this fault, and approach those expected for Franciscan Complex basement rocks. Basement penetrations define large impedence contrasts at the sediment/basement contact along the margins of several basins, where Quaternary, Pliocene, and even Miocene deposits directly overlie Franciscan or Salinian basement rocks at depths as much as 1.7 km. In contrast, in the deepest, geographic centers of the basins, such logs exhibit only a modest impedance contrast at the sediment/basement contact at depths exceeding 2 km. Prominent (up to 1 km/sec) and thick (up to several hundred meters) velocity and density reversals in the logs refute the common assumption that velocities and densities increase monotonically with depth.

  8. Geometry of the El Fresnal basin, northern Chihuahua, Mexico, as inferred from three-dimensional gravity modeling (parte A)

    OpenAIRE

    W. L. Bandy; J. Ortega Ramírez; J. M. Maillol; A. Valiente Banuet; Rodríguez, J. A.

    2002-01-01

    A multidisciplinary study of the El Fresnal basin, Chihuahua, Mexico is being conducted to investigate the relationships between the structure, vegetation and geomorphology and the Quaternary paleoenvironment. As part of this study, 221 new gravity measurements were collected within the basin and combined with 506 preexisting measurements from the surrounding area to determine the basin geometry and the depth of the sediment infill. A basement-depth model calculated from these data indicates ...

  9. Pockmark development in the Petrel Sub-basin, Timor Sea, Northern Australia: Seabed habitat mapping in support of CO2 storage assessments

    Science.gov (United States)

    Nicholas, W. A.; Nichol, S. L.; Howard, F. J. F.; Picard, K.; Dulfer, H.; Radke, L. C.; Carroll, A. G.; Tran, M.; Siwabessy, P. J. W.

    2014-07-01

    The extent to which fluids may leak from sedimentary basins to the seabed is a critical issue for assessing the potential of a basin for carbon capture and storage. The Petrel Sub-basin, located beneath central and eastern Joseph Bonaparte Gulf in tropical northern Australia, was identified as potentially suitable for the geological storage of CO2 because of its geological characteristics and proximity to offshore gas and petroleum resources. In May 2012, a multidisciplinary marine survey (SOL5463) was undertaken to collect data in two targeted areas of the Petrel Sub-basin to facilitate an assessment of its CO2 storage potential. This paper focuses on Area 1 of that survey, a 471 km2 area of sediment-starved shelf (water depths of 78 to 102 m), characterised by low-gradient plains, low-lying ridges, palaeo-channels and shallow pockmarks. Three pockmark types are recognised: small shallow unit pockmarks 10-20 m in diameter (generally mangrove deposits and shells to have begun after 15.5 cal ka BP when a rapid marine transgression of Bonaparte Shelf associated with meltwater pulse 1A drowned coastal mangrove environments. Pockmark development is likely an ongoing process driven by fluid seepage at the seabed, and sourced from CO2 produced in the shallow sub-surface (<2 m) sediment. No evidence for direct connection to deeper features was observed.

  10. Application of the authigenic 10Be/9Be dating method to Late Miocene-Pliocene sequences in the northern Danube Basin (Pannonian Basin System): Confirmation of heterochronous evolution of sedimentary environments

    Science.gov (United States)

    Šujan, Michal; Braucher, Régis; Kováč, Michal; Bourlès, Didier L.; Rybár, Samuel; Guillou, Valéry; Hudáčková, Natália

    2016-02-01

    Authigenic 10Be/9Be dating method was applied to lacustrine, deltaic and alluvial sequences of the northern Danube Basin (Pannonian Basin System), to bridge the insufficiency of geochronological data for the Late Miocene to Pliocene period. The measurements of 51 samples (both lacustrine and floodplain), ranging from 11.6 to 0.95 Ma are consistent with the existing magnetostratigraphic and biostratigraphic data standing mainly on the evolution degree of endemic mollusk fauna, mammals and dinocysts. This agreement confirms our assumption that the incoming beryllium fluxes remained constant over the studied time period and thus that the two initial 10Be/9Be ratios determined in actual Holocene/Late Pleistocene sediments (lacustrine and floodplain) are valid for these environments. The obtained ages indicate gradual progradation of the deltaic depositional systems across the Danube Basin with a clear time-transgressional character, replacing basin floor and shelfal environments. Deltaic sedimentation occurred firstly in the north at foothills of the Western Carpathians from 11.0 Ma, and changed to the alluvial environment after 10.5 Ma. At the same time (~ 10.5 Ma), the paleo-Danube deltaic system draining the Eastern Alps entered the study area from the Vienna Basin situated on the West. Later, the deltaic systems were merged in the central part of the basin and reached its southeastern margin at ~ 9.4 Ma. Regression of the Lake Pannon from the southernmost part of the study area is evidenced after 8.7 Ma. Alluvial deposition of meandering rivers lasting until 6.0-5.0 Ma followed and was interrupted by the early Pliocene basin inversion. Sedimentation of braided streams took place during the late Pliocene and Pleistocene, reflecting uplift of mountains surrounding the basin margins. This study documents the powerful potential of the authigenic 10Be/9Be dating method and its reliability in a basin with complicated tectonic and sedimentary history. It demonstrates that

  11. Miocene Bahean stratigraphy in the Longzhong Basin,northern central China and its implications in environmental change

    Institute of Scientific and Technical Information of China (English)

    LI; Jijun; ZHANG; Jun; SONG; Chunhui; ZHAO; Zhijun; ZHANG; Yong; WANG; Xiuxi; ZHANG; Jianming; CUI; Qiaoyu

    2006-01-01

    Fossil mammal-riched Neogene strata are widely distributed in the southeast corner of the huge Longzhong Basin at Tianshui,Gansu Province,northern central China.Hipparion weihoense,a typical member of late Middle Miocene Bahean stage,was recently excavated at Yaodian along a well-exposed outcrop.Owing to the importance of the Bahean stage in the mammalian evolution and its potential for environmental change,we suggested a name of Yaodian Formation for the stratigraphy,which is correlated to the Bahe Formation at Lantian,Shaanxi.High resolution paleomagnetic dating of the section shows that the Yaodian Formation covers the period between 11.67 Ma and 7.43 Ma,with the site bearing Hipparion weihoense being estimated at about 10.54-10.30 Ma,providing first magnetostratigraphic chronology for the Bahean Stage.The Yaodian Formation consists of fluvial channel deposits (11.67-10.40 Ma) at the bottom,floodplain deposits in the middle (10.40-9.23 Ma) and shallow lake sediments at the top (9.23-7.43 Ma).This upward fining sequence suggests that the relief in nearby mountain ranges such as West Qinling to the south and Huajia Ling to the north was greatly reduced after long-term denudation,fluvial transport capacity was low,and finally the drainage system was disintegrated,replaced with broad-shallow lakes in which only fine sediments like mud and marlite were deposited,indicating an old stage of development of a planation surface.A remarkable shift in ecology and climatic environment was found at 7.4-7.7 Ma when paleoclimate changed from early warm humid to late dry as indicated by sedimentary facies changed from early shallow lake sequence to late eolian red clays and a former coniferous-deciduous mixed forest was replaced by grassland,leading to great growth of Hipparion Fauna of Baodean stage in the region.Therefore,it is estimated that the present high relief of Qinling and drainage pattern did not come into being until Late Pliocene in response to intensive

  12. Report on the Predation Index, Predator Control Fisheries, and Program Evaluation for the Columbia River Basin Experimental Northern Pikeminnow Management Program, 2008 Annual Report.

    Energy Technology Data Exchange (ETDEWEB)

    Porter, Russell [Pacific States Marine Fisheries Commission].

    2009-09-10

    This report presents results for year seventeen in the basin-wide Experimental Northern Pikeminnow Management Program to harvest northern pikeminnow1 (Ptychocheilus oregonensis) in the Columbia and Snake Rivers. This program was started in an effort to reduce predation by northern pikeminnow on juvenile salmonids during their emigration from natal streams to the ocean. Earlier work in the Columbia River Basin suggested predation by northern pikeminnow on juvenile salmonids might account for most of the 10-20% mortality juvenile salmonids experience in each of eight Columbia River and Snake River reservoirs. Modeling simulations based on work in John Day Reservoir from 1982 through 1988 indicated that, if predator-size northern pikeminnow were exploited at a 10-20% rate, the resulting restructuring of their population could reduce their predation on juvenile salmonids by 50%. To test this hypothesis, we implemented a sport-reward angling fishery and a commercial longline fishery in the John Day Pool in 1990. We also conducted an angling fishery in areas inaccessible to the public at four dams on the mainstem Columbia River and at Ice Harbor Dam on the Snake River. Based on the success of these limited efforts, we implemented three test fisheries on a system-wide scale in 1991 - a tribal longline fishery above Bonneville Dam, a sport-reward fishery, and a dam-angling fishery. Low catch of target fish and high cost of implementation resulted in discontinuation of the tribal longline fishery. However, the sport-reward and dam-angling fisheries were continued in 1992 and 1993. In 1992, we investigated the feasibility of implementing a commercial longline fishery in the Columbia River below Bonneville Dam and found that implementation of this fishery was also infeasible. Estimates of combined annual exploitation rates resulting from the sport-reward and dam-angling fisheries remained at the low end of our target range of 10-20%. This suggested the need for additional

  13. Late Mesozoic to Paleogene stratigraphy of the Salar de Atacama Basin, Antofagasta, Northern Chile: Implications for the tectonic evolution of the Central Andes

    Science.gov (United States)

    Mpodozis, Constantino; Arriagada, César; Basso, Matilde; Roperch, Pierrick; Cobbold, Peter; Reich, Martin

    2005-04-01

    The Salar de Atacama basin, the largest "pre-Andean" basin in Northern Chile, was formed in the early Late Cretaceous as a consequence of the tectonic closure and inversion of the Jurassic-Early Cretaceous Tarapacá back arc basin. Inversion led to uplift of the Cordillera de Domeyko (CD), a thick-skinned basement range bounded by a system of reverse faults and blind thrusts with alternating vergence along strike. The almost 6000-m-thick, upper Cretaceous to lower Paleocene sequences (Purilactis Group) infilling the Salar de Atacama basin reflects rapid local subsidence to the east of the CD. Its oldest outcropping unit (Tonel Formation) comprises more than 1000 m of continental red sandstones and evaporites, which began to accumulate as syntectonic growth strata during the initial stages of CD uplift. Tonel strata are capped by almost 3000 m of sandstones and conglomerates of western provenance, representing the sedimentary response to renewed pulses of tectonic shortening, which were deposited in alluvial fan, fluvial and eolian settings together with minor lacustrine mudstone (Purilactis Formation). These are covered by 500 m of coarse, proximal alluvial fan conglomerates (Barros Arana Formation). The top of the Purilactis Group consists of Maastrichtian-Danian alkaline lava and minor welded tuffs and red beds (Cerro Totola Formation: 70-64 Ma K/Ar) deposited during an interval of tectonic quiescence when the El Molino-Yacoraite Late Cretaceous sea covered large tracts of the nearby Altiplano-Puna domain. Limestones interbedded with the Totola volcanics indicate that this marine incursion advanced westwards to reach the eastern CD slope. CD shortening in the Late Cretaceous was accompanied by volcanism and continental sedimentation in fault bounded basins associated to strike slip along the north Chilean magmatic arc to the west of the CD domain, indicating that oblique plate convergence prevailed during the Late Cretaceous. Oblique convergence seems to have

  14. The onset of flood basalt volcanism, Northern Paraná Basin, Brazil: A precise U-Pb baddeleyite/zircon age for a Chapecó-type dacite

    Science.gov (United States)

    Janasi, Valdecir de Assis; de Freitas, Vivian Azor; Heaman, Larry H.

    2011-02-01

    We report the first U-Pb baddeleyite/zircon date for a felsic volcanic rock from the Paraná Large Igneous Province in south Brazil. The new date of 134.3 ± 0.8 Ma for a hypocrystalline Chapecó-type dacite from Ourinhos (northern Paraná basin) is an important regional time marker for the onset of flood basalt volcanism in the northern and western portion of the province. The dated dacite was erupted onto basement rocks and is overlain by a high-Ti basalt sequence, interpreted to be correlative with Pitanga basalts elsewhere. This new U-Pb date for the Ourinhos dacite is consistent with the local stratigraphy being slightly older than the few reliable step-heating 40Ar/39Ar dates currently available for overlying high-Ti basalts (133.6-131.5 Ma). This indicates an ~ 3 Ma time span for the building of the voluminous high-Ti lava sequence of the Paraná basin. On the other hand, it overlaps the 40Ar/39Ar dates (134.8-134.1 Ma) available for the stratigraphically older low-Ti basalt (Gramado + Esmeralda types) and dacite-rhyolite (Palmas type) sequences from South Brazil, which is consistent with the short-lived character of this volcanism and its rapid succession by the high-Ti sequence.

  15. Occurrence of Highly Mature Organic Matter in Marine Black Shale Petroleum Source Rocks of Basal Cambrian from Northern Tarim Basin, China

    Institute of Scientific and Technical Information of China (English)

    YU Bingsong (于炳松); Hailiang DONG; CHEN Jianqiang (陈建强); CHEN Xiaolin (陈晓林); LIANG Shiyou (梁世友)

    2004-01-01

    More and more evidence indicates that organic matter (OM) in immature organic-rich sediments and sedimentary rocks is chemically adsorbed onto the outer surfaces of minerals and into interlayer (inner) surfaces of smectitic clay minerals in the form of amorphous molecular-scale carbon. But there have been few reports about the occurrence of highly mature OM in marine black shales (petroleum source rocks). The occurrence of highly mature OM in the black shales of basal Cambrian from northern Tarim Basin is studied in this paper. Based on the comprehensive analyses of total organic carbon contents (TOC), maximum thermolysis temperatures (T max ) of OM, mineral surface areas (MSA), and scanning electronic microscopic (SEM) and transmission electronic microscopic (TEM) observations of the black shales, it is concluded that the highly mature OM in the marine black shales of the basal Cambrian from northern Tarim Basin occurs in particulates ranging in size from 1 to 5 μm in diameter. Through the contrast of the occurrence of the highly mature OM in the black shales with that of the immature ones in modern marine continental margin sediments, some scientific problems are proposed, which are worth to study further in detail.

  16. Study on the relationships between the structural evolution and sandstone-type uranium mineralization in mesozoic era and cenozoic era in the northern of Chaidam basin

    International Nuclear Information System (INIS)

    By detailed expounding the characteristics of the Mesozoic and Cenozoic structural evolution in northern of Chaidam basin, the author inquires into its relationships with the sandstone-type uranium mineralization, analyzes the prospect of forming uranium deposit, and thinks that the Mesozoic and Cenozoic strata are mainly controlled by the tectonic role of the later Yanshan movement and the later Cenozoic era. The north-west palaeo-structural slope belt is formed in the later Cretacous Epoch that is favorable for developing palaeo-interlayer oxidized zone. After the slightly extensional role of the oldest Tertiary and the early Plioeene, the middle and lower Jurassic were buried, and the block-imbricated slope belts are formed in the tectonic movement of the later Cenozoic, which are favorable for developing recent interlayer oxidized zone. According to drilling, it has the conditions for forming palaeo-recent interlayer oxidized zone sandstone-type uranium deposit at the northern of Chaidam basin. Finally, the author lays his finger on the prospecting of uranium. (authors)

  17. Chemical and isotopic tracers of the contribution of microbial gas in Devonian organic-rich shales and reservoir sandstones, northern Appalachian Basin

    International Nuclear Information System (INIS)

    In this study, the geochemistry and origin of natural gas and formation waters in Devonian age organic-rich shales and reservoir sandstones across the northern Appalachian Basin margin (western New York, eastern Ohio, northwestern Pennsylvania, and eastern Kentucky) were investigated. Additional samples were collected from Mississippian Berea Sandstone, Silurian Medina Sandstone and Ordovician Trenton/Black River Group oil and gas wells for comparison. Dissolved gases in shallow groundwaters in Devonian organic-rich shales along Lake Erie contain detectable CH4 (0.01-50.55 mol%) with low δ13C-CH4 values (-74.68 to -57.86 per mille) and no higher chain hydrocarbons, characteristics typical of microbial gas. Nevertheless, these groundwaters have only moderate alkalinity (1.14-8.72 meq/kg) and relatively low δ13C values of dissolved inorganic C (DIC) (-24.8 to -0.6 per mille), suggesting that microbial methanogenesis is limited. The majority of natural gases in Devonian organic-rich shales and sandstones at depth (>168 m) in the northern Appalachian Basin have a low CH4 to ethane and propane ratios (3-35 mol%; C1/C2 + C3) and high δ13C and δD values of CH4 (-53.35 to -40.24 per mille, and -315.0 to -174.6 per mille, respectively), which increase in depth, reservoir age and thermal maturity; the molecular and isotopic signature of these gases show that CH4 was generated via thermogenic processes. Despite this, the geochemistry of co-produced brines shows evidence for microbial activity. High δ13C values of DIC (>+10 per mille), slightly elevated alkalinity (up to 12.01 meq/kg) and low SO4 values (13C-DIC values (4 concentrations (up to 12.31 mmole/L) in many brine samples point to SO4 reduction, which likely limits microbial CH4 generation in the Appalachian Basin. Together the formation water and gas results suggest that the vast majority of CH4 in the Devonian organic-rich shales and sandstones across the northern Appalachian Basin margin is thermogenic in

  18. THE AUGUST CRISIS IN THE CAUCASUS AND ITS CONSEQUENCES

    OpenAIRE

    Skakov, Alexander

    2009-01-01

    Until the summer of 2008 the situation in the Caucasus was determined by the balance of power and parity between the main actors-America and Russia; there were other actors as well-the European Union, Turkey, and Iran. It was Georgia that wanted to defrost the situation in order to change the format of the peacekeeping operation and join NATO. Control over the breakaway regions and the status of the region's leader were its final aims. The United States and the EU (NATO) would not have object...

  19. Russia’s backyard – unresolved conflicts in the Caucasus

    Directory of Open Access Journals (Sweden)

    Sonnleitner Dominik

    2016-04-01

    Full Text Available The Caucasus played a prominent role in the Russian foreign policy for a long time, which has not changed since the dissolution of the Soviet Union. Beginning with four general hypothesis about Russia’s interests in its “near abroad” the essays gives an insights in the current status and developments in the relations between Russia and its southern neighbors Armenia, Georgia and Azerbaijan. A special focus is on the frozen conflicts in South Ossetia and Naghorno-Karabakh and Russia’s role in these conflicts.

  20. Late Pleistocene river migrations in response to thrust belt advance and sediment-flux steering - The Kura River (southern Caucasus)

    Science.gov (United States)

    von Suchodoletz, Hans; Gärtner, Andreas; Hoth, Silvan; Umlauft, Josefine; Sukhishvili, Lasha; Faust, Dominik

    2016-08-01

    One reaction of rivers toward allogenic triggers is the large-scale river channel migration in the form of avulsions or progressive lateral migrations (combing) that are widespread phenomena around the world during the late Quaternary. Because they potentially cause significant human and economic losses and significantly change geomorphic processes in the affected regions, a deeper knowledge about causes and rates is essential and furthermore helps to identify the dominant drivers of regional landscape evolution during different periods. One possible cause for river channel migrations is sediment-flux steering, i.e. the shift of rivers in sedimentary basins against a tectonically driven trend caused by transverse sediment discharge. During the last 30 years, sediment-flux steering has been investigated by field and experimental studies in extensional half-grabens with generally small-sized transverse catchments and/or volcaniclastic sedimentation. This study presents geomorphologic, geochronologic, and heavy mineral analyses together with complementary tectonomorphometric and earthquake data to investigate late Quaternary channel migrations of the Kura River in the southern foreland basin of the Greater Caucasus, a region where the late Quaternary landscape evolution is rather fragmentarily understood so far. Special emphasis of this study is given to the interplay between axial river flow and transverse sediment supply leading to sediment-flux steering. Large-scale migrations of the course of the Kura River during the late Quaternary reflect the interplay between tectonic processes leading to the southwestward advance of the Kura Fold-and-Thrust-Belt and climatically-triggered sediment-flux steering caused by aggradation phases of transverse rivers with comparatively large catchment areas in the Lesser Caucasus. During generally warmer periods such as the Holocene with fluvial incision and low sediment supply from the transverse rivers, the main Kura River could

  1. The Pre-historical Eruption of Volcanoes Near a Capital-city: Inferred From Tephra Deposits in the Taipei Basin, northern Taiwan

    Science.gov (United States)

    Chen, C.; Lin, C.

    2006-12-01

    The volcanic pyroclastic flows, lahars and/or ashes derived from volcanic eruptions are a serious threat of human lives and regional economies, especially in the densely populated area. In case, more than two million populations in the capital-city Taipei, northern Taiwan just live in the vicinity of the Tatun Volcanic Group (TVG), how to make effective and reliable volcanic hazard mitigation is absolutely mandatory. Volcano is a pretty complex system. Hazard mitigation can be achieved only by applying numerous techniques. Understanding the recent eruptive history will be the most important information for prediction the future activity of eruption. After 1995, the Center Geological Survey of Ministry of Economic Affair handled to drill more than 20 wells in the Taipei basin to investigate the subsurface geology of basin. These continuous core samples offered the best materials to investigate if any volcanic ashes had deposited in the basin. The young juvenile volcanic ashes V pumice tuff were firstly identified in the two cores of the Kuantu well (KT- 1) and the Shihlin well (SL-1 in the late Pleistocene Sunshan formation. According to the radiocarbon (C-14) ages of core samples (Lin et al, 1998, Shieh, 2001), the time of this tephra deposit was extrapolated around 18.6 kyrs C-14 B.P.. Respecting, this tephra would like to be temperately named as the 18 kyrs Taipei Tuff (18 KTT). These air-fall ash deposits found in the core directly demonstrated that there had been re-active in the TVG in the recent time. More notable thing is that there are three historical records of submarine eruptions in northern offshore Taiwan, then, a program of the volcanic hazard reduction should be seriously considered around the capital city-Taipei.

  2. Large-scale thrusting along the northern margin of the Tibetan Plateau and the southwest Tarim basin: 230 km long active Hotian thrust sheet

    Science.gov (United States)

    Suppe, J.; Wang, X.; He, D.; Liang, H.

    2015-12-01

    We present the geometry, kinematics and mechanics of large-scale active thrusting in the western Kunlunshan and southwest Tarim basin, which accounts for ~130-165km total shortening of Tarim crust at the northern margin of Tibet. The great frontal structure is the ~230km long bedding-parallel Hotian thrust sheet, which is perhaps the longest active intact thrust sheet in the world, composed of flat-lying strata of the Tarim basin sliding northward on a regional gypsum detachment at the base of the Cenozoic sequence. The toe of the Hotian thrust ramps to the surface two thirds of the way across the Tarim basin, forming the Selibuya-Mazartag hills in the Taklamakan sand desert. At the southern edge of the Tarim basin in the Kunlunshan foothills, a set of high-amplitude anticlines are growing by complex break-forward ramping and wedging in the Hotian thrust sheet as it steps up to the Cenozoic gypsum detachment from a regional Cambrian evaporate detachment that extends under Tibet. More interior structures such as the Tiklik thrust bring older strata and Proterozoic basement to the surface, together with their Cenozoic Tarim cover in the Buya basin. The Cambrian detachment also extends northward under the Tarim basin with minor hanging-wall deformation that locally warps the overlying Hotian thrust sheet, producing a complete syntectonic record in seismically imaged growth strata of its northward motion over these warps. Seismic profiles in the southwest Tarim foothill belt also reveal widespread growth strata that record much of the structural history beginning in the early Pliocene Atushi Formation. Ages of seismic reflectors are calibrated to a surface magnetostratigraphic sequence (Zheng et al., 2000). The beginning of thrusting and folding in the southwest Tarim basin north of the Tiklik thrust is dated at 3.6Ma with shortening >25km and a progressive northward propagation toward the Selibuya-Mazartag hills. The overall shortening rate is ~10 mm/yr. The gypsum

  3. Actual Evapotranspiration in the Al-Khazir Gomal Basin (Northern Iraq Using the Surface Energy Balance Algorithm for Land (SEBAL and Water Balance

    Directory of Open Access Journals (Sweden)

    Hussein Jassas

    2015-04-01

    Full Text Available Increasing dependence on groundwater requires a detailed determination of the different outputs and inputs of a basin for better water management. Determination of spatial and temporal actual evapotranspiration (ETa, in this regard, is of vital importance as there is significant water loss from drainage basins. This research paper uses the Surface Energy Balance Algorithm for Land (SEBAL, as well as the water balance, to estimate the spatial and temporal ETa in the Al-Khazir Gomal Basin, Northern Iraq. To compensate for the shortage in rainfall, and to irrigate summer crops, farmers in this basin have been depending, to a large extent, on groundwater extracted from the underlying unconfined aquifer, which is considered the major source for both domestic and agricultural uses in this basin. Rainfed farming of wheat and barley is one of the most important activities in the basin in the winter season, while in the summer season, agricultural activity is limited to small rice fields and narrow strips of vegetable cultivation along the Al-Khazir River. The Landsat Thematic Mapper images (TM5 acquired on 21 November 2006, 9 March 2007, 5 May 2007, 21 July 2007, and 23 September 2007 were used, along with a digital elevation model (DEM and ground-based meteorological data, measured within the area of interest. Estimation of seasonal ETa from periods between satellite overpasses was computed using the evaporative fraction (Ʌ. The water balance approach was utilized, using meteorological data and river hydrograph analysis, to estimate the ETa as the only missing input in the predefined water balance equation. The results of the two applied methods were comparable. SEBAL results were compared with the land use land cover (LULC map. The river showed the highest ETa, as evaporation from the free-water surface. Rice fields, irrigated in the summer season, have a high ETa in the images, as these fields are immersed in water during June, July and August

  4. Advanced interpretation of land subsidence by validating multi-interferometric SAR data: the case study of the Anthemountas basin (Northern Greece

    Directory of Open Access Journals (Sweden)

    F. Raspini

    2013-10-01

    Full Text Available The potential of repeat-pass space borne SAR (Synthetic Aperture Radar interferometry has been exploited to investigate spatial patterns of land subsidence in the Anthemountas basin, in the northern part of Greece. The PSI (Persistent Scatterer Interferometry approach, based on the processing of long series of SAR acquisitions, has been applied to forty-two images acquired in 1995–2001 by ERS1/2 satellites. Interferometric results have been analysed at a basin scale as support for land motion mapping and at a local scale for the characterisation of ground motion events affecting the village of Perea in the Thermaikos municipality and the "Macedonia" international airport. PSI results revealed a moderate subsidence phenomenon along the wider coastal zone of Anthemountas basin corresponding to intense groundwater extraction. Highest values, exceeding −20 mm yr−1, were measured in the airport area where the thickest sequence of compressible Quaternary sediments occurs. Intense subsidence has been detected also in the Perea village (maximum deformation of −10 to −15 mm yr−1, where a series of fractures, causing damages to both buildings and infrastructure, occurred in 2005–2006.

  5. Geodetic vs. Geologic Measures of Fault Slip Rates in the Northern Walker Lane, Basin and Range Province, Western United States

    Science.gov (United States)

    Hammond, W. C.; Kreemer, C.; Blewitt, G.

    2008-05-01

    Quantifying faults slip rates and styles is an important objective in the study of crustal deformation. Fault slip rates are used to quantify seismic hazard associated with active faults, and are an important input into the U.S.G.S. seismic hazard maps. However, when multiple types of data (e.g. geologic, seismic and geodetic) are used to measure slip rates, results from the different techniques can be corroborative, complementary, or in direct conflict. Geologic methods provide some of the only constraints on slip rates of individual faults over hundreds to tens of thousands of years, time scales that are significant with respect to observed deformation patterns, and likely representative of modern hazard. On the other hand geodetic measurements provide strong constraints on the medium to long spatial wavelength (>50 km) budgets of deformation, and on geographic changes in deformation style, and have the potential to provide geographically complete measurements of surface deformation. However, geodetic measurements can be influenced by earthquake cycle effects, e.g. owing to interseismic fault locking and postseismic relaxation, which limit their ability to resolve individual slip rates, especially in complex systems with many closely spaced faults. The northern Walker Lane (NWL), in the western Basin and Range Province (BRP) of the United States, is an example of a complex system of dextral, normal and sinestral faults that work together to accommodate approximately 10 mm/yr of relative motion between the Sierra Nevada/Great Valley block and the central part of the BRP. To exploit the strengths of each dataset, we have built a detailed model of NWL crustal blocks and are using geodetic and geologic data to resolve patterns of crustal deformation. We use a block modeling technique that incorporates the strengths of both targeted geologic investigations of slip rates on individual faults and longer wavelength constraints offered by GPS geodesy. To constrain these

  6. Platform-induced clay-mineral fractionation along a northern Tethyan basin-platform transect: implications for the interpretation of Early Cretaceous climate change (Late Hauterivian-Early Aptian)

    OpenAIRE

    Godet, Alexis; Bodin, Stéphane; Adatte, Thierry; Föllmi, Karl B.

    2009-01-01

    High-resolution clay-mineral analyses were performed on upper Hauterivian to lower Aptian sediments along a platform-to-basin transect through the northern Tethyan margin from the Neuchâtel area (Switzerland), to the Vocontian Trough (France) in order to investigate links between climate change, carbonate platform evolution, and fractionation patterns in clay minerals during their transport. During the Hauterivian, the northern Tethyan carbonate platform developed in a heterozoan mode, and t...

  7. The stratigraphic record of the Messinian salinity crisis in the northern margin of the Bajo Segura Basin (SE Spain)

    OpenAIRE

    Soria Mingorance, Jesús Miguel; Caracuel Martín, Jesús Esteban; Yébenes Simón, Alfonso; Fernández Martínez, Juan (1945-); Viseras Alarcón, César

    2005-01-01

    The Bajo Segura Basin is a marginal basin of the Western Mediterranean located on the eastern end of the Betic Cordillera (southeastern Spain). Its Messinian and Pliocene stratigraphic record is divided into four allostratigraphic units, with bounding unconformities represented by erosional surfaces corresponding to palaeogeographic changes. The Messinian Unit I (MI) is composed of three depositional systems (fluvial, coastal lagoon, and shelf) which lateral facies changes, deposited...

  8. Development of an integrated water resources management plan for the Lake Manyara sub-basin, Northern Tanzania

    Science.gov (United States)

    Ngana, J. O.; Mwalyosi, R. B. B.; Madulu, N. F.; Yanda, P. Z.

    Water resources management in Lake Manyara sub-basin is an issue of very high significance as the sub-basin hosts a number of national and global assets of great socio-cultural, ecological and economic values. The sub-basin comprise of a Biosphere Reserve with boosting tourism from Lake Manyara National Park with a variety of wildlife population, large livestock population and highly fertile land for agricultural production. The prevailing system of uncoordinated water resources management in the sub-basin cannot sustain the ever increasing water needs of the various expanding sectors, therefore a strategy must be sought to integrate the various sectoral needs against the available water resources in order to attain both economic and ecological sustainability. Through participatory approach with the stakeholders, the study has established key issues, demonstrated considerable experience in water resources management in the sub-basin including existence of water boards, water committees in some districts as well as land resources management practices However, a number of constraints were noted which inhibit sustainable water resources management including ignorance of water policies, conflicting sectoral policies, lack of coordination between sectors, high in migration rates into the basin, heavy in migration of livestock, conflicts between sectors, poor land use resulting in soil erosion and sedimentation, lack of comprehensive data base on water resources and water needs for : domestic, tourism, livestock, irrigation, wild life and environmental flows. As a way forward it was recommended that a basin wide legally mandated body (involving all levels) be established to oversee water use in the sub-basin. Other strategies include capacity building of stakeholders on water natural resources management policies, water rights and enforcement of laws. This progress report paper highlights the wealth of knowledge that stakeholders possess on water resources management and

  9. Eocene to Miocene back-arc basin basalts and associated island arc tholeiites from northern Sulawesi (Indonesia): Implications for the geodynamic evolution of the Celebes basin

    International Nuclear Information System (INIS)

    Eocene BABB basalts intruded by tholeiitic and calk-alkalic island arc magmatic rocks are reported from the north arm of Sulawesi (Indonesia). Age and geochemical similarities between these basalts and those drilled in the Celebes Sea indicate this North Sulawesi volcanic arc was built on the same oceanic crust. The 25 deg late Neogene clockwise rotation of the north arm of Sulawesi following its collision with fragments of Australia (Sula, Buton) is not sufficient to explain the asymmetrical magnetic anomalies in the Celebes basin. The North Sulawesi island arc could be interpreted as having progressively retreated northward on its own Celebes sea back arc basin, during an episode of Palaeogene-early Neogene tectonic erosion along the trench. (authors)

  10. Geological framework and thorium resources exploration condition of Georgia (The Caucasus)

    International Nuclear Information System (INIS)

    The Caucasus represents a Phanerozoic collisional orogeny, that formed along the Eurasian North continental margin, extends over 1200 km from the Caspian to Black Sea. Georgian republic is situated in the central part of Caucasus Region. Here are marked 3 ore occurrences of thorium : 1-in the Greater Caucasus (Th concentrations vary between 51 g/t - 3882 g/t); 2- in the Dzirula massif (Th concentrations vary between 117 g/t -266 g/t); 3- in Vakijvari orefield (Th concentrations vary between 185 g/t - 428 g/t). Based on these data thorium ore occurrences found in Georgia should be treated as prospective resources. (author)

  11. Numerical Weather Prediction Over Caucasus Region With Nested Grid Models

    Science.gov (United States)

    Davitashvili, Dr.; Kutaladze, Dr.; Kvatadze, Dr.

    2010-09-01

    Global atmosphere models, which describe the weather processes, give the general character of the weather but can't catch the smaller scale processes, especially local weather for the territories with compound topography. Small-scale processes such as convection often dominate the local weather, which cannot be explicitly represented in models with grid size more then 10 km. A much finer grid is required to properly simulate frontal structures and represent cumulus convection. Georgia lies to the south of the Major Caucasian Ridge and the Lesser Caucasus mountains occupy the southern part of Georgia. About 85 percent of the total land area occupies complex mountain ranges.Therefore for the territory of Georgia it is necessary to use atmosphere models with a very high resolution nested grid system taking into account main orographic features of the area. We have elaborated and configured Whether Research Forecast - Advanced Researcher Weather (WRF-ARW) model for Caucasus region considering geographical-landscape character, topography height, land use, soil type and temperature in deep layers, vegetation monthly distribution, albedo and others. Porting of WRF-ARW application to the grid was a good opportunity for running model on larger number of CPUs and storing large amount of data on the grid storage elements. On the grid WRF was compiled for both Open MP and MPI (Shared + Distributed memory) environment and WPS was compiled for serial environment using PGI (v7.1.6, MPI- version 1.2.7) on the platform Linux-x86. In searching of optimal execution time for time saving different model directory structures and storage schema was used. Simulations were performed using a set of 2 domains with horizontal grid-point resolutions of 15 and 5 km, both defined as those currently being used for operational forecasts The coarser domain is a grid of 94x102 points which covers the South Caucasus region, while the nested inner domain has a grid size of 70x70 points mainly

  12. Active folded structures of the Western Caucasus (Sochi region)

    Science.gov (United States)

    Trikhunkov, Yaroslav; Zelenin, Egor

    2014-05-01

    The Western Caucasus as a margin segment of folded system of the Greater Caucasus was formed at the periphery of collision interaction of the Scythian Plate and the Transcaucasian Massif. The estimated age of the primary folded deformations of the initial surface of that territory ranges from the late Eocene to late Neogene. We have obtained new data on modern folded deformations of the anticlinal ridges, which prevail in Sochi region in the southern macroslope of the mountain system. Very similar Alek, Galitsinsky, Akhun, Nikolaevsky anticlinal ridges are uplifting in the main Caucasus direction (NW - SE) and are crossed by narrow antecedent river valleys. These ridges stand out contrasting to sinclinal depressions, where fluviatile accumulation prevails. At the intersection of the Mzymta river and the Galitsinsky anticlinal ridge a narrow Akhshtyr canyon with steep, 150 meters high slopes were formed. Downstream in the neighboring Akhshtyr synclinal depression the valley expands. Here the floodplain and two levels of terraces with the height of 20 - 30 and 50 - 60 m correspondingly were formed. The age of the first terrace was defined by archeologic data of V. Shchelinsky (2007) and by correlation with marine Black Sea Late Karangat terrace as a 135 - 90 ka (Eemian interglacial). The second terrace is apparently older and dates back to Middle Pleistocene. The field research and analysis of the elevations by ASTER GDEM allowed us to trace both terraces in the southern structural slope of the Galitsinsky ridge above the canyon, adjacent to the Akhshtyr depression, at the heights 70 and 110 m correspondingly. Alluvial deposits in outcrops of lower terrace (elongated pebbles, which look like modern alluvium of the Mzymta) were traced on the surface of the slope. Thereby, described fragments of the Mzymta terraces were uplifted above the level of the corresponding terraces in the synclinal depression as a result of dislocation on the slope of the actively uplifting

  13. Detection of detached forced-regressive nearshore wedges: a case study from the central-southern Siena Basin (Northern Apennines, Italy)

    Science.gov (United States)

    Martini, Ivan; Arragoni, Simone; Aldinucci, Mauro; Foresi, Luca Maria; Bambini, Anna Maria; Sandrelli, Fabio

    2013-07-01

    The detection of detached nearshore wedges formed in response to relative sea-level drops is considered one of the hottest topics in sequence stratigraphic analysis due to their importance as reservoir analogues. In fact, they usually constitute sandy and porous bodies generally encased in impermeable clay, thus presenting a good potential as traps for fluids. This paper focuses on the sequence stratigraphic analysis of the Pliocene deposits cropping out in the central-southern sector of the Siena Basin (Tuscany, Italy), a post-collisional basin of the Northern Apennines. The exposed sedimentary succession was investigated through a detailed sedimentological and stratigraphic approach, integrated by biostratigraphic analyses, aimed at a better characterization of the infilling history of this sector of the basin. Specifically, this study revealed the occurrence of repeated facies shifts that allowed the identification of two depositional sequences. In detail, a thick sand-rich body far from the basin margins, and previously considered as a turbiditic lobe, has been reinterpreted as formed in a nearshore setting during a fall in relative sea level. This body is totally encased in offshore clay, and due to the lack of physical connection with the related HST deposits, it has to be considered as a detached forced-regressive wedge. The present work led to the recognition of some sedimentological and stratigraphic features typical of falling stage systems tract deposits (e.g. presence of intrabasinal recycled materials, sedimentological evidence of a pre-existing fluvial network subsequently eroded) that can provide useful clues for the identification of detached forced-regressive nearshore wedges in core studies and poorly exposed settings.

  14. Imaging 3D geological structure of the Mygdonian basin (Northern Greece) with geological numerical modeling and geophysical methods.

    Science.gov (United States)

    Cédric, Guyonnet-Benaize; Fabrice, Hollender; Maria, Manakou; Alexandros, Savvaidis; Elena, Zargli; Cécile, Cornou; Nikolaos, Veranis; Dimitrios, Raptakis; Artemios, Atzemoglou; Pierre-Yves, Bard; Nikolaos, Theodulidis; Kyriazis, Pitilakis; Emmanuelle, Chaljub

    2013-04-01

    The Mygdonian basin, located 30 km E-NE close to Thessaloniki, is a typical active tectonic basin, trending E-NW, filled by sediments 200 to 400 m thick. This basin has been chosen as a European experimental site since 1993 (European Commission research projects - EUROSEISTEST). It has been investigated for experimental and theoretical studies on site effects. The Mygdonian basin is currently covered by a permanent seismological network and has been mainly characterized in 2D and 3D with geophysical and geotechnical studies (Bastani et al, 2011; Cadet and Savvaidis, 2011; Gurk et al, 2007; Manakou et al, 2007; Manakou et al, 2010; Pitilakis et al, 1999; Raptakis et al, 2000; Raptakis et al, 2005). All these studies allowed understanding the influence of geological structures and local site conditions on seismic site response. For these reasons, this site has been chosen for a verification exercise for numerical simulations in the framework of an ongoing international collaborative research project (Euroseistest Verification and Validation Project - E2VP). The verification phase has been made using a first 3D geophysical and geotechnical model (Manakou, 2007) about 5 km wide and 15 km long, centered on the Euroseistest site. After this verification phase, it has been decided to update, optimize and extend this model in order to obtain a more detailed model of the 3D geometry of the entire basin, especially the bedrock 3D geometry which can affect drastically the results of numerical simulations for site effect studies. In our study, we build a 3D geological model of the present-day structure of the entire Mygdonian basin. This "precise" model is 12 km wide, 65 km long and is 400 m deep in average. It has been built using geophysical, geotechnical and geological data. The database is heterogeneous and composed of hydrogeological boreholes, seismic refraction surveys, array microtremor measurements, electrical and geotechnical surveys. We propose an integrated

  15. Alkali element enrichments on the BABBs at the IODP Expedition 333 Site C0012 in the northern Shikoku Basin

    Science.gov (United States)

    Haraguchi, S.; Nakamura, K.; Fujinaga, K.

    2015-12-01

    The Shikoku Basin is a back arc basin located westside of the Izu-Ogasawara (Bonin) arc, spreading was from 25 to 15 Ma. The drilling of the DSDP, ODP and IODP recovered the backarc basin basalt (BABB) of the Shikoku Basin. Site C0012, south of the Kii Peninsula, was operated during the IODP Exp 333, and BABB was recovered 100m thickness under the 520m of sediment. This BABB is divided into upper aphyric pillow (Unit 1) and lower massive flow (Unit 2) divided at the 560 mbsf, and show variable degree of alteration, clay mineral and zeolite depositions. SiO2 and MgO contents of these basalts are 47-55 and 5-8 wt%. These basalts show wide variation of enrichment of alkali elements, 2.3-7.5 and 0.4-4.2 wt% of Na2O and K2O. Na2O+K2O contents show 3.2-8.0 wt%, and 2 wt% higher trends than other BABBs in the Shikoku Basin at the same SiO2 contents. Na2O and K2O show proportional and anti-proportional trends with increasing LOI. Therefore, both alkali element enrichments in these rocks are caused by secondary mineralization, and host phase of Na2O is hydrous and that of K2O is anhydrous minerals. Secondary mineral phases was mainly identified by XRD. The identified host phases of Na are analcime and thomsonite. Analcime is observed in rocks of more than 4 wt% of Na2O. Chlorite and smectite are identified to clay minerals. This mineral assemblage indicates the high-temperature zeolite facies alteration. The host phases of K are mainly identified into K-feldspar. We assume that secondary mineralization of K-fd is associated with low-temperature albitization. Compared to the lithostratigraphy, the Na enrichment is prominent in the Unit 1 and upper 20 m of the Unit 2, and the K enrichment is prominent in lower part of the Unit 2. We consider that the Na enrichment associated with zeolite depositions occurred under high water/rock ratio with active hydrothermal circulation because of high water permeability of pillow lava, and K enrichment associated with albitization occurred

  16. Numerical Simulation of Inter-basin Groundwater Flow into Northern Yucca Flat, Nevada National Security Site, Using the Death Valley Regional Flow System Model

    Energy Technology Data Exchange (ETDEWEB)

    Pohlmann Karl,Ye Ming

    2012-03-01

    Models of groundwater flow for the Yucca Flat area of the Nevada National Security Site (NNSS) are under development by the U.S. Department of Energy (DOE) for corrective action investigations of the Yucca Flat-Climax Mine Corrective Action Unit (CAU). One important aspect of these models is the quantity of inter-basin groundwater flow from regional systems to the north. This component of flow, together with its uncertainty, must be properly accounted for in the CAU flow models to provide a defensible regional framework for calculations of radionuclide transport that will support determinations of the Yucca Flat-Climax Mine contaminant boundary. Because characterizing flow boundary conditions in northern Yucca Flat requires evaluation to a higher level of detail than the scale of the Yucca Flat-Climax Mine CAU model can efficiently provide, a study more focused on this aspect of the model was required.

  17. Interpreting lineaments in the southern slope of the greater Caucasus (within the Azerbaijan SSR)

    Energy Technology Data Exchange (ETDEWEB)

    Budagov, B.A.; Aliyev, A.S.; Mikailov, A.Ya.

    1982-01-01

    Faults and block morphostructures of the southern slope of the greater Caucasus are revealed by interpreting space photographs. A plan of lineaments is compiled. Interpretation signs of the most important faults are described.

  18. Historical Review of the Formation of Geopolitical and Ethnic Space of the North Caucasus

    Directory of Open Access Journals (Sweden)

    Hope O. Blejсh

    2016-03-01

    Full Text Available The article said that the North Caucasus was one of the centers of early civilization, as it was settled by nomads since ancient times, thanks in no small measure contributed to the very favorable natural and geographical conditions of the region. It was here that establish trade, political, military and cultural contacts between the near Eastern countries and Eastern Europe and the North Caucasus because the region gradually formed as a multiethnic region. It consisted of three language families: the Caucasian, Turkic and Indo-European (Ural-Altaic. The article describes the history of the formation of ethnic resettlement in the Caucasus and considered their ethnographic map. It is proved that at the beginning of the XVIII century ended with the formation of the ethnic composition of the population of the North Caucasus, which has survived unchanged to this day.

  19. Geoethnopolitical Aspect of the Caucasus Development in terms of Sochi Preparation for Winter Olympic Games

    Directory of Open Access Journals (Sweden)

    Svetlana V. Petrova

    2012-03-01

    Full Text Available The article is concerned with geopolitical problems within the Caucasus Region in terms of modern regional processes, indicates major features of the region and their impact on Sochi preparation for Winter Olympic Games.

  20. Impact of Cenozoic strike-slip tectonics on the evolution of the northern Levant Basin (offshore Lebanon)

    Science.gov (United States)

    Ghalayini, Ramadan; Daniel, Jean-Marc; Homberg, Catherine; Nader, Fadi H.; Comstock, John E.

    2014-11-01

    Sedimentary basins adjacent to plate boundaries contain key tectonic and stratigraphic elements to understand how stress is transmitted through plates. The Levant Basin is a place of choice to study such elements because it flanks the Levant Fracture System and the Africa/Anatolia boundary. This paper uses new high-quality 3-D seismic reflection data to unravel the tectonic evolution of the margin of this basin during the Cenozoic, the period corresponding to the formation of the Levant Fracture System, part of the Africa/Arabia plate boundary. Four major groups of structures are identified in the interpreted Cenozoic units: NW-SE striking normal faults, NNE-SSW striking thrust-faults, ENE-WSW striking dextral strike-slip faults, and NNE trending anticlines. We demonstrate that all structures, apart of the NW-SE striking normal faults, are inherited from Mesozoic faults. Their reactivation and associated folding started during the late Miocene prior to the Messinian salinity crisis due to a NW-SE compressional stress field. No clear evidence of shortening at present-day offshore Lebanon and no large NNE-SSW strike-slip faults parallel to the restraining bend are found indicating that the Levant Fracture System is mainly contained onshore at present day. The intermittent activity of the interpreted structures correlates with the two stages of Levant Fracture System movement during late Miocene and Pliocene. This paper provides a good example of the impact of the evolution of plate boundaries on adjacent basins and indicates that any changes in the stress field, as controlled by the plate boundary, will affect immediately the preexisting structures in adjacent basins.

  1. Drought : Management and Mitigation Assessment for Central Asia and the Caucasus

    OpenAIRE

    World Bank, (WB)

    2005-01-01

    The objective of this study is to raise awareness and understanding of exposure and vulnerability to drought in Central Asian countries and the Caucasus and to introduce a strategic, pro-active framework of mitigation and prevention. The audiences of the report are the governments of Armenia, Azerbaijan and Georgia in the Caucasus and Kazakhstan, Uzbekistan, Turkmenistan, Tajikistan and the Kyrgyz Republic in Central Asia. The report will further be of interest to NGOs and civil society, as w...

  2. European Tips on Tourism development in the Caucasus in Early ХХ Century

    OpenAIRE

    Tamar Tamarashvili

    2013-01-01

    The article presents tips, recommendations, advice by the Europeans. Their consideration was important for further development of tourism in the Caucasus. Namely, for the development of the organization, established in early 20th century “Caucasus Tourism Promotion Committee" and its relation with the countries with well-developed tourism, such as: Austria, Hungary, Germany, France, Bosnia and Herzegovina and etc. Using archive sources, we can consider the issues, concerning foreign tourism e...

  3. Seismic structure of the crust and uppermost mantle beneath Caucasus based on regional earthquake tomography

    Science.gov (United States)

    Zabelina, Irina; Koulakov, Ivan; Amanatashvili, Iason; El Khrepy, Sami; Al-Arifi, Nassir

    2016-04-01

    We present a new seismic model of the crust beneath the Caucasus based on tomographic inversion of P and S arrival times from earthquakes occurred in the region recorded by regional seismic networks in the Caucasian republics. The resulting P and S velocity models clearly delineate major tectonic units of the study area. A high velocity anomaly in Transcaucasian separating the Great and Lesser Caucasus possibly represents a rigid crustal block corresponding to the remnant oceanic lithosphere of Tethys. Another high-velocity pattern coincides with the southern edge of the Scythian Plate. Strongly deformed areas of Great and Lesser Caucasus are mostly associated with low-velocity patterns representing thickened felsic part of the crust and strong fracturing of rocks. Most Cenozoic volcanic centers of Caucasus match to the low-velocity seismic anomalies in the crust. For example, the Kazbegi volcano group is located above an elongated low-velocity anomaly squeezed between high-velocity segments of Transcaucasian and Scythian Plate. We propose that mantle part of the Arabian and Eurasian Plates has been delaminated due to the continental collision in the Caucasus region. As a result, overheated asthenosphere appeared nearly the bottom of the crust and facilitated melting of the crustal material that caused the origin of recent volcanism in Great and Lesser Caucasus.

  4. Nitrogen Budget in a Lowland Coastal Area Within the Po River Basin (Northern Italy): Multiple Evidences of Equilibrium Between Sources and Internal Sinks

    Science.gov (United States)

    Castaldelli, Giuseppe; Soana, Elisa; Racchetti, Erica; Pierobon, Enrica; Mastrocicco, Micol; Tesini, Enrico; Fano, Elisa Anna; Bartoli, Marco

    2013-09-01

    Detailed studies on pollutants genesis, path and transformation are needed in agricultural catchments facing coastal areas. Here, loss of nutrients should be minimized in order to protect valuable aquatic ecosystems from eutrophication phenomena. A soil system N budget was calculated for a lowland coastal area, the Po di Volano basin (Po River Delta, Northern Italy), characterized by extremely flat topography and fine soil texture and bordering a network of lagoon ecosystems. Main features of this area are the scarce relevance of livestock farming, the intense agriculture, mainly sustained by chemical fertilizers, and the developed network of artificial canals with long water residence time. Average nitrogen input exceeds output terms by ~60 kg N ha-1 year-1, a relatively small amount if compared to sub-basins of the same hydrological system. Analysis of dissolved inorganic nitrogen in groundwater suggests limited vertical loss and no accumulation of this element, while a nitrogen mass balance in surface waters indicates a net and significant removal within the watershed. Our data provide multiple evidences of efficient control of the nitrogen excess in this geographical area and we speculate that denitrification in soil and in the secondary drainage system performs this ecosystemic function. Additionally, the significant difference between nitrogen input and nitrogen output loads associated to the irrigation system, which is fed by the N-rich Po River, suggests that this basin metabolizes part of the nitrogen excess produced upstream. The traditionally absent livestock farming practices and consequent low use of manure as fertilizer pose the risk of excess soil mineralization and progressive loss of denitrification capacity in this area.

  5. Evidence for intercontinental parasite exchange through molecular detection and characterization of haematozoa in northern pintails (Anas acuta) sampled throughout the North Pacific Basin

    Science.gov (United States)

    Ramey, Andy M.; Schmutz, Joel A.; Reed, John A.; Fujita, Go; Scotton, Bradley D.; Casler, Bruce; Fleskes, Joseph P.; Konishi, Kan; Uchida, Kiyoshi; Yabsley, Michael J.

    2015-01-01

    Empirical evidence supports wild birds as playing a role in the interhemispheric exchange of bacteria and viruses; however, data supporting the redistribution of parasites among continents are limited. In this study, the hypothesis that migratory birds contribute to the redistribution of parasites between continents was tested by sampling northern pintails (Anas acuta) at locations throughout the North Pacific Basin in North America and East Asia for haemosporidian infections and assessing the genetic evidence for parasite exchange. Of 878 samples collected from birds in Alaska (USA), California (USA), and Hokkaido (Japan) during August 2011 - May 2012 and screened for parasitic infections using molecular techniques, Leucocytozoon, Haemoproteus, and Plasmodium parasites were detected in 555 (63%), 44 (5%), and 52 (6%) samples, respectively. Using an occupancy modeling approach, the probability of detecting parasites via replicate genetic tests was estimated to be high (p ≥ 0.95). Multi-model inference supported variation of Leucocytozoon parasite prevalence by northern pintail age class and geographic location of sampling in contrast to Haemoproteus and Plasmodium parasites for which there was only support for variation in parasite prevalence by sampling location. Thirty-one unique mitochondrial DNA haplotypes were detected among haematozoa infecting northern pintails including seven lineages shared between samples from North America and Japan. The finding of identical parasite haplotypes at widely distributed geographic locations and general lack of genetic structuring by continent in phylogenies for Leucocytozoon and Plasmodium provides evidence for intercontinental genetic exchange of haemosporidian parasites. Results suggest that migratory birds, including waterfowl, could therefore facilitate the introduction of avian malaria and other haemosporidia to novel hosts and spatially distant regions.

  6. Early-Middle Miocene subtle compressional deformation in the Ebro foreland basin (northern Spain); insights from magnetic fabrics

    Science.gov (United States)

    Soto, Ruth; Larrasoaña, Juan C.; Beamud, Elisabet; Garcés, Miguel

    2016-03-01

    The results of anisotropy of magnetic susceptibility analyses of 19 sites carried out on magnetostrigraphically-dated, Lower to Middle Miocene (20.4 to 13.7 Ma) "non-deformed" mudstones from the central part of the Ebro basin reveal the presence of a subtle tectonic overprint lasting at least until the Langhian (Middle Miocene) in the southern Pyrenean foreland. Magnetic ellipsoids show a sedimentary fabric in 42% of sites and a weak and well-defined magnetic lineation in 47% and 11% of sites. The magnetic lineation is roughly oriented around the east-west direction, compatible with a very weak deformation occurring there and related to the north-south compression linked to the convergence between Europe, Iberia and Africa during the Early-Middle Miocene. A slight variation of the magnetic parameters Km, Pj, and T exists through time, probably due to changes in the sedimentary conditions in the basin.

  7. Investigation of Climate Change Impact on Water Resources for an Alpine Basin in Northern Italy: Implications for Evapotranspiration Modeling Complexity

    OpenAIRE

    Ravazzani, Giovanni; Ghilardi, Matteo; Mendlik, Thomas; Gobiet, Andreas; Corbari, Chiara; Mancini, Marco

    2014-01-01

    Assessing the future effects of climate change on water availability requires an understanding of how precipitation and evapotranspiration rates will respond to changes in atmospheric forcing. Use of simplified hydrological models is required beacause of lack of meteorological forcings with the high space and time resolutions required to model hydrological processes in mountains river basins, and the necessity of reducing the computational costs. The main objective of this study was to quanti...

  8. Geophysical evidence for a major palaeochannel within the Obosum Group of the Volta Basin, Northern Region, Ghana

    OpenAIRE

    Jessell, Mark; Boamah, K.; Duodu, J. A.; Ley-Cooper, Y.

    2015-01-01

    We have identified a 230 km long palaeochannel cutting through the sediments of the Obosum Group within the Volta Basin, Ghana. The channel is visible in regional airborne magnetic data as a pair of parallel magnetic anomalies which we interpret to be lateral terrace placer deposits of magnetite or maghemite and show both meandering and braided geometries. The palaeochannel is also visible in the airborne radiometric data for part of its length, as well as in airborne electromagnetic data, wh...

  9. Rotational differencies between the northern and southern Tyrrhenian domains: paleomagnetic constraints from the Amantea basin (Calabria, Italy)

    OpenAIRE

    Speranza, F.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma2, Roma, Italia; Mattei, M.; Dipartimento di Scienze Geologiche, Universita` di Roma TRE, Rome; Sagnotti, L.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma2, Roma, Italia; Grasso, F.; Dipartimento di Scienze Geologiche, Università di Roma Tre, Largo S. Leonardo Murialdo 1, 00143 Roma, Italy

    2000-01-01

    We report on a palaeomagnetic study of upper Miocene sediments from the Amantea basin, located on the Tyrrhenian coast of Calabria. The magnetic mineralogy is dominated by greigite and subordinate magnetite in the Tortonian-Messinian clays (ten sites), and by hemoilmenite and magnetite in the underlaying sands and volcanic ashes (three sites), which have not been dated. Data from the Tortonian, Messinian clays pass both a reversal and a fold test, and define a 19° ± 11° clockwise rotation (wi...

  10. Luminescence ages for three 'Middle Palaeolithic' sites in the Nihewan Basin, northern China, and their archaeological and palaeoenvironmental implications

    Science.gov (United States)

    Guo, Yu-Jie; Li, Bo; Zhang, Jia-Fu; Yuan, Bao-Yin; Xie, Fei; Roberts, Richard Graham

    2016-05-01

    The Nihewan Basin is a key region for studying the Palaeolithic archaeology of East Asia. However, because of the lack of suitable dating methods and representative lithic technologies in this region, the 'Middle Palaeolithic' sites in this basin have been designated based mainly on stratigraphic correlation, which may be unreliable. In this study, three Palaeolithic sites, Motianling, Queergou and Banjingzi, which have been assigned previously to the 'Middle Palaeolithic', are dated based on luminescence dating of K-feldspar grains. Our results show that the cultural layers at Motianling, Queergou and Banjingzi have ages of 315 ± 13, 268 ± 13 and 86 ± 4 ka (corresponding to Marine Isotope Stages 9, 8 and 5), respectively, suggesting that Motianling and Queergou should be assigned to the Lower Palaeolithic, while the age of Banjingzi is consistent with a Middle Palaeolithic attribution. Our results suggest that reassessing the age of 'Middle Palaeolithic' sites in the Nihewan Basin, and elsewhere in North China, is crucial for understanding the presence or absence of the Middle Palaeolithic phase in China. Our dating results also indicate that the Sanggan River developed sometime between about 270 and 86 ka ago.

  11. Holocene Paleoseismic Activity Along the Northern Piedmont Fault of the Hengshan Mountain, South of Datong Basin in Shanxi Province

    Institute of Scientific and Technical Information of China (English)

    Jiang Wali; Xie Xinsheng; Wang Huanzhen; Feng Xiying; Zhang Kangfu

    2003-01-01

    Our field investigation indicates that the northern piedmont fault of the Hengshan Mountain hasdislocated proluvial fan and terrace I of the gully mouth on the northern border of theHengshan Mountain. Stratigraphic age data indicates that the surface layer in the middle andrear part of the proluvial fan and on the terrace I of the gully mouth on the mountain borderconsists of sediments of about 5200 ~ 6800a B.P. The Hezhuang and Niucaoyu trenchesexcavated in the front of Hengshan Mountain revealed that 3 paleoseismic events have occurredalong the northern piedmont fault of Hengshan Mountain since the early Holocene. The 3paleoseismic events occurred in 2260 ± 190 ~ 4370 ± 150a BP, nearly 5628 ± 150a BP, and 8083± 250 ~ 8430 ± 720a BP, respectively, and their recurrence interval is 2313a, 2628a and 2471aon average. The coseismic vertical displacement produced by these events is 1.0 ~ 3.0m. Theelapsed time of the latest movement along the fault has exceeded the recurrence interval of thesepaleoearthquakes. Thus, there exists the possibility of strong earthquake occurrence along thefault from now onward, so the fault is in need of observation.

  12. Karyotype characteristics and polymorphism peculiarities of Chironomus bernensis Wülker & Klötzli, 1973 (Diptera, Chironomidae) from the Central Caucasus and Ciscaucasia

    Science.gov (United States)

    Karmokov, Mukhamed Kh.; Polukonova, Natalia V.; Sinichkina, Olga V.

    2015-01-01

    Abstract Data about the karyotype characteristics, features of chromosomal polymorphism and larval morphology of populations of Chironomus bernensis Wülker & Klötzli, 1973 (Diptera, Chironomidae) from the Central Caucasus (the northern macroslope) and Ciscaucasia are presented. The characteristics of the pericentromeric regions of the long chromosomes of this species from Caucasian populations were very similar to the ones from some European populations (from Poland and Italy), but differed from Swiss and Siberian populations. In the North Caucasian populations 10 banding sequences were found: two in arms A, C, and E, and one in arms B, D, F, and G. Nine of them were already known for this species, and one, berC2, is described for the first time. Cytogenetic distances between all the studied populations of Chironomus bernensis show that close geographical location of all studied populations from the Central Caucasus and Ciscaucasia is reflected in their similar cytogenetic structure, but on the other hand, that they are more closely related to populations from Europe than to populations from Western Siberia. At the same time, all studied larvae from Caucasian populations have a four-bladed premandible, instead of a two-bladed one, as in the description of Chironomus bernensis from Switzerland (Wülker and Klötzli 1973, Polukonova 2005c). These peculiarities may indicate the relative isolation of the Caucasus from the viewpoint of microevolution. Further research on karyological and morphological characteristics of Chironomus bernensis from geographically distant regions is necessary as there is a possibility that the presently known species is actually polytypic and consists of several sibling species. PMID:26312128

  13. Record of glacial-eustatic sea-level fluctuations in complex middle to late Pennsylvanian facies in the Northern Appalachian Basin and relation to similar events in the Midcontinent basin

    Science.gov (United States)

    Belt, Edward S.; Heckel, Philip H.; Lentz, Leonard J.; Bragonier, William A.; Lyons, Timothy W.

    2011-06-01

    Pennsylvanian cycles in the Northern Appalachian Basin (NAB) were historically considered to result from delta-lobe switching, and more recently from sea-level fluctuation with sandy deltas prograding during highstand. These interpretations are revised using new data from cores and outcrop exposures. Thick (> 5 m) channel deposits with a marked erosion surface at their base cutting down across previous cycles are re-interpreted as incised valley fill (IVF) deposits in paleovalleys, because the basal erosion surfaces are widespread, and thus reflect a record of lowstand. Most common are simple paleovalleys that contain mainly sandy fluvial deposits. Compound paleovalleys with sequence boundaries above the basal erosion surface, contain terrestrial, estuarine, and marine deposits. Early to late highstand deposits in interfluvial parts of the cycles are dominated by shale and mudstone, with paleosols, coals, and local non-marine limestone, which reflect floodbasin to lacustrine conditions. These reinterpretations are applied to previously and newly recognized cycles in ascending order: Upper Kittanning, Lower Freeport, Upper Freeport Leader (new), Upper Freeport, Piedmont (new), Mahoning, Mason interval (locally includes Upper New Galilee in the north), and Brush Creek, across a 300-km arc in the Northern Appalachian Basin. These deposits accumulated in a 'high shelf' setting that experienced fewer marine transgressions, and were interrupted by more frequent exposure and downcutting, in contrast to the thicker and more complete succession with more numerous marine units in the Midcontinent. Magnitudes of highstand transgressions into this basin, deduced from the up-dip extent of marine and brackish fossil assemblages, were greatest for the Brush Creek, less so for the Upper Kittanning and Mahoning, and least for the Lower Freeport, Upper Freeport Leader, Piedmont, and Mason. The anomalous basin-wide fresh-water roofshales and equivalents of the Upper Freeport coal may

  14. Development of a systemwide predator control program: Stepwise implementation of a predator index, predator control fisheries, and evaluation plan in the Columbia River basin (Northern Squawfish Management Program). Section 1: Implementation; Annual report 1995

    International Nuclear Information System (INIS)

    The authors report their results from the fifth year of a basinwide program to harvest northern squawfish (Ptychocheilus oregonensis) in an effort to reduce mortality due to northern squawfish predation on juvenile salmonids during their emigration from natal streams to the ocean. Earlier work in the Columbia River Basin suggested predation by northern squawfish on juvenile salmonids may account for most of the 10--20% mortality juvenile salmonids experience in each of eight Columbia and Snake River reservoirs. Modeling simulations based on work in John Day Reservoir from 1982 through 1988 indicated that if predator-sized northern squawfish were exploited at a 10--20% rate, the resulting restructuring of their population could reduce their predation on juvenile salmonids by 50%

  15. Modelling runoff and glacier melt in the Hunza basin in northern Pakistan using satellite remote sensing techniques

    International Nuclear Information System (INIS)

    The glaciers in western Karakoram are important for freshwater supply in the rivers of Pakistan. Global warming influences the future water supply from glaciers. In order to study the hydrological conditions and possible impacts of climate change, runoff simulations are performed for the Hunza basin. The hydrological modelling system SRM (Snowmelt Runoff Model) is customized and applied to the Hunza basin. Various data obtained from satellite remote sensing imagery and meteorological stations in the study area are processed, prepared and used as input to SRM. For runoff simulations the basin is divided into five sub-basins. The (sub-) basins are defined by the hydrological response units (HRU) based on the elevation zones and land-cover types. The spatially distributed data are aggregated HRU-wise as input for the model simulations. The energy available for snow and glacier melt is parameterized in SRM by degree day factors which are defined separately for seasonal snow, ice and debris covered glaciers. The model is calibrated for the Hunza basin using the meteorological and remote sensing data from years 2002 and 2003. The daily runoff is simulated and compared with the measured discharge data obtained from the power company. The Nash-Sutcliffe correlation coefficient of simulated versus measured runoff data is 0.87 for year 2002 and 0.96 for year 2003 which indicates a good agreement. An estimation of mass balance of Baltoro glacier is made using the meteorological data from Shigar station applying the hydrological method to estimate accumulation and melt. Based on these data is found that Baltoro glacier has slightly negative mass balance. The ablation rates of debris covered parts of Baltoro glacier at 4150 m elevation are estimated to be between 3 and 4 cm per day. However, the uncertainty in mass balance modelling is high due to poor knowledge of accumulation inferred by spatial extrapolation from station data.Keeping the glacier area unchanged, for the 2002

  16. The thick-bedded tail of turbidite thickness distribution as a proxy for flow confinement: Examples from tertiary basins of central and northern Apennines (Italy)

    Science.gov (United States)

    Marini, Mattia; Felletti, Fabrizio; Milli, Salvatore; Patacci, Marco

    2016-07-01

    This study reviews the thickness statistics of non-channelized turbidites from four tertiary basins of Central-Northern Apennines (Italy), where bed geometry and sedimentary character have been previously assessed. Though very different in terms of size and, arguably, character of feeder system, these basins share a common stratigraphic evolution consisting in transition from an early ponded to a late unconfined setting of deposition. Based on comparison of thickness subsets from diverse locations and stratigraphic heights within the studied turbidite fills, this paper seeks to answer the following questions: i) how data collection procedures and field operational constraints (e.g. measure location, outcrop quality, use of thicknesses data from single vs. multiple correlative sections, stratigraphic thickness of the study interval) can affect statistics of sample data? ii) how depositional controls of confined vs. unconfined turbidite basins can result in different thickness-frequency distributions?; and iii) is there in thickness statistics a 'flow confinement' signature which can be used to distinguish between confined and unconfined turbidites? Results suggest that: i) best practices of data collection are crucial to a meaningful interpretation of sample data statistics, especially in presence of stratigraphic and spatial trends of turbidite bed thickness; ii) a systematic bias against cm-thick Tcd Bouma sequence turbidites exists in sample data, which can result in the low-end tail of empirical thickness-frequency distributions to depart significantly from the actual distribution of turbidite thickness; and iii) thickness statistics of beds starting with a basal Ta/Tb Bouma division bear a coherent relationship to the transition from ponded to unconfined depositional settings, consisting in reduction of variance and mean and, consequently, parameters, or even type, of best fit model distribution. This research highlights the role of flow stripping, sediment by

  17. Development of the alluvial and lacustrine terraces on the northern margin of the Hetao Basin, Inner Mongolia, China: Implications for the evolution of the Yellow River in the Hetao area since the late Pleistocene

    Science.gov (United States)

    Jia, Liyun; Zhang, Xujiao; Ye, Peisheng; Zhao, Xitao; He, Zexin; He, Xiangli; Zhou, Qingshuo; Li, Jie; Ye, Mengni; Wang, Zhen; Meng, Jing

    2016-06-01

    Terrace formation processes can reflect the evolution of large rivers. The Hetao Basin is a floodplain of the Yellow River, and there are two to three terraces that extend E-W on the northern margin. Based on a detailed field geological survey and measurement of the terrace sections, combined with sedimentological and chronological analyses, we reconstructed the developmental processes of the three terraces and inferred that three river terraces were formed by the Yellow River. The OSL dating results show that the time of deposition of terrace 3 was prior to 118 ka BP. Subsequently, the terrace began to experience incision and formed the geomorphic surface of terrace T3. Similarly, terrace 2 and terrace 1 were mainly deposited from ~ 109 and 59 ka, respectively; and began to be incised prior to 71 and 46 ka, respectively. The three terraces in the northern Hetao Basin are the products of the combined actions of climatic shifts and tectonic uplift. The Yellow River's evolutionary history in the Hetao area since the Late Pleistocene is discussed. Before about 120 ka BP, the Yellow River may have flowed through the northern Hetao Basin. Between 110 and 70 ka BP, the Yellow River experienced at least two changes between river and lake sedimentation. From 60 to 50 ka, a very large river-connected lake of the Yellow River was developed in the Hetao Basin. After 50 ka, the Hetao river-connected paleolake of the Yellow River gradually dried.

  18. A Side-by-side Comparison of Eddy Covariance and Bowen Ratio Evapotranspiration From a Northern Great Basin Ecosystem

    Science.gov (United States)

    Lyles, B. F.; Jasoni, R. L.

    2008-12-01

    Development of new ground water resources in rural lands surrounding urban areas of the arid western United States has been identified as a key to maintaining urban growth. The extent and rate at which ground water can be sustainably extracted, while minimizing environmental impacts, depends to a large degree on how much of the existing resource escapes back to the atmosphere via the process of evapotranspiration (ET). ET is the sum of water that evaporates (E) from soil surfaces and is transpired (T) from plant leaves. This study was conducted in a northeast/southwest trending closed basin, bounded by mountains on all sides, with no surface water outflow. The playa which is located in the center of the basin encompasses 59,600 hectares, while phreatophytic plants bordering the playa encompass 20,000 hectares. ET data was collected from a sagebrush/greasewood plant community from October 2004 to August 2008 by the Bowen Ratio technique. Eddy covariance ET monitoring equipment was installed in April of 2007 and a side-by-side comparison was conducted from April to October, 2007. At the end of the study period a 25% difference in ET was calculated between the eddy covariance and Bowen ratio techniques. The major factors for the differences in ET from the two different methods will be presented.

  19. Investigation of climate change impact on water resources for an Alpine basin in northern Italy: implications for evapotranspiration modeling complexity.

    Science.gov (United States)

    Ravazzani, Giovanni; Ghilardi, Matteo; Mendlik, Thomas; Gobiet, Andreas; Corbari, Chiara; Mancini, Marco

    2014-01-01

    Assessing the future effects of climate change on water availability requires an understanding of how precipitation and evapotranspiration rates will respond to changes in atmospheric forcing. Use of simplified hydrological models is required because of lack of meteorological forcings with the high space and time resolutions required to model hydrological processes in mountains river basins, and the necessity of reducing the computational costs. The main objective of this study was to quantify the differences between a simplified hydrological model, which uses only precipitation and temperature to compute the hydrological balance when simulating the impact of climate change, and an enhanced version of the model, which solves the energy balance to compute the actual evapotranspiration. For the meteorological forcing of future scenario, at-site bias-corrected time series based on two regional climate models were used. A quantile-based error-correction approach was used to downscale the regional climate model simulations to a point scale and to reduce its error characteristics. The study shows that a simple temperature-based approach for computing the evapotranspiration is sufficiently accurate for performing hydrological impact investigations of climate change for the Alpine river basin which was studied. PMID:25285917

  20. High level of population genetic structuring in lake-run brown trout, Salmo trutta, of the Inari Basin, northern Finland.

    Science.gov (United States)

    Swatdipong, A; Vasemägi, A; Niva, T; Koljonen, M-L; Primmer, C R

    2010-12-01

    Rivers draining into (Lake) Inarijärvi, northern Finland, sustain a number of lake-run brown trout, Salmo trutta, populations but, as with most lake-run S. trutta systems, the level of population genetic structuring among populations is unknown. To address this and to assist fish stock management in the region, the population genetic structure of S. trutta collected from 28 sampling sites in rivers flowing into Inarijärvi was studied using 13 microsatellite loci. Populations were clustered into three separate groups, largely corresponding to geographic regions, with between-region F(ST) values ranging from 0·11 to 0·16. The significant differentiation observed between most populations within each region also implies that individual populations should be recognized as separate management units and actions to improve, and subsequently maintain, conditions for natural spawning should be prioritized. The results of this study further indicate that the trout from each of these regions may have different biological characteristics, such as local-lake feeding behaviour among the western populations and strong isolation among the northern stocks. As a consequence, further research is warranted to better understand the level of ecological uniqueness of lake-run S. trutta populations. PMID:21133916

  1. Present geotemperature and its suggestion to natural gas generation in Xujiaweizi fault-depression of the northern Songliao Basin

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    According to stastistic of present geotemperatures at the depths of 1000,2000,3000 and 4000 m,respectively in the Xujiaweizi fault-depression of the north Songliao Basin,the result indicates that Xujiaweizi fault-depression falls in the high geotemperature area,with the higher geothermal gradient in the depression layer than that in the fault-depression layer.The geothermal gradient decreases with the increasing of the depth.The thermal conductivity of rock greatly controls the geothermal gradient.The main factors constraining the current geotemperature include thermal configuration of the earth’s crust, deep faults,distribution and abundance of radioelements.The high geotemperature is in favour of generation of deep gas.

  2. Diamond drilling for geologic information in the middle Precambrian basins in the western portion of northern Michigan. Final report

    International Nuclear Information System (INIS)

    Between September 26, 1977, and May 11, 1978, six initially vertical holes probed a total of 9896 feet (1109 feet or 11.2% in overburden, 155 feet or 1.6% in Precambrian Y mafic dikes, 8386 feet or 84.7% in Precambrian X Goodrich Quartzite and Michigamme Formation, and 246 feet or 2.5% in Precambrian W basement lithologies). In addition to normal examination of core, logging, and storing of core, the holes were extensively logged geophysically, acidized core was tested for phosphate content by ammonium molybdate, splits from five out of every thirty feet of core were subjected to chemical scrutiny, thin sections of all lithologies were examined, and radiometric determinations of geologic age were made for confirmation of Precambrian W basement which was encountered in each of the three basins in Marquette County

  3. Permian paleogeography of west-central Pangea: Reconstruction using sabkha-type gypsum-bearing deposits of Parnaíba Basin, Northern Brazil

    Science.gov (United States)

    Abrantes, Francisco R.; Nogueira, Afonso C. R.; Soares, Joelson L.

    2016-07-01

    Extreme aridity during Late Permian - Early Triassic period was the main factor for resetting the entire paleoclimate of the planet. Permian evaporite basins and lacustrine red beds were widely distributed along the supercontinent of Pangea. Sulphate deposits in Western Pangea, particularly in Northern Brazil, accumulated in an extensive playa lake system. Outcrop-based facies and stratigraphic analysis of up to 20 m thick evaporite-siliciclastic deposits reveal the predominance of laminated reddish mudstone with subordinate limestone, marl and lenses of gypsum. The succession was deposited in shallow lacustrine and inland sabkha environments associated with saline pans and mudflats. Gypsum deposits comprise six lithofacies: 1) bottom-growth gypsum, 2) nodular/micronodular gypsum, 3) mosaic gypsum, 4) fibrous/prismatic gypsum, 5) alabastrine gypsum, and 6) rosettes of gypsum. Gypsum types 1 and 2 are interpreted as primary deposition in saline pans. Bottom-growth gypsum forms grass-like crusts while nodular/micronodular gypsum indicates displacive precipitation of the crust in shallow water and the groundwater capillary zone. Types 3 and 4 are early diagenetic precipitates. Abundant inclusions of tiny lath-like anhydrite crystals suggest a primary origin of anhydrite. Alabastrine gypsum, fibrous gypsum (satinspar) and rosettes of gypsum probably derived from near-surface hydration of anhydrite. The gypsum-bearing deposits in the Parnaíba Basin contribute towards understanding paleogeographic changes in Western Pangea. A progressive uplift of East Pangea, culminated in the forced regression and retreat of epicontinental seas to the West. Restricted seas or large lakes were formed before the definitive onset of desert conditions in Pangea, leading to the development of extensive ergs.

  4. Mid-Wisconsin to Holocene permafrost and landscape dynamics based on a drained lake basin core from the northern Seward Peninsula, northwest Alaska

    Science.gov (United States)

    Lenz, Josefine; Grosse, Guido; Jones, Benjamin M.; Anthony, Katey M. Walter; Bobrov, Anatoly; Wulf, Sabine; Wetterich, Sebastian

    2016-01-01

    Permafrost-related processes drive regional landscape dynamics in the Arctic terrestrial system. A better understanding of past periods indicative of permafrost degradation and aggradation is important for predicting the future response of Arctic landscapes to climate change. Here, we used a multi-proxy approach to analyse a ~ 4 m long sediment core from a drained thermokarst lake basin on the northern Seward Peninsula in western Arctic Alaska (USA). Sedimentological, biogeochemical, geochronological, micropalaeontological (ostracoda, testate amoebae) and tephra analyses were used to determine the long-term environmental Early-Wisconsin to Holocene history preserved in our core for central Beringia. Yedoma accumulation dominated throughout the Early to Late-Wisconsin but was interrupted by wetland formation from 44.5 to 41.5 ka BP. The latter was terminated by the deposition of 1 m of volcanic tephra, most likely originating from the South Killeak Maar eruption at about 42 ka BP. Yedoma deposition continued until 22.5 ka BP and was followed by a depositional hiatus in the sediment core between 22.5 and 0.23 ka BP. We interpret this hiatus as due to intense thermokarst activity in the areas surrounding the site, which served as a sediment source during the Late-Wisconsin to Holocene climate transition. The lake forming the modern basin on the upland initiated around 0.23 ka BP and drained catastrophically in spring 2005. The present study emphasises that Arctic lake systems and periglacial landscapes are highly dynamic and that permafrost formation as well as degradation in central Beringia was controlled by regional to global climate patterns as well as by local disturbances.

  5. Deep seismic reflection images of the Wharton Basin oceanic crust and uppermost mantle offshore Northern Sumatra: Relation with active and past deformation

    Science.gov (United States)

    Carton, Hélène; Singh, Satish C.; Hananto, Nugroho D.; Martin, James; Djajadihardja, Yusuf S.; Udrekh; Franke, Dieter; Gaedicke, Christoph

    2014-01-01

    present deep seismic reflection images along two profiles collected in 2006 in the Wharton Basin offshore Northern Sumatra. The main profile is located subparallel to the Sumatran trench at a distance of 32-66 km. Faulting of the entire sedimentary section (strike-slip deformation sometimes accompanied by a dip-slip component) is imaged over two fracture zones of the extinct Wharton Spreading Center that prior studies have shown to be reactivated as left-lateral faults. The western fracture zone is associated with a wide region of strong basement topography, a difference in crustal thickness of ~1.5 km, and an age offset of 9 Ma. The epicenters of the 11 April 2012 Mw 8.6 great strike-slip earthquake, its Mw 7.2 foreshock, and Mw 8.2 aftershock align along this major structure > 100 km south of the profile intersection. Our high-quality long-offset seismic reflection data also reveal bright dipping reflections extending down to a maximum of ~24 km into the oceanic mantle (~37 km below sea level). Apparent dips are mostly 25-35°, corresponding to 30-55° along either N-S to NNE-SSW or E-W to WNW-ESE directions, which encompass the directions of plate fabric and nodal planes of the Mw 8.6 event. We suggest that these enigmatic reflections arise from presently inactive dip-slip fault planes reaching for the deepest ones to the base of the brittle layer. Possible origins include extension related to plate bending or an episode of now inactive thrust-type deformation reactivating paleonormal faults, similar to that taking place in the Central Indian Basin.

  6. Constraints on the duration of the Paleocene-Eocene Thermal Maximum by orbitally-influenced fluvial sediment records of the northern Bighorn Basin, Wyoming, USA

    Science.gov (United States)

    van der Meulen, Bas; Abels, Hemmo; Meijer, Niels; Gingerich, Philip; Lourens, Lucas

    2016-04-01

    The addition of major amounts of carbon to the exogenic carbon pool caused rapid climate change and faunal turnover during the Paleocene-Eocene Thermal Maximum (PETM) around 56 million years ago. Constraints are still needed on the duration of the onset, main body, and recovery of the event. The Bighorn Basin in Wyoming provides expanded terrestrial sections spanning the PETM and lacking the carbonate dissolution present in many marine records. Here we provide new carbon isotope records for the Polecat Bench and Head of Big Sand Coulee sections, two parallel sites in the northern Bighorn Basin, at unprecedented resolution. Cyclostratigraphic analysis of these fluvial sediment records using descriptive sedimentology and proxy records allows subdivision into intervals dominated by avulsion deposits and intervals dominated by overbank deposits. These sedimentary sequences alternate in a regular fashion and are related to climatic precession. Correlation of the two, 8-km-spaced sections shows that the avulsion-overbank cycles are laterally consistent. The presence of longer-period alternations, related to modulation by the 100-kyr eccentricity cycle, corroborates the precession influence on the sediments. Sedimentary cyclicity is then used to develop a floating precession-scale age model for the PETM carbon isotope excursion (CIE). We find a CIE body encompassing 95 kyrs aligning with marine cyclostratigraphic age models. The duration of the CIE onset is estimated at 5 kyrs, but difficult to determine because sedimentation rates vary at the sub-precession scale. The CIE recovery starts with a 2 to 4 per mille step and lasts 40 or 90 kyrs, depending on what is considered the carbon isotope background state.

  7. Organic matter iron and nutrient transport and nature of dissolved organic matter in the drainage basin of a boreal humic river in northern Finland

    International Nuclear Information System (INIS)

    Organic carbon and iron transport into the Gulf of Bothnia and the seasonal changes in the nature of dissolved organic matter (DOM) were studied in 1983 and 1984 at the mouth of the River Kiiminkijoki, which crosses an area of minerotrophic mires in northern Finland. Organic and inorganic transport within the drainage basin was studied in the summer and autumn of 1985 and 1986. The results indicate that the dissolved organic carbon (DOC) is mainly of terrestrial origin, leaching mostly from peatlands. The DOC concentrations decrease under low flow conditions. The proportion of drifting algae as a particulate organic carbon (POC) source seems to increase in summer. The changes in the ratio of Fe/DOC, the colour of the DOM and the ratio of Fe/DOC, the colour of the DOM and the ratio of fluorescence to DOC with discharge give indications of the origin, formation, nature and fate of the DOM in the river water. Temperature-dependent microbiological processes in the formation and sedimentation of Fe-organic colloids seem to be important. Estimates are given for the amounts and transport rates of organic carbon and Fe discharged into the Gulf of Bothnia by river. High apparent molecular weight (HAMW) organic colloids are important for the organic, Fe and P transport in the basin. The DOM in the water consists mainly of fulvic acids, although humic acids are also important. The results indicate an increase in the mobilization of HAMW Fe-organic colloids in the peatlands following drainage and peat mining. The transport of inorganic nitrogen from the peatlands in the area and in the river is increasing due to peat mining. The changes in the transport of organic matter, Fe and P are less marked

  8. Subaqueous landslides at the distal basin of Lago Nahuel Huapi (Argentina): Towards a tsunami hazard evaluation in Northern Patagonian lakes

    Science.gov (United States)

    Beigt, Débora; Villarosa, Gustavo; Gómez, Eduardo A.; Manzoni, Carolina

    2016-09-01

    The May 22nd, 1960 Valdivia earthquake, Chile (Mw 9.5) triggered a series of subaqueous mass-wasting processes (debris flows and slides) in Lago Nahuel Huapi (Argentina), generating a tsunami-like wave that hit the coasts of San Carlos de Bariloche. Aiming to provide a first preliminary insight into tsunami hazards for the lakeshore communities, in this paper we identify and characterize the subaqueous landslides at the populated distal basin of the lake. Swath bathymetric and seismic profiling surveys were carried out and high-resolution digital elevation models were derived from these data to perform a landslide inventory map. A series of morphometrical parameters (including the landslide area, the volume of displaced materials and the run-out distance, among others) were estimated upon selected events. The results indicated that landslide activity at the distal basin of Lago Nahuel Huapi has been concentrated in the vicinity of Bariloche (massive landslide triggered by the 1960 earthquake) and within steep delta fronts where the slope failures typically initiate at shallow waters (9-11 m depth). The sliding mass frequently travels basinward along a great distance (≥ 1000 m). At the delta fronts, the volume of material removed by landslides can reach ~ 40 × 104 m3, leaving scar areas of up to 13 m thick. The periodic occurrence of rotational-translational mass movements initiating at the upper edge of the delta fronts, with vertical displacements of the mobilized materials reaching ~ 200 m, probably represents a potential tsunami hazard for the nearby populated coasts.

  9. Drainage basin and topographic analysis of a tropical landscape: Insights into surface and tectonic processes in northern Borneo

    Science.gov (United States)

    Mathew, Manoj Joseph; Menier, David; Siddiqui, Numair; Ramkumar, Mu.; Santosh, M.; Kumar, Shashi; Hassaan, Muhammad

    2016-07-01

    We investigated the recent landscape development of Borneo through geomorphic analysis of two large drainage basins (Rajang and Baram basins). The extraction of morphometric parameters utilizing digital terrain data in a GIS environment, focusing on hydrography (stream length-gradient index, ratio of valley floor width to valley height, and transverse topographic symmetry factor) and topography (local relief and relief anomaly), was carried out in order to elucidate processes governing drainage and landscape evolution. Anomalously high and low values of stream length-gradient indices of main tributary streams associated with faults and multiple knick-points along the channel profiles are linked to deformation events. The development of deeply incised V-shaped valleys show enhanced incision capability of streams in response to steepening of hillslope gradients following tectonic inputs. Deflection of streams and probable dynamic reorganization of the drainage system through stream capture processes as feedbacks to tectonic uplift and orographic effect are observed. Local relief and relief anomaly maps highlight the presence of preserved elevation-accordant relict portions of landscapes characterized by low amplitude relief, nested between ridgelines in regions of complex folding. Our results reveal dynamic geomorphic adjustment of the landscape due to perturbations in tectonic and climatic boundary conditions. The implication is that the landscape of north Borneo experienced a tectonic phase of rapid uplift after 5 Ma and undergoes active folding of the Rajang Group thrust belts in the present-day. Active shortening combined with high rates of denudation in Sarawak, demonstrates transience emphasized by the drainage system attempting to adjust to tectonic and climatic forcing.

  10. 76 FR 30987 - In the Matter of the Designation of Caucasus Emirate aka Imarat Kavkaz aka Imirat Kavkaz aka...

    Science.gov (United States)

    2011-05-27

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF STATE In the Matter of the Designation of Caucasus Emirate aka Imarat Kavkaz aka Imirat Kavkaz aka Islamic Emirate of... Imarat Kavkaz, also known as Imirat Kavkaz, also known as Islamic Emirate of the Caucasus, poses...

  11. Geology and geochemistry of newly discovered Tertiary carbonatite occurrences near Villa Ahumada area, Basin and Range province, Chihuahua, northern Mexico

    Science.gov (United States)

    Nandigam, Ravi Chenchu

    This study targets some newly discovered carbonatite occurrences located in the eastern Mexican Basin and Range province, a few kilometers to the east of Villa Ahumada, Chihuahua. The region containing these occurrences experienced compression related to subduction of the Farallon plate until about 32 Ma that was followed by Basin and Range extension. Geological mapping (1:5,000 scale), petrography, study of drill hole cuttings and satellite images, and major and trace element chemical analyses were utilized to understand the intrusive style of the carbonatites, their mineralogy and petrogenesis. The carbonatites, named Yuca, Mariana and El Indio, collectively intrude limestones, granitic intrusives and subduction-related tuffs and lavas mainly as a stock, breccias and dikes. The Yuca carbonatite was emplaced as a 900-m diameter stock, 500 x 350 m breccia body, numerous dikes and networks of fracture fillings. Crosscutting field relationships at Yuca suggest at least two stages of carbonatite emplacement. At Mariana, carbonatite was emplaced as a 750 x 350 m breccia. Four out of nine reverse circulation drill holes penetrated and bottomed in the breccia at an average depth of about 300 m At El Indio, carbonatite was emplaced as a 20 m diameter breccia pipe and a 1m thick sill. Major minerals present are calcite, Fe-rich calcite and hematite. Sporadic presence of fluorite is common. At Mariana, two generations of grossular-rich garnets associated with limestones and granite porphyry respectively are recognized. It is inferred that garnets in granite porphyry represent metasomatic alteration due to the emplacement of carbonatite breccia. Parental magmas of Yuca carbonatites have undergone differentiation under low fO2 conditions during which they were progressively enriched in iron. The carbonatite compositional types recognized based on major element data, in the sequence of least to most highly differentiated, are (1) magnesio-, (2) calcio- and (3

  12. Whole water column distribution and carbon isotopic composition of bulk particulate organic carbon, cholesterol and brassicasterol from the Cape Basin to the northern Weddell Gyre in the Southern Ocean

    OpenAIRE

    Cavagna, Anne-Julie; F. Dehairs; Woule-Ebongué, V.; Bouillon, Steven; F. Planchon; Delille, Bruno; Bouloubassi, Ioanna

    2012-01-01

    International audience The combination of concentrations and δ13C signatures of Particulate Organic Carbon (POC) and sterols provides a powerful approach to study ecological and environmental changes both in the modern and ancient ocean, but its application has so far been restricted to the surface area. We applied this tool to study the biogeochemical changes in the modern ocean water column during the BONUS-GoodHope survey (Feb-Mar 2008) from Cape Basin to the northern part of the Weddel...

  13. Occurrence of arsenic species in algae and freshwater plants of an extreme arid region in northern Chile, the Loa River Basin.

    Science.gov (United States)

    Pell, Albert; Márquez, Anna; López-Sánchez, José Fermín; Rubio, Roser; Barbero, Mercedes; Stegen, Susana; Queirolo, Fabrizio; Díaz-Palma, Paula

    2013-01-01

    This study reports data on arsenic speciation in two green algae species (Cladophora sp. and Chara sp.) and in five aquatic plants (Azolla sp., Myriophyllum aquaticum, Phylloscirpus cf. desserticola, Potamogeton pectinatus, Ruppia filifolia and Zannichellia palustris) from the Loa River Basin in the Atacama Desert (northern Chile). Arsenic content was measured by Mass spectrometry coupled with Inductively Coupled Plasma (ICP-MS), after acidic digestion. Liquid chromatography coupled to ICP-MS was used for arsenic speciation, using both anionic and cationic chromatographic exchange systems. Inorganic arsenic compounds were the main arsenic species measured in all samples. The main arsenic species in the extracts of freshwater algae and plants were arsenite and arsenate, whereas glycerol-arsenosugar (gly-sug), dimethylarsinic acid (DMA) and methylarsonic acid (MA) were present only as minor constituents. Of the samples studied, algae species accumulated more arsenic than aquatic plants. Total arsenic content ranged from 182 to 11100 and from 20 to 248 mg As kg(-1) (d.w.) in algae and freshwater plants, respectively. In comparison with As concentration in water samples, there was hyper-accumulation (>0.1% d.w.) in Cladophora sp. PMID:22981629

  14. Post-Seismic Deformation from the 2009 Mw 6.3 Dachaidan Earthquake in the Northern Qaidam Basin Detected by Small Baseline Subset InSAR Technique

    Directory of Open Access Journals (Sweden)

    Yang Liu

    2016-02-01

    Full Text Available On 28 August 2009, one thrust-faulting Mw 6.3 earthquake struck the northern Qaidam basin, China. Due to the lack of ground observations in this remote region, this study presents high-precision and high spatio-temporal resolution post-seismic deformation series with a small baseline subset InSAR technique. At the temporal scale, this changes from fast to slow with time, with a maximum uplift up to 7.4 cm along the line of sight 334 days after the event. At the spatial scale, this is more obvious at the hanging wall than that at the footwall, and decreases from the middle to both sides at the hanging wall. We then propose a method to calculate the correlation coefficient between co-seismic and post-seismic deformation by normalizing them. The correlation coefficient is found to be 0.73, indicating a similar subsurface process occurring during both phases. The results indicate that afterslip may dominate the post-seismic deformation during 19–334 days after the event, which mainly occurs with the fault geometry and depth similar to those of the c-seismic rupturing, and partly extends to the shallower and deeper depths.

  15. Post-Seismic Deformation from the 2009 Mw 6.3 Dachaidan Earthquake in the Northern Qaidam Basin Detected by Small Baseline Subset InSAR Technique.

    Science.gov (United States)

    Liu, Yang; Xu, Caijun; Wen, Yangmao; Li, Zhicai

    2016-01-01

    On 28 August 2009, one thrust-faulting Mw 6.3 earthquake struck the northern Qaidam basin, China. Due to the lack of ground observations in this remote region, this study presents high-precision and high spatio-temporal resolution post-seismic deformation series with a small baseline subset InSAR technique. At the temporal scale, this changes from fast to slow with time, with a maximum uplift up to 7.4 cm along the line of sight 334 days after the event. At the spatial scale, this is more obvious at the hanging wall than that at the footwall, and decreases from the middle to both sides at the hanging wall. We then propose a method to calculate the correlation coefficient between co-seismic and post-seismic deformation by normalizing them. The correlation coefficient is found to be 0.73, indicating a similar subsurface process occurring during both phases. The results indicate that afterslip may dominate the post-seismic deformation during 19-334 days after the event, which mainly occurs with the fault geometry and depth similar to those of the c-seismic rupturing, and partly extends to the shallower and deeper depths. PMID:26861330

  16. Influence of climate and eolian dust on the major-element chemistry and clay mineralogy of soils in the northern Bighorn basin, U.S.A.

    Science.gov (United States)

    Reheis, M.C.

    1990-01-01

    Soil chronosequences in the northern Bighorn basin permit the study of chronologic changes in the major-element chemistry and clay mineralogy of soils formed in different climates. Two chronosequences along Rock Creek in south-central Montana formed on granitic alluvium in humid and semiarid climates over the past two million years. A chronosequence at the Kane fans in north-central Wyoming formed on calcareous alluvium in an arid climate over the past 600,000 years. Detailed analyses of elemental chemistry indicate that the soils in all three areas gradually incorporated eolian dust that contained less zirconium, considered to be chemically immobile during weathering, than did the alluvium. B and C horizons of soils in the wettest of the chronosequences developed mainly at logarithmic rates, suggesting that leaching, initially rapid but decelerating, dominated the dust additions. In contrast, soils in the most arid of the chronosequences developed at linear rates that reflect progressive dust additions that were little affected by leaching. Both weathering and erosion may cause changes with time to appear logarithmic in A horizons of soils under the moist and semiarid climatic regimes. Clay minerals form with time in the basal B and C horizons and reflect climatic differences in the three areas. Vermiculite, mixed-layer illite-smectite, and smectite form in the soils of the moist-climate chronosequence; smectite forms in the semiarid-climate chronosequence; and smectite and palygorskite form in the arid-climate chronosequence. ?? 1990.

  17. The early Miocene (~25 Ma) volcanism in the northern Kyushu-Palau Ridge, enriched mantle source injection during rifting prior to the Shikoku backarc basin opening

    Science.gov (United States)

    Haraguchi, Satoru; Ishii, Teruaki; Kimura, Jun-Ichi; Kato, Yasuhiro

    2012-03-01

    The northern Kyushu-Palau Ridge (KPR), remnant conjugate arc of the Izu-Ogasawara (Bonin)-Mariana (IBM) active arc, is dominated by basalt-andesite except for the Komahashi-Daini Seamount where acidic plutonic rocks of 38 Ma were recovered. These mafic to intermediate volcanics are produced by the rifting volcanism in the proto-IBM arc associated with spreading of the Shikoku Basin. The HFSE and HREE contents and ratios of these volcanics indicate enriched source mantle composition compared to recent volcanic front. The LILE ratios exhibit similar characteristics to reararc volcanism of the recent Izu arc, and some enriched volcanics exhibit high abundance of sediment melt inputs. Based on these observations and compilations of the published data set, the replacement event of the wedge mantle under the IBM arc occurred two times. The first event occurred between 45 and 38 Ma, with Pacific type mantle being replaced by depleted Indian type mantle. The second event occurred between 36 and 25 Ma, enriched mantle flowed from reararc side. The slab component during the proto-IBM arc rifting was a similar characteristic to recent reararc volcanism of the Izu arc, and sediment melt added in a local area.

  18. New data on Mustelidae (Carnivora) from Southeast Asia: Siamogale thailandica, a peculiar otter-like mustelid from the late middle Miocene Mae Moh Basin, northern Thailand

    Science.gov (United States)

    Grohé, Camille; Chaimanee, Yaowalak; de Bonis, Louis; Yamee, Chotima; Blondel, Cécile; Jaeger, Jean-Jacques

    2010-11-01

    We report new dental remains of Mustelidae from the late middle Miocene of Mae Moh Basin, northern Thailand, improving the poor fossil record of the family in Southeast Asia. Siamogale thailandica is a poorly known mustelid, previously recorded from just a single tooth. Here we present over a hundred new specimens attributable to this species. S. thailandica shows a combination of primitive and convergent features of the dentition that makes its original subfamilial assignment to Lutrinae doubtful. Evidence from the dental morphology suggests that it belongs to a bunodont otter-like mustelid that evolved in convergence with “true” otters (Lutrinae) toward a semi-aquatic way of life. Autapomorphic features such as the height and the position of the m1 metaconid and the shape of the P4 lingual shelf make S. thailandica unique among Mustelidae. The morphology of this species is mostly similar to Mionictis species and Lartetictis dubia, reported in the Miocene of North America and Europe, respectively. These similarities could imply immigration events to Thailand in the early or middle Miocene. Alternately, the lineage leading to Siamogale might have deeper origins from an endemic early Miocene Southeast Asian mustelid.

  19. Artificial recharge in the northern part of Chino ground-water basin, upper Santa Ana Valley, California

    Science.gov (United States)

    Koehler, J.H.

    1983-01-01

    This study was made to help management design and implement a recharge-recapture system for State Water Project water in Chino Basin. Nine test holes were drilled in the study area. Analyses of data from these test holes and drillers ' logs of water wells indicate the presence of clay deposits. The clay deposits cannot be correlated between holes which indicates that they are in the form of discontinuous beds or lenses. The existence and location of two ground-water barriers (Barrier ' J ' and Red Hill Barrier) have been postulated in previous reports. Water-level data indicate that Barrier ' J ' is probably not effectively stopping the movement of ground water. Data are insufficient to determine the effectiveness of the Red Hill barrier. Five existing recharge facilities in the study area were previously constructed to control floodflow. Infiltration tests were conducted at three of the facilities, and results of these tests indicate infiltration rates of 2.6 feet per day at Day Creek, 2.0 feet per day at East Etiwanda, and 1.3 feet per day at San Sevaine. A total of about 9,000 acre-feet of State Water Project water was recharged between June 1980 and July 1981. Rising water levels in wells indicate that recharge water is percolating down to the water table. (USGS)

  20. Structural pattern of the Saïss basin and Tabular Middle Atlas in northern Morocco: Hydrological implications

    Science.gov (United States)

    Dauteuil, O.; Moreau, F.; Qarqori, K.

    2016-07-01

    The plain of Saïss is a fertile area of great agricultural production with major economic interests. Therefore, the improved knowledge about the water supply is imperative within a context of recurrent droughts and overexploitation of the groundwater. This plain is located in the Meknes-Fes basin and between two deformed domains: the Rif and Middle Atlas. The aquifers are fed by water coming from the Tabular Middle Atlas, for which the pathways are poorly constrained. This study provides new data to determine the water pathways based on a structural map produced from a novel analysis of SPOT images and a digital elevation model. This structural map reveals two fracture sets trending NE-SW and NW-SE. The first set is well known and corresponds to a main trend that controlled the tectonic and stratigraphic evolution of the study area. On the other hand, the NW-SE set was poorly described until now: it is both diffuse and widespread on the Tabular Middle Atlas. A comparison between the regional water flow trend, drainage pattern and structural map shows that the NW-SE fractures control the water flow from the Tabular Middle Atlas to the Saïss plain. A hydrological model is discussed where the water flow is confined onto Liassic carbonates and driven by NW-SE fractures. This study explains how a detailed structural mapping shows hydrology constraints.

  1. Morphologies, classification and genesis of pockmarks, mud volcanoes and associated fluid escape features in the northern Zhongjiannan Basin, South China Sea

    Science.gov (United States)

    Chen, Jiangxin; Song, Haibin; Guan, Yongxian; Yang, Shengxiong; Pinheiro, Luis M.; Bai, Yang; Liu, Boran; Geng, Minghui

    2015-12-01

    Based on new high-resolution multi-beam bathymetry and multichannel seismic reflection data, two new groups of numerous pockmarks and mud volcanoes were discovered in the northern Zhongjiannan Basin at water depths between 600 and 1400 m. Individual pockmarks are circular, elliptical, crescent-shaped or elongated, with diameters ranging from several hundreds to thousands of meters and tens or hundreds of meters in depth, and they often form groups or strings. Crescent pockmarks, approximately 500-1500 m wide in cross-section and 50-150 m deep, occur widely in the southern study area, both as individual features and in groups or curvilinear chains, and they are more widespread and unique in this area than anywhere else in the world. Conical mud volcanoes, mostly with kilometer-wide diameters and ca. 100 m high, mainly develop in the northern study area as individual features or in groups. Seismic data show that the observed pockmarks are associated with different kinds of fluid escape structures and conduits, such as gas chimneys, diapirs, zones of acoustic blanking, acoustic turbidity and enhanced reflections, inclined faults, small fractures and polygonal faults. The mapped mud volcanoes appear to be fed from deep diapirs along two main conduit types: the conventional conduits with downward tapering cones and another other conduit type with a narrow conduit in the lower half and emanative leakage passages in the upper half. Various types of pockmarks are found and a comprehensive pockmark classification scheme is proposed, according to: (a) their shape in plan view, which includes circular, elliptical, crescent, comet-shape, elongated and irregular; (b) their magnitude, which includes small, normal, giant and mega-pockmarks; and (c) their composite pattern, which includes composite pockmarks, pockmark strings and pockmark groups. For the genesis of the crescent pockmark (strings), a 5-stage speculative formation model is proposed, implying possible controlling

  2. Detrital zircon and apatite fission track data in the Liaoxi basins: Implication to Meso-Cenozoic thermo-tectonic evolution of the northern margin of the North China Craton

    Indian Academy of Sciences (India)

    Yi Yan; Xiaoqiong Hu; Ge Lin; Weiliang Liu; Zhengjiang Song

    2010-08-01

    Detrital zircon and apatite fission track (ZFT and AFT) data of the sandstones collected from the Liaoxi basins served as a significant probe to study the Meso-Cenozoic thermo-tectonic reactivation events in the northern margin of the North China Craton. All sandstones show wide ZFT and AFT age spectrum and most of ZFT and AFT ages are younger than depositional age of respective host rocks, which suggest widespread track resetting of the host rocks in the Liaoxi basins after deposition. This hot geothermal status in the Liaoxi basins deduced from ZFT and AFT data is temporal consistent with the lithospheric evolution of the North China Craton, which implies that the lithosphere under the northern margin of the North China Craton underwent similar thermo-tectonic destruction process as the intracratonic Bohai Sea. The young ZFT peak age, which ranges from ∼50Ma to 20 Ma, to some extend, provides a temporal constraint on the time that lithosphere significantly thinned and following reverse of the Liaoxi basins and uplift of the eastern part of the Yan-Liao Orogenic Belt. Exhumation of 1.5–2 km can be estimated in the eastern part of the Yan-Liao Orogenic Belt since ∼30Ma to 10 Ma.

  3. Geology and geochemistry of the Reocín zinc-lead deposit, Basque-Cantabrian Basin, Northern Spain

    Science.gov (United States)

    Velasco, Francisco; Herrero, Jose Miguel; Yusta, Inaki; Alonso, Jose Antonio; Seebold, Ignacio; Leach, David

    2003-01-01

    fluids responsible for sulfide deposition and the infilling of karst cavities were broadly contemporaneous, indicating a post-Albian age. Vitrinite reflectance data are consistent with previously measured fluid inclusion temperatures and indicate temperatures of ore deposition that were less than 100??C. Carbon and oxygen isotopic data from samples of regional limestone, host-rock dolostone and ore-stage dolomite suggest an early hydrothermal alteration of limestone to dolostone. This initial dolomitization was followed by a second period of dolomite formation produced by the mixing of basinal metal-rich fluids with local modified seawater. Both dolomitization events occurred under similar conditions from fluids exhibiting characteristics of basinal brines. The ??34S values of sulfides are between -1.8 and +8.5 per mil, which is consistent with thermochemical sulfate reduction involving organic matter as the main source of reduced sulfur. Galena lead isotope compositions are among the most radiogenic values reported for Zn-Pb occurrences in Europe, and they are distinct from values reported for galena from other Basque-Cantabrian deposits. This suggests that a significant part of the lead was scavenged from the local underlying Asturian sediments. The stratigraphic and structural setting, timing of epigenetic mineralization, mineralogy, and isotopic geochemistry of sulfide and gangue minerals of the Reoci??n deposit are consistent with the features of most of Mississippi Valley-type ore deposits.

  4. Tree-ring reconstructed May-June precipitation in the Caucasus since 1752 CE

    Science.gov (United States)

    Martin-Benito, Dario; Ummenhofer, Caroline C.; Köse, Nesibe; Güner, Hüseyin Tuncay; Pederson, Neil

    2016-02-01

    The Caucasus region experiences recurrent droughts that affect natural vegetation and the agriculture-based economies of several countries. Because meteorological records are in general scarce and of short timespan, little is known about the magnitude and frequency of past climate variability. Despite the recent increase of climate reconstructions for parts of Eurasia, no study has focused on past hydroclimate variability in the Caucasus. Here, we use a multispecies network of tree-ring width chronologies from the Lesser Caucasus to develop the first precipitation reconstruction for the region back to 1752 CE. Despite the high annual precipitation in the region, our reconstruction accounted for 51.2 % of the variability in May-June precipitation from 1930 to 2001. In comparison with reconstructions in the eastern Mediterranean, our new reconstruction revealed important and distinct drought periods and pluvials. Previous winter North Atlantic Oscillation (NAO), and spring East Atlantic/Western Russia (EA/WR) and North Sea Caspian patterns are likely key drivers of May-June precipitation in the Caucasus and Anatolia. NAO appeared to negatively affect rainfall low-frequency variability while effects of EA/WR were more apparent at the interannual timescales. We also show a potential positive effect of Black Sea surface temperatures on May-June precipitation. In the Caucasus, May-June represents the period of major water supply in semi-arid areas and the period with the highest potential of water scarcity in mesic areas. It is also a period of potential catastrophic flood events. Thus, changes to the precipitation regime during this season will be critical to both human and natural systems of the Caucasus region.

  5. Hydrogeochemical and stable isotope data of groundwater of a multi-aquifer system: Northern Gafsa basin - Central Tunisia

    Science.gov (United States)

    Mokadem, Naziha; Demdoum, Abedslem; Hamed, Younes; Bouri, Salem; Hadji, Rihab; Boyce, Adrian; Laouar, Rabah; Sâad, Abedaziz

    2016-02-01

    The hydrodynamic of the multi-aquifer system (the Continental Intercalaire " C.I " and the Complex Terminal " C.T ") of the North Gafsa basin is largely determined by tectonics (Tebessa - Gafsa fault). The composition of groundwater is controlled by complex reactions at gas-liquid-solid "mineralogical composition of associated rocks" interfaces, which depend on the natural surrounding and potential anthropogenic impact. The hydrochemical data (major ion geochemistry) indicate that these groundwaters are characterized by the dominance a Ca-Mg-HCO3/SO4 and Na-Cl-NO3 water types. Geochemical pattern is mainly controlled by the dissolution of halite, gypsum and/or anhydrite as well as by the incongruent dissolution of carbonate minerals. The pH of these samples range from 6.54 to 8.89, supporting the conclusion that the H2CO3/HCO3 couple control pH buffering. Oxygen-18 (δ18O‰SMOW) and deuterium (dD‰SMOW) isotopic data show the exchange between the groundwater and the rock (water-rock interaction) and the evaporation effect. The isotopic content of the boreholes waters is of mixed Mediterranean - Atlantic origin and is opposite to the quantity of rainwater distribution, both in space and time in the study area. This is due to its geographical situation in the southern and south-western of the Mediterranean Sea and between the Atlas area and the Sahara Platform. The concentrations of the isotopic composition of the groundwater are significantly higher than the rainwater. This is indicative of the dissolution of salts and other processes modifying the rainwater geochemical composition during infiltration into the vadose zone. The hydraulic interconnection of these components of the system has led to the evolution of these interesting groundwater types.

  6. Spatial and Temporal Patterns in Fish Assemblages Following an Artificially Extended Floodplain Inundation Event, Northern Murray-Darling Basin, Australia

    Science.gov (United States)

    Rolls, Robert J.; Wilson, G. Glenn

    2010-04-01

    Water extraction from dryland rivers is often associated with declines in the health of river and floodplain ecosystems due to reduced flooding frequency and extent of floodplain inundation. Following moderate flooding in early 2008 in the Narran River, Murray-Darling Basin, Australia, 10,423 ML of water was purchased from agricultural water users and delivered to the river to prolong inundation of its terminal lake system to improve the recruitment success of colonial waterbirds that had started breeding in response to the initial flooding. This study examined the spatial and temporal patterns of fish assemblages in river and floodplain habitats over eight months following flooding to assess the possible ecological benefits of flood extension. Although the abundances of most fish species were greater in river channel habitats, the fish assemblage used floodplain habitats when inundated. Young-of-the-year (4-12 months age) golden perch ( Macquaria ambigua) and bony bream ( Nematalosa erebi) were consistently sampled in floodplain sites when inundated, suggesting that the floodplain provides rearing habitat for these species. Significant differences in the abundances of fish populations between reaches upstream and downstream of a weir in the main river channel indicates that the effectiveness of the environmental water release was limited by restricted connectivity within the broader catchment. Although the seasonal timing of flood extension may have coincided with sub-optimal primary production, the use of the environmental water purchase is likely to have promoted recruitment of fish populations by providing greater access to floodplain nursery habitats, thereby improving the ability to persist during years of little or no flow.

  7. Atmospheric nutrient inputs to the northern levantine basin from a long-term observation: sources and comparison with riverine inputs

    Directory of Open Access Journals (Sweden)

    M. Koçak

    2010-12-01

    Full Text Available Aerosol and rainwater samples have been collected at a rural site located on the coastline of the Eastern Mediterranean, Erdemli, Turkey between January 1999 and December 2007. Riverine sampling was carried out at five Rivers (Ceyhan, Seyhan, Göksu, Berdan and Lamas draining into the Northeastern Levantine Basin (NLB between March 2002 and July 2007. Samples have been analyzed for macronutrients of phosphate, silicate, nitrate and ammonium (PO43−, Sidiss, NO3 and NH4+. Phosphate and silicate in aerosol and rainwater showed higher and larger variations during the transitional period when air flows predominantly originate from North Africa and Middle East/Arabian Peninsula. Deficiency of alkaline material have been found to be the main reason of the acidic rain events whilst high pH values (>7 have been associated with high Sidiss concentrations due to sporadic dust events. In general, lowest nitrate and ammonium concentrations in aerosol and rainwater have been associated with air flow from the Mediterranean Sea. Comparison of atmospheric with riverine fluxes demonstrated that DIN and PO43− fluxes to NLB have been dominated by atmosphere (~90% and ~60% respectively whereas the input of Si was mainly derived from riverine runoff (~90%. N/P ratios in the atmospheric deposition (233; riverine discharge (28 revealed that NLB receives excessive amounts of DIN and this unbalanced P and N inputs may provoke even more phosphorus deficiency. Observed molar Si/N ratio suggested Si limitation relative to nitrogen might cause a switch from diatom dominated communities to non-siliceous populations particularly at coastal NLB.

  8. Favorable exploration targets in northern Avat and northern Shuntuoguole areas, Tarim Basin%塔里木盆地阿瓦提北—顺托果勒北地区有利勘探方向分析

    Institute of Scientific and Technical Information of China (English)

    吕海涛; 耿锋; 毛庆言; 伍齐乔; 贺凯

    2012-01-01

    In the past years, few achievements in accordance with the scale of hydrocarbon generation depression have been obtained in petroleum explorations in Avat area of the Tarim Basin and the favorable exploration targets still remain exploring. Based on new exploration data and research progresses, it is discussed in this paper the petroleum geologic conditions in the northern Avat and the northern Shuntuoguole areas. Three petroleum systems have been identified according to petroleum system theory. As to the Cambrian-Ordovician petroleum system ( I) in Avat area, the most favorable exploration target is the middle-lower Ordovician karst-vuggy carbonate reservoir in the east of the study area. The traps formed in or before Yanshan period along big faults are less favorable. For the Triassic -Jurassic petroleum system ( \\) in Kuche area, the most favorable exploration targets include Paleogene-Cretaceous lithologic traps and various traps of unconformity fluctuation of early Himalayan epoch in the east of the area. Delta sandbody and lacustrine turbidite mass are favorable targets in the Triassic petroleum system (?) in Avat area.%塔里木盆地阿瓦提断陷长期以来未能取得与生烃坳陷相对应的油气勘探成果,勘探部署方向正处于探索之中.结合近期勘探取得的资料和新的研究进展,综合分析了阿瓦提北—顺托果勒北地区的石油地质条件,从含油气系统的角度,指出了阿瓦提寒武—奥陶系含油气系统(!)的最有利目标为研究区东部的中下奥陶统碳酸盐岩缝洞型储集体,其次为顺大断裂带分布并在燕山期及以前定型的圈闭;库车三叠—侏罗系含油气系统(!)的有利目标为研究区东部白垩系、古近系岩性圈闭和喜山早期不整合面上下的各类圈闭;阿瓦提三叠系含油气系统(?)有利方向为三叠系近烃源岩三角洲砂体、湖相浊积岩体.

  9. Methane in the Northern West Siberian Basin. Generation, dynamics of the reservoirs and exchange with the atmosphere

    International Nuclear Information System (INIS)

    Based on compositional data and isotope geochemistry natural gas in northern West Siberia can be divided into three groups. These are: natural gas in Jurassic rocks, natural gas in Neocomian rocks and natural gas from the Aptian to Cenomanian Pokur Formation. Natural gas in Jurassic rocks was generated thermogenically from rocks of the Jurassic Tyumen Formation. Natural gas in Neocomian rocks is also of thermogenic origin, possibly being generated from the organic matter of Lower Cretaceous sediments. The largest accumulation of natural gas occurs in sandstone reservoirs in the Pokur Formation. This gas can be described as a mixture between thermogenic gas from deeper strata and isotopically light almost pure methane. 98.6% of this gas consists of methane with an unusual isotope signature of -51.2 permille. It is not possible to explain the existence of this methane with established concepts of gas generation. A new model was developed to examine the possibility of a thermogenic origin of the isotopically light methane in early mature rocks of the Pokur Formation. Based on pyrolysis experiments and reaction kinetic calculations the model enables the simulation of stable carbon isotope ratios of hydrocarbon components in natural gas. The temperature dependent kinetic isotope fractionation is defined by a difference in the activation energies of 12C-and 13C-methane generation. The application of the new method to two coaly sandstones of the Pokur Formation results in a good correspondence between modelled carbon isotope ratios of δ13C values of methane in the reservoirs. The mass of methane thermogenically generated within the Pokur Formation under the gas field structures, however, is not sufficient to explain the mass of accumulated methane. (orig./SR)

  10. Geo-economy of the Caspian basin; Geoeconomie du bassin caspien

    Energy Technology Data Exchange (ETDEWEB)

    Raballand, G

    2003-05-15

    The Caspian area is essential for the development of the central Asia countries and Caucasus. Excepted the Iran and the Russia, these areas economy is poor. The hydrocarbons exploitation should reinforce the economic weight of these States. The author analyzes the Caspian area economies and shows that the basin economies are confronted with three handicaps, and that even with different economic ways, the soviet economic system is still present in the basin. (A.L.B.)

  11. European Tips on Tourism development in the Caucasus in Early ХХ Century

    Directory of Open Access Journals (Sweden)

    Tamar Tamarashvili

    2013-01-01

    Full Text Available The article presents tips, recommendations, advice by the Europeans. Their consideration was important for further development of tourism in the Caucasus. Namely, for the development of the organization, established in early 20th century “Caucasus Tourism Promotion Committee" and its relation with the countries with well-developed tourism, such as: Austria, Hungary, Germany, France, Bosnia and Herzegovina and etc. Using archive sources, we can consider the issues, concerning foreign tourism experience, types of advertisement in XX century, means of information, transport, tourist accommodation, tourism infrastructure, etc

  12. Study of hydro-saline characteristics of soils a palm grove in basin of Ouargla (Northern Algerian Sahara)

    Science.gov (United States)

    Rezagui, D.; Bouhoun, M. Dabbi; Boutoutaou, D.; Djaghoubi, A.

    2016-07-01

    Saharan soils are often faced with several problems of development, taking account the hydro-edaphic constraints, mainly of hydric types by water table, mechanical by gypso-calcareous crusts and saline by irrigation waters and upwelling of water table. Our work consists in doing a soil characterization of a palm grove in Ouargla in order to study the constraints hydro-halomorphes. The results show that irrigation water by two plies of Senonian and Mioplcène had a high salinity with a value of 2.83 and 5.10 dS.m-1 respectively. The conduct of irrigation is traditional random of submersion type. The palm grove has a poor drainage with a level of water table 156.67±15.71 cm and salinity of 31.37±34.04 dS.m-1. The drains are open type and their maintenance is not regular. This situation of management of irrigation-drainage promotes the upwelling of water table and the waterlogging in soils. The study of soil profiles shows the existence of mechanical obstruction of gypso-calcareous crusts which limit the entrenchment of the date palms and the leaching of salts. Soil salinity is excessive in profiles with a range of 8.98 ± 4.58 dS.m-1. This accumulation of salts is due to the dynamic ascending and descending of salts respectively under the effect of upwelling of water table and leaching by irrigation. The salinization, the upwelling of water table and the presence of gypso-calcareous crusts recorded in Ouargla testify to a degradation hydro-halomorphe and mechanic of soil which constitute the major constraints in the management of system irrigation-drainage and sustainable agricultural development of the palm groves of the basin of Ouargla. Some hydro-agricultural planning are necessary to apply in the oasis to improve the hydro-mechanical properties of soils in order to reduce their degradation.

  13. Eocene to Pleistocene lithostratigraphy, chronostratigraphy and tectono-sedimentary evolution of the Calama Basin, northern Chile Litoestratigrafía, cronoestratigrafía durante el Eoceno al Pleistoceno y evolución tectono-sedimentaria de la Cuenca de Calama, norte de Chile

    OpenAIRE

    Geoffrey May; Adrian J Hartley; Guillermo Chong; Fin Stuart; Peter Turner; Stephanie J Kape

    2005-01-01

    New 40Ar/39Ar radiometric, sedimentological and structural data from post-Paleocene sedimentary strata in the Calama Basin, northern Chile suggest that the established lithostratigraphy of the basin-fill requires revision. A new lithostratigraphic scheme for the Eocene-Pleistocene stratigraphy of the Calama Basin is proposed here. The key features of this scheme are that the existing Calama Formation is retained although the age of the formation is redefined as (?Lower) Eocene to (?)Lower Mio...

  14. Exhumation history of the Northern Andes from the Cenozoic syn-tectonic sedimentary fill of the Middle Magdalena Valley Basin, Colombia

    Science.gov (United States)

    Moreno, C. J.; Caballero, V. M.; Horton, B. K.; Mora, A.

    2009-12-01

    The Central Cordillera and the Eastern Cordillera of the northern Andes form the western and eastern flanks of the Colombian Middle Magdalena Valley Basin, respectively. Previous estimates of the timing of onset of exhumation of the two cordilleras vary, and although some recent studies have been in agreement, more work is needed to develop a clear picture. The spatial and chronological distribution of deformation has direct implications for the shortening history of the greater South American Andean margin, as well as for improving predictions of the rapid, lateral facies changes associated with the varying nearby sediment sources. Field-based analyses of the basin fill using paleocurrent measurements of trough-cross-beds, clast imbrication and flute casts, not only provide new insights into the tectonic history, but directly complement recent detrital zircon U-Pb work completed in the MMVB. Between the lower and upper Paleocene strata, the paleocurrent direction shifts from northward to eastward, indicating that uplift of the Central Cordillera was underway by the mid-Paleocene and consistent with the shift from a cratonic to Central Cordilleran sediment source observed in the detrital zircon record. This paleocurrent shift occurs coevally with a shift from delta to fluvial facies. An eastward paleoflow in upper Eocene through lowest Oligocene strata indicate a continuing influence of the Central Cordillera. Paleocurrent directions in the lower Oligocene deposits are highly variable, and, beginning in the middle Oligocene strata, show a switch to a dominantly westward orientation that continues through the Neogene. As the orientation changes, deposits show an increase in energy from muddy, meandering river deposits, to coarser, braided channel facies. We attribute this switch, from eastward to westward paleocurrent orientations, to the onset of exhumation of the Eastern Cordillera. The results of a current, detailed sandstone petrographic study combined with

  15. Morphologies and depositional/erosional controls on evolution of Pliocene-Pleistocene carbonate platforms: Northern Carnarvon Basin, Northwest Shelf of Australia

    Science.gov (United States)

    Goktas, P.; Austin, J. A.; Fulthorpe, C. S.; Gallagher, S. J.

    2016-08-01

    The detailed morphologies, evolution and termination of latest Neogene tropical carbonate platforms in the Northern Carnarvon Basin (NCB), on the passive margin of the Northwest Shelf (NWS) of Australia, defined based upon mapping using 3D seismic images, reveal the history of local/regional oceanographic processes, fluctuations in relative sea-level and changing climate. Cool-water carbonate deposition, dominant during the early-middle Miocene, was followed by a siliciclastic influx, which prograded across the NWS beginning in the late-middle Miocene, during a period of long-term global sea-level fall. The resulting prograding clinoform sets, interpreted as delta lobes, created relict topographic highs following Pliocene termination of the siliciclastic influx. These highs constituted multiple favorable shallow-water environments for subsequent photozoan carbonate production. Resultant platform carbonate development, in addition to being a response to cessation of siliciclastic influx and the existence of suitable shallow-water substrate, was also influenced by development of the warm-water Leeuwin Current (LC), flowing southwestward along this margin. Four flat-topped platforms are mapped; each platform top is a sequence boundary defined by reflection onlap above and truncation below. Successive platforms migrated southwestward through time, along margin strike. All platforms exhibit predominantly progradational seismic geometries. Mapped tops are ≥10 km wide. Seismic evidence of karst on three of four platform tops, e.g., v-shaped troughs up to 50 m deep and ~1 km wide, and broader basins with areas up to 20 km2, suggests episodic subaerial exposure that may have contributed to platform demise. Platform 4, the most recent, is unique in having interpreted biohermal build-ups superimposed on the progradational platform base. The base of these interpreted patch reefs now lies at a water depth of ~153 m; therefore, we suggest that these reefs developed post

  16. Miocene and early Pliocene epithermal gold-silver deposits in the northern Great Basin, western United States: Characteristics, distribution, and relationship to Magmatism

    Science.gov (United States)

    John, D.A.

    2001-01-01

    Numerous important Miocene and early Pliocene epithermal Au-Ag deposits are present in the northern Great Basin. Most deposits are spatially and temporally related to two magmatic assemblages: bimodal basalt-rhyolite and western andesite. These magmatic assemblages are petrogenetic suites that reflect variations in tectonic environment of magma generation. The bimodal assemblage is a K-rich tholeiitic series formed during continental rifting. Rocks in the bimodal assemblage consist mostly of basalt to andesite and rhyolite compositions that generally contain anhydrous and reduced mineral assemblages (e.g., quartz + fayalite rhyolites). Eruptive forms include mafic lava flows, dikes, cinder and/or spatter cones, shield volcanoes, silicic flows, domes, and ash-flow calderas. Fe-Ti oxide barometry indicates oxygen fugacities between the magnetite-wustite and fayalite-magnetite-quartz oxygen buffers for this magmatic assemblage. The western andesite assemblage is a high K calc-alkaline series that formed a continental-margin are related to subduction of oceanic crust beneath the western coast of North America. In the northern Great Basin, most of the western andesite assemblage was erupted in the Walker Lane belt, a zone of transtension and strike-slip faulting. The western andesite assemblage consists of stratovolcanoes, dome fields, and subvolcanic plutons, mostly of andesite and dacite composition. Biotite and hornblende phenocrysts are abundant in these rocks. Oxygen fugacities of the western andesite assemblage magmas were between the nickel-nickel oxide and hematite-magnetite buffers, about two to four orders of magnitude greater than magmas of the bimodal assemblage. Numerous low-sulfidation Au-Ag deposits in the bimodal assemblage include deposits in the Midas (Ken Snyder), Sleeper, DeLamar, Mule Canyon, Buckhorn, National, Hog Ranch, Ivanhoe, and Jarbidge districts; high-sulfidation gold and porphyry copper-gold deposits are absent. Both high- and low

  17. Two new solid solutions in calcite-magnesite system identified in a sample from coral reefs in the northern Perth basin

    International Nuclear Information System (INIS)

    Full text: Dolomite, CaMg(CO3)2, is an economically important mineral, being of particular significance in petroleum geology. Carbonate rocks have long been a focus of investigation because these rocks contain an estimated 60 percent of the world's recoverable petroleum, and include most of the world's largest reservoirs. Correct phase identification in carbonates has concerned sedimentologists and petroleum geologists for decades. A new type of solid solution in the calcite (CaCO3) - magnesite (MgCO3) system has been identified at Curtin University by Rietveld XRD and neutron diffraction data analysis in a sample from late Pleistocene reefs in the northern Perth Basin. It is known that the structure of calcite (space group R3C) will be transformed to dolomite (R3), which has an ordered distribution of Ca and Mg in the structure, if 50% of its Ca atoms are substituted by Mg in terms of the Ca-Mg atomic ratio. However, the upper limit of Mg substitution for Ca in calcite under sedimentary-geological conditions without there being a change in structure to dolomite is still unknown. Two carbonates examined at Curtin showed Mg substitution for Ca in calcite under coral reef sedimentary conditions of 18.1% and 37.7%, whereas Bragg peak shifts for a 'dolomite, line for these samples were interpreted by geologists as indicative of dolomite with a certain extent of order-disorder distribution between Ca and Mg atoms. The observations have provided an opportunity to re-examine the origins of dolomite and aspects of dolomitization in a coral reef environment in the Quaternary

  18. Low frequency amplification in deep alluvial basins: an example in the Po Plain (Northern Italy) and consequences for site specific SHA

    Science.gov (United States)

    Mascandola, Claudia; Massa, Marco; Barani, Simone; Lovati, Sara; Santulin, Marco

    2016-04-01

    This work deals with the problem of long period seismic site amplification that potentially might involve large and deep alluvial basins in case of strong earthquakes. In particular, it is here presented a case study in the Po Plain (Northern Italy), one of the most extended and deep sedimentary basin worldwide. Even if the studied area shows a low annul seismicity rate with rare strong events (Mw>6.0) and it is characterized by low to medium seismic hazard conditions, the seismic risk is significant for the high density of civil and strategic infrastructures (i.e. high degree of exposition) and the unfavourable geological conditions. The aim of this work is to provide general considerations about the seismic site response of the Po Plain, with particular attention on deep discontinuities (i.e. geological bedrock), in terms of potential low frequency amplification and their incidence on the PSHA. The current results were obtained through active and passive geophysical investigations performed near Castelleone, a site where a seismic station, which is part of the INGV (National Institute for Geophysics and Volcanology) Seismic National Network, is installed from 2009. In particular, the active analyses consisted in a MASW and a refraction survey, whereas the passive ones consisted in seismic ambient noise acquisitions with single stations and arrays of increasing aperture. The results in terms of noise HVSR indicate two main peaks, the first around 0.17 Hz and the second, as already stated in the recent literature, around 0.7 Hz. In order to correlate the amplified frequencies with the geological discontinuities, the array acquisitions were processed to obtain a shear waves velocity profile, computed with a joint inversion, considering the experimental dispersion curves and the HVSR results. The obtained velocity profile shows two main discontinuities: the shallower at ~165 m of depth, which can be correlated to the seismic bedrock (i.e. Vs > 800 m/) and the deeper

  19. Immigrants from Russia, Ukraine and the Caucasus Region: Differential Drug Use, Infectious Disease, and Related Outcomes

    Science.gov (United States)

    Isralowitz, Richard; Reznik, Alexander; Rawson, Richard A.; Hasson, Albert

    2009-01-01

    This study examined drug use patterns, HIV/AIDS, and related outcomes among former Soviet Union (FSU) immigrants from Russia, Ukraine and the Caucasus mountain region in Israel who reported heroin use. A total of 253 FSU heroin users were interviewed from 2002 to 2007 as part of a large drug use surveillance study in Israel. Individuals were…

  20. Could Baltic experiences be applicable to the countries of South Caucasus? / Kristian Fischer

    Index Scriptorium Estoniae

    Fischer, Kristian

    2003-01-01

    Taani kaitseministri Kristian Fischeri ettekanne Taani ja Balti riikide vahelisest kaitsealasest koostööst 22.-23. septembrini 2003 Vilniuses toimunud seminaril "South Caucasus: making the best use of external assistance for stability building and for co-operation with NATO"

  1. PS-InSAR Monitoring of Landslide Activity in the Black Sea Coast of the Caucasus

    NARCIS (Netherlands)

    Kiseleva, E.; Mikhailov, V.; Smolyaninova, E.; Dmitriev, P.; Golubev, V.; Timoshkina, E.; Hooper, A.; Samiei-Esfahany, S.; Hanssen, R.F.

    2014-01-01

    The landslide activity in the area of Bolshoy Sochi (Big Sochi) situated at the Black Sea coast of the Great Caucasus has been studied using the StaMPS PS-InSAR method. We incorporated three sets of radar images from the satellites with different wavelengths ALOS, Envisat and Terra-SAR-X from both a

  2. The Development of Agriculture and Trade Relations in the Caucasus in the Early 20th Century

    Directory of Open Access Journals (Sweden)

    Tatiana E. Gvarliani

    2015-12-01

    Full Text Available The article analyzes the development of agriculture and trade relations in the Caucasus in the early 20th century. This article utilizes the records of Georgian national archives, pre-revolutionary periodicals and monographic literature published in pre-revolutionary, soviet and Russian contemporary periods. The authors used the research methods such as principles of objectivity, historicism, systematic, comprehensive accounting of the economic indicators of agriculture development and trade in the Caucasus and the maximum possible neutrality of the researcher to interpret factual material. The authors come to the conclusion that the development of agriculture in the Caucasus after the revolutionary upheavals of 1905-1907 years in the subsequent period before the First World War entered into the stage of recovery. The reasons of this phenomenon became the discovery of significant quantities of oil, cement, manganese and other fields. The objects of the industry demanded also the additional food supply, this enabled the agriculture in the Caucasus to develop actively.

  3. INVENTORY AND PLANT DIVERSITY CONSERVATION IN THE NORTH-WESTERN PART OF THE GREAT CAUCASUS

    Directory of Open Access Journals (Sweden)

    Litvinskaya S. A.

    2012-11-01

    Full Text Available The problems of floristic inventory within four floristic areas are underlined, namely for Western Ciscaucasia, Western Caucasus, Northwest, and the Western Transcaucasia. The issue questions towards taxonomy, species protection, devastation in ecosystems, and adventizion of vegetation are considered.

  4. AGRICULTURAL RESOURCES OF THE NORTH CAUCASUS IN GERMANY’S ECONOMIC STRATEGY IN 1942-1943

    Directory of Open Access Journals (Sweden)

    Tatarov A. A.

    2015-03-01

    Full Text Available The article explores shift of emphasis in the Third Reich policy in the North Caucasus when agricultural resources of the region became the main object of economic exploitation and one of the most important source of Germany's food supply. Firstly the author shows the place the North Caucasus had in agriculture of the Soviet Union on the eve of the Great Patriotic War. Despite a relatively small area and population, the region played an important role in the production of wheat, corn, sunflower, meat and other products. It is emphasized that the region was of special interest to Germany primarily for its oil fields which allowed solving the fuel problems. But with the failure of Hitler’s "oil plans" the agricultural products became the most important revenue source for the German economy in the North Caucasus in 1942-1943. The author shows that for stable agricultural exploitation the occupation regime not only refused the collective farms’ accelerated elimination but also adapted them to harvesting crops and saving huge livestock. Using the pro-Nazi newspapers and archival documents, the author reveals the occupier’s methodology of action and propaganda by local supporters of the regime for a timely crops harvest. In conclusion, the results of agrarian policy of Germany in the North Caucasus are shown. This article is intended for specialists in the field of history and economics as well as a wide range of readers

  5. Genetic diversity in walnut (Juglans regia) from the caucasus nation of Azerbaijan

    Science.gov (United States)

    Analysis of genetic structure and differentiation using 12 microsatellite loci of six walnut populations, three each from the Greater Caucasus and the Talysh, revealed a moderate range of variation. The observed number of alleles ranged from 2 to 11 alleles with a mean of 5.6 alleles per locus. The ...

  6. INFORMATION OPPOSITION TO EXTREMISM AS A WAY TO REDUCE TENSION IN THE NORTHERN CAUCASUS

    OpenAIRE

    Zeti, Polina; Zhirukhina, Elena

    2012-01-01

    Russia's southern regions have been the regular targets of extremism and terrorism for more than one decade now, which is hampering the development of the region's economic potential and the overall integration processes. The need to lower the extremely high level of the region's conflict potential, which is partially manifested in the activity of terrorist sabotage groups, is prompting reconsideration of the state strategy to combat extremism and terrorism. The forceful approach, which consi...

  7. EU Humanitarian Programs and regional identity in the South Caucasus

    Directory of Open Access Journals (Sweden)

    Arkhipova Ekaterina Vladimirovna

    2013-11-01

    Full Text Available EU Humanitarian Programs in the Southern Caucasus States are considered in the article. The increasing number and importance of the programs developing person-toperson contacts for the conflicting areas are noted. The influence of TRACECA and INOGATE programs was very significant in developing the local economies. Humanitarian aspects became important since 1992 when the first peace-building conferences of the Minsk group on Nagorno-Karabakh conflict took place. The political cooperation was institutionalized in 2004 with the implementing the European Neighborhood program. According to the “Eastern Partnership” a number of grants was offered to develop so called “new democracies”. A lot of educational programs provided the space for the personal cooperation in the area now are implementing. Mobility Partnerships program provides the regional cooperation in the migration policy. Consequently all the EU programs make the European volumes popular for the Caucasian inhabitants. That’s why the author puts the question about possible transformations in the regional identity. The states elites declare the importance for developing close contacts with EU institutes. Still there are some arguable issues. The status of sexual minorities in Azerbaijan provides the base for the mutual discontent in their relations with EU. Yet Azerbaijan has enough financial resources (based on the petrol supplies to reduce the EU influence in some objectionable fields. Georgia under M. Saakashvili ruling showed a strong trend towards EU and “Western” values on the whole. But this trend was mainly based on the strategies of the state financial surviving. There are some evidences proving that the main target of this police was to make a distance from the Russian policy. Armenia may be introduces as the state with strong interests in European cooperation for developing its economy. But there are also some important projects connecting Armenia with Russia, still

  8. 新疆准噶尔盆地北缘中中新世早期的原圆齿鼠(Promylagaulinae,Mylagaulidae)%Mylagaulids (Mammalia: Rodentia) from the early Middle Miocene of northern Junggar Basin

    Institute of Scientific and Technical Information of China (English)

    吴文裕; 倪喜军; 叶捷; 孟津; 毕顺东

    2013-01-01

    Application of CT (computed tomography) scanning technology to the study of tooth morphology of mylagaulids makes better understanding the tooth structure of high-crowned mylagaulids. Two genera and species from the early Middle Miocene Halamagai Formation innorthern Junggar Basin of Xinjiang are recognized: Tschalimys ckhikvadzei Shevyreva, 1971,the senior synonym of Sinomylagaulus halamagaiensis Wu, 1988 and Simpligaulus yangi gen.et sp. nov. Both taxa undoubtedly belong to the subfamily Promylagaulinae. The integrated lithological, paleontological and paleomagnetic studies on sediments of the Late Oligocene through Late Miocene in the northern Junggar Basin of Xinjiang demonstrate that Halamagai Formation is fluvial-lacustrine sediments formed during the time coincident to the Mid-Miocene Climatic Optimum. T. ckhikvadzei and S. yangi probably inhabit the humid and warm regions with forests and densely vegetated thickets as the living mountain beaver Aplodontia rufa does. Thesemylagaulids are probably immigrants or the descendants of the immigrants from west North America.

  9. Actual Evapotranspiration in the Al-Khazir Gomal Basin (Northern Iraq) Using the Surface Energy Balance Algorithm for Land (SEBAL) and Water Balance

    OpenAIRE

    Hussein Jassas; Wael Kanoua; Broder Merkel

    2015-01-01

    Increasing dependence on groundwater requires a detailed determination of the different outputs and inputs of a basin for better water management. Determination of spatial and temporal actual evapotranspiration (ETa), in this regard, is of vital importance as there is significant water loss from drainage basins. This research paper uses the Surface Energy Balance Algorithm for Land (SEBAL), as well as the water balance, to estimate the spatial and temporal ETa in the Al-Khazir Gomal Basin, No...

  10. 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.

  11. Geochemistry of the Cretaceous coals from Lamja Formation, Yola Sub-basin, Northern Benue Trough, NE Nigeria: Implications for paleoenvironment, paleoclimate and tectonic setting

    Science.gov (United States)

    Sarki Yandoka, Babangida M.; Abdullah, Wan Hasiah; Abubakar, M. B.; Hakimi, Mohammed Hail; Adegoke, Adebanji Kayode

    2015-04-01

    The Cretaceous coals of Lamja Formation located in Yola Sub-basin of the Northern Benue Trough, northeastern Nigeria, were analyzed based on a combined investigation of organic and inorganic geochemistry to define the paleodepositional environment condition, organic matter source inputs and their relation to paleoclimate and tectonic setting. The total organic carbon and sulfur contents of Lamja Formation coals ranges from 48.2%-67.8% wt.% and 0.42%-0.76% wt.%, respectively, pointing their deposition in freshwater environment with inferred marine influence during burial. Biomarkers and chemical compositions provide evidence for a major contribution of land-derived organic matter, with minor aquatic organic matter input. Minerals such as quartz, pyrite, kaolinite, illite, montmorillonite and calcite were present in the coals, suggesting that these minerals were sourced from terrigenous origin with slightly marine influence, considered as post-depositional. This is consistent with a significant amount of the oxides of major elements such as SiO2, Fe2O3, Al2O3, TiO2, CaO, and MgO. The investigated biomarkers are characterized by dominant odd carbon numbered n-alkanes (n-C23 to n-C33), moderately high Pr/Ph ratios (1.72-3.75), very high Tm/Ts ratios (18-29), and high concentrations of regular sterane C29, indicating oxic to relatively suboxic conditions, delta plain marine environment of deposition with prevalent contribution of land plants and minor aquatic organic matter input. Concentrations of trace elements such as Ba, Sr, Cr, Ni, V, Co and their standard ratios also suggested that the organic matter was deposited under oxic to relatively suboxic conditions, which is in parts deposited under marine influenced. Some standard binary plots of SiO2 versus (Al2O3 + K2O + Na2O) indicate a semi-arid paleoclimatic condition whereas log SiO2 versus (K2O/Na2O) also revealed passive continental margin setting. The inferred tectonic setting is in agreement with the tectonic

  12. Integrated stratigraphy of the Smirra Coring: a new reference sedimentary record for the early Paleogene from the Umbria-Marche Basin (Northern Apennines, Italy)

    Science.gov (United States)

    Turtù, Antonio; Lauretano, Vittoria; Catanzariti, Rita; Galeotti, Simone; Lanci, Luca; Moretti, Matteo; Lourens, Lucas J.

    2016-04-01

    The early Paleogene represents a critical time interval in Earth's history characterized by prolonged greenhouse conditions, culminating in a series of extreme global warming events (i.e. hyperthermals), as well as large uncertainties in the Geological Time Scale. Therefore new, high-resolution, geological records are crucial in providing novel constraints on these topics. The Paleogene Umbria-Marche sections of the Northern Apennines (Italy) have shown to be suitable for integrated stratigraphy allowing regional-to-global correlations and environmental reconstructions across this time interval. Among several well-known sections, a new sedimentary record is provided by the Smirra Coring, which recovered an undisturbed sequence of rocks (~120 m from 4 overlapping holes) spanning the upper Scaglia Fms. (early Paleocene - middle Eocene) of the Umbria-Marche pelagic succession. Here we present a new, high-resolution, integrated stratigraphic framework (magnetostratigraphy, calcareous nannofossil biostratigraphy, physical properties, calibrated XRF core scanning and cyclostratigraphy) of the ~93 m composite section drilled in Smirra Holes 1 and 2. The succession extends almost continuously, with modest tectonic disturbance affecting its lowermost part with minor faulting. The resulting magnetic stratigraphy defines a succession of normal and reversed polarity magnetozones. The correlation of the paleomagnetic polarity sequence with the latest Geomagnetic Polarity Timescales (GPTSs; e.g. CK95, GTS 2004 and 2012), also constrained through nannofossil biostratigraphy, shows that the section spans the late Paleocene - middle Eocene from chrons C21n (~46 Ma) to C26r (~60 Ma). The overall sedimentation rates computed at Smirra are fully comparable with those from coeval sections from the Umbria-Marche Basin, ranging from ~10 m/Ma, between chrons C21n and C22n, to ~6 m/Ma, between chrons C22r and the base of the section. However, the sedimentation rates vary considerably

  13. Development of a System-Wide Predator Control Program: Stepwise Implementation of a Predation Index, Predator Control Fisheries, and Evaluation Plan in the Columbia River Basin; Northern Pikeminnow Management Program, 2001 Annual Report.

    Energy Technology Data Exchange (ETDEWEB)

    Porter, Russell G.; Winther, Eric C.; Fox, Lyle G.

    2003-03-01

    This report presents results for year eleven in a basin-wide program to harvest northern pikeminnow (Ptychocheilus oregonensis). This program was started in an effort to reduce predation by northern pikeminnow on juvenile salmonids during their emigration from natal streams to the ocean. Earlier work in the Columbia River Basin suggested predation by northern pikeminnow on juvenile salmonids might account for most of the 10-20% mortality juvenile salmonids experience in each of eight Columbia River and Snake River reservoirs. Modeling simulations based on work in John Day Reservoir from 1982 through 1988 indicated that, if predator-size northern pikeminnow were exploited at a 10-20% rate, the resulting restructuring of their population could reduce their predation on juvenile salmonids by 50%. To test this hypothesis, we implemented a sport-reward angling fishery and a commercial longline fishery in the John Day Pool in 1990. We also conducted an angling fishery in areas inaccessible to the public at four dams on the mainstem Columbia River and at Ice Harbor Dam on the Snake River. Based on the success of these limited efforts, we implemented three test fisheries on a system-wide scale in 1991--a tribal longline fishery above Bonneville Dam, a sport-reward fishery, and a dam-angling fishery. Low catch of target fish and high cost of implementation resulted in discontinuation of the tribal longline fishery. However, the sport-reward and dam-angling fisheries were continued in 1992 and 1993. In 1992, we investigated the feasibility of implementing a commercial longline fishery in the Columbia River below Bonneville Dam and found that implementation of this fishery was also infeasible.

  14. Glacier area changes in Northern Eurasia

    International Nuclear Information System (INIS)

    Glaciers are widely recognized as key indicators of climate change. Recent evidence suggests an acceleration of glacier mass loss in several key mountain regions. Glacier recession implies landscape changes in the glacial zone, the origin of new lakes and activation of natural disaster processes, catastrophic mudflows, ice avalanches, outburst floods, etc. The absence or inadequacy of such information results in financial and human losses. A more comprehensive evaluation of glacier changes is imperative to assess ice contributions to global sea level rise and the future of water resources from glacial basins. One of the urgent steps is a full inventory of all ice bodies and their changes. The first estimation of glacier state and glacier distribution on the territory of the former Soviet Union has been done in the USSR Glacier Inventory (UGI) published in 1965–1982. The UGI is based on topographic maps and air photos and reflects the status of the glaciers in the 1940s–1970s. There is information about 28 884 glaciers with an area of 7830.75 km2 in the inventory. It covers 25 glacier systems in Northern Eurasia. In the 1980s the UGI has been transformed into digital form as a part of the World Glacier Inventory (WGI). Recent satellite data provide a unique opportunity to look again at these glaciers and to evaluate changes in glacier extent for the second part of the 20th century. About 15 000 glacier outlines for the Caucasus, Polar Urals, Pamir Alay, Tien Shan, Altai, Kamchatka and Russian Arctic have been derived from ASTER and Landsat imagery and can be used for glacier change evaluation. Results of the analysis indicate the steady trend in glacier shrinkage in all mountain regions for the second part of the 20th century. Glacier area loss for the studied regions varies from 13% (Tien Shan) to 22.3% (Polar Urals). The common driver, most likely, is an increase in summer air temperature. There is also a very large variability in the degree of individual

  15. Mass balance and surface velocity reconstructions of two reference Caucasus glaciers

    Science.gov (United States)

    Rybak, Oleg; Kaminskaia, Mariia; Kutuzov, Stanislav; Lavrentiev, Ivan; Morozova, Polina; Popovnin, Victor; Rybak, Elena

    2016-04-01

    Total glacial volume of the Greater Caucasus exceeds 40 cubic km and its area exceeds 1 thousand square km. During the 20th century, mountain glaciers at the Greater Caucasus were continuously degrading. According to various estimates, their area reduced more than one-third and their volume almost by half. The process of degradation was accompanied by growing population and economical development on surrounding territories. In the 21st century under proceeding global warming, a tendency of shrinking of area and volume of glaciation is obviously expected to continue. Working out of strategy of sustainable economic development of the region is the main motivation for elaboration of predictions of glaciers' evolution in the changing environment. Growing demand of fresh water is the basic challenge for the local economy, and efficient planning of water resources is impossible without knowing future state of glaciation. Therefore our research aims at obtaining accurate evaluation of probable future change of the most prominent mountain glaciers of the Greater Caucasus in forthcoming decades and at studying impacts of changing characteristics of glaciation on the run-off in the area. Initially, we focus on two so-called reference glaciers - Marukh (Western Caucasus) and Djankuat (Central Caucasus). Intensive field observations on both of them have been conducted during the last half of the century and essential amount of detailed relevant information has been collected on their geometry change and on mass balance. Besides, meteorological measurements were episodically carried out directly on the glaciers providing enough data for correlation of the local weather conditions with the data from the closest meteorological stations. That is why studying of response of Marukh and Djankuat on the environmental change can be accurately verified, which is crucial for understanding mechanisms driving evolution of large glaciated area in the Caucasus. As the instrument of research

  16. Using the significant dust deposition event on the glaciers of Mt. Elbrus, Caucasus Mountains, Russia on 5 May 2009 to develop a method for dating and

    Directory of Open Access Journals (Sweden)

    G. Nosenko

    2013-02-01

    Full Text Available A significant desert dust deposition event occurred on Mt. Elbrus, Caucasus Mountains, Russia on 5 May 2009, where the deposited dust later appeared as a brown layer in the snow pack. An examination of dust transportation history and analysis of chemical and physical properties of the deposited dust were used to develop a new approach for high-resolution "provenancing" of dust deposition events recorded in snow pack using multiple independent techniques. A combination of SEVIRI red-green-blue composite imagery, MODIS atmospheric optical depth fields derived using the Deep Blue algorithm, air mass trajectories derived with HYSPLIT model and analysis of meteorological data enabled identification of dust source regions with high temporal (hours and spatial (ca. 100 km resolution. Dust, deposited on 5 May 2009, originated in the foothills of the Djebel Akhdar in eastern Libya where dust sources were activated by the intrusion of cold air from the Mediterranean Sea and Saharan low pressure system and transported to the Caucasus along the eastern Mediterranean coast, Syria and Turkey. Particles with an average diameter below 8 μm accounted for 90% of the measured particles in the sample with a mean of 3.58 μm, median 2.48 μm. The chemical signature of this long-travelled dust was significantly different from the locally-produced dust and close to that of soils collected in a palaeolake in the source region, in concentrations of hematite. Potential addition of dust from a secondary source in northern Mesopotamia introduced uncertainty in the "provenancing" of dust from this event. Nevertheless, the approach adopted here enables other dust horizons in the snowpack to be linked to specific dust transport events recorded in remote sensing and meteorological data archives.

  17. Development of a System-Wide Predator Control Program: Stepwise Implementation of a Predation Index, Predator Control Fisheries, and Evaluation Plan in the Columbia River Basin; Northern Pikeminnow Management Program, 2002 Annual Report.

    Energy Technology Data Exchange (ETDEWEB)

    Porter, Russell G.; Winther, Eric C.; Fox, Lyle G.

    2004-01-01

    This report presents results for year twelve in a basin-wide program to harvest northern pikeminnow1 (Ptychocheilus oregonensis). This program was started in an effort to reduce predation by northern pikeminnow on juvenile salmonids during their emigration from natal streams to the ocean. Earlier work in the Columbia River Basin suggested predation by northern pikeminnow on juvenile salmonids might account for most of the 10-20% mortality juvenile salmonids experience in each of eight Columbia River and Snake River reservoirs. Modeling simulations based on work in John Day Reservoir from 1982 through 1988 indicated that, if predator-size northern pikeminnow were exploited at a 10-20% rate, the resulting restructuring of their population could reduce their predation on juvenile salmonids by 50%. To test this hypothesis, we implemented a sport-reward angling fishery and a commercial longline fishery in the John Day Pool in 1990. We also conducted an angling fishery in areas inaccessible to the public at four dams on the mainstem Columbia River and at Ice Harbor Dam on the Snake River. Based on the success of these limited efforts, we implemented three test fisheries on a system-wide scale in 1991--a tribal longline fishery above Bonneville Dam, a sport-reward fishery, and a dam-angling fishery. Low catch of target fish and high cost of implementation resulted in discontinuation of the tribal longline fishery. However, the sport-reward and dam-angling fisheries were continued in 1992 and 1993. In 1992, we investigated the feasibility of implementing a commercial longline fishery in the Columbia River below Bonneville Dam and found that implementation of this fishery was also infeasible. Estimates of combined annual exploitation rates resulting from the sport-reward and damangling fisheries remained at the low end of our target range of 10-20%. This suggested the need for additional effective harvest techniques. During 1991 and 1992, we developed and tested a modified

  18. THE CAUCASUS AND THE CASPIAN IN THE GREAT GEOSTRATEGIC GAME ON THE EVE OF AND DURING WORLD WAR II (GEOHISTORICAL ESSAY)

    OpenAIRE

    Darabadi, Parvin

    2008-01-01

    The author has chosen a geohistorical approach for looking at the main events which were part of the Great Game in the Caucasus and the Caspian on the eve of and during World War II. He describes such key elements as the secret maneuvering in the Caucasus between the wars; the British-French military-strategic plans in the Caucasus during the Phony War of 1939-1940; Germany’s attempts to make a “geostrategic breakthrough” in the Caucasus in 1941-1943, as well as the “cold” continuation of geo...

  19. Development of a System-Wide Predator Control Program: Stepwise Implementation of a Predation Index, Predator Control Fisheries, and Evaluation Plan in the Columbia River Basin; Northern Pikeminnow Management Program, 2000 Annual Report.

    Energy Technology Data Exchange (ETDEWEB)

    Porter, Russell G.; Glaser, Bryce G.; Amren, Jennifer

    2003-03-01

    This report presents results for year ten in a basin-wide program to harvest northern pikeminnow (Ptychocheilus oregonensis). This program was started in an effort to reduce predation by northern pikeminnow on juvenile salmonids during their emigration from natal streams to the ocean. Earlier work in the Columbia River Basin suggested predation by northern pikeminnow on juvenile salmonids might account for most of the 10-20% mortality juvenile salmonids experience in each of eight Columbia River and Snake River reservoirs. Modeling simulations based on work in John Day Reservoir from 1982 through 1988 indicated that, if predator-size northern pikeminnow were exploited at a 10-20% rate, the resulting restructuring of their population could reduce their predation on juvenile salmonids by 50%. To test this hypothesis, we implemented a sport-reward angling fishery and a commercial longline fishery in the John Day Pool in 1990. We also conducted an angling fishery in areas inaccessible to the public at four dams on the mainstem Columbia River and at Ice Harbor Dam on the Snake River. Based on the success of these limited efforts, we implemented three test fisheries on a system-wide scale in 1991--a tribal longline fishery above Bonneville Dam, a sport-reward fishery, and a dam-angling fishery. Low catch of target fish and high cost of implementation resulted in discontinuation of the tribal longline fishery. However, the sport-reward and dam-angling fisheries were continued in 1992 and 1993. In 1992, we investigated the feasibility of implementing a commercial longline fishery in the Columbia River below Bonneville Dam and found that implementation of this fishery was also infeasible. Estimates of combined annual exploitation rates resulting from the sport-reward and damangling fisheries remained at the low end of our target range of 10-20%. This suggested the need for additional effective harvest techniques. During 1991 and 1992, we developed and tested a modified

  20. Geochronology of quaternary volcanoes eruptions in Krestovyi pass region (Kazbek neovolcanic area, Greater Caucasus)

    International Nuclear Information System (INIS)

    For studying the latest volcanism in the area of the Greater Caucasus the K-Ar dating of Quaternary lavas in the vicinity of Krestovyi pass region was conducted. The obtained age estimates for all the studied bodies are distinctly subdivided into three groups, i.e. 205-170, 130-70 and less than 30 thousand years, which actually coincide with the time ranges previously identified for basic volcanism phases in this area

  1. Analysis of the lactic acid bacteria microflora in traditional Caucasus cow's milk cheeses

    OpenAIRE

    Terzić-Vidojević Amarela; Nikolić Milica; Veljović Katarina; Tolinački Maja; Busarčević M.; Topisirović L.

    2009-01-01

    A total of 157 lactic acid bacteria (LAB) were isolated from three hand-made cheeses taken from different households in the region of the Caucasus Mountains. The cheeses were manufactured from cow's milk without the addition of a starter culture. The isolates of LAB were characterized by subjecting them to phenotypic and genotypic tests. The results of identification of LAB indicate that the examined cheeses contained 10 species, viz., Lactobacillus plantarum, Lactobacillus paraplantarum, Lac...

  2. The healthcare system in the Caucasus at the beginning of the XX century: the development features

    OpenAIRE

    Tatiana E. Gvarliani; Rashad A. Kurbanov; Teymur E. Zulfugarzade

    2016-01-01

    The article based on the archival material deals with the healthcare system in the Caucasus at the beginning of the XX century. In writing this article, the authors made use of reports from national archives of Georgia (Tbilisi, Georgia), the archival department of administration of Sochi (Sochi, Russian Federation). There is given the statistics from the works of Russian and foreign authors, and also reference literature. The authors‘ use of the principles of objectivity, historicism, ...

  3. Seismological and Geodynamic Monitoring Network in the "javakheti" Test Zone in the Southern Caucasus

    Science.gov (United States)

    Arakelyan, A.; Babayan, H.; Karakhanyan, A.; Durgaryan, R.; Basilaia, G.; Sokhadze, G.; Bidzinashvili, G.

    2012-12-01

    The Javakheti Highland located in the border region between Armenia and Georgia (sharing a border with Turkey) is an area in the Southern Caucasus of young Holocene-Quaternary volcanism and a region with convergence of a number of active faults. Issues related to the geometry, kinematics and slip-rate of these faults and assessment of their seismic hazard remain unclear in part due to the fragmentary nature of the studies carried out soley within the borders of each of the countries as opposed to region wide. In the frame of the ISTC A-1418 Project "Open network of scientific Centers for mitigation risk of natural hazards in the Southern Caucasus and Central Asia" the Javakheti Highland was selected as a trans-border test-zone. This designation allowed for the expansion and upgrading of the seismological and geodynamic monitoring networks under the auspices of several international projects (ISTC CSP-053 Project "Development of Communication System for seismic hazard situations in the Southern Caucasus and Central Asia", NATO SfP- 983284 Project "Caucasus Seismic Emergency Response") as well as through joint research programs with the National Taiwan University and Institute of Earth Sciences (IES, Taiwan), Universite Montpellier II (France) and Ecole et Observatoire des Sciences de la Terre-Université de Strasbourg (France). Studies of geodynamic processes, and seismicity of the region and their interaction have been carried out utilizing the newly established seismological and geodynamic monitoring networks and have served as a basis for the study of the geologic and tectonic structure . Upgrading and expansion of seismological and geodynamic networks required urgent solutions to the following tasks: Introduction of efficient online systems for information acquisition, accumulation and transmission (including sattelite systems) from permanent and temporary installed stations, Adoption of international standards for organization and management of databases in GIS

  4. Religiosity and Trust in Religious Institutions: Tales from the South Caucasus (Armenia, Azerbaijan and Georgia)

    OpenAIRE

    Charles, Robia

    2009-01-01

    Abstract: The paper examines the determinants of trust in religious institutions in Armenia, Azerbaijan and Georgia—three countries with low levels of religiosity as measured by attendance, prayer and fasting, yet high levels of trust in religious institutions. The analysis employs individual-level survey data from the Caucasus Research Resource Centers’ (CRRC) 2007 Data Initiative and uses OLS regression to show that while religious practices do not determine trust in religious instituti...

  5. Estimation of Erosion Dissection of North-Eastern Caucasus Relief for Recreational Land Use

    Directory of Open Access Journals (Sweden)

    Zagir V. Ataev

    2012-02-01

    Full Text Available The digital model of the relief (DMR of North-East Caucasus relief was used for an estimation of an erosive partition of territory. The card of usages of erosive forms and density of an erosive partition of a relief was made on basis of GIS-technology. The analysis of these parameters has allowed to estimate the potential of a relief of studied territory for such kinds of touristic and recreational activity, as foot and a cycle tourism

  6. NOTES ON PALAEARCTIC XANTHOLININI. VI. NEW SPECIES AND NEW RECORDS FROM CAUCASUS (Coleoptera, Staphylinidae (*

    Directory of Open Access Journals (Sweden)

    Arnaldo Bordoni

    2011-04-01

    Full Text Available (* 223° contribution on the knowledge of the Staphylinidae.Leptacinus khachikovi n. sp., Gyrohypnus khachikovi n. sp., Xantholinus biseriatus n. sp., Xantholinus circassicus n. sp., Xantholinus daghestanicus n. sp. are described from South European Territory of Russia. New records are listed for the named regions: Gauropterus notabilis Kirshenblat, 1951 (Daghestan, Xantholinus fortepunctatus Motschulsky, 1860 (Russian Caucasus, X. audrasi Coiffait, 1956 and Hypnogyra angularis (Ganglbauer, 1895 (South European Territory of Russia. Neotype of Xantholinus maykopensis Coiffait, 1966 is designated.

  7. Agroecological evaluation of soils suitable for viniculture on the southeastern macroslope of the Great Caucasus (Azerbaijan)

    Science.gov (United States)

    Mamedov, G. Sh.; Yusifova, M. M.

    2013-08-01

    Data on the agroecological evaluation of soils suitable for viniculture on the southeastern macroslope of the Great Caucasus in Azerbaijan are discussed. The quality of major soil types and subtypes has been assessed on the basis of special scales developed for the particular soil properties. The agroecological classes of soils have been specified, and the limiting and favorable ecological factors for winegrowing have been determined. On this basis, the areas with best ecological conditions for the development of viniculture have been outlined.

  8. Genetic diversity for drought tolerance in lentils from Central Asia and the Caucasus: CACLentil

    OpenAIRE

    SEVDA BABAYEVA; ZEYNAL AKPAROV; ADI DAMANIA

    2014-01-01

    The drought tolerance of 96 lentil accessions collected from Central Asia and Caucasus (CAC) region was analysed through two sets of field experiment conditions: irrigated and rain-fed. Several yield components of these accessions were evaluated and compared by means of statistical analyses. Analysis of variance revealed significant variation among the genotypes between and within the two experimental conditions. Based on regression analysis, seed and pod number per plant had significant asso...

  9. The impact of protected areas on local livelihoods in the South Caucasus

    OpenAIRE

    Schott, Johanna; Kalatas, Talin; Nercissians, Emilia; Barkmann, Jan; Shelia, Vakhtang

    2016-01-01

    Nature conservation has a long tradition in the South Caucasus, a region with very high biodiversity. Alongside century old nature reserves (NR) in Azerbaijan and Georgia, two new transboundary national parks (NP) have recently been created in Armenia and Georgia. All of these protected areas exert an influence on the local populations, which use land located inside or in proximity to these areas. To investigate the impact of protected areas on the local populations, we conducted a qualitativ...

  10. INTERNATIONAL RECOGNITION OF ABKHAZIA AND SOUTH OSSETIA:A (DE)STABILIZING FACTOR IN THE CAUCASUS

    OpenAIRE

    Amelina, Yana

    2012-01-01

    The August 2008 war and recognition, on 26 August, 2008, of the independence of the Republic of Abkhazia and the Republic of South Ossetia by the Russian Federation and, later, by several other countries created a new situation in the Greater Caucasus, which many of the regional and world geopolitical players have found unpalatable. Their active efforts to change the new reality run up against the recognition of independence of these two states, which Russia cannot revoke without losing its i...

  11. Thematic dimension of geological heritage: An evidence from the Western Caucasus

    Directory of Open Access Journals (Sweden)

    Plyusnina Ekaterina E.

    2015-01-01

    Full Text Available The geodiversity hotspot comprising 14 geological heritage sites is located on the territory of Mountainous Adygeja in the Western Caucasus (southwestern Russia. The geosites represent some lengthy intervals of the geological history from the Precambrian to the Quaternary, as well as changes in the palaeotectonical affinity of the Greater Caucasus. Visitors of this territory can observe rocks, fossils, and facies, which are typical for the geological periods, especially the Permian, the Triassic, and Jurassic, and the Cretaceous. The same geosites permit to trace shift of the Greater Caucasus Terrane from the Gondwanan margin, where it was before the Devonian, to Laurussia and then Laurasia. Therefore, the geosites can be grouped thematically to facilitate arrangement of geoconservation and geotourism activities. This approach permits to increase the scientific and educational values of the geological heritage in Mountainous Adygeja and to make it more attractive for geotourists. However, such a thematic treatment of the regional geological heritage should not lead to underestimation of the other geological features.

  12. A Brief History of Building the Geopolitical Space across the North Caucasus

    Directory of Open Access Journals (Sweden)

    Ruslan A. Khachidogov

    2015-03-01

    Full Text Available Based on little-studied materials, the article provides a brief history of building the geopolitical space across the North Caucasus. The author establishes that North Caucasus Krai has had a unique geographical and political significance for countless centuries. Its territories stretched between two seas – the Caspian Sea and the Black Sea, which was of great strategic significance: it is here that Europe and Asia locked into each other, with various trade, political, and cultural relations established through them. It has been proven that the ancient region had from the very beginning been formed as a polyethnic one, inhabited by as many as 120 different nationalities. Today there are now 10 autochthonous peoples living in the area, which speak languages belonging to three language families: Caucasian, Indo-European, and Turkic. By the time the North Caucasus was made part of Russia, quite independent language communities had already been formed in the region, which occupied territories that have remained almost unchanged to this day.

  13. Data Archived for Events in the Caucasus for the CauSINCollaboration Project

    Energy Technology Data Exchange (ETDEWEB)

    Godoladze, T; Hunt, D; Aliyev, F; Arakelyan, A; Kalafat, D; Javakhishvil, Z; Panahi, B; Arzumanyan, V; Hutchings, L J; Vergino, E

    2007-08-17

    The Causin project is a joint effort between the countries in the Caucasus region to develop a Probabilistic Seismic Hazard Analysis. To that end, we have compiled a database of all available network data in the region. The information contained in the database is from four countries: Armenia, Georgia, Azerbaijan, and Turkey and from the Incorporated Research Institutions for Seismology (IRIS). Table 1 lists the networks from which data were obtained. Figure 1 shows the locations of stations, and Figure 2 shows ray paths for event locations of the archived data. An ongoing effort in the region is the Caucasus Seismic Information Network (CauSIN) is an international scientific project enabling the countries and scientists of the region to: better understand the seismicity of the greater Caucasus; develop new monitoring networks to support the scientific understanding; provide access to seismic data from local networks in the participating countries; and develop a probabilistic seismic hazards assessment for the region enabling the governments in the region to better mitigate the damaging effects from large earthquakes. In parallel with this effort, training has been conducted on modern techniques for probabilistic hazards assessment. CauSIN is also an ongoing effort to promote cooperation in the geosciences between Georgia, Armenia, Azerbaijan, European Union and the United States. The DOE supports the American team from New England Research, Inc. (NER), Massachusetts Institute of Technology (MIT), Boston College, and Lawrence Livermore National Laboratory (LLNL).

  14. Active tectonics of the Caucasus/Caspian region : Deduced from GPS, neotectonic, gravity and seismically date

    International Nuclear Information System (INIS)

    Full text : The Caucasus and Caspian sea are historically among the most seismically active regions on earth. These earthquakes had caused thousands of deaths and great economic distress following the collapse of the Soviet Union. Future earthquakes in the Caucasus and Caspian sea must be considered and planned for in order to limit their impact on the people, ecology and infrastructure of the region. The geodynamic and earthquake activity in the Caucasus/Caspian region is due to the ongoing collision of the Arabian and African plates with Eurasia. Major problems persist because of the complexity of the region and the need for more detailed studies of both existing data and new data relevant to active tectonics. The Global Positioning System consists of a constellation of 24 satellites, a control segment operated by the US Department of Defence and the end user. The GPS measurement date have been analysed using the GAMIT/GLOBK software. There are number of questions that are critical to the earthquake hazard in Azerbaijan. It was proposed to acquire under this project and it will be incorporated other existing data to help develop realistic models for active tectonics and earthquakes hazards.

  15. Jurassic evaporite facies of the Afghan-Tajik and Amu Darya basins in northern Afghanistan and adjacent areas (evapfacafg.shp)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This shapefile contains polygons that describe the spatial extent of Jurassic age evaporite facies (Gaurdak formation) in the Afghan-Tajik and Amu Darya basins.

  16. Thickness of Jurassic evaporite facies in the Afghan-Tajik and Amu Darya basins of northern Afghanistan and adjacent areas (evapisoafg.shp)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This shapefile contains polylines (isopachs) that describe the thickness of Jurassic age evaporite facies (Gaurdak formation) in the Afghan-Tajik and Amu Darya basins

  17. 3D Virtual Reality Applied in Tectonic Geomorphic Study of the Gombori Range of Greater Caucasus Mountains

    Science.gov (United States)

    Sukhishvili, Lasha; Javakhishvili, Zurab

    2016-04-01

    Gombori Range represents the southern part of the young Greater Caucasus Mountains and stretches from NW to SE. The range separates Alazani and Iori basins within the eastern Georgian province of Kakheti. The active phase of Caucasian orogeny started in the Pliocene, but according to alluvial sediments of Gombori range (mapped in the Soviet geologic map), we observe its uplift process to be Quaternary event. The highest peak of the Gombori range has an absolute elevation of 1991 m, while its neighboring Alazani valley gains only 400 m. We assume the range has a very fast uplift rate and it could trigger streams flow direction course reverse in Quaternary. To check this preliminary assumptions we are going to use a tectonic and fluvial geomorphic and stratigraphic approaches including paleocurrent analyses and various affordable absolute dating techniques to detect the evidence of river course reverses and date them. For these purposes we have selected river Turdo outcrop. The river itself flows northwards from the Gombori range and nearby region`s main city of Telavi generates 30-40 m high continuous outcrop along 1 km section. Turdo outcrop has very steep walls and requires special climbing skills to work on it. The goal of this particularly study is to avoid time and resource consuming ground survey process of this steep, high and wide outcrop and test 3D aerial and ground base photogrammetric modelling and analyzing approaches in initial stage of the tectonic geomorphic study. Using this type of remote sensing and virtual lab analyses of 3D outcrop model, we roughly delineated stratigraphic layers, selected exact locations for applying various research techniques and planned safe and suitable climbing routes for getting to the investigation sites.

  18. Cronología y paleogeografía del Terciario de la Cuenca Intermontana de Iglesia septentrional, Andes de San Juan, Argentina Geochronology and paleogeographic of the Tertiary intermontaneous basin of northern Iglesia, Andes of San Juan, Argentina

    Directory of Open Access Journals (Sweden)

    G.H. Ré

    2003-03-01

    Full Text Available El sector norte de la cuenca no-marina de Iglesia, una cuenca a cuestas (piggyback del sistema plegado y corrido de Precordillera y al este de la Cordillera de los Andes, está subdividida en cinco subcuencas por altos estructurales con tendencia de orientación norte. La combinación de datos estratigráficos, de sísmica de reflexión y de geología de superficie con datos de estratigrafía magnética y dataciones de circones por trazas de fisión de depósitos volcánicos intercalados, permitieron determinar edades, correlaciones, y evolución paleogeográfica entre las subcuencas. Dos unidades estratigráficas distintas llenan la cuenca. La Secuencia 1, ligeramente proximal y con fuerte influencia volcánica se acumuló aproximadamente a los 17 Ma, cuando la cuenca de Iglesia era estrecha y elongada, pero sin disrupciones internas. Las secuencias 2 hasta la 11 se acumularon entre los 9 y los 4 Ma en un depocentro que primero se extendió a través del tiempo en forma simultánea con la subdivisión en subcuencas estructurales, y luego se restringió a la subcuenca estructural occidental. Resulta claro que las secuencias 2 a 11 corresponden al Grupo Iglesia, mientras que la asignación estratigráfica de la Secuencia 1 es incierta.The northern Iglesia nonmarine basin, piggyback to the Precordillera thrust belt and east of the main Andean ranges, is subdivided into 5 sub-basins by north-trending structural highs. We combine stratigraphic data from seismic reflection and surface geology with magnetic polarity stratigraphy and fission-track zircon dates on intercalated volcanic deposits to determine ages, correlations and paleogeographic evolution among the sub-basins. Two distinct stratigraphic units fill the basin. Sequence 1, with strong and seemingly proximal volcanic influence accumulated approximately 17 Ma when the Iglesia basin was narrow and elongate, but not internally disrupted. Sequences 2 through 11 accumulated between 9 and 4 Ma in

  19. Effects of recharge and discharge on delta2H and delta18O composition and chloride concentration of high arsenic/fluoride groundwater from the Datong Basin, northern China.

    Science.gov (United States)

    Xie, Xianjun; Wang, Yanxin; Su, Chunli; Duan, Mengyu

    2013-02-01

    To better understand the effects of recharge and discharge on the hydrogeochemistry of high levels of arsenic (As) and fluoride (F) in groundwater, environmental isotopic composition (delta2H and delta18O) and chloride (Cl) concentrations were analyzed in 29 groundwater samples collected from the Datong Basin. High arsenic groundwater samples (As > 50 micog/L) were found to be enriched in lighter isotopic composition that ranged from -92 to -78 per thousand for deuterium (delta2H) and from -12.5 to -9.9 per thousand for oxygen-18 (delta18O). High F-containing groundwater (F > 1 mg/L) was relatively enriched in heavier isotopic composition and varied from -90 to -57 per thousand and from -12.2 to -6.7 per thousand for delta2H and delta18O, respectively. High chloride concentrations and delta18O values were primarily measured in groundwater samples from the northern and southwestern portions of the study area, indicating the effect of evaporation on groundwater. The observation of relatively homogenized and low delta18O values and chloride concentrations in groundwater samples from central part of the Datong Basin might be a result of fast recharge by irrigation returns, which suggests that irrigation using arsenic-contaminated groundwater affected the occurrence of high arsenic-containing groundwater in the basin. PMID:23472327

  20. The evolution of Devonian hydrocarbon gases in shallow aquifers of the northern Appalachian Basin: Insights from integrating noble gas and hydrocarbon geochemistry

    Science.gov (United States)

    Darrah, Thomas H.; Jackson, Robert B.; Vengosh, Avner; Warner, Nathaniel R.; Whyte, Colin J.; Walsh, Talor B.; Kondash, Andrew J.; Poreda, Robert J.

    2015-12-01

    The last decade has seen a dramatic increase in domestic energy production from unconventional reservoirs. This energy boom has generated marked economic benefits, but simultaneously evoked significant concerns regarding the potential for drinking-water contamination in shallow aquifers. Presently, efforts to evaluate the environmental impacts of shale gas development in the northern Appalachian Basin (NAB), located in the northeastern US, are limited by: (1) a lack of comprehensive "pre-drill" data for groundwater composition (water and gas); (2) uncertainty in the hydrogeological factors that control the occurrence of naturally present CH4 and brines in shallow Upper Devonian (UD) aquifers; and (3) limited geochemical techniques to quantify the sources and migration of crustal fluids (specifically methane) at various time scales. To address these questions, we analyzed the noble gas, dissolved ion, and hydrocarbon gas geochemistry of 72 drinking-water wells and one natural methane seep all located ≫1 km from shale gas drill sites in the NAB. In the present study, we consciously avoided groundwater wells from areas near active or recent drilling to ensure shale gas development would not bias the results. We also intentionally targeted areas with naturally occurring CH4 to characterize the geochemical signature and geological context of gas-phase hydrocarbons in shallow aquifers of the NAB. Our data display a positive relationship between elevated [CH4], [C2H6], [Cl], and [Ba] that co-occur with high [4He]. Although four groundwater samples show mantle contributions ranging from 1.2% to 11.6%, the majority of samples have [He] ranging from solubility levels (∼45 × 10-6 cm3 STP/L) with below-detectable [CH4] and minor amounts of tritiogenic 3He in low [Cl] and [Ba] waters, up to high [4He] = 0.4 cm3 STP/L with a purely crustal helium isotopic end-member (3He/4He = ∼0.02 times the atmospheric ratio (R/Ra)) in samples with CH4 near saturation for shallow

  1. BODY CONDITION OF SPRING MIGRATORY FEMALE NORTHERN PINTAILS AND MEASURES OF PLASMA LIPID METABOLITES TO ASSESS HABITAT QUALITY IN THE RAINWATER BASIN

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Northern Pintails Anas acuta are below population goals and low survivability or reproductive success has contributed to population decline. Survivability and...

  2. Magmatism, sedimentation and stratigraphy of the northern region of the Santos Basin; Magmatismo, sedimentacao e estratigrafia da porcao norte da Bacia de Santos

    Energy Technology Data Exchange (ETDEWEB)

    Moreira, Jobel Lourenco Pinheiro [PETROBRAS S.A., Rio de de Janeiro, RJ (Brazil). E e P. Grupo de Interpretacao Exploratoria da Bacia de Santos], E-mail: jobel@petrobras.com.br; Esteves, Carlos Augusto; Rodrigues, Jose Joaquim Goncalves; Vasconcelos, Claudemir Severiano de

    2005-11-15

    The Santos Basin, passive margin basin, had its sedimentary history disrupted by intra and extra-basinal tectonic activity that took place during the Eocene and Santonian-Campanian. Many authors have identified these events; however this matter still deserves an integrated study including basement and basin areas. Recent Ar/Ar geochronological data from intrusive and extrusive rocks in the Santos basin have identified two events precisely at 82 {+-} 1 Ma and 48,9 Ma. Among the depositional sequences individualized from seismic and well data in the Santos Basin, the K90 depositional sequence - of Santonian- Campanian age - is the best example to investigate magmatism, sedimentation and stratigraphy. Substantial volcanic building, intrusive and extrusive rocks can be observed in this sequence and have a strong impact on in the mineralogical and sedimentary composition of the siliciclastic deposits (sandstones and shales). Subaerial and subaqueous volcanisms are well identified and its characteristics are described herein in terms of seismic facies, log facies and lithofacies. Siliciclastic depositional systems from the transgressive tract (shallow marine) and from lowstand (deep marine) of this sequence are lithic arkosean sandstones, composed mainly by quartz, Kfeldspar, plagioclase and fragments of igneous rocks. An intensive diagenetic chloritization, probably due to the presence of ferromagnesian minerals, has a strong impact on the reservoir quality. (author)

  3. Specific weather biotrop factors in the mountain resorts of North Caucasus

    Science.gov (United States)

    Efimenko, Natalia; Chalaya, Elena; Povolotckaia, Nina; Senik, Irina; Slepykh, Victor

    2015-04-01

    Key aspects of weather therapeutic action in the mountain resorts of the Northern Caucasus (RNC) are formed under the combined influence of global, regional and local atmospheric processes, picturesque landscape, vegetation which create specificity and attraction of the weather regime for the interests of resort rehabilitation, recreation and tourism practically during the whole year. They include high purity of surface atmosphere (background level of aerosols for the countryside, the transparency of the atmosphere 0.780 -0.890); natural hypo barium and hypoxia (5-10%); increased natural aeroionization (N+=400-1000 ion/cm3; N- = 600-1200 ion/cm3; KUI = 0.8 -1.0); the softness of temperature rate (± 600 W/m ); regime of solar radiation favourable for heliotherapy. Pathogenic effects in the mountains can occur both in front atmospheric processes and in conditions of relatively favorable weather. For example, in a stable anti-cyclonic air mass with the sunny weather, foehn effects can happen that are accompanied by excessively low air humidity (lower than 20-30%), the air temperature rises in the afternoon (in winter until 15- 20°C, in summer - up to 25-35°C). The situation can be worsened by ozone intrusion (O3) with the increase of its concentration by 20 ppb or more, temperature stratification change, formation of pollution accumulation conditions in the gorges and valleys where the resort towns are located. We can observe: the increase in the concentration of aerosol pollution from 1.78 to 4 and even up to 8-10 particles/cm (particle diameter is 500-1000 nm); the rise in mass concentration of submicron aerosol up to 75 mkg/m3 and the gas pollution (CO, COx, O3) of the surface atmosphere. Against this backdrop the effects of rapid changes in the chemical composition of natural ions due to the formation of positive nitrogen ions (often with a prevalence of positive over negative air ions) can be sometimes developed. In such situations people suffering from

  4. Lithology and late postglacial stratigraphy of bottom sediments in isolated basins of the White Sea coast exemplified by a small lake in the Chupa settlement area (Northern Karelia)

    Science.gov (United States)

    Korsakova, O. P.; Kolka, V. V.; Tolstobrova, A. N.; Lavrova, N. B.; Tolstobrov, D. S.; Shelekhova, T. S.

    2016-05-01

    The complex lithological, geochemical, geochronological, and micropaleontological (diatoms, spores, pollen) investigations of stratified bottom sediments that constitute facies-variable sedimentary sequences in a small isolated lake located near the upper limit of the sea on the White Sea coast made it possible to define lithostratigraphic units (LSU) forming the complete sedimentary succession in deep parts of isolated basins. It is shown that stratigraphy of heterogeneous sequences is determined by two regional transgressive-regressive cycles in relative sea level fluctuations: alternating late Glacial and Holocene transgressions and regressions. The lower part of a clastogenic clayey-sandy-silty sequence successively composed of freshwater (LSU 1) and brackish-water (LSU 2) sediments of the ice-marginal basins and marine postglacial facies (LSU 3) was formed during the late Glacial glacioeustatic marine transgression. Its upper part formed in different isolated basins at different stages of the Holocene is represented depending on its altimetric position on the coastal slope by costal marine sediments (LSU 4) and facies of the partly isolated inlet (LSU 5). The organogenic sapropelic sequence, which overlies sediments of the marine basin and partly isolated bay, corresponds to lithostratigraphic units represented by Holocene sediments accumulated in the meromictic lake (LSU 6), onshore freshwater basin (LSU 7), and freshwater basin with elevated water mineralization (LSU 8) deposited during maximum development of Holocene transgression and lacustrine sediments (LSU 9) formed in coastal environments during terminal phases of the Holocene. The defined lithostratigraphic units differ from each other in lithological, micropaleontological, and geochemical features reflected in structural and textural properties of their sediments, their composition, inclusions, and composition of paleophytocoenoses and diatom assemblages.

  5. Palaeostress inversion in a multiphase deformed area: Kinematic and structural evolution of the Cankiri Basin (central Turkey), Part 1 - northern area

    OpenAIRE

    Kaymakci, N.; White, S. H.; van Dijk, P.M.

    2000-01-01

    The kinematic and structural evolution of the major structures affecting the Çankırı Basin, central Turkey, has been deduced from a palaeostress inversion study. Four palaeostress tensor configurations indicative of four-phase structural evolution have been constructed from the fault slip data collected from the Çankırı Basin. The first two phases indicate the dominant role of thrusting and folding, and are attributed to the collision between the Pontides and the Taurides, the proposed interf...

  6. South Caspian Pliocene-Anthropogenic basin (summary of existing views)

    Science.gov (United States)

    Amrakhov, Rashad; Shiraliyeva, Sevinj; Kerimova, Nailya

    2016-04-01

    On the basis of long-time integrated sedimentology, paleogeographic and structural - formation studies covering Pliocene-Anthropogenic sediments of South Caspian Basin (SCB) and design of structural - formation, paleogeographic and catagenetic models applying geophysical studies in the region, the author has interred rift nature on this basin during Pliocene-Anthropogenic stage of its evolution. It is assumed that SCB is intercontinental with absence of continental crust. Evolution of SCR started from Miocene, continental stage of development Lesser and Great Caucasus and Kopetdag. At initial stage of South Caspian rift-graben evolution the crystal uplift of Caucasus, Kopetdag and Talysh organic system took place. Extension forces within their borders caused collapse of central part of South Caspian block. We assumed that at later stage folded blocks of Lesser Caucasus and Talysh on the other hand Alborz and Kopetdagh on the other were moving apart. As a result of these riftogene processes the contemporary structure of SCB Antropogene was formed. Starting from Miocene, subsidence of central part of SCB and later movements of folded blocks of Great and Lesser Caucasus, Talysh and Elbrus occurred along Western Caspian, Sangachal - Ogurcghy deep faults and Turkmenistan thrust. During rift generation within SCB, magmatic troughs emerged in the rift zone - South Absheron, Lower Kura. Enzaly and Western Turkmenistan. Structural-formation studies with application of geophysical data acquired in the region, allow assuming that massive Godina can be considered as interrift horst with large gravity anomaly. Its generation relates to Miocene-Pliocene ages and was formed due to South Caspian riftogenesis. The following are sedimentologic evidences of South Caspian rift basin: a) Avalanche sedimentation and development of large thickness (2.5-3 km/106 years) even within border of Lower Pliocene (Productive Series); b) Morphology of Lower Pliocene molasses formation covering 600

  7. Accessions of the Crimean Khanate (1783: Influence on Prospects and Problems of Folding of the Russian North Caucasus

    Directory of Open Access Journals (Sweden)

    Boris V. Vinogradov

    2015-12-01

    Full Text Available The article explores the long-term and ambiguously estimated by historiographies the consequences of accession to Russia of the Crimean khanate in the context of prospects and problems of folding of the Russian North Caucasus. Peculiar features of the Russian citizenship of a number of the mountain people in the conditions of obvious strengthening of Russia in the Caucasus, dynamics of the corresponding views and actions of the Kabardian nobility in the conditions of removal Crimean and weakening of the Turkish threat of Kabarde are analyzed. Nuances of integration in structure of Russia of the Right bank of Kuban in the context of imperial migration policy and features of an ethnopolitical and confessional situation in the North Caucasus are exposed to research. It is proved that accession of the Crimea and Prikubanya opened for the Russian authorities, both new opportunities, and new problems which permission demanded both considerable time, and elaboration of new approaches to interaction with mountaineers.

  8. Morphological determinants of the course of laminated sedimentation in the basin of Lake Czechowskie (northern Poland) in the Late Glacial and Holocene

    Science.gov (United States)

    Kramkowski, Mateusz; Kordowski, Jarosław; Tyszkowski, Sebastian; Błaszkiewicz, Mirosław

    2014-05-01

    The analyses of the annually laminated lacustrine sediments are particularly important in the studies of global climate change. They provide information about the ecosystem response to environmental and climate changes. The condition for the laminated sedimentation with the annual resolution is the calm sedimentation environment where there is no mixing and thus there are anaerobic conditions in the benthic zone. Water mixing occurs mainly as a result of weather factors such as wind and temperature. Below a certain depth water does not undergo mixing evoked by waves and also has a constant temperature which causes its stagnation. In shallower areas such conditions are favoured by the morphology of the lake basin and the long presence of ice cover (bradymictic). The combination of these environmental features predispose to the deposition of laminated sediments. Lake Czechowskie is situated in a deep kettle-hole type basin in the marginal zone of the maximum range of the Pomeranian Phase of the last Weichselian ice sheet. Taking into account the thickness of the lacustrine sediments, the maximum depth of the basin exceeds 70 m. Detailed surveying as well as geological drilling using the GIS techniques made it possible to reconstruct the morphology of the basin of Lake Czechowskie and its adjacent areas back to the state from before the biogenic sedimentation started in Allerød. The analysis of the morphology of the lake basin becomes the basis for modelling the sedimentation conditions considering, inter alia, the wind direction and velocity, fluctuations in water levels and the degree of filling the basin with the deposits in different periods of the Late Glacial and Holocene. It allows specifying the variability and sedimentation rate within the basin. The analysis shows the spatial variation of erosion and accumulation zones, and enables to determine the zones of quiet sedimentation revealing places particularly predisposed to accumulate annually laminated

  9. Caucasus and the petroleum stakes of Caspian Sea; Le Caucase et les enjeux petroliers de la Mer Caspienne

    Energy Technology Data Exchange (ETDEWEB)

    Jalillosoltan, N. [Universite de Franche Comte, 25 - Montbeliard (France); Faculte de Droit de Besancon, 25 (France)

    2001-07-01

    The splitting of the former USSR block in 1991 has generated a shock wave in the Caucasus area with the will of all ex-soviet republics to reach their complete independence. Because of the historical and geographical complexity of Caucasus, both geopolitical and human, this disorder has generated even more hazardous results, enhanced by the coveted oil and gas reserves of the Caspian Sea. This article analyses the petroleum stakes as factors of rivalry and instability (sovereignty of oil and gas fields, rivalries about the exploitation and transport of hydrocarbons), but also as factors of cooperation and re-composition. (J.S.)

  10. Detrital zircon U-Pb and (U-Th)/He double-dating of Upper Cretaceous-Cenozoic Zagros foreland basin strata in the Kurdistan Region of northern Iraq

    Science.gov (United States)

    Barber, D. E.; Stockli, D. F.; Koshnaw, R. I.; Horton, B. K.; Tamar-Agha, M. Y.; Kendall, J. J.

    2014-12-01

    The NW Zagros orogen is the result of the multistage collisional history associated with Late Cretaceous-Cenozoic convergence of the Arabian and Eurasian continents and final closure of Neotethys. Siliciclastic strata preserved within a ~400 km segment of the NW Zagros fold-thrust belt and foreland basin in the Iraqi Kurdistan Region (IKR) provide a widespread record of exhumation and sedimentation. As a means of assessing NW Zagros foreland basin evolution and chronostratigraphy, we present coupled detrital zircon (DZ) U-Pb and (U-Th)/He geo-thermochronometric data of Upper Cretaceous to Pliocene siliciclastic strata from the Duhok, Erbil, and Suleimaniyah provinces of IKR. LA-ICP-MS U-Pb age analyses reveal that the foreland basin fill in IKR in general was dominantly derived from Pan-African/Arabian-Nubian, Peri-Gondwandan, Eurasian, and Cretaceous volcanic arc terrenes. However, the provenance of these strata varies systematically along strike and through time, with an overall increase in complexity upsection. DZ age distribution of Paleocene-Eocene strata is dominated by a ~95 Ma grain age population, likely sourced from the Late Cretaceous Hassanbag-Bitlis volcanic arc complex along the northern margin of Arabia. In contrast, DZ U-Pb age distributions of Neogene strata show a major contribution derived from various Eurasian (e.g., Iranian, Tauride, Pontide; ~45, 150, 300 Ma) and Pan-African (~550, 950 Ma) sources. The introduction of Eurasian DZ ages at the Paleogene-Neogene transition likely records the onset of Arabian-Eurasian collision. Along strike to the southeast, the DZ U-Pb spectra of Neogene strata show a decreased percentage of Pan-African, Peri-Gondwandan, Tauride, and Ordovician ages, coupled with a dramatic increase in 40-50 Ma DZ ages that correspond to Urumieh-Dokhtar magmatic rocks in Iran. Combined with paleocurrent data, this suggests that Neogene sediments were transported longitudinally southeastward through an unbroken foreland basin

  11. Nature of orogenesis and volcanism in the Caucasus region based on results of regional tomography

    Directory of Open Access Journals (Sweden)

    I. Koulakov

    2012-10-01

    Full Text Available In the paper, we discuss the problem of continental collision and related volcanism in the Caucasus and surrounding areas based on the analysis of the upper mantle seismic structure in a recently derived model by Koulakov (2011. This model, which includes P and S-velocity anomalies down to 1000 km depth, was obtained from tomographic inversion of worldwide travel time data from the catalogue of the International Seismological Center. It can be seen that the Caucasus region is squeezed between two continental plates, Arabian to the south and European to the north, which are displayed in the tomographic model as high-velocity bodies down to about 200–250 km depth. On the contrary, a very bright low-velocity anomaly beneath the collision area implies that the lithosphere in this zone is very thin, which is also supported by strong horizontal deformations and crustal thickening indicating weak properties of the lithosphere. In the contact between stable continental and collision zones, we observe a rather complex alternation of seismic anomalies having the shapes of sinking drops. We propose that the convergence process causes crustal thickening and transformation of the lower crust material into the dense eclogite. When achieving a critical mass, the dense eclogitic drops trigger detachment of the mantle lithosphere and its delamination. The observed high-velocity bodies in the upper mantle may indicate the parts of the descending mantle lithosphere which were detached from the edges of the continental lithosphere plates. Very thin, or even absent, mantle parts of the lithosphere leads to the presence of hot asthenosphere just below the crust. The crustal shortening and eclogitisation of the lower crustal layer leads to the dominantly felsic composition of the crust which is favourable for the upward heat transport from the mantle. This, and also the factors of frictional heating and the radioactivity of felsic rocks, may be the origin of

  12. Nature of orogenesis and volcanism in the Caucasus region based on results of regional tomography

    Directory of Open Access Journals (Sweden)

    I. Koulakov

    2012-06-01

    Full Text Available In the paper we discuss the problem of continental collision and related volcanism in the Caucasus and surrounding areas based on analysis of the upper mantle seismic structure in a recently derived model by Koulakov (2011. This model, which includes P- and S-velocity anomalies down to 1000 km depth, was obtained from tomographic inversion of worldwide travel time data from the catalogue of the International Seismological Center. It can be seen that the Caucasus region is squeezed between two continental plates, Arabian to the south and European to the north, which are displayed in the tomographic model as high-velocity bodies down to about 200–250 km depth. On the contrary, a very bright low-velocity anomaly beneath the collision area implies that the lithosphere in this zone is very thin, which is also supported by strong deformations indicating weak properties of the lithosphere. In the contact between stable continental and collision zones we observe a rather complex alternation of seismic anomalies having the shapes of sinking drops. We propose that the convergence process causes crustal thickening and transformation of the lower crust material into the dense eclogite. When achieving a critical mass, the dense eclogitic drops trigger detachment of the mantle lithosphere and its delamination. The observed high-velocity bodies in the upper mantle may indicate the parts of the descending mantle lithosphere which were detached from the edges of the continental lithosphere plates. Very thin or even absent mantle part of the lithosphere leads to the presence of hot asthenosphere just below the crust. The crustal shortening and eclogitization of the lower crustal layer leads to the dominantly felsic composition of the crust which is favorable for the upward heat transport from the mantle. This, and also the factor of frictional heating, may cause to the origin of volcanic centers in the Caucasus and surrounding collisional areas.

  13. Bondi Cave and the Middle-Upper Palaeolithic transition in western Georgia (south Caucasus)

    Science.gov (United States)

    Pleurdeau, David; Moncel, Marie-Hélène; Pinhasi, Ron; Yeshurun, Reuven; Higham, Tom; Agapishvili, Tamar; Bokeria, Maka; Muskhelishvili, Alexander; Le Bourdonnec, François-Xavier; Nomade, Sébastien; Poupeau, Gérard; Bocherens, Hervé; Frouin, Marine; Genty, Dominique; Pierre, Monique; Pons-Branchu, Edwige; Lordkipanidze, David; Tushabramishvili, Nikoloz

    2016-08-01

    The late Pleistocene expansion of anatomically modern humans (AMHs) into Eurasia and the concurrent demise of the Neanderthals appears to be a complex and regionally variable process. The southern Caucasus region, with its rich cave-sites, has recently provided important results regarding this process. In this paper we report on the results of fieldwork in Bondi Cave, Western Georgia, providing a new radiocarbon chronology, stratigraphic observations, analyses of lithic technology and provenance, faunal and floral remains as well as paleoenvironmental data. The cave includes Middle Palaeolithic (ca, 45,000 ka cal. BP) cultural horizons and a long Upper Palaeolithic sequence (ca. 40,000-27,000 cal. BP from layer V to IV). A modern human tooth was found in layer Vb. We estimate its age at 39,000-35,800 Cal BP (95.4%), based on the Bayesian age model we built. If the context of the tooth is reliable, as we think it is, this would make it the oldest morphologically modern human in the Caucasus. Upper Palaeolithic hunting of tur and bison, as well as the collection of various plants including flax is attested. Mobile Upper Palaeolithic foragers inhabited the cave in generally cold and dry periods, but a mosaic of environments, including forests and meadows, was nonetheless available to them. The archaeological sequence of Bondi and adjacent sites indicates a substantial time gap between the Middle and Upper Palaeolithic occupations, thus disproving Neanderthal-AMH interaction in this area and lending support to a replacement scenario in the southern Caucasus, assuming of course that the Early Upper Palaeolithic (EUP) is related to the arrival of AMHs.

  14. Culture creates genetic structure in the Caucasus: Autosomal, mitochondrial, and Y-chromosomal variation in Daghestan

    Directory of Open Access Journals (Sweden)

    Harpending Henry C

    2008-07-01

    Full Text Available Abstract Background Near the junction of three major continents, the Caucasus region has been an important thoroughfare for human migration. While the Caucasus Mountains have diverted human traffic to the few lowland regions that provide a gateway from north to south between the Caspian and Black Seas, highland populations have been isolated by their remote geographic location and their practice of patrilocal endogamy. We investigate how these cultural and historical differences between highland and lowland populations have affected patterns of genetic diversity. We test 1 whether the highland practice of patrilocal endogamy has generated sex-specific population relationships, and 2 whether the history of migration and military conquest associated with the lowland populations has left Central Asian genes in the Caucasus, by comparing genetic diversity and pairwise population relationships between Daghestani populations and reference populations throughout Europe and Asia for autosomal, mitochondrial, and Y-chromosomal markers. Results We found that the highland Daghestani populations had contrasting histories for the mitochondrial DNA and Y-chromosome data sets. Y-chromosomal haplogroup diversity was reduced among highland Daghestani populations when compared to other populations and to highland Daghestani mitochondrial DNA haplogroup diversity. Lowland Daghestani populations showed Turkish and Central Asian affinities for both mitochondrial and Y-chromosomal data sets. Autosomal population histories are strongly correlated to the pattern observed for the mitochondrial DNA data set, while the correlation between the mitochondrial DNA and Y-chromosome distance matrices was weak and not significant. Conclusion The reduced Y-chromosomal diversity exhibited by highland Daghestani populations is consistent with genetic drift caused by patrilocal endogamy. Mitochondrial and Y-chromosomal phylogeographic comparisons indicate a common Near Eastern

  15. THE RISKS OF POLITICIZATION OF ISLAMIC IDENTITY IN CONTEMPORARY RUSSIA (ON MATERIALS OF THE NORTH CAUCASUS

    Directory of Open Access Journals (Sweden)

    Said-Hamzat Mahmudovich NUNUEV

    2015-04-01

    Full Text Available The main topic of the article is the politicization of Islamic identity in post-Soviet Russia. The problem is in competitive and conflict type of interaction of religious identity with Russian civil, regional, ethnic, political identities. The purpose of the article is to identify the risks of politicization of Islamic identity in contemporary Russia (on materials of the North Caucasian republics. The article determines the causes of the politicization of Islamic identity, highlights the factors of territorial unevenness of the politicization of Islam in the North-East and NorthWest Caucasus. The novelty of the work is manifested in the systematization and comparative analysis of the results of opinion polls on the religiosity in all the republics of the North Caucasus. Based on the instrumentalist methodology, the article sets parameters of Islamic identity, which are subject to purposeful design by religious elites and associations. It is concluded that the leading causes for politicization of Islam in the macro-region are: delegitimation of the secular political order, the weakening of the state secular institutions and their regulatory functions, uncertainty of goal-setting development, lack of regulatory abilities of secular norms that entail archaization of the regional community, facilitate geopolitical pressure of foreign countries, international organizations and the spread of religious radicalism. The article notes the growing influence of Islamic identity, which becomes the basis of group solidarity and mobilization, political positioning. Instability creates grounds for extremist religious groups. The most tolerant interaction of religious and civic identities is noted in Stavropol region and the republics of the North-West Caucasus, and among the middle and older generations of respondents. More intolerant interaction of civil and religious identities is noted in the North-East Caucasus, as well as among young people. This can be

  16. The post-cold war decade in the Caucasus: the wars in Chechnya

    Directory of Open Access Journals (Sweden)

    Nora Sainz Gsell

    2002-10-01

    Full Text Available This article focuses on the conflict in Chechnya, its origins, development and international repercussions within the context of the Russian Federation and the more general context of the Caucasus, which since the end of the cold war has experienced the appearance of new conflicts and the re-emergence of old ones, largely as a result of the economic and strategic value given to the region due both to the region’s lying on the most direct route between the Caspian and Black Seas and well as to its natural gas and petroleum reserves.

  17. Sequence Stratigraphy and Sedimentary Facies of Lower Oligocene Yacheng Formation in Deepwater Area of Qiongdongnan Basin, Northern South China Sea:Implications for Coal-Bearing Source Rocks

    Institute of Scientific and Technical Information of China (English)

    Jinfeng Ren; Hua Wang; Ming Sun; Huajun Gan; Guangzeng Song; Zhipeng Sun

    2014-01-01

    For unveiling coal-bearing source rocks in terrestrial-marine transitional sequences, the sequence stratigraphic framework and sedimentary facies of Lower Oligocene Yacheng Formation of Qiongdongnan Basin were investigated using seismic profiles, complemented by well bores and cores. Three third-order sequences are identified on the basis of unconformities on basin margins and cor-relative conformities in the basin center, namely SQYC3, SQYC2 and SQYC1 from bottom to top. Coal measure in Yacheng Formation of Qiongdongnan Basin were deposited within a range of facies asso-ciations from delta plain/tidal zone to neritic sea, and three types of favourable sedimentary facies as-sociations for coal measure were established within the sequence stratigraphic framework, including braided delta plain and alluvial fan, lagoon and tidal flat, and fan delta and coastal plain facies associa-tions. Results shown that, in the third-order sequences, coal accumulation in landward areas (such as delta plain) of the study area predominantly correlates with the early transgressive systems tract (TST) to middle highstand systems tract (HST), while in seaward areas (such as tidal flat-lagoon) it correlates with the early TST and middle HST. The most potential coal-bearing source rocks formed where the accommodation creation rate (Ra) and the peat-accumulation rate (Rp) could reach a state of balance, which varied among different sedimentary settings. Furthermore, intense tectonic subsidence and fre-quent alternative marine-continental changes of Yacheng Formation during the middle rift stage were the main reasons why the coal beds shown the characteristics of multi-beds, thin single-bed, and rapidly lateral changes. The proposed sedimentary facies associations may aid in predicting distribution of coal-bearing source rocks. This study also demonstrates that controlling factors analysis using sequence stratigraphy and sedimentology may serve as an effective approach for coal

  18. The Immatsiak network of groundwater wells in a small catchment basin in the discontinuous permafrost zone of Northern Quebec, Canada: A unique opportunity for monitoring the impacts of climate change on groundwater (Invited)

    Science.gov (United States)

    Fortier, R.; Lemieux, J.; Molson, J. W.; Therrien, R.; Ouellet, M.; Bart, J.

    2013-12-01

    During a summer drilling campaign in 2012, a network of nine groundwater monitoring wells was installed in a small catchment basin in a zone of discontinuous permafrost near the Inuit community of Umiujaq in Northern Quebec, Canada. This network, named Immatsiak, is part of a provincial network of groundwater monitoring wells to monitor the impacts of climate change on groundwater resources. It provides a unique opportunity to study cold region groundwater dynamics in permafrost environments and to assess the impacts of permafrost degradation on groundwater quality and availability as a potential source of drinking water. Using the borehole logs from the drilling campaign and other information from previous investigations, an interpretative cryo-hydrogeological cross-section of the catchment basin was produced which identified the Quaternary deposit thickness and extent, the depth to bedrock, the location of permafrost, one superficial aquifer located in a sand deposit, and another deep aquifer in fluvio-glacial sediments and till. In the summer of 2013, data were recovered from water level and barometric loggers which were installed in the wells in August 2012. Although the wells were drilled in unfrozen zones, the groundwater temperature is very low, near 0.4 °C, with an annual variability of a few tenths of a degree Celsius at a depth of 35 m. The hydraulic head in the wells varied as much as 6 m over the last year. Pumping tests performed in the wells showed a very high hydraulic conductivity of the deep aquifer. Groundwater in the wells and surface water in small thermokarst lakes and at the catchment outlet were sampled for geochemical analysis (inorganic parameters, stable isotopes of oxygen (δ18O) and hydrogen (δ2H), and radioactive isotopes of carbon (δ14C), hydrogen (tritium δ3H) and helium (δ3He)) to assess groundwater quality and origin. Preliminary results show that the signature of melt water from permafrost thawing is observed in the

  19. Responses of streamflow to climate change in the northern slope of Tianshan Mountains in Xinjiang: A case study of the Toutun River basin

    Institute of Scientific and Technical Information of China (English)

    LI WeiHong; CHEN YaNing; HAO XingMing; HUANG Xiang; CHEN YaPeng

    2007-01-01

    A case study on the responses of streamflow to climate change in the Toutun River basin was carried out based on data analysis of streamflow, precipitation, and temperatures during the past 50 years.Temporal series of the streamflow change in the Toutun River basin was analyzed and tested using the Mann-Kendall nonparametric test. Results revealed that the annual runoff of the Toutun River had been in a monotonic decreasing trend for the past 50 years. Compared with the 1950s and 1960s, the annual runoff in the 1990s decreased by 4.0×105 m3 and 7.2×105 m3. The precipitation did not show monotonic trend during the past 50 years, but the annual temperature increased by 1.12℃ since the 1950s. Further data analysis indicated that the monthly runoff of the Toutun River decreased significantly from August to October, with precipitation displaying the similar pattern of seasonal change. Analysis suggests that the reduction of streamflow in the Toutun River basin is possibly caused by the seasonal change of precipitation, especially the precipitation reduction in summer, and temperature increases.

  20. Determining Deep Basin Structure of the Hueco and southern Mesilla Bolsons, West Texas, Southern New Mexico and Northern Chihuahua Using Nonseismic Geophysical Techniques

    Science.gov (United States)

    Doser, D. I.; Avila, V.; Budhathoki, P.; Marrufo, S.; Montana, C. J.; Kaip, G.; Moncada, M.; Dena Ornelas, O.

    2012-12-01

    The Hueco and southern Mesilla bolsons are the primary groundwater source for much of the El Paso/Ciudad Juarez metropolitan region of over 1 million residents. The bolsons lie at the point where the strike of the southern Rio Grande rift changes from north-south to northwest-southeast, likely due to its interaction with pre-existing Mesozoic and Paleozoic structures. Tectonic activity continues with recent (< 750,000 years) movement along basin bounding and low level (M<4) seismicity. Over the past 4 years we have been using a conjunction of microgravity, magnetic, water well logs and electrical resistivity studies to image the complex structure of these basins within a heavily urbanized environment. These studies suggest the presence of several northwest-southeast striking cross faults within the southern Mesilla Bolson as well as an extensive subsurface andesite body related to the Cristo Rey laccolith. Intrabasin faults in the Hueco Bolson appear to cut the basin into at least 3 smaller subbasins and to control the boundary between fresh and saline water within the aquifer system beneath El Paso. We are also able to trace the East Franklins Mountain fault (last movement < 15,000 ya) at least 15 km south of the U.S.-Mexico border.

  1. On the Applicability of Joint Inversion of Gravity and Resistivity Data to the Study of a Tectonic Sedimentary Basin in Northern Portugal

    Science.gov (United States)

    Represas, Patricia; Monteiro Santos, F. A.; Ribeiro, Joana A.; Andrade Afonso, A.; Ribeiro, José; Moreira, Mário; Mendes-Victor, L. A.

    2015-10-01

    The Chaves basin is a pull-apart tectonic depression implanted on granites, schists, and graywackes, and filled with a sedimentary sequence of variable thickness. It is a rather complex structure, as it includes an intricate network of faults and hydrogeological systems. The topography of the basement of the Chaves basin still remains unclear, as no drill hole has ever intersected the bottom of the sediments, and resistivity surveys suffer from severe equivalence issues resulting from the geological setting. In this work, a joint inversion approach of 1D resistivity and gravity data designed for layered environments is used to combine the consistent spatial distribution of the gravity data with the depth sensitivity of the resistivity data. A comparison between the results from the inversion of each data set individually and the results from the joint inversion show that although the joint inversion has more difficulty adjusting to the observed data, it provides more realistic and geologically meaningful models than the ones calculated by the inversion of each data set individually. This work provides a contribution for a better understanding of the Chaves basin, while using the opportunity to study further both the advantages and difficulties comprising the application of the method of joint inversion of gravity and resistivity data.

  2. Relationships between physical and chemical factors and aquatic macroinvertebrates in perennial streams in the arid northern mountain basin El Batinah, Oman

    OpenAIRE

    S. Boulaaba; S. Zrelli; Boumaiza, M.; B. Rossaro

    2014-01-01

    The relationships between physical properties, water chemistry and aquatic macroinvertebrates were investigated in riffles of four perennial streams in the arid northern Oman. Samples were collected monthly in autumn, winter and spring with a Surber net. Thirty two invertebrate taxa were recorded, most species are widely distributed, but few species with very restricted distribution were also captured. Diptera followed by Pulmonata, Coleoptera and Odonata were the most represented taxa, Trich...

  3. Distinct magnetic fabric in weakly deformed sediments from extensional basins and fold-and-thrust structures in the Northern Apennine orogenic belt (Italy)

    Science.gov (United States)

    Caricchi, Chiara; Cifelli, Francesca; Kissel, Catherine; Sagnotti, Leonardo; Mattei, Massimo

    2016-02-01

    We report on results from anisotropy of magnetic susceptibility (AMS) analyses carried out on weakly deformed fine-grained sediments from the Northern Apennine orogenic system (Italy). We sampled 63 sites from preorogenic, synorogenic, and postorogenic sequences, which differ in age, composition, depositional environment, degrees of deformation, and tectonic regimes. The magnetic fabric is typical of weakly deformed sediments, with a magnetic foliation subparallel to the bedding plane and a magnetic lineation well defined in this plane. Northern Apennine chain deposits are characterized by strongly oblate magnetic susceptibility ellipsoids, indicating that the magnetic fabric is the result of both compaction process and tectonic load experienced by the sediments during diagenesis and orogenic events. The orientation of magnetic lineation is significantly different depending whether the studied sites underwent extensional or compressional tectonic regimes. In the Northern Apennine chain, the magnetic lineation is mostly oriented NNW-SSE, parallel to the main compressional structures. It suggests a tectonic origin of the magnetic lineation with an acquisition related to the Apennines compressional phases. In the extensional Tuscan Tyrrhenian margin, magnetic lineation is oriented ENE-WSW, almost perpendicular to the main extensional faults, which represent the main deformation elements of the area. Our results demonstrate a close relationship between the shape and orientation of magnetic fabric and the tectonic history of rocks, confirming that AMS represents a valuable tool to investigate the tectonic history of weakly deformed sedimentary rocks.

  4. An Analysis of Late Mesozoic Tectonic Evolution Process in Northern China:Based on Basin Sedimentary Records in Northern Taihang Mountains%华北晚中生代构造演化过程--根据太行山北部盆地沉积记录

    Institute of Scientific and Technical Information of China (English)

    王永超; 董树文; 施炜; 岑敏; 李江瑜

    2016-01-01

    The northern Taihang Mountains are located at the junction of the Yanshan tectonic belt with the Taihang Mountains belt, and their superimposed basin development process documented the basin trending conversion process from EW to NE during Jurassic to Cretaceous, which is significant for depicting the intracontinental deformation process and its dynamic background during the late Mesozoic in North China. Caogoubu basin and Zhaobai basin located in northern Taihang Mountains were selected as examples in this paper. According to the basic structural framework analysis of basins in combination with isotope chronologic data from magmatic rocks and sedimentology methods which include the detailed analysis of sediment provenance, prototype basin reconstruction and so on, tectonic evolution history of the northern Taihang Mountains during the late Mesozoic can be detected, which includes four stage evolution sequences : (1) nearly N–S contraction and flexural basin development during the late middle Jurassic, (2) nearly N–S low-magnitude extention and crust sources volcanic eruption that occurred in the late Jurassic, (3) NW–SE contraction and foreland basin development from the end of the late Jurassic to the earliest Cretaceous, and (4) NW–SE extension and mantle sources volcanic eruption during the early Cretaceous. The conversion of tectonic regimes is essentially the transformation of its geodynamic systems, and on the context of the East Asia multi-direction convergent tectonic system during the Middle–Late Jurassic, the multi-phases tectonic and basin superposition that occurred in northern Taihang Mountains during the late Mesozoic indicates the conversion process during which the Mogolia–Okhotsk tectonic system graded into the Marginal–Pacific tectonic system.%太行山北部地区处于燕山山脉和太行山山脉的交汇处,其侏罗纪—白垩纪叠加盆地发育过程记录了东西向盆地向北东向盆地转化过程,对刻画华

  5. Censorship and Printing in the Caucasus at the end of XIX – early XX centuries

    Directory of Open Access Journals (Sweden)

    Pavel N. Biriukov

    2016-03-01

    Full Text Available The article deals with the issues of censorship and printing in the Caucasus at the end of XIX – early XX centuries. The special attention is given to censorship during the First Russian revolution (1905-1907 years. Among the materials are the archival documents from the national archives of Georgia, as well as materials of pre-revolutionary periodicals and legislation dedicated to this issue. The scientific publications are important too. The authors come to the conclusion that in the late of XIX – early XX centuries in the Caucasus, as in the whole of the territory of the Russian Empire, there was a sharp rise of printing and publishing periodicals – magazines. With the growth of revolutionary events there was a need in the institute of censorship to control over the printed word. Especially the role of this institution was high during the First Russian revolution. Despite the small number of states and different problems, the censorship has contributed to the stabilization of the political and crime situation in the territory of the Caucasian viceroyalty.

  6. 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.  

  7. Western Gas Sands Project. Quarterly basin activities report, October 1-December 31, 1979

    Energy Technology Data Exchange (ETDEWEB)

    1979-01-01

    This report is a summation of three months drilling and testing activitie in the four primary study areas of the WGSP: Greater Green River Basin, Northern Great Plains Province, Piceance Basin, and Uinta Basin.

  8. Mineralogical and geochemical characters of surface sediments from the central Indian Basin

    Digital Repository Service at National Institute of Oceanography (India)

    Banerjee, R.

    and siliceous sediments of the northern part of the basin indicate the influence of continental influx. This influence, however, decreases in the southern part of the basin where smectite is predominant, indicating volcanic input. The basinal sediments...

  9. Geochemical and Nd-Sr-Pb-O isotopic constrains on Permo-Triassic magmatism in eastern Qaidam Basin, northern Qinghai-Tibetan plateau: Implications for the evolution of the Paleo-Tethys

    Science.gov (United States)

    Chen, Xuanhua; Gehrels, George; Yin, An; Zhou, Qi; Huang, Penghui

    2015-12-01

    Eastern Qaidam Basin of the northern Qinghai-Tibetan plateau is located in a transitional zone between the Permo-Triassic Paleo-Tethyan orogenic belt in the south and the early Paleozoic Qilian orogenic belt in the north. Here we present geochemical and Sr-Nd-Pb-O isotopic data for the Permo-Triassic plutons in eastern Qaidam Basin. Bulk-rock geochemical data and regional geological studies indicate that these plutons consist mainly of subduction-related high-K calc-alkaline metaluminous, I-type granitoids, which occurred during the northward subduction of the Paleo-Tethyan oceanic lithosphere below the southern continental margin of the Kunlun-Qaidam terrane. The εNd(t) values of these Permo-Triassic granitoids are between -9.4 and -3.0, and εSr(t) values are from -20.33 to +168.20. Nd isotopic compositions indicate that the granitoids can come from a pre-existed materials formerly originated from an enriched mantle (EM II) source. The TDM2 model ages of 1.28-1.78 Ga implies that the arc-induced Triassic granitoids were derived melts of Meso-Proterozoic basement rocks of the Kunlun-Qaidam terrane that is bounded by the early Paleozoic Qilian suture zone to the north and the Triassic Kunlun suture zone in the south. The Permo-Triassic granitoids yield initial ratios of 206Pb/204Pb, 207Pb/204Pb, and 208Pb/204Pb values from 18.295 to 19.096, 15.617 to 15.692, and 37.960 to 38.531, respectively. The Pb isotope composition of the granitoids is very similar to that of the Mesozoic granitoids from the western segment of the east of the study area. Geochemical analyses of the plutons, integrated with previous LA ICP-MS U-Pb zircon dating, reveal two series of Permo-Triassic arc magmatisms in eastern Qaidam Basin. Both the series of magmatism display reversed trends with the classic Bowen's reaction series. The new geochemical evidence suggest that the arc magmatism in eastern Qaidam Basin was induced by fluid-fluxing melting of an enriched lithospheric mantle and rock

  10. How the EU can contribute to security and stability in South Caucasus? / Harri Kämäräinen

    Index Scriptorium Estoniae

    Kämäräinen, Harri

    2003-01-01

    Ettekanne 22.-23. septembrini 2003 Vilniuses toimunud seminaril "South Caucasus: making the best use of external assistance for stability building and for co-operation with NATO" käsitleb Euroopa Liidu eesmärke ja programme Lõuna-Kaukaasias, mille täitmist koordineerib Euroopa Liidu eriesindaja, suursaadik Heikki Talvitie

  11. High-resolution provenance of desert dust deposited on Mt. Elbrus, Caucasus in 2009–2012 using snow pit and firn core records

    Directory of Open Access Journals (Sweden)

    S. Kutuzov

    2013-09-01

    Full Text Available The first record of dust deposition events on Mt. Elbrus, Caucasus Mountains derived from a snow pit and a shallow firn core is presented for the 2009–2012 period. A combination of isotopic analysis, SEVIRI red-green-blue composite imagery, MODIS atmospheric optical depth fields derived using the Deep Blue algorithm, air mass trajectories derived using the HYSPLIT model and analyses of meteorological data enabled identification of dust source regions with high temporal (hours and spatial (ca. 20–100 km resolution. Seventeen dust deposition events were detected; fourteen occurred in March–June, one in February and two in October. Four events originated in the Sahara, predominantly in northeastern Libya and eastern Algeria. Thirteen events originated in the Middle East, in the Syrian Desert and northern Mesopotamia, from a mixture of natural and anthropogenic sources. Dust transportation from Sahara was associated with vigorous Saharan depressions, strong surface winds in the source region and mid-tropospheric southwesterly flow with daily winds speeds of 20–30 m s−1 at 700 hPa level. Although these events were less frequent than those originating in the Middle East, they resulted in higher dust concentrations in snow. Dust transportation from the Middle East was associated with weaker depressions forming over the source region, high pressure centred over or extending towards the Caspian Sea and a weaker southerly or southeasterly flow towards the Caucasus Mountains with daily wind speeds of 12–18 m s−1 at 700 hPa level. Higher concentrations of nitrates and ammonium characterised dust from the Middle East deposited on Mt. Elbrus in 2009 indicating contribution of anthropogenic sources. The modal values of particle size distributions ranged between 1.98 μm and 4.16 μm. Most samples were characterised by modal values of 2.0–2.8 μm with an average of 2.6 μm and there was no significant difference between dust from the Sahara and

  12. High-resolution provenance of desert dust deposited on Mt. Elbrus, Caucasus in 2009-2012 using snow pit and firn core records

    Science.gov (United States)

    Kutuzov, S.; Shahgedanova, M.; Mikhalenko, V.; Ginot, P.; Lavrentiev, I.; Kemp, S.

    2013-09-01

    The first record of dust deposition events on Mt. Elbrus, Caucasus Mountains derived from a snow pit and a shallow firn core is presented for the 2009-2012 period. A combination of isotopic analysis, SEVIRI red-green-blue composite imagery, MODIS atmospheric optical depth fields derived using the Deep Blue algorithm, air mass trajectories derived using the HYSPLIT model and analyses of meteorological data enabled identification of dust source regions with high temporal (hours) and spatial (ca. 20-100 km) resolution. Seventeen dust deposition events were detected; fourteen occurred in March-June, one in February and two in October. Four events originated in the Sahara, predominantly in northeastern Libya and eastern Algeria. Thirteen events originated in the Middle East, in the Syrian Desert and northern Mesopotamia, from a mixture of natural and anthropogenic sources. Dust transportation from Sahara was associated with vigorous Saharan depressions, strong surface winds in the source region and mid-tropospheric southwesterly flow with daily winds speeds of 20-30 m s-1 at 700 hPa level. Although these events were less frequent than those originating in the Middle East, they resulted in higher dust concentrations in snow. Dust transportation from the Middle East was associated with weaker depressions forming over the source region, high pressure centred over or extending towards the Caspian Sea and a weaker southerly or southeasterly flow towards the Caucasus Mountains with daily wind speeds of 12-18 m s-1 at 700 hPa level. Higher concentrations of nitrates and ammonium characterised dust from the Middle East deposited on Mt. Elbrus in 2009 indicating contribution of anthropogenic sources. The modal values of particle size distributions ranged between 1.98 μm and 4.16 μm. Most samples were characterised by modal values of 2.0-2.8 μm with an average of 2.6 μm and there was no significant difference between dust from the Sahara and the Middle East.

  13. Physical and Chemical Characteristics of Desert Dust Deposited on Mt. Elbrus, Caucasus as Documented in Snow Pit and Shallow Core Records

    Science.gov (United States)

    Kutuzov, S.; Shahgedanova, M.; Mikhalenko, V.; Ginot, P.; Lavrentiev, I.; Popov, G.

    2013-12-01

    We present a study of dust deposition events and its physical and chemical characteristics in Caucasus Mountains as documented by snow and firn pack at Mt Elbrus. Dust samples were collected from the shallow ice cores and snow pits in 2009-2013 at the western Elbrus plateau (5150 m a.s.l.). Particle size distribution and chemical analysis (major ions, trace elements) were completed for each sample using Coulter Counter Multisizer III, scanning electron microscopy (SEM), IC and ICPMS analysis. It was shown that desert dust deposition occurred in Caucasus 4-8 times a year and originates from the Northern Sahara and the deserts of the Middle East. Analysis of volumetric particle size distributions showed that the modal values ranged between 2 μm and 4 μm although most samples were characterised by modal values of 2.0-2.8 μm with an average of 2.6 μm. These values are lower than those obtained from the ice cores in central and southern Asia following the deposition of long-travelled dust and are closer to those reported for the European Alps and the polar ice cores. All samples containing dust have a single mode which is usually interpreted as a single source region. They do not reveal any significant differences between the Saharan and the Middle Eastern sources. The annual average dust mass concentrations were 10-15 mg kg-1 which is higher than the average concentrations reported for other mountain regions and this was strongly affected by dust deposition events. The deposition of dust resulted in elevated concentrations of most ions, especially Ca2+, Mg2+, K+, and sulphates. Dust originated from multiple sources in the Middle East including Mesopotamia or passing over the Middle East was characterised by the elevated concentrations of nitrates and ammonia which is related to a high atmospheric loads of ammonium emitted by agricultural sources and high concentrations of ammonium in dust originating from this region. By contrast, samples of the Saharan dust showed

  14. Investigation of the geothermal state of sedimentary basins using oil industry thermal data: case study from Northern Alberta exhibiting the need to systematically remove biased data

    International Nuclear Information System (INIS)

    Subsurface temperature data from industrial sources may contain significant biases that greatly reduce their overall quality. However, if these biases can be identified and removed, the data can provide a good preliminary source of information for further studies. In this paper, industrial thermal data from three sources: bottom hole temperatures, annual pool pressure tests and drill stem tests are evaluated to provide an updated view of the subsurface temperatures below the oil sand regions of Northern Alberta. The study highlights some of the potentially large systematic biases inherent in industrial temperature data which affect estimates of geothermal gradient and regional mapping of the geothermal field. (paper)

  15. Western Gas Sands Project. Quarterly Basin Activities Report

    Energy Technology Data Exchange (ETDEWEB)

    Atkinson, C H

    1979-01-31

    This report is a summation of 3 months' drilling and testing activities in the four primary WGSP study areas: Greater Green River Basin, Northern Great Plains Province, Piceance Basin, and Uinta Basin. The monitoring of basin activities is part of resource assessment. (DLC)

  16. Whole water column distribution and carbon isotopic composition of bulk particulate organic carbon, cholesterol and brassicasterol from the Cape Basin to the northern Weddell Gyre in the Southern Ocean

    Directory of Open Access Journals (Sweden)

    A.-J. Cavagna

    2012-02-01

    Full Text Available The combination of concentrations and δ13C signatures of Particulate Organic Carbon (POC and sterols provides a powerful approach to study ecological and environmental changes both in the modern and ancient ocean, but its application has so far been restricted to the surface area. We applied this tool to study the biogeochemical changes in the modern ocean water column during the BONUS-GoodHope survey (Feb–Mar 2008 from Cape Basin to the northern part of the Weddell Gyre. Cholesterol and brassicasterol were chosen as ideal biomarkers of the heterotrophic and autotrophic carbon pools, respectively, because of their ubiquitous and relatively refractory nature.

    We document depth distributions of concentrations (relative to bulk POC and δ13C signatures of cholesterol and brassicasterol from the Cape Basin to the northern Weddell Gyre combined with CO2 aq. surface concentration variation. While relationships between surface water CO2 aq. and δ13C of bulk POC and biomarkers have been previously established for surface waters, our data show that these remain valid in deeper waters, suggesting that δ13C signatures of certain biomarkers could be developed as proxies for surface water CO2 aq. Our data suggest a key role of zooplankton fecal aggregates in carbon export for this part of the Southern Ocean. We observed a general increase in sterol δ13C signatures with depth, which is likely related to a combination of particle size effects, selective feeding on larger cells by zooplankton, and growth rate related effects Additionally, in the southern part of the transect south of the Polar Front (PF, the release of sea-ice algae is hypothesized to influence the isotopic signature of sterols in the open ocean. Overall, combined use of δ13C and concentrations measurements of both bulk organic C and specific sterol markers throughout the water

  17. 宁芜北段火山岩型金矿类型及找矿方向%Types of volcanic rock gold deposits in northern Ningwu Basin and their prospecting direction

    Institute of Scientific and Technical Information of China (English)

    2015-01-01

    宁芜北段是长江中下游重要的火山岩型金矿成矿远景区。金矿类型繁多,主要有火山热液充填脉型金矿、陆相火山―沉积期后热液充填交代型金矿、蚀变破碎带型金矿、爆发角砾岩筒型金矿、铁帽型金矿以及伴生金。矿床主要受 NNE、NW 向区域性大断裂及其派生次级断裂控制,与安山质火山角砾岩、辉石闪长玢岩关系密切。梅山地区、铜井地区碱性火山岩内及外围、谷里地区及宁芜北段东部隆起带是今后的找矿方向。%Northern Ningwu Basin is an important volcanic rock type gold mineralization prospect area inside the regions along the middle and lower reaches of Yangtze River.Various types of gold deposits in this area include volcanic hydrothermal filling vein type gold deposit,continental volcano-post depositional hydrother-mal filling metasomatic gold deposit,alteration fracture zone type gold deposit,diatreme breccia pipe type gold deposit,gossan type gold deposit and associated gold deposit.The deposits are primarily controlled by NNE-and NW-trending regional major fractures and their derived subsidiary fractures,and they are closely related to andesitic volcanic breccia and pyroxene diorite porphyrite.The prospecting direction of this area are interior of the alkaline volcanic rocks and its peripheries in Meishan area and Tongjing area,as well as the uplift zone in Guli area and eastern part of northern Ningwu Basin.

  18. Activation of northern margin of the North China Craton in Late Paleozoic: Evidence from U-Pb dating and Hf isotopes of detrital zircons from the Upper Carboniferous Taiyuan Formation in the Ningwu-Jingle basin

    Institute of Scientific and Technical Information of China (English)

    LI HongYan; XU YiGang; HUANG XiaoLong; HE Bin; LUO ZhenYu; YAN Bin

    2009-01-01

    LA-MC-ICPMS U-Pb dating has been performed on detrital zircons from the Upper Carboniferous Tai-yuan Formation (N-8) in the Ningwu-Jingle Basin, west of the North China Craton (NCC). The ages of 72 detrital zircon grains are divided into three groups: 303-320 Ma (6 grains), 1631-2194 Ma (37 grains, peaked at 1850 Ma), 2318-2646 Ma (29 grains, peaked at 2500 Ma). Detrital zircons of Group 2 and Group 3 were likely derived from the basement of the NCC. Group 1 zircons exhibit 176Hf/177Hf ratios ranging from 0.281725 to 0.282239, with corresponding negative εHf(t) values of -12.4-30.3 and old Hf model ages of 1.4-2.2 Ga. These characteristics show a strong resemblance to those of Carboniferous igneous zircons from the Inner Mongolia Paleo-uplift (IMPU) on the northern margin of the NCC, but differ significantly from those of the Xing-Meng Orogenic Belt, suggesting that the source of the Tai-yuan Formation partly came from the IMPU. All detrital zircons of Group 1 have relatively high Th/U ratios (0.67), indicating a magmatic origin. The mean age (304±6 Ma) of the two youngest grains is close to the depositional age of the Taiyuan Formation, suggesting a strong tectonic uplift and mag-matism in the IMPU during the Late Carboniferous. This paper provides important geological evidence for the activation of the northern margin of the NCC in the Late Paleozoic.

  19. Lead isotope study of Zn-Pb ore deposits associated with the Basque-Cantabrian basin and Paleozoic basement, Northern Spain

    Science.gov (United States)

    Velasco, F.; Pesquera, A.; Herrero, J. M.

    1996-01-01

    A total of forty-three galena samples from syngenetic and epigenetic Pb-Zn mineralizations emplaced in the Lower Cretaceous Basque-Cantabrian basin and Paleozoic basement of the Cinco Villas massif in the western Pyrenees, have been analyzed for Pb-isotopic composition. Galena from sedex mineralizations hosted in Carboniferous clastic rocks in the Cinco Villas massif display an homogeneous lead isotopic signature (206Pb/2044Pb ≈ 18.43, 207Pb/204Pb ≈ 15.66, 208Pb/ 204Pb ≈ 38.69) suggesting a single lead reservoir. These values are slightly more radiogenic than lead from other European Hercynian deposits, possibly reflecting the influence of a more evolved upper crustal source. Underlying Paleozoic sediments are proposed as lead source for the Cinco Villas massif ores. Analyses from twenty-six galena samples from the four strata-bound ore districts hosted in Mesozoic rocks reveal the existence of two populations regarding their lead isotopic composition. Galena from the western Santander districts (e.g., Reocin) is characterized by more radiogenic isotope values (206Pb/204Pb ≈ 18.74, 207Pb/204Pb ≈ 15.67, 208Pb/ 204Pb ≈ 38.73) than those from the central and eastern districts (Troya-Legorreta, Central and Western Vizcaya, 206Pb/204Pb ≈ 18.59, 207Pb/204Pb ≈ 15.66, 208Pb/ 204Pb ≈ 38.73). In all districts, the most likely source for these mineralizations was the thick sequence of Lower Cretaceous clastic sediments. The existence of two separate lead isotopic populations could be the result of regional difference in the composition of the basement rocks and the clastic sediments derived of it or different evolution histories. In both sub-basins, isotopic ratios indicate an increase in crustal influence as the age of the ores decreases.

  20. SOVIET GOVERNMENT RELIGIOUS POLICY REGARDING TO RENOVATIVE ASSOCIATIONS IN THE NORTH CAUCASUS IN 1917-1946

    Directory of Open Access Journals (Sweden)

    Aleksandr N. RIYBICOV

    2016-02-01

    Full Text Available In this article, basing on archival materials and the research literature, the authors analyzed the characteristics of the religious policy of the Soviet power in the North Caucasus in 1917-1946 years regarding the renovative associations. The various definitions of the concept of «renovationism» were studied and the own wording were appeared to achieve this goal. According to new concept, the Renovationism is difficult phenomenon, developing under the influence of the processes, having various nature: inside-church processes due to the growth of democratic sentiment among the clergy and policy processes, initiated by the Soviet power to conduct their own religious course. The theoretical basis of this article advocates a synthesis of two modeling methods. Basing on these methods, it is proved that the revolution of 1917 led to the creation of a new separation model of the churchstate relations, basing on the principle of gradual elimination of the religious organizations` influence in the public life. The activity of Renovationist Synod of the North Caucasus were assessed; the dynamics of the beginning a new dioceses in various parts of the region were analyzed; the changes in the conduct of worship were discussed. It is concluded that the supporting of the Renovationism was an important part of religious policy during the 20's - early 30-ies XX century. The cooperation of local governments with the hierarchs of the new church structure had a longer duration of time than in the central areas of the country. This situation was explained largely by the low success of atheistic propaganda, the preservation of the religious consciousness on the part of party functionaries. At the same time the abolition of renovationist organizations in the North Caucasus (as well as in other areas of the country was caused by a common factor, the change in the line of the Stalin's religious course in the direction of the

  1. Structural problems and prospects of innovative development of economies of countries of the South Caucasus

    Directory of Open Access Journals (Sweden)

    A.A. Egiazarian

    2013-12-01

    Full Text Available The aim of the article. The aim of the article is justification of prospects of further innovative development of economies of three countries of the South Caucasus. The results of the analysis. After the collapse of the Soviet Union, the South Caucasus countries have found their place in the capitalist world economy as peripheral states. However, all three states in the region have their own economic structural features and differences, both in terms of their current situation and prospects in terms of economic development. In this paper, key features and prospects of economic development are analyzed and identified. In terms of economic prospects the opportunities and challenges of participation in the South Caucasus countries and the Eurasian Customs Unions are discussesed. In the last years the South Caucasian countries showed rather high rates of economic growth, but the level of economic development of their economy is low. Economic systems of those countries are characterized with a number of structural imbalances and problems. In Azerbaijan economic growth was provided at the expense of increase of oil’s production and export. In Georgia and Armenia economic growth was provided at the expense of external financing that stimulated consumer demand, growth in building sector and in sectors of services. Nowadays economies of the South Caucasian countries have been practically exhausted opportunities of extensive growth. In Azerbaijan the oil boom will come to the end soon. In Armenia and Georgia quite high shortage level of the current account remains and both countries have rather big external debt. In the conditions of world economy growth deterioration, especially in Russia, volumes of foreign trade and streams of money transfers will be reduce. It will negatively affect the prospects of their economic growth. All countries of the region need some new markets and strategic investments. The Customs Union represents an attempt to make

  2. Detrital and volcanic zircon U-Pb ages from southern Mendoza (Argentina): An insight on the source regions in the northern part of the Neuquén Basin

    Science.gov (United States)

    Naipauer, Maximiliano; Tapia, Felipe; Mescua, José; Farías, Marcelo; Pimentel, Marcio M.; Ramos, Victor A.

    2015-12-01

    The infill of the Neuquén Basin recorded the Meso-Cenozoic geological and tectonic evolution of the southern Central Andes being an excellent site to investigate how the pattern of detrital zircon ages varies trough time. In this work we analyze the U-Pb (LA-MC-ICP-MS) zircon ages from sedimentary and volcanic rocks related to synrift and retroarc stages of the northern part of the Neuquén Basin. These data define the crystallization age of the synrift volcanism at 223 ± 2 Ma (Cerro Negro Andesite) and the maximum depositional age of the original synrift sediments at ca. 204 Ma (El Freno Formation). Two different pulses of rifting could be recognized according to the absolute ages, the oldest developed during the Norian and the younger during the Rhaetian-Sinemurian. The source regions of the El Freno Formation show that the Choiyoi magmatic province was the main source rock of sediment supply. An important amount of detrital zircons with Triassic ages was identified and interpreted as a source area related to the synrift magmatism. The maximum depositional age calculated for the Tordillo Formation in the Atuel-La Valenciana depocenter is at ca. 149 Ma; as well as in other places of the Neuquén Basin, the U-Pb ages calculated in the Late Jurassic Tordillo Formation do not agree with the absolute age of the Kimmeridgian-Tithonian boundary (ca. 152 Ma). The main source region of sediment in the Tordillo Formation was the Andean magmatic arc. Basement regions were also present with age peaks at the Carboniferous, Neoproterozoic, and Mesoproterozoic; these regions were probably located to the east in the San Rafael Block. The pattern of zircon ages summarized for the Late Jurassic Tordillo and Lagunillas formations were interpreted as a record of the magmatic activity during the Triassic and Jurassic in the southern Central Andes. A waning of the magmatism is inferred to have happened during the Triassic. The evident lack of ages observed around ca. 200 Ma suggests

  3. Passive seismic experiment and receiver functions analysis to determine crustal structure at the contact of the northern Dinarides and southwestern Pannonian Basin

    Science.gov (United States)

    Šumanovac, Franjo; Hegedűs, Endre; Orešković, Jasna; Kolar, Saša; Kovács, Attila C.; Dudjak, Darko; Kovács, István J.

    2016-06-01

    Passive seismic experiment was carried out at the SW contact of the Dinarides and Pannonian basin to determine the crustal structure and velocity discontinuities. The aim of the experiment was to define the relationship between the Adriatic microplate and the Pannonian segment as a part of the European plate. Most of the temporary seismic stations were deployed in Croatia along the Alp07 profile-a part of the active-source ALP 2002 project. About 300-km-long profile stretches from Istra peninsula to the Drava river, in a WSW-ESE direction. Teleseismic events recorded on 13 temporary seismic stations along the profile were analysed by P-receiver function method. Two types of characteristic receiver functions (RF) have been identified, belonging to Dinaridic and Pannonian crusts as defined on the Alp07 profile, while in transitional zone there are both types. Three major crustal discontinuities can be identified for the Dinaridic type: sedimentary basement, intracrustal discontinuity and Mohorovičić discontinuity, whereas the Pannonian type revealed only two discontinuities. The intracrustal discontinuity was not observed in the Pannonian type, thus pointing to a single-layered crust in the Pannonian basin. Two interpretation methods were applied: forward modelling of the receiver functions and H-κ stacking method, and the results were compared with the active-source seismic data at deep refraction profile Alp07. The receiver function modelling has given reliable results of the Moho depths that are in accordance with the seismic refraction results at the end of the Alp07 profile, that is in the area of Pannonian crust characterized by simple crustal structure and low seismic velocities (Vp between 5.9 and 6.2 km s-1). In the Dinarides and its peripheral parts, receiver function modelling regularly gives greater Moho depths, up to +15 per cent, due to more complex crustal structure. The depths of the Moho calculated by the H-κ stacking method vary within wide

  4. Upper Cretaceous to Holocene magmatism and evidence for transient Miocene shallowing of the Andean subduction zone under the northern Neuquén Basin

    Science.gov (United States)

    Kay, Suzanne M.; Burns, W. Matthew; Copeland, Peter; Mancilla, Oscar

    2006-01-01

    Evidence for a Miocene period of transient shallow subduction under the Neuquén Basin in the Andean backarc, and an intermittent Upper Cretaceous to Holocene frontal arc with a relatively stable magma source and arc-to-trench geometry comes from new 40Ar/39Ar, major- and trace-element, and Sr, Pb, and Nd isotopic data on magmatic rocks from a transect at ∼36°–38°S. Older frontal arc magmas include early Paleogene volcanic rocks erupted after a strong Upper Cretaceous contractional deformation and mid-Eocene lavas erupted from arc centers displaced slightly to the east. Following a gap of some 15 m.y., ca. 26–20 Ma mafic to acidic arc-like magmas erupted in the extensional Cura Mallín intra-arc basin, and alkali olivine basalts with intraplate signatures erupted across the backarc. A major change followed as ca. 20–15 Ma basaltic andesite–dacitic magmas with weak arc signatures and 11.7 Ma Cerro Negro andesites with stronger arc signatures erupted in the near to middle backarc. They were followed by ca. 7.2–4.8 Ma high-K basaltic to dacitic hornblende-bearing magmas with arc-like high field strength element depletion that erupted in the Sierra de Chachahuén, some 500 km east of the trench. The chemistry of these Miocene rocks along with the regional deformational pattern support a transient period of shallow subduction that began at ca. 20 Ma and climaxed near 5 Ma. The subsequent widespread eruption of Pliocene to Pleistocene alkaline magmas with an intraplate chemistry in the Payenia large igneous province signaled a thickening mantle wedge above a steepening subduction zone. A pattern of decreasingly arc-like Pliocene to Holocene backarc lavas in the Tromen region culminated with the eruption of a 0.175 ± 0.025 Ma mafic andesite. The northwest-trending Cortaderas lineament, which generally marks the southern limit of Neogene backarc magmatism, is considered to mark the southern boundary of the transient shallow subduction zone.

  5. CFD simulation on the generation of turbidites in deepwater areas:a case study of turbidity current processes in Qiongdongnan Basin, northern South China Sea

    Institute of Scientific and Technical Information of China (English)

    JIANG Tao; ZHANG Yingzhao; TANG Sulin; ZHANG Daojun; ZUO Qianmei; LIN Weiren; WANG Yahui; SUN Hui; WANG Bo

    2014-01-01

    Turbidity currents represent a major agent for sediment transport in lakes, seas and oceans. In particu-lar, they formulate the most significant clastic accumulations in the deep sea, which become many of the world’s most important hydrocarbon reservoirs. Several boreholes in the Qiongdongnan Basin, the north-western South China Sea, have recently revealed turbidity current deposits as significant hydrocarbon res-ervoirs. However, there are some arguments for the potential provenances. To solve this problem, it is es-sential to delineate their sedimentary processes as well as to evaluate their qualities as reservoir. Numerical simulations have been developed rapidly over the last several years, offering insights into turbidity current behaviors, as geologically significant turbidity currents are difficult to directly investigate due to their large scale and often destructive nature. Combined with the interpretation of the turbidity system based on high-resolution 3D seismic data, the paleotophography is acquired via a back-stripping seismic profile integrated with a borehole, i.e., Well A, in the western Qiongdongnan Basin; then a numerical model is built on the basis of this back-stripped profile. After defining the various turbidity current initial boundary conditions, includ-ing grain size, velocity and sediment concentration, the structures and behaviors of turbidity currents are investigated via numerical simulation software ANSYS FLUENT. Finally, the simulated turbidity deposits are compared with the interpreted sedimentary bodies based on 3D seismic data and the potential provenances of the revealed turbidites by Well A are discussed in details. The simulation results indicate that a sedimen-tary body develops far away from its source with an average grain size of 0.1 mm, i.e., sand-size sediment. Taking into account the location and orientation of the simulated seismic line, the consistence between normal forward simulation results and the revealed cores

  6. Variation of the scaling characteristics of temporal and spatial distribution of earthquakes in Caucasus

    Science.gov (United States)

    Matcharashvili, T.; Chelidze, T.; Javakhishvili, Z.; Zhukova, N.

    2016-05-01

    In the present study we investigated the character of variation of long-range correlations features in earthquakes' temporal and spatial distribution in Caucasus. Scaling exponents of data sets of interearthquakes time intervals (waiting times) and interearthquakes distances were calculated by method of Detrended Fluctuation Analysis (DFA). Scaling exponent values were calculated for time windows with consecutive 500 data as well as for 5 year long sliding windows. It was shown that scaling exponents calculated for different windows vary in a wide range indicating variable behavior from antipersistent to persistent type. In the overwhelming majority of cases scaling exponents manifest persistent behavior both in the earthquakes time and spatial distributions. Close to 0.5 and antipersistent scaling exponents were obtained for the time periods when the strongest regional earthquakes occurred. We observed slow trend in long-range correlation features variation for the considered time period.

  7. M9 Tohoku earthquake hydro- and seismic response in the Caucasus and North Turkey

    Science.gov (United States)

    Chelidze, Tamaz L.; Shengelia, Ia; Zhukova, Natalya; Matcharashvili, Teimuraz; Melikadze, George; Kobzev, Genady

    2016-06-01

    Presently, there are a lot of observations on the significant impact of strong remote earthquakes on underground water and local seismicity. Teleseismic wave trains of strong earthquakes give rise to several hydraulic effects in boreholes, namely permanent water level changes and water level oscillations, which closely mimic the seismograms (hydroseismograms). Clear identical anomalies in the deep borehole water levels have been observed on a large part of the territory of Georgia during passing of the S and Love-Rayleigh teleseismic waves (including also multiple surface Rayleigh waves) of the 2011 Tohoku M9 earthquake. The analysis carried out in order to find dynamically triggered events (non-volcanic tremors) of the Tohoku earthquake by the accepted methodology has not revealed a clear tremor signature in the test area: the Caucasus and North Turkey. The possible mechanisms of some seismic signals of unknown origin observed during passage of teleseismic waves of Tohoku earthquake are discussed.

  8. THE HALOPHILICITY OF FILAMENTOUS FUNGI ISOLATED FROM SALINE SOILS OF SOUTH CAUCASUS

    Directory of Open Access Journals (Sweden)

    Kvesitadze E.

    2015-08-01

    Full Text Available The work is devoted to the isolation, purification, determination of taxonomical characteristics and application in soil improvement and other biotechnological processes halophilic microscopic fungi strains isolated from saline soils of Eastern Georgia (middle part of South Caucasus, where their existence is maximally supposed. In all soilclimatic zones the dominate forms of spread fungi are genera Aspergillus, Penicillium and Fusarium, followed by Trichoderma and Mucor. Other genera are met less intensively. The genera Aspergillus is widely spread in chestnut soils and in chernozem, in green forest soils the genera Penicillium is prevailing. The salinity of soil, lake or any other objects from which the isolation of microscopic fungi is performed greatly determines halophilisity of isolated strains. Finally, the collection of halophilic microscopic fungi has been created accounting 96 isolates of extreme halophiles, halophiles and week halophiles.

  9. Analysis of the lactic acid bacteria microflora in traditional Caucasus cow's milk cheeses

    Directory of Open Access Journals (Sweden)

    Terzić-Vidojević Amarela

    2009-01-01

    Full Text Available A total of 157 lactic acid bacteria (LAB were isolated from three hand-made cheeses taken from different households in the region of the Caucasus Mountains. The cheeses were manufactured from cow's milk without the addition of a starter culture. The isolates of LAB were characterized by subjecting them to phenotypic and genotypic tests. The results of identification of LAB indicate that the examined cheeses contained 10 species, viz., Lactobacillus plantarum, Lactobacillus paraplantarum, Lactobacillus arizonensis, Lactobacillus farciminis, Lactobacillus brevis, Lactococcus lactis subsp. lactis, Leuconostoc mesenteroides subsp. mesenteroides, Leuconostoc pseudomesenteroides, Enterococcus faecium, and Enterococcus faecalis. The strains within the species L. plantarum, L. arizonensis, L. paraplantarum, L. farciminis, and L. pseudomesenteroides showed good proteolytic activity.

  10. Genetic diversity for drought tolerance in lentils from Central Asia and the Caucasus: CACLentil

    Directory of Open Access Journals (Sweden)

    SEVDA BABAYEVA

    2014-07-01

    Full Text Available The drought tolerance of 96 lentil accessions collected from Central Asia and Caucasus (CAC region was analysed through two sets of field experiment conditions: irrigated and rain-fed. Several yield components of these accessions were evaluated and compared by means of statistical analyses. Analysis of variance revealed significant variation among the genotypes between and within the two experimental conditions. Based on regression analysis, seed and pod number per plant had significant associations with seed yield per plant. Cluster analyses based on drought tolerance index (DTI grouped accessions into five subgroups with different numbers of accessions in each group. Three groups out of five were characterized by high DTI values and high yields were observed in both, under irrigated and rainfed conditions. This collective group of genotypes demonstrated valuable germplasm traits under stress and may therefore serve as source of useful genes in breeding lentils for drought tolerance.

  11. FORMATION OF SOCIAL AND LEGAL FRAMEWORK FOR REVIVAL OF TRADITIONAL ISLAMIC EDUCATION IN THE NORTH CAUCASUS

    Directory of Open Access Journals (Sweden)

    R. A. Khachidogov

    2016-01-01

    Full Text Available The article analyzes the legal establishment of the government in the field of Islamic education in the North Caucasus region. It is noted that the establishment of the Russian state did not bring any significant changes in the everyday life of Muslims of the North Caucasus. For the first time on "foreigners" of the state-level education has been fixed 26 March 1870 "Rules", which talked about the struggle "with a tribal organization and Mohammedan civilization, aimed at the Russification of early Muslims and their coalescence with the Russian people." The next step came Nov. 20, 1874 with the approval of the State Supreme Council, which introduced the system of Islamic education in the school accountability department. So finally implement a project of Russification of the Muslim community, which was the most negative factor hindering the mental development of children who are accustomed to speak the mother tongue. Even in 1838, in the report the Minister of War Chernyshev commander of a separate Caucasian Corps, General Golovin wrote that "it is necessary, wherever possible, to establish Muslim schools for the education of the clergy, through which you can act on the minds of the people." Caucasian leaders were in no hurry to close Muslim schools, trying to use them as centers of education spread. During the Caucasian War, the Russian government is trying to pursue such a policy among the Muslims, which would cause the sympathy not only among the common people, but also among the educated elite of the Muslim community in order to drag her to his side. December 18, 1848 Nicholas I approved the "Regulations on the Caucasian school district and the school district, his subordinate", in which the military gymnasium in Ekaterinodar started teacher "Mohammedan law." In 1853 Muslim students of military schools of the empire received an official entitled to exemption from the training sessions in the days of religious feasts and fasts.

  12. Using the significant dust deposition event on the glaciers of Mt. Elbrus, Caucasus Mountains, Russia on 5 May 2009 to develop a method for dating and provenancing of desert dust events recorded in snow pack

    Science.gov (United States)

    Shahgedanova, M.; Kutuzov, S.; White, K.; Nosenko, G.

    2012-09-01

    A significant desert dust deposition event occurred on Mt. Elbrus, Caucasus Mountains, Russia on 5 May 2009, where the deposited dust later appeared as a brown layer in the snow pack. An examination of dust transportation history and analysis of chemical and physical properties of the deposited dust were used to develop a new approach for high-resolution provenancing of dust deposition events recorded in snow pack using multiple independent techniques. A combination of SEVIRI red-green-blue composite imagery, MODIS atmospheric optical depth fields derived using the Deep Blue algorithm, air mass trajectories derived with HYSPLIT model and analysis of meteorological data enabled identification of dust source regions with high temporal (hours) and spatial (ca. 100 km) resolution. Dust, deposited on 5 May 2009, originated in the foothills of the Djebel Akhdar in eastern Libya where dust sources were activated by the intrusion of cold air from the Mediterranean Sea and Saharan low pressure system and transported to the Caucasus along the eastern Mediterranean coast, Syria and Turkey. Particles with an average diameter below 8 μm accounted for 90% of the measured particles in the sample with a mean of 3.58 μm, median 2.48 μm and the dominant mode of 0.60 μm. The chemical signature of this long-travelled dust was significantly different from the locally-produced dust and close to that of soils collected in a palaeolake in the source region, in concentrations of hematite and oxides of aluminium, manganese, and magnesium. Potential addition of dust from a secondary source in northern Mesopotamia introduced uncertainty in the provenancing of dust from this event. Nevertheless, the approach adopted here enables other dust horizons in the snowpack to be linked to specific dust transport events recorded in remote sensing and meteorological data archives.

  13. Using the significant dust deposition event on the glaciers of Mt. Elbrus, Caucasus Mountains, Russia on 5 May 2009 to develop a method for dating and provenancing of desert dust events recorded in snow pack

    Directory of Open Access Journals (Sweden)

    M. Shahgedanova

    2012-09-01

    Full Text Available A significant desert dust deposition event occurred on Mt. Elbrus, Caucasus Mountains, Russia on 5 May 2009, where the deposited dust later appeared as a brown layer in the snow pack. An examination of dust transportation history and analysis of chemical and physical properties of the deposited dust were used to develop a new approach for high-resolution provenancing of dust deposition events recorded in snow pack using multiple independent techniques. A combination of SEVIRI red-green-blue composite imagery, MODIS atmospheric optical depth fields derived using the Deep Blue algorithm, air mass trajectories derived with HYSPLIT model and analysis of meteorological data enabled identification of dust source regions with high temporal (hours and spatial (ca. 100 km resolution. Dust, deposited on 5 May 2009, originated in the foothills of the Djebel Akhdar in eastern Libya where dust sources were activated by the intrusion of cold air from the Mediterranean Sea and Saharan low pressure system and transported to the Caucasus along the eastern Mediterranean coast, Syria and Turkey. Particles with an average diameter below 8 μm accounted for 90% of the measured particles in the sample with a mean of 3.58 μm, median 2.48 μm and the dominant mode of 0.60 μm. The chemical signature of this long-travelled dust was significantly different from the locally-produced dust and close to that of soils collected in a palaeolake in the source region, in concentrations of hematite and oxides of aluminium, manganese, and magnesium. Potential addition of dust from a secondary source in northern Mesopotamia introduced uncertainty in the provenancing of dust from this event. Nevertheless, the approach adopted here enables other dust horizons in the snowpack to be linked to specific dust transport events recorded in remote sensing and meteorological data archives.

  14. Using the significant dust deposition event on the glaciers of Mt.~Elbrus, Caucasus Mountains, Russia on 5 May 2009 to develop a method for dating and "provenancing" of desert dust events recorded in snow pack

    Science.gov (United States)

    Shahgedanova, M.; Kutuzov, S.; White, K. H.; Nosenko, G.

    2013-02-01

    A significant desert dust deposition event occurred on Mt. Elbrus, Caucasus Mountains, Russia on 5 May 2009, where the deposited dust later appeared as a brown layer in the snow pack. An examination of dust transportation history and analysis of chemical and physical properties of the deposited dust were used to develop a new approach for high-resolution "provenancing" of dust deposition events recorded in snow pack using multiple independent techniques. A combination of SEVIRI red-green-blue composite imagery, MODIS atmospheric optical depth fields derived using the Deep Blue algorithm, air mass trajectories derived with HYSPLIT model and analysis of meteorological data enabled identification of dust source regions with high temporal (hours) and spatial (ca. 100 km) resolution. Dust, deposited on 5 May 2009, originated in the foothills of the Djebel Akhdar in eastern Libya where dust sources were activated by the intrusion of cold air from the Mediterranean Sea and Saharan low pressure system and transported to the Caucasus along the eastern Mediterranean coast, Syria and Turkey. Particles with an average diameter below 8 μm accounted for 90% of the measured particles in the sample with a mean of 3.58 μm, median 2.48 μm. The chemical signature of this long-travelled dust was significantly different from the locally-produced dust and close to that of soils collected in a palaeolake in the source region, in concentrations of hematite. Potential addition of dust from a secondary source in northern Mesopotamia introduced uncertainty in the "provenancing" of dust from this event. Nevertheless, the approach adopted here enables other dust horizons in the snowpack to be linked to specific dust transport events recorded in remote sensing and meteorological data archives.

  15. Petrological, geochemical and geochronological evidence for a Neoproterozoic ocean basin recorded in the Marlborough terrane of the northern New England Fold Belt

    International Nuclear Information System (INIS)

    Petrological, geochemical and radiogenic isotopic data on ophiolitic-type rocks from the Marlborough terrane, the largest (∼700 km2) ultramafic-mafic rock association in eastern Australia, argue strongly for a sea-floor spreading centre origin. Chromium spinel from partially serpentinised mantle harzburgite record average Cr/(Cr + Al) = 0.4 with associated mafic rocks displaying depleted MORB-like trace-element characteristics. A Sm/Nd isochron defined by whole-rock mafic samples yields a crystallisation age of 562 ± 22 Ma (2σ). These rocks are thus amongst the oldest rocks so far identified in the New England Fold Belt and suggest the presence of a late Neoproterozoic ocean basin to the east of the Tasman Line. The next oldest ultramafic rock association dated from the New England Fold Belt is ca 530 Ma and is interpreted as backarc in origin. These data suggest that the New England Fold Belt may have developed on oceanic crust, following an oceanward migration of the subduction zone at ca 540 Ma as recorded by deformation and metamorphism in the Anakie Inlier. Fragments of late Neoproterozoic oceanic lithosphere were accreted during progressive cratonisation of the east Australian margin. Copyright (1999) Geological Society of Australia

  16. Problems modern radiobiology in valeilogy and ecology aspects of regions Caucasus

    International Nuclear Information System (INIS)

    Full text: Ecological and hygienic aspects in studying radiation background leaves far off for frames radiation ecologies and radiation hygiene. From a time of openings of phenomena of radioactivity pass slightly more one age. Huge source of energy in the manner of the nucleus disintegration, but else more - a making a nucleus weapon, capable to destroy all alive, for the first time have forced will be conceived all mankind on fetters of technical progress, on the further fate and development to modern civilizations. Evaluations of doses of irradiating a population of Caucasus were systematically conducted from the end 50-h s both organs of Ministry of public healths, and Commission on isotopes and radiating an Academy of sciences. Relatively well was contributed of natural radioactivity, variation natural background, questions of using the mineral baths. With the appearance artificial toxigenic radionuclides were accumulated data on direct dose measurements of external irradiation. Done attempts of evaluation of doses of professional irradiating certain contingent of medical work mans, as well as doses of internal irradiating, to the account of different ways of penetration an radionuclides different genesis in the organism of person. The first attempts of complex evaluations of doses of external and internal irradiating are connected with performing the special studies at the beginning initially 60-h s of past age. It was evaluated contribution of the different sources and different ways of irradiation. Hereto, time pertain attempts of dozes evaluations from global fallout. Finished form of these attempts of evaluation of dozes load levels have taken by the end of 80-h s only. To a period of catastrophes on Chernobyl hygienic evaluations of contribution of contamination were founded on given special gamma-analyses SVO 'Typhon'. Series of studies published by US 'Radiation studies', manage real to value scales of soiling a region Caucasus. It was shown that levels

  17. Preliminary Basin Analysis of Latest Miocene Conglomerate Near Bahía Kino, Coastal Sonora: A New Record of Crustal Deformation During Initial Opening of the Northern Gulf of California

    Science.gov (United States)

    Dorsey, R. J.; Peryam, T. C.; Bennett, S.; Oskin, M. E.; Iriondo, A.

    2008-12-01

    In coastal Sonora northwest of Bahía Kino, we have initiated a basin-analysis study of nonmarine conglomerate (Tcg) that overlies and is locally interbedded with the 6.4-Ma Tuff of Mesa Cuadrada (Tmc). Tcg conglomerate is deeply eroded and cut by a complex set of syn- to post-basinal, N- to NNE-striking normal faults and NW-striking dextral strike-slip faults. We carried out detailed mapping and field descriptions, measured stratigraphic sections, and collected paleocurrent and clast-count data in Tcg. Zircons from the newly discovered Seri tuff near the base of the section, 160 m below Tmc, were dated using U-Pb SHRIMP geochronology at Stanford University. We obtained a 206Pb/238U weighted mean age of 6.53+/-0.18 Ma (n=14; MSWD=1.3), which yields a sediment-accumulation rate of 0.8+/-0.2 mm/yr for lower Tcg. Tcg is dominated by debris-flow facies consisting of massive, poorly sorted, weakly bedded, matrix-rich, pebble, cobble, to small-boulder conglomerate. A subsidiary sheet-flood facies is somewhat better sorted, generally lacks boulders, and contains weak but pervasive horizontal stratification. Both facies of Tcg record deposition in an alluvial fan environment. Well sorted and stratified stream deposits are conspicuously lacking. Preserved sections of Tcg range up to 170 to 240 meters thick in the southern part of the study area, and increase to at least 470 meters in the north where the Punta Chueca fault, a large NW-directed low-angle normal fault, apparently produced more extension and subsidence than smaller faults in the south. Clasts in Tcg are dominated by middle Miocene andesite, the 12.6-Ma Tuff of San Felipe, minor amounts of Tmc, and variable amounts of older basement rocks including tonalite, granodiorite, quartzite, metavolcanic rock, and a megacrystic K-spar-bearing granite that we have not seen in the local bedrock. After correcting for bedding dips and vertical-axis clockwise rotations determined from paleomagnetic analysis, restored

  18. Evidencia geofísica del umbral de Trenque Lauquen en la extensión norte de la cuenca de Claromecó, provincia de Buenos Aires Geophysical evidence of the Trenque Lauquen High in the northern extension of the Claromecó Basin, province of Buenos Aires

    Directory of Open Access Journals (Sweden)

    J. Kostadinoff

    2007-11-01

    Full Text Available La exploración geofísica del borde norte de la cuenca de Claromecó sugieren la existencia de importantes espesores de sedimentos paleozoicos. Estas secuencias sedimentarias se extienden en el área NW de la provincia de Buenos Aires. Las cuencas de Claromecó y Chaco Paranense están divididas por un área semipositiva. Sin embargo un bajo con dirección NNO de 165 km de longitud, cubierto por sedimentos paleozoicos conecta ambas cuencas.The geophysical survey of the northern border of Claromecó basin suggests the existence of Paleozoic sequences with important thickness. Such sequences extend along the NW area of Buenos Aires province. The Claromecó and Chaco Paranense Basins are divided by a semi positive area. A NNW-trending through, 165 km long, filled with Paleozoic sediments connects important thickness of both basins.

  19. Relationships between physical and chemical factors and aquatic macroinvertebrates in perennial streams in the arid northern mountain basin El Batinah, Oman

    Directory of Open Access Journals (Sweden)

    S. Boulaaba

    2014-08-01

    Full Text Available The relationships between physical properties, water chemistry and aquatic macroinvertebrates were investigated in riffles of four perennial streams in the arid northern Oman. Samples were collected monthly in autumn, winter and spring with a Surber net. Thirty two invertebrate taxa were recorded, most species are widely distributed, but few species with very restricted distribution were also captured. Diptera followed by Pulmonata, Coleoptera and Odonata were the most represented taxa, Trichoptera and Heteroptera were a significant component only in one station (the Fezeh, where the lowest mean water temperature (23°C was recorded. In the dry months from May to October, aquatic macroinvertebrates were completely absent. In order to summarise the community response some biotic indices were calculated. The highest diversity was observed in the Fezeh station. A seasonal gradient was also observed, with the highest diversity values in January, April, and December. The low faunal diversity was attributed to the high air and water temperature and the hydrological regime instability. A between station and a between month coinertia analysis was carried out, to analyse the response to spatial and seasonal factors. The first coinertia axis was correlated with altitude and substrate composition, while the second axis was correlated with air and water temperature. The present research emphasizes the urgency for preserving the less disturbed wadis in arid zones, because, despite their species poorness, their uniqueness in faunal composition requires special attention. The presence of few endemic species with very restricted distribution highlights the topicality and the value in investigating these areas, allowing the increase of our knowledge on biodiversity, ecology and biogeography about the benthic macroinvertebrates living in these extreme habitats.

  20. “Fear or Love Thy Neighbour”? The EU Framework for Promoting Regional Cooperation in the South Caucasus

    Directory of Open Access Journals (Sweden)

    Nelli Babayan

    2011-12-01

    Full Text Available Building on the model of the enlargement policy, the European Union (EU designed the European Neighbourhood Policy and the Eastern Partnership to further promote its norms and principles. One of the goals of its new policies has been to foster regional cooperation among partner countries and their neighbours. This article specifies the EU’s framework for promoting regional cooperation through the aforementioned policies and discusses its potential impact on the example of the South Caucasus republics of Armenia, Azerbaijan, and Georgia. The South Caucasus has not only been an arena of intraregional conflicts, but has also often been troubled by disputes between its neighbours. This article argues that, due to a lack of proactive and consistent engagement, the EU’s framework risks leaving regional conflicts in the current state of stagnation and without advancement in regional cooperation.

  1. Determination of nitrate pollution sources by using isotopes and hydro-chemical techniques in the shallow Aquifer of Bara basin Northern Kordofan State Sudan

    International Nuclear Information System (INIS)

    This study investigates the nature of the nitrate concentration and its effect on the quality of groundwater in the Bara basin in North Kordofan State Sudan. The principal objective of this study is to: detect possible NO3 sources affecting groundwater quality. The δ15N results included two range of values, which suggested two different nitrogen sources in different parts of the study area. The data used in this study includes lithological logs, pumping and recovery data and chemical analysis. Rock ware, surfer, aquitest and aquichem software programs were used to analyze the data. which is the based on the lithological logs from nine shallow wells and seven deep boreholes. The geological formation was found to be the Umm Ruwaba formation which consists of two aquifers an upper shallow one and the other deep aquifer. The transmissivity of the upper aquifer was found to be 0.528m2 / day, which is good and the average of hydraulic conductivity was found to be 0.084 m/ day, which is high and the storativity is 0.081. The direction of flow of groundwater was found to be from North West to North East over all the area. Chemical analysis showed that the TDS concentration in the study area is within the permissible limits of the Sudanese and the WHO standards. The calcium concentration in the study area also found to be within the permissible limits of the Sudanese and the WHO standards. The nitrate concentration in the upper aquifer ranges between 9.68 and 891 mg/1 which is above the permissible limit of the Sudanese and the WHO standards. The water type in the upper aquifer was found to be calcium-nitrate-chloride-bicarbonate. It appears that the source of the calcium is either for the decay of dead animal bones or the dissolution of calcareous deposits within the upper aquifer. It can be concluded that the quality of groundwater in the study area is good for the human consumption. (Author)

  2. Geochemical correlation of oil from the Ayoluengo field to Liassic black shale units in the southwestern Basque-Cantabrian Basin (northern Spain)

    Energy Technology Data Exchange (ETDEWEB)

    Quesada, Santiago; Robles, Sergio [University of the Basque Country, Stratigraphy and Paleontology Dept., Bilbao (Spain); Dorronsoro, Carmen [University of the Basque Country, Geology Dept., Bilbao (Spain); Chaler, Roser; Grimalt, Joan O. [C.I.D.-C.S.I.C., Environmental Chemistry Dept., Barcelona (Spain)

    1997-12-31

    A study of the Liassic sequence in the Basque-Cantabrian Basin has shown the presence of organic-rich (TOC, HI and S{sub 2} up to 8.7%, 760 and 56.5 mg/g, respectively) Pliensbachian-early Toarcian black shales that constitute the only feasible source rock for Ayoluengo oil. The stratigraphical and sedimentological data show that these black shales developed into a major transgressive sequence of hemipelagic Lotharingian-Toarcian facies, which suggests the presence of anoxic or near anoxic bottom water conditions in troughs during their deposition. The {delta}{sup 13}C composition, and a detailed study of the linear, branched, isoprenoid, steroid and hopanoid aliphatic hydrocarbons in these shales, marls and the Ayoluengo oil confirms this hypothesis. Specifically, the {delta}{sup 13}C values of the total solvent extract of the thicker shale (No. 2) and the oil are -29.93 and -29.88``per mille``, respectively; also a close similarity in the relative compositions of steranes and hopanes is observed between these samples. The distributions of these compounds exhibit several distinct features. The steranes in this shale and crude oil are characterized by a depletion of C{sub 28} vs C{sub 27} and C{sub 29} homologues (24 vs 32 and 44%, respectively), which is consistent with the carbon number sterane distributions generally observed among Upper Paleozoic to Liassic rock-sourced oils. Furthermore, hopanes and steranes are characterized by their high relative content of rearranged molecules. Diasteranes (13{beta}(H),17{alpha}(H)- and 13{alpha}(H),17{beta}(H)- series) are the dominant compounds among the steranes and significant amounts of 18{alpha}(H)-17{alpha}methyl-28-norhopanes (C{sub 27}, C{sub 29} and C{sub 30} homologues) and 17{alpha}(H)-15{alpha}-methyl- 27 norhopanes (C{sub 30} homologue) are found in the hopanoid hydrocarbons. Conversely, the proportion of these rearranged molecules in other sediment samples from the same formation decrease with increasing

  3. Magnetostratigraphic study of a continental succession in the Alessandria Basin: contribution to the chronological reconstruction of the Pliocene-Pleistocene transition in Northern Italy.

    Science.gov (United States)

    Tema, Evdokia; Irace, Andrea; Monegato, Giovanni; Martinetto, Edoardo; Gianolla, Daniele; Pini, Roberta

    2013-04-01

    In this work we present the results of a detailed magnetostratigraphic study carried out on fine-grained lenses of a fluvial succession, exposed in the southern border of the Alessandria Basin (NW Italy), of Plio-Quaternary age. The studied succession mainly consists of coarse sands and gravels. Several fine-grained lenses, related to abandoned channels, also occur. For palaeomagnetic analyses, five laminated clayey and silty lenses were sampled, following a systematic 5-10 cm sampling interval. All samples were oriented in situ using a magnetic compass and an inclinometer. Isothermal remanent magnetization measurements show that for most of the samples saturation is reached at low applied fields, varying from 0.3 to 0.4 T, indicating the presence of a low-coercivity mineral such as magnetite. No systematic variation of the magnetic properties along the whole section has been registered, except for samples coming 8.5 to 10 m from the base of the fluvial succession, where the presence of sulphurs such as greigite has been identified. All samples were systematically stepwise demagnetized in alternating field (AF) following 7 to 9 steps in the range 5 to 80 mT. AF demagnetizations show that in most cases the NRM consists of a soft, low-coercivity component erased at around 10-15 mT, probably of viscous origin, and a more stable component isolated from 15 to 60 mT that can be confidently considered as the Characteristic Remanent Magnetization (ChRM). Interpretation of the demagnetization results based on principal component analysis shows a polarity reversal for the upper part of the section, while the lower part of the section is characterized by normal polarities. The results from the part of the section where the presence of greigite has been identified have not been taken into consideration as they may be unreliable due to remagnetization procedures. The obtained palaeomagnetic data, combined with stratigraphic and biostratigraphic evidences, suggest that the

  4. Plant-Arthropod Associations from the Lower Miocene of the Most Basin in Northern Bohemia(Czech Republic):A Preliminary Report

    Institute of Scientific and Technical Information of China (English)

    Jakub PROKOP; Torsten WAPPLER; Stanislav KNOR; Zlatko KVA(C)EK

    2010-01-01

    Terrestrial plants and insects currently account for the majority of the Earth's biodiversity,and approximately half of insect species are herbivores.Thus,insects and plants share ancient associations that date back more than 400 Myr.However,investigations of their past interactions are at the preliminary stages in Western Europe.Herein,we present the first results of our study of various feeding damage based on a dataset of nearly 3500 examined plant specimens from the Lower Miocene of the Lagerstatte Bilina Mine in the Most Basin,Czech Republic.This site provides a unique view of the Neogcue freshwater ecosystems.It has long been studied by scientists working in different branches of sedimentology,paleobotany,and paleozoology.The fossils are preserved in three characteristic horizons overlaying the coal seam(Clayey Superseam Horizon,Delta Sandy Horizon,and Lake Clayey Horizon),reflecting paleoenvironmental changes in a short time period of development.The trace fossils are classified as functional feeding groups or"guilds",without searching for a direct cause or a recent analog host relation.Approximately 23% of specimens of dicotyledonous plant leaves were found to be damaged and associated with some leaf"morphotypes".Deciduous plant-host taxa,and those with a chartaceons texture typical of riparian habitats,were frequently damaged,such as Populus,recorded with two species Populus zaddachii and Populus populina(57.9% and 31% herbivory levels,respectively),followed by Acer,Alnus,and Carya,averaging almost 30% of damaged leaves/leaflets.There has been evidence of 60 damage types(DT)representing all functional feeding groups recorded at the Bilina Mine,including 12 types of leaf mines and 16 galltype DT.In total,Lower Miocene of the Lagerstatte Bilina Mine exhibits a high level of external foliage feeding types(23.7%),and a low level of more specialized DT,such as galls(4.3%)and leaf mines(<1%).A broader comparison based on DT of the main sedimentary environments

  5. CREATING NATIONAL LITERATURE AS A FACTOR IN THE SOVIETIZATION OF THE NORTH CAUCASUS (TO THE HISTORY OF ADYGHE INTELLECTUALS

    Directory of Open Access Journals (Sweden)

    Bochkareva A. S.

    2015-09-01

    Full Text Available The article describes the creation and use of the national literature and national Circassia’s language, as a major factor of Sovietization of the North Caucasus in the process of integration of the region in Soviet geopolitical space in the 1920s-1930s. The article is made in the framework of regional competition: "The North Caucasus: Tradition and Modernity" in 2014 - the Krasnodar Territory. 14-11-23007 Project Type "(p", the theme: "The Role of the national intelligentsia in the incorporation of the North Caucasus in the Russian geopolitical space of the. Nineteenth century. - 20-ies. Twentieth century. (based on the Adyghe people. " It is pointed out that the development of the national writing by Circassian intelligence became not only an important matter of national life of Adyghe people, but also a key part of the national policy of the Soviet authorities towards national minorities. It is noted, that in many respects, revolutionary events in Russia became one of the most powerful external factors that stimulated the revitalization of Circassian intelligentsia in the development and diffusion of national literature. It is shown that in the course of the policy of "language building" in the national autonomies within the first twenty years of the Soviet government the graphics based writing changed three times (Arabic, Latin, Russian and three times they were eliminating illiteracy. The conclusion is that intellectuals deprived of the possibility to solve these issues, and a key influence on the development of national literature evolution of Circassians had views of the Bolsheviks in the language policy. In general, the issue of writing, mostly related to the problem of education in specific historical circumstances, has acquired great social and political importance, and has become an important part of the national policy of the Soviet government in matters of Sovietization of the North Caucasus

  6. Return migration to the Caucasus: the Adyge-Abkhaz diaspora(s), transnationalism and life after return

    OpenAIRE

    Erciyes, Jade Cemre

    2014-01-01

    This thesis investigates the dual transnationalism of ancestral return migrants, that is to say people “returning” to the territory where their ancestors had once migrated from. Dispersed from their homeland in the second half of the 19th century, the Adyge-Abkhaz diaspora has been involved in a variety of transnational practices in relation to their homeland in the Caucasus; and some, with considerable effort, have been settling there especially in the last two decades. The transnational inv...

  7. MONUMENTS OF MATERIAL CULTURE AND CONFLICTS IN THE CAUCASUS(A FORTRESS OF IREVAN CASE-STUDY)

    OpenAIRE

    Huseynov, Rizvan

    2012-01-01

    The author deals with the destruction and falsification of monuments of material culture, one of the most painful repercussions of the ethnic conflicts in the Caucasus. He uses the medieval Fortress of Irevan (Irevan Gala), the now destroyed historical and architectural center of Erevan, to illustrate the sad fate of the monuments of material culture that became victims of the conflict between Armenia and Azerbaijan.

  8. CHARACTER AND FORMS OF INDUSTRIAL GOODS DISTRIBUTION ON DON AND THE NORTH CAUCASUS IN THE GREAT PATRIOTIC WAR DAYS

    Directory of Open Access Journals (Sweden)

    E. V. PANARINA

    2016-01-01

    Full Text Available This article is devoted to realization of a state policy of distribution of industrial goods on Don and the North Caucasus in days of the Great Patriotic War. The principles of use of a rationing system of distribution of essentials, her differentiated character, preferential categories of consumers providing allocation are considered. Concrete examples of application of coupons at acquisition of clothes, footwear and other goods are given. Conditions of execution of this order by local bodies of Don and the North Caucasus are analyzed; the attention to limitation of the allocated manufactured goods from the centralized funds is paid. Much attention is paid to the measures for research of additional sources of providing the population of Don and the North Caucasus taken from local bodies by essentials. The attention to especially difficult situation with providing the population of the region, owing to occupation consequences is paid. Data on restoration and development of the local industry, cooperative artels, increase in release of goods, necessary for the population, are provided. The role of the trade-union organizations in supply of the most needing workers with clothes, footwear and other manufactured goods reveals. The assessment is given to results of collaboration of local bodies and public organizations in providing the population with manufactured goods, the remaining difficult situation in questions of providing inhabitants of Don and the North Caucasus by essentials throughout the entire period of the Great Patriotic War is noted.

  9. Glaciers Fluctuation over the Last Half Century in the Headwaters of the Enguri River, Caucasus Mountains, Georgia

    OpenAIRE

    Levan G. Tielidze; George Lominadze; Nino Lomidze

    2015-01-01

    The article considers the variability glaciers parameters of Headwaters of the Enguri River in the years of 1960-1986-2014. The headwaters of The Enguri Riverare located on the southern slope of the Greater Caucasus, in Georgia. Detailed morphologic and morphometric description of glaciers is given. During our research, we used the topographic maps of 1960 and Landsat L5 TM (Thematic Mapper) aerial images, taken in August 1986 and 2014, and the GPS data of 2014. In the...

  10. New morpho-stratigraphic constraints for the evolution of the alluvial fan system along the northern slopes of the Taburno-Camposauro Mountains (Calore River basin, Southern Italy)

    Science.gov (United States)

    Leone, Natalia; Amato, Vincenzo; Aucelli, Pietro P. C.; Cesarano, Massimo; Filocamo, Francesca; Petrosino, Paola; Rosskopf, Carmen M.; Valente, Ettore; Giralt, Santiago; Casciello, Emilio

    2016-04-01

    The Lower Calore River Valley is a morphostructural depression located in the inner sector of the Campanian Apennine, between the Taburno-Camposauro and the Matese carbonate massifs. The river is the main left tributary of the Volturno River, it has a meandering channel partially structural-controlled. Numerous morphotectonic clues and historical seismicity data suggest that this part of the Apennine chain was particularly active during the late-Quaternary. In detail, the valley is E-W oriented and presents an asymmetry of the opposed valley slopes. The left side, corresponding to the northern flank of the Camposauro massif, is characterized by a steep slope (70°-35°), partially controlled by a ~E-W oriented fault system, and by a wide less-inclined piedmont aggradation zone. The latter started growing since middle Pleistocene, with the deposition of alluvial fans and slope deposits over the well cemented early Pleistocene breccias of Laiano Synthem. The alluvial fan deposition has been active until present giving rise to three main generations of alluvial fans. The right side of the valley, instead, is characterized by seven orders of fluvial terraces, both of erosional and depositional origin. The quaternary morpho-stratigraphic evolution of alluvial fans and fluvial terraces has been strongly conditioned by the interaction of tectonic phases and climatic variations. A detailed geomorphological study (1:5.000 in scale) was carried out with the aim to map the main depositional and erosional fluvial landforms and to identify the main tectonic lineaments of the area. A detailed field survey allowed to better define the stratigraphic and paleoenvironmental context in which the alluvial deposits developed and also to find chrono-stratigraphic markers. Tephra-stratigraphic analyses were performed on pyroclastic deposits interbedded into the alluvial fan and fluvial successions. At the moment the age of the first generation of alluvial fans is still under

  11. Multi-method provenance model for early Paleozoic sedimentary basins of southern Peru and northern Bolivia (13°-18°S)

    Science.gov (United States)

    Reimann Zumsprekel, Cornelia R.; Bahlburg, Heinrich; Carlotto, Victor; Boekhout, Flora; Berndt, Jasper; Lopez, Shirley

    2015-12-01

    In early Paleozoic time the Peru-Bolivia Trough at the South American Gondwana margin accommodated large volumes of siliciclastic detritus of hitherto largely unknown provenance. A multi-method provenance study of framework components, heavy minerals and whole rock geochemistry of Ordovician to Devonian formations of southern Peru and northern Bolivia reveals the predominant contribution from upper crustal sources. Main heavy minerals include zircon, tourmaline, rutile, apatite, garnet, epidote, monazite, and titanite and are strongly biased diagenetically towards the stable phases. Electron microprobe single grain analysis of tourmaline and rutile indicate that detrital tourmalines were derived mainly from metasedimentary, and subordinately, from granitic sources. Cr/Nb ratios in rutiles point to a metamafic derivation for 20-40% of grains, the remainder originating in felsic lithologies. Zr in rutile thermometry indicates a provenance from relatively high-grade metamorphic rocks transformed at temperatures between 500 °C and 900 °C, with clusters at c. 600 °C, 700 °C and 800 °C. U-Pb geochronological analysis of rutiles was largely unsuccessful due to high concentrations of common Pb. Three ages could be obtained and fall between 525 and 545 Ma, probably linking this detritus to the hidden Neoproterozoic orogen in what are now Cordillera Oriental and Sierras Subandinas. The most notable feature of the whole rock geochemical data is a high Cr content in the majority of samples, which otherwise have a composition similar to weathered upper continental crust. The elevated Cr contents indicates that ophiolitic rocks were either exposed to erosion abundantly in the source areas or had previously supplied significant volumes of detritus to intermittent sediment storage systems now eroded into the studied sedimentary rocks. Potential source candidates include the Ordovician metamorphic Tapo Ultramafic Complex in the Cordillera Oriental of central Peru, and the

  12. Hydrothermal Evolution of the Giant Cenozoic Kadjaran porphyry Cu-Mo deposit, Tethyan metallogenic belt, Armenia, Lesser Caucasus: mineral paragenetic, cathodoluminescence and fluid inclusion constraints

    Science.gov (United States)

    Hovakimyan, Samvel; Moritz, Robert; Tayan, Rodrik; Rezeau, Hervé

    2016-04-01

    The Lesser Caucasus belongs to the Central segment of the Tethyan metallogenic belt and it is a key area to understand the metallogenic evolution between the Western & Central parts of the Tethyan belt and its extension into Iran. Zangezur is the most important mineral district in the southernmost Lesser Caucasus. It is a component of the South Armenian block, and it was generated during the convergence and collision of the southern margin of the Eurasian plate and the northern margin of the Arabian plate, and terranes of Gondwana origin (Moritz et al., in press). The Zangezur ore district consists of the Tertiary Meghri-Ordubad composite pluton, which is characterized by a long-lasting Eocene to Pliocene magmatic, tectonic and metallogenic evolution. It hosts major porphyries Cu-Mo and epithermal Au - polymetallic deposits and occurrences, including the giant world class Kadjaran porphyry Cu-Mo deposit (2244 Mt reserves, 0.3% Cu, 0.05% Mo and 0.02 g/t Au). The Kadjaran deposit is hosted by a monzonite intrusion (31.83±0.02Ma; Moritz et al., in press). Detailed field studies of the porphyry stockwork and veins of the different mineralization stages, their crosscutting and displacement relationships and the age relationship between different paragenetic mineral associations were the criteria for distinction of the main stages of porphyry mineralization at the Kadjaran deposit. The economic stages being: quartz- molybdenite, quartz-molybdenite-chalcopyrite, and quartz-chalcopyrite. The main paragenetic association of the Kadjaran porphyry deposit includes pyrite, molybdenite, chalcopyrite, bornite, chalcocite, pyrrhotite, covellite, sphalerite, and galena. Recent field observations in the Kadjaran open pit revealed the presence of epithermal veins with late vuggy silica and advanced argillic alteration in the north-eastern and eastern parts of the deposit. They are distributed as separate veins and have also been recognized in re-opened porphyry veins and in

  13. Integrated provenance analysis of a convergent retroarc foreland system: U-Pb ages, heavy minerals, Nd isotopes, and sandstone compositions of the Middle Magdalena Valley basin, northern Andes, Colombia

    Science.gov (United States)

    Nie, Junsheng; Horton, Brian K.; Saylor, Joel E.; Mora, Andrés; Mange, Maria; Garzione, Carmala N.; Basu, Asish; Moreno, Christopher J.; Caballero, Victor; Parra, Mauricio

    2012-01-01

    Sediment provenance analysis remains a powerful method for testing hypotheses on the temporal and spatial evolution of uplifted source regions, but issues such as recycling, nonunique sources, and pre- and post-depositional modifications may complicate interpretation of results from individual provenance techniques. Convergent retroarc systems commonly contain sediment sources that are sufficiently diverse (continental magmatic arc, fold-thrust belt, and stable craton) to enable explicit provenance assessments. In this paper, we combine detrital zircon U-Pb geochronology, heavy mineral identification, Nd isotopic analyses, conventional sandstone petrography, and paleocurrent measurements to reconstruct the clastic provenance history of a long-lived sedimentary basin now exposed in an intermontane zone of the northern Andean hinterland of Colombia. The Middle Magdalena Valley basin, situated between the Central Cordillera and Eastern Cordillera, contains a 5-10 km-thick succession of Upper Cretaceous to Quaternary fill. The integrated techniques show a pronounced change in provenance during the Paleocene transition from the lower to upper Lisama Formation. We interpret this as a shift from an eastern cratonic source to a western Andean source composed of magmatic-arc rocks uplifted during initial shortening of the Central Cordillera. The appearance of detrital chloritoid and a shift to more negative ɛ Nd(t=0) values in middle Eocene strata of the middle La Paz Formation are attributed to shortening-related exhumation of a continental basement block (La Cira-Infantas paleohigh), now buried, along the axis of the Magdalena Valley. The diverse provenance proxies also show distinct changes during middle to late Eocene deposition of the Esmeraldas Formation that likely reflect initial rock uplift and exhumation of the fold-thrust belt defining the Eastern Cordillera. Upsection, detrital zircon U-Pb ages and heavy mineral assemblages for Oligocene and younger clastic

  14. Tibet and Beyond: Magmatic Records from CIA (Caucasus-Iran-Anatolia) and Southern Tibet with Implications for Asian Orogeny and Continental Growth

    Science.gov (United States)

    Chung, Sun-Lin

    2016-04-01

    This study, based on an ongoing joint research project "Tibet and Beyond", presents a synthesis of principal magmatic records from the CIA (Caucasus-Iran-Anatolia) and Tibet-Himalaya orogens resulting from the continental collisions of Arabia and India, respectively, with Eurasia. In both orogens, through this and other recent studies, the temporal and spatial variations in magmatism pre-, syn- and post-dating the collisions can now be much better defined, thus improving our understanding of collision zone magmatism that appears to have evolved with changes in the lithospheric structures over time and space by collisional processes. The two "collisional" Tethyan orogens were preceded by accretionary orogenic processes, which not only had produced a substantial amount of juvenile continental crust but also fulfill the "orogenic cycle" that evolved from an accretionary into a collisional system. Geochemical data reveal that in contrast to generating vast portions of juvenile crust in the early, accretionary stages of orogenic development, crustal recycling plays a more important role in the later, collisional stages. The latter, as exemplified in SE Turkey and southern Tibet, involves addition of older continental crust material back into the mantle, which subsequently melted and caused compositional transformation of the juvenile crust produced in the accretionary stages. Similar features are observed in young volcanic rocks from eastern Taiwan, the northern Luzon arc complex and part of the active subduction/accretion/collision system in Southeast Asia that may evolve one day to resemble the eastern Tethyan and central Asian orogenic belts by collision with the advancing Australian continent.

  15. POPULATION OF THE NORTHWEST CAUCASUS AND EURASIAN NOMADS: MILITARY-POLITICAL COOPERATION «ALGORITHM»

    Directory of Open Access Journals (Sweden)

    Samir Kh. KHOTKO

    2016-02-01

    Full Text Available Autochthonous ethnic array of Northwest Caucasus was formed under constant pressure by the nomadic peoples. This article is an attempt to trace the repeated historical scenario (a kind of algorithm of the interaction of the agricultural area with a series of nomadic cultures. The 1st stage of this algorithm – the chaotic inroads of nomads or the planned military campaign. The 2nd stage – mainly peaceful coexistence with a nomadic ethnic group, which could be accompanied by recognition of both the military and political supremacy of nomadic empire (the Khazar Khanate, the Golden Horde, and an equal relationship with the mutual periodic forays (Cumans, Nogais, Kalmyks. Stage 3 is the inevitable emergence of a new wave of newcomers, who sought to destroy the old nomads of Don-Kuban region. Old nomads sought to enter into a defensive alliance with the Circassians. This model, when the old Turkic population enlists the help of the Circassians, applies not only to the nomadic ethnic groups, whose political system is characterized by considerable decentralization (Cumans, Nogai, but also to the nomadic states: Tokhtamysh with the Circassians against Tamerlane, the Crimean Khanate with the Circassians against Kalmyks. During the third phase the Turkic khanates necessarily experiencing cultural, military and political influence of the Circassians. Natives of Circassia are becoming part of the administrative elite of the Golden Horde, and of the Crimean Khanate. Stage 4 – the integration of nomadic tribal groups in Circassian space and some dependence on Circassians. A striking example of the pressure of the Circassians on the nomadic state – the Astrakhan Khanate, the capital of which Circassians seized several times, promoting the enthronement of the Khans, who were their relatives. This stage is characterized by a high level of cross-cultural communication. Assimilation of nomads helped to strengthen the

  16. Mudflow Hazards in the Georgian Caucasus - Using Participatory Methods to Investigate Disaster Risk

    Science.gov (United States)

    Spanu, Valentina; McCall, Michael; Gaprindashvili, George

    2014-05-01

    The Caucasus form an extremely complex mountainous area of Georgia in terms of geology and the scale and frequency of natural disaster processes. These processes, especially mudflows, frequently result in considerable damage to the settlements, farmlands and infrastructure facilities. The occurrence intervals between mudflows are becoming significantly shorter, therefore the most populated areas and infrastucture need to be included in risk zones. This presentation reviews the case of the mudflow problem in Mleta village in the region of Dusheti where the mudflow risk is critical. The villages of Zemo Mleta (Higher Mleta) and Kvemo Mleta (Lower Mleta) are entirely surrounded by unstable slopes where mudslides, landslides and floods are often generated. These hazards occur at least twice per year and sometimes result in severe events. In 2006 and 2010 in Mleta village a very severe mudflow event occurred creating heavy damage. This paper focuses on the recognition of the importance of cooperating with the local communities affected by these disasters, in order to get useful information and local knowledge to apply to disaster prevention and management. In October 2010, the EU-financed MATRA Project (Institutional Capacity Building in Natural Disaster Risk Reduction) in Georgia included fieldworks in several locations. Particular attention was given to Mleta village in the Caucasus Mountains, where the activities focused on institutional capacity-building in disaster risk reduction, including modern spatial planning approaches and technologies and the development of risk communication strategies. Participatory methods of acquiring local knowledge from local communities reveal many advantages compared to traditional survey approaches for collecting data. In a participatory survey and planning approach, local authorities, experts and local communities are supposed to work together to provide useful information and eventually produce a plan for Disaster Risk Reduction

  17. Northern employment

    International Nuclear Information System (INIS)

    Hiring practices and policies and employment opportunities that were available in the Beaufort Sea and MacKenzie Delta project for local residents and for people from southern Canada were dealt with in this chapter. Depending on the source, Northern hiring was a mere token, or a genuine and successful effort on the part of the companies to involve the native population and to share with them the benefits of the project. The fact remains that opening up job opportunities for Northerners was not easily attained, and would never have been realized without the involvement of government and community organizations. Government also played a major role in developing policies and training regimes. By the end of exploration operations, the hiring of Northern residents in the oil and gas industry had become a requirement of drilling applications. Training programs were also created to ensure that Northern residents received the means necessary to take advantage of Northern employment opportunities

  18. The Snezhnaya-Mezhennogo-Illyuziya cave system in the western Caucasus

    International Nuclear Information System (INIS)

    The Snezhnaya-Mezhennogo-Illyuziya cave system (SMI) is located within the Khipstinsky karstic massif, in the Western Caucasus. The cave is a branched, arborescent system of cave channels through which underground water streams flow and change in an upwards direction in sub-vertical shafts. Now 3 such shafts, which have a connection with the cave river, are being studied: the Snezhnaya (1970 m a.s.l.), the Mezhennogo (2 015 m a.s.l.) and the Illyuziya (2 389 m a.s.l.). The SMI cave system has been investigated since 1971 and the currently known depth of the system is 1 760 m, the extent of the galleries ≥32 km, the volume ≥2.7 million m3, the specific volume - 84 m3/m. The size of the biggest cave chamber the Thronnyj - is 309x109x40 m. The average discharge of the underground river is about 500 l/s. The temperature in the cavity changes from 0 to 6.5 degree centigrade. Research on the SMI cave system continues. (Author)

  19. Drastic underestimation of amphipod biodiversity in the endangered Irano-Anatolian and Caucasus biodiversity hotspots.

    Science.gov (United States)

    Katouzian, Ahmad-Reza; Sari, Alireza; Macher, Jan N; Weiss, Martina; Saboori, Alireza; Leese, Florian; Weigand, Alexander M

    2016-01-01

    Biodiversity hotspots are centers of biological diversity and particularly threatened by anthropogenic activities. Their true magnitude of species diversity and endemism, however, is still largely unknown as species diversity is traditionally assessed using morphological descriptions only, thereby ignoring cryptic species. This directly limits evidence-based monitoring and management strategies. Here we used molecular species delimitation methods to quantify cryptic diversity of the montane amphipods in the Irano-Anatolian and Caucasus biodiversity hotspots. Amphipods are ecosystem engineers in rivers and lakes. Species diversity was assessed by analysing two genetic markers (mitochondrial COI and nuclear 28S rDNA), compared with morphological assignments. Our results unambiguously demonstrate that species diversity and endemism is dramatically underestimated, with 42 genetically identified freshwater species in only five reported morphospecies. Over 90% of the newly recovered species cluster inside Gammarus komareki and G. lacustris; 69% of the recovered species comprise narrow range endemics. Amphipod biodiversity is drastically underestimated for the studied regions. Thus, the risk of biodiversity loss is significantly greater than currently inferred as most endangered species remain unrecognized and/or are only found locally. Integrative application of genetic assessments in monitoring programs will help to understand the true magnitude of biodiversity and accurately evaluate its threat status. PMID:26928527

  20. Tectónica extensional triásica en el sector norte de la cuenca Cuyana: primeros datos cinemáticos Triassic extensional tectonics at the northern branch of the Cuyana basin (South Precordillera: First kinematic data

    Directory of Open Access Journals (Sweden)

    María S. Japas

    2008-06-01

    . 35º- 40° obtenida en los afloramientos de la quebrada El Salto, se infiere en forma preliminar una importante componente sinestral durante la extensión en el tramo norte de la cuenca.Triassic clastic and volcanic rocks from the Precordillera were deposited in the Cuyana rift basin filling half-graben systems. Contractional/ transpressional Andean tectonics leads to the almost complete inversion of some portions of the basin which resulted in present-day isolated, structurally controlled outcrops of these Triassic rocks. In the Southern Precordillera both the degree of Neogene tectonic inversion and structural compexities are variable. At the regional scale, these variations in Andean deformation are related to first order anisotropies like the Cuyana basin borders and previous shear zones of Permian age (San Rafael orogenic phase. This paper focuses on the kinematic analysis done in the Cerro Manantial thrust sheet area (Cordón San Bartolo, central sector of the South Precordillera where tectonic inversion was not that strong and the influence of oblique strain zones is practically null. Four sets of extensional / transtensional faults were recognized affecting Triassic sedimentary rocks of the El Cielo Formation (Uspallata Group at the Quebrada El Salto. Fault displacements are of decimetric to metric scale. Mesoscopic kinematic indicators (en-échèlon tensional gashes, Riedel shear fractures, sigmoidal fractures were measured. Once Andean deformation was restored, a NNE direction for the Triassic extension was determined. Considering a northern branch of the Cuyana basin trending NNW (Az. 150° and oblique to the direction of extension (Az. 35-40°, a sinistral strike-slip component could be inferred for this portion of the basin.

  1. MILITARY AND ADMINISTRATIVE AND POLITICAL ACTIVITY OF E.A. GOLOVIN IN THE CAUCASUS (1838–1842

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    Kondusov V. S.

    2015-12-01

    Full Text Available The article is devoted to military and administrative activity of one of imperial deputies – Evgeny Aleksandrovich Golovin in the Caucasus in 1838-1842. The general spent more than three months studying data on the area he did not know in the archives of SaintPetersburg. E. A. Golovin paid special attention to road and fortification construction. He aimed at making them “centres of Russian nationhood by establishing schools and markets”. On December 15, 1838 E. A. Golovin submitted a report to A. I. Chernyshov, the military minister, where he described the nearest political tasks of the Russian government. In Golovin’s opinion, the main military actions in Dagestan were supposed to be seizure of Chirkat, construction of fortifications therein and devastation of Akhulgo, residence of Shamil. However, E. A. Golovin turned out to be bound with instructions written in Petersburg more than his predecessors. Programmes for military actions in the Caucasus region specifying even troop units to participate in expeditions down to the last detail were drawn on an annually basis. By the end of his term in the position of the Commander-in-Chief of the Independent Caucasian Corps Golovin started supporting the siege system by combining it, the same way as A. P. Ermolov, with periodic temporary offensive operations. After the Evgenievskoe Fortification (named so to honour Golovin by Royal Decree had been constructed at the Sulak River, Evgeniy Aleksandrovich was dismissed in October 1842. The author concludes that in process of recognition of the world of mountaineers the commander-in-chief showed aspiration to searches of other, less dramatic solutions of the Caucasian question, opened for the successors of prospect of the movement of Russia and the people of Chechnya, Dagestan and Western Caucasus towards each other

  2. Coal quality in the northern Appalachian Basin

    Energy Technology Data Exchange (ETDEWEB)

    Bragg, L.J.; Tewalt, S.J.; Ruppert, L.F.; Wallack, R.N. [Geological Survey, Reston, VA (United States)

    1998-12-31

    The national coal resource assessment, being conducted by the US Geological Survey (USGS), provides information on both the quantity and quality of the coal beds and zones of the coals that are expected to provide most of the coal utilized in the US during the next few decades. As part of this assessment, the USGS developed comprehensive geochemical databases for the Pittsburgh and the Upper Freeport coal beds, which are then used to map and model trends in the ash yield, sulfur (S) content, and calorific value of the coals, as well as trends in selected major-, minor-, and trace- element contents. Compilation of the databases, mapping of geochemical trends, and comparisons of the trends and mean values for ash yield, S content, calorific value (Btu/lb), arsenic (As) content, selenium (Se) content, mercury (Hg) content, and chlorine (Cl) content for these beds are discussed in the paper. Final results for the complete database are presented for the Pittsburgh coal bed. Preliminary results for ash yield, S content and calorific value are presented for the Upper Freeport coal bed.

  3. CHARACTER AND FORMS OF INDUSTRIAL GOODS DISTRIBUTION ON DON AND THE NORTH CAUCASUS IN THE GREAT PATRIOTIC WAR DAYS

    OpenAIRE

    E. V. PANARINA

    2016-01-01

    This article is devoted to realization of a state policy of distribution of industrial goods on Don and the North Caucasus in days of the Great Patriotic War. The principles of use of a rationing system of distribution of essentials, her differentiated character, preferential categories of consumers providing allocation are considered. Concrete examples of application of coupons at acquisition of clothes, footwear and other goods are given. Conditions of execution of this order by local bodie...

  4. Aude Merlin and Silvia Serrano (Ed., Ordres et désordres au Caucase [Orders and Disorders in the Caucasus

    Directory of Open Access Journals (Sweden)

    Giulia Prelz Oltramonti

    2011-12-01

    Full Text Available It is usually the full-intensity phases of conflicts that draw most scrutiny, and this is true for the conflicts of the Caucasus too. Much has been written on the wars that took place in Nagorno Karabakh, Abkhazia and South Ossetia in the early 1990s, on the two Chechen conflicts, and on the more recent (2008 conflict in Georgia. While a cessation of full-scale hostilities does not necessarily entail the establishment of order and stability, attention fades away. This is why the mechanisms t...

  5. Late Holocene climate history recorded in Karakel lake sediments, Central Caucasus

    Science.gov (United States)

    Solomina, Olga; Kalugin, Ivan; Darin, Andrey; Chepurnaya, Anna; Alexandrin, Mikhail

    2013-04-01

    The Holocene climatic history in Caucasus is poorly studied. Two lake sediment cores up to 180 cm long retrieved from the Karakel lake (N 43° 26' 12,13" E 41° 44' 34,72" H=1335 m, Teberda valley, Western Caucasus) in 2010 provide a unique opportunity for the high resolution reconstruction of climate and environment in the Late Holocene in this region. For this purpose we used the scanning X-ray Fluorescence Analyses on Synchrotron Radiation technique (SRXFA) (0.1 mm resolution equal to 4 years), providing data of distribution of more than 50 micro- and macroelements, the loss-on-ignition, magnetic susceptibility, water content, wet and dry bulk density and other physical properties of the sediments as well as palynology (10 mm resolution approximately equal to 40 years). The surface of the lake Karakel is 140x280 m, the lake is 6-8 m deep and is dammed by an old moraine covered by a sparse pine forest. Two units are clearly distinguished in the sediments: the uppermost part (0-54 cm) consists of dark brown to black organic reach sediments, the lower part is light gray laminated clay, poor in organic. Three radiocarbon dates (AMS) from the depth 30-31 cm (1550 ± 30 BP), 52-54 cm (2235 ± 35 BP), 143-145 μm (9760 ± 80 BP) provide the chronological control for the sedimentation rate. The hiatus between the lower and upper units is possible, while the uniform continuous accumulation rate 0.22-0.23 mm/year without major episodes of erosion is supposed for the upper part of the sediments. Seven years from the uppermost part of the sediments is lost in the column collected by the borer in comparison with those retrieved by the box. The late Holocene unit is subdivided into four palynological zones characterizing the changes in the surrounding vegetation and climate. The very good correspondence exists between the total pollen productivity, especially for the tree pollen, and the bromide content in the sediments, which is in turn correlative with the total

  6. Global surgery in a postconflict setting - 5-year results of implementation in the Russian North Caucasus

    Directory of Open Access Journals (Sweden)

    Fatima I. Lunze

    2015-10-01

    Full Text Available Background: Collaborations for global surgery face many challenges to achieve fair and safe patient care and to build sustainable capacity. The 2004 terrorist attack on a school in Beslan in North Ossetia in the Russian North Caucasus left many victims with complex otologic barotrauma. In response, we implemented a global surgery partnership between the Vladikavkaz Children's Hospital, international surgical teams, the North Ossetian Health Ministry, and civil society organizations. This study's aim was to describe the implementation and 5-year results of capacity building for complex surgery in a postconflict, mid-income setting. Design: We conducted an observational study at the Children's Hospital in Vladikavkaz in the autonomous Republic of North Ossetia-Alania, part of the Russian Federation. We assessed the outcomes of 15 initial patients who received otologic surgeries for complex barotrauma resulting from the Beslan terrorism attack and for other indications, and report the incidence of intra- and postoperative complications. Results: Patients were treated for trauma related to terrorism (53% and for indications not related to violence (47%. None of the patients developed peri- or postoperative complications. Three patients (two victims of terrorism who underwent repair of tympanic perforations presented with re-perforations. Four junior and senior surgeons were trained on-site and in Germany to perform and teach similar procedures autonomously. Conclusions: In mid-income, postconflict settings, complex surgery can be safely implemented and achieve patient outcomes comparable to global standards. Capacity building can build on existing resources, such as operation room management, nursing, and anesthesia services. In postconflict environments, substantial surgical burden is not directly attributable to conflict-related injury and disease, but to health systems weakened by conflicts. Extending training and safe surgical care to include

  7. Seismic hazard assessment based on the Unified Scaling Law for Earthquakes: the Greater Caucasus

    Science.gov (United States)

    Nekrasova, A.; Kossobokov, V. G.

    2015-12-01

    Losses from natural disasters continue to increase mainly due to poor understanding by majority of scientific community, decision makers and public, the three components of Risk, i.e., Hazard, Exposure, and Vulnerability. Contemporary Science is responsible for not coping with challenging changes of Exposures and their Vulnerability inflicted by growing population, its concentration, etc., which result in a steady increase of Losses from Natural Hazards. Scientists owe to Society for lack of knowledge, education, and communication. In fact, Contemporary Science can do a better job in disclosing Natural Hazards, assessing Risks, and delivering such knowledge in advance catastrophic events. We continue applying the general concept of seismic risk analysis in a number of seismic regions worldwide by constructing regional seismic hazard maps based on the Unified Scaling Law for Earthquakes (USLE), i.e. log N(M,L) = A - B•(M-6) + C•log L, where N(M,L) is the expected annual number of earthquakes of a certain magnitude M within an seismically prone area of linear dimension L. The parameters A, B, and C of USLE are used to estimate, first, the expected maximum magnitude in a time interval at a seismically prone cell of a uniform grid that cover the region of interest, and then the corresponding expected ground shaking parameters including macro-seismic intensity. After a rigorous testing against the available seismic evidences in the past (e.g., the historically reported macro-seismic intensity), such a seismic hazard map is used to generate maps of specific earthquake risks (e.g., those based on the density of exposed population). The methodology of seismic hazard and risks assessment based on USLE is illustrated by application to the seismic region of Greater Caucasus.

  8. New paleomagnetic and paleointensity results from late pliocene volcanic sequences from southern Georgia (Caucasus)

    International Nuclear Information System (INIS)

    Complete text of publication follows. Paleomagnetic and rock-magnetic experiments were carried out on 21 basaltic lava flows belonging to four different sequences of late Pliocene age from southern Georgia (Caucasus): Dmanisi (11 flows), Diliska (5 flows), Kvemo Orozmani (5 flows), and Zemo Karabulaki (3 flows). Paleomagnetic analysis generally showed the presence of a single component (mainly in the Dmanisi sequence) but also two more or less superimposed components in several other cases. All sites except one clearly displayed a normal-polarity characteristic component. Rock-magnetic experiments included measurement of thermomagnetic curves and hysteresis parameters. Susceptibility-versus-temperature curves measured in argon atmosphere on whole-rock powdered samples yielded low-Ti titanomagnetite as main carrier of remanence, although a lower TC-component was also observed in several cases. Both reversible and non-reversible k-T curves were measured. A pilot paleointensity study was performed with the Coe (1967) method on two samples of each of those sites considered suitable after interpretation of rock-magnetic and paleomagnetic data from all sites. The pilot study showed that reliable paleointensity results were mainly obtained from sites of the Dmanisi sequence. This thick sequence of basaltic lava flows records the upper end of the normal-polarity Olduvai subchron, a fact confirmed by 40Ar/39Ar dating of the uppermost lava flow and overlying volcanogenic ashes, which yields ages of 1.8 to 1.85 My. A second paleointensity experiment was carried out only on samples belonging to the Dmanisi sequence. Preliminary results show that paleointensities often are low, their values lying between 10 and 20 μT in many cases. For comparison, present day field is 47 μT. The Dmanisi sequence of lava flows directly underlies the Dmanisi paleoanthropologic site, in which the end of the Olduvai subchron is recorded.

  9. Investigation of a deep ice core from the Elbrus western plateau, the Caucasus, Russia

    Science.gov (United States)

    Mikhalenko, V.; Sokratov, S.; Kutuzov, S.; Ginot, P.; Legrand, M.; Preunkert, S.; Lavrentiev, I.; Kozachek, A.; Ekaykin, A.; Faïn, X.; Lim, S.; Schotterer, U.; Lipenkov, V.; Toropov, P.

    2015-12-01

    A 182 m ice cor