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Sample records for subandean thrust belt

  1. Stress history and fracture pattern in fault-related folds based on limit analysis: application to the Sub-Andean thrust belt of Bolivia

    Science.gov (United States)

    Barbe, Charlotte; Leroy, Yves; Ben Miloud, Camille

    2017-04-01

    A methodology is proposed to construct the stress history of a complex fault-related fold in which the deformation mechanisms are essentially frictional. To illustrate the approach, fours steps of the deformation of an initially horizontally layered sand/silicone laboratory experiment (Driehaus et al., J. of Struc. Geol., 65, 2014) are analysed with the kinematic approach of limit analysis (LA). The stress, conjugate to the virtual velocity gradient in the sense of mechanicam power, is a proxy for the true statically admmissible stress field which prevailed over the structure. The material properties, friction angles and cohesion, including their time evolution are selected such that the deformation pattern predicted by the LA is consistent with the two main thrusting events, the first forward and the second backward once the layers have sufficiently rotated. The fractures associated to the stress field determined at each step are convected on today configuration to define the complete pattern which should be observed. The end results are presented along virtual vertical wells and could be used within the oil industry at an early phase of exploration to prepare drealing operations.

  2. Control of syntectonic erosion and sedimentation on kinematic evolution of a multidecollement fold and thrust zone: Analogue modeling of folding in the southern subandean of Bolivia

    Science.gov (United States)

    Darnault, Romain; Callot, Jean-Paul; Ballard, Jean-François; Fraisse, Guillaume; Mengus, Jean-Marie; Ringenbach, Jean-Claude

    2016-08-01

    Several analogue modeling studies have been conducted during the past fifteen years with the aim to discuss the effects of sedimentation and erosion on Foreland Fold and Thrust Belt, among which a few have analyzed these processes at kilometric scale (Malavieille et al., 1993; Nalpas et al., 1999; Barrier et al., 2002; Pichot and Nalpas, 2009). The influence of syn-deformation sedimentation and erosion on the structural evolution of FFTB has been clearly demonstrated. Here, we propose to go further in this approach by the study of a more complex system with a double decollement level. The natural study case is the Bolivian sub-Andean thrust and fold belt, which present all the required criteria, such as the double decollement level. A set of analogue models performed under a CT-scan have been used to test the influence of several parameters on a fold and thrust belt system, among which: (i) the spatial variation of the sediment input, (ii) the spatial variation of the erosion rate, (iii) the relative distribution of sedimentation between foreland and hinterland. These experiments led to the following observations: 1. The upper decollement level acts as a decoupling level in case of increased sedimentation rate: it results in the verticalization of the shallower part (above the upper decollement level), while the deeper parts are not impacted. 2. Similarly, the increase of the erosion rate involves the uplift of the deeper part (below the upper decollement level), whereas the shallower parts are not impacted. 3. A high sedimentation rate in the foreland involves a fault and fold vergence reversal, followed by a back-thrusting of the shallower part. 4. A high sedimentation rate in the hinterland favours thrust development toward the foreland in the shallower parts.

  3. Hydrocarbon potential of Altiplano and northern Subandean, Bolivia

    Energy Technology Data Exchange (ETDEWEB)

    Edman, J.D.; Kirkpatrick, J.R.; Lindsey, D.D.; Lowell, J.D.; Cirbian, M.; Lopez, M.

    1989-03-01

    Seismic, stratigraphic, structural, and geochemical data from the Altiplano, northern Subandean, and northern plains of Bolivia were interpreted in order to evaluate the exploration potential of each province. Identification of three possible source rock intervals, primarily the Devonian and secondarily the Permian and Cretaceous, was used as the basis for recognizing active hydrocarbon systems. For those areas containing source intervals, their analysis revealed that possible reservoir and seal units range in age from Paleozoic to Tertiary; the majority of structures, however, are Eocene or younger. With these general concepts in mind, traps were identified in all three sedimentary provinces. In the northern Altiplano, the most prospective area is along the eastern margin near a southwest and west-vergent thrust belt where hanging-wall anticlines and a warped Eocene-Oligocene(.) unconformity surface form the most likely potential traps. In the central and southern Altiplano, both thrust-related and wrench-related structures present possible exploration targets. In the northern Subandean and Beni plains north of the Isiboro-Chapare area, traps can be classified into two broad groups. First, there are a wide variety of structural traps within the northern Subandean thrust belt, the most attractive of which are footwall structures that have been shielded from surface flushing by hanging-wall strata. Second, in the plains just northeast of the thrust belt, hydrocarbons sourced from the remnant Paleozoic basin may have migrated onto the Isarsama and Madidi highs.

  4. Control of syntectonic erosion and sedimentation on kinematic evolution of a multidecollement thrust zone: Analogue modeling of folding in the southern subandean of Bolivia

    OpenAIRE

    Darnault, Romain; Callot, Jean-Paul; Ballard, Jean-François; Fraisse, Guillaume; Mengus, Jean-Marie; Ringenbach, Jean-Claude

    2016-01-01

    International audience; 13 Several analogue modeling studies have been conducted during the past fifteen years with the 14 aim to discuss the effects of sedimentation and erosion on Foreland Fold and Thrust Belt, 15 among which a few have analyzed these processes at kilometric scale (Nalpas et al., 1999; 16 Barrier et al., 2002; Pichot and Nalpas, 2009). The influence of syn-deformation 17 sedimentation and erosion on the structural evolution of FFTB has been clearly demonstrated. 18 Here, we...

  5. The Madong Early Paleozoic fold-thrust belt in southern Tarim Basin

    Science.gov (United States)

    Li, Yue-Jun; Wen, Lei; Li, Hui-Li; Peng, Geng-Xin; Qiu, Bin; Zheng, Duo-Ming; Luo, Jun-Cheng; Zhang, Qiang; Jia, Tie-Gan

    2016-01-01

    The Madong fold-thrust belt, which strikes NE-SW and thrusts southeastward, locates in the southern Tarim Basin. It is a part of the Kunlun Early Paleozoic foreland fold-thrust belt, and so is the Tangnan fold-thrust belt on the southeast of Madong. The Madong and Tangnan fold-thrust belts developed in Cambrian-Ordovician strata, and the Middle Cambrian gypsum-salt layer serves as the main décollement surface. The Middle Silurian and above strata unconformably overlie Madong while the upper Lower Silurian unconformably overlie Tangnan. On the basis of the facts that: (1) the Upper Ordovician is the youngest strata involved in the fold-thrust deformation, (2) the upper-Lower to Middle Silurian is the oldest strata unconformably overlying the foreland fold-thrust belt (including Madong and Tangnan), and growth strata exist in the upper part of the Upper Ordovician, we infer that the deformation time of the Kunlun Early Paleozoic foreland fold-thrust belt (including Madong and Tangnan) was during the Late Ordovician-Early Silurian. Tangnan is the residual of the major part of the foreland fold-thrust belt. Its northwestward thrust direction represents the main thrust direction of the foreland fold-thrust belt. Madong is the front belt of the foreland fold-thrust belt. It mainly thrusts southeastward and serves as the back-thrust belt of the Kunlun Early Paleozoic foreland fold-thrust belt. It is a triangle zone between Madong and Tangnan. The Madong fold-thrust belt is the best-preserved section of the Kunlun Early Paleozoic collisional orogenic belt, and thus is an important geological record of the Kunlun Early Paleozoic orogeny.

  6. Why style matters - uncertainty and structural interpretation in thrust belts.

    Science.gov (United States)

    Butler, Rob; Bond, Clare; Watkins, Hannah

    2016-04-01

    Structural complexity together with challenging seismic imaging make for significant uncertainty in developing geometric interpretations of fold and thrust belts. Here we examine these issues and develop more realistic approaches to building interpretations. At all scales, the best tests of the internal consistency of individual interpretations come from structural restoration (section balancing), provided allowance is made for heterogeneity in stratigraphy and strain. However, many existing balancing approaches give misleading perceptions of interpretational risk - both on the scale of individual fold-thrust (trap) structures and in regional cross-sections. At the trap-scale, idealised models are widely cited - fault-bend-fold, fault-propagation folding and trishear. These make entirely arbitrary choices for fault localisation and layer-by-layer deformation: precise relationships between faults and fold geometry are generally invalidated by real-world conditions of stratigraphic variation and distributed strain. Furthermore, subsurface predictions made using these idealisations for hydrocarbon exploration commonly fail the test of drilling. Rarely acknowledged, the geometric reliability of seismic images depends on the assigned seismic velocity model, which in turn relies on geological interpretation. Thus iterative approaches are required between geology and geophysics. The portfolio of commonly cited outcrop analogues is strongly biased to examples that simply conform to idealised models - apparently abnormal structures are rarely described - or even photographed! Insight can come from gravity-driven deep-water fold-belts where part of the spectrum of fold-thrust complexity is resolved through seismic imaging. This imagery shows deformation complexity in fold forelimbs and backlimbs. However, the applicability of these, weakly lithified systems to well-lithified successions (e.g. carbonates) of many foreland thrust belts remains conjectural. Examples of

  7. Imaging deformation in submarine thrust belts using seismic attributes

    Science.gov (United States)

    Iacopini, David; Butler, Robert W. H.

    2011-02-01

    Uncertainty exists as to the patterns of deformation that develop within submarine thrust belts. This case study uses a large-scale gravity-driven fold-thrust structure as an analogue for submarine fold thrust systems in general. Seismic attribute analysis and mapping provide ways of identifying complex fault patterns and associated deformation that are otherwise unresolved in conventional amplitude displays. These methods are developed and applied to a 3D dataset and used to investigate the geometry, internal architecture and the nature of the low signal/noise incoherency and discontinuities observed on the km-scale. Semblance (coherency), curvatures and spectral decomposition were all computed and used as attributes. Collectively these define volumes within the seismic data where the signal is greatly reduced — features termed here "disturbance geobodies". The study shows that thrust faults that, on conventional amplitude displays appear to be simple and continuous, are likely to consist of complex arrays of anastamosing fault strands. Adjacent to these composite fault zones are greater volumes of deformed rocks (disturbance geobodies) across which there are only minor stratal offsets. Similarly volumes of high stratal curvature coincide with disturbance geobodies, again interpreted as zones of weak, distributed deformation. These relationships between narrow thrust faults and broader zones of deformation are broadly comparable to those observed in outcrops within exhumed thrust systems. Application of the seismic imaging techniques developed here will improve the understanding of the localization of deformation in sedimentary successions with important implications for predicting fluid flow within other deep water structures such as subduction accretion complexes.

  8. A 3-D Model of Stacked Thrusts in the Sevier Thrust Belt, Eastern Idaho

    Science.gov (United States)

    Clayton, R. W.; Clayton, S. R.

    2014-12-01

    Using published and new geologic map data and two exploratory wells for control, we constructed a three-dimensional geological model of the Pine Creek area in the Big Hole Mountains of eastern Idaho, where stacked Sevier thrust sheets are exposed at the surface. In this area, Cretaceous crustal shortening displaced and folded strata from Cambrian to Cretaceous in age. Using geologic map data as a primary input to a 3-D model presents a number of challenges, especially representing fault geometries at depth and maintaining strata thicknesses. The highly variable attitudes measured at the surface are also difficult to represent in a subsurface model because they require extensive extrapolation to depth. To overcome these challenges we EarthVision software, which has tools for model construction with minimal data inputs and uses a minimum tension algorithm to create geologically realistic surfaces. We also constructed two primary cross-sections to constrain strata and fault geometries according to structural principles, and used these to guide construction of fault and horizon surfaces. We then designated horizons with the best control as reference horizons to constrain strata geometries, and built the remaining horizons using isochores to add or subtract from those surfaces. The model shows classic flat-ramp thrust geometries as seen farther southeast in the Wyoming section of the thrust belt. The model also shows uniform southwestward tilting of faults and strata in the north end above younger thrusts, but strong effects from a duplex on a younger thrust fault encountered in the southern well, which rotated the strata and older faults above it.

  9. Role of detachments and thrust kinematics in Structural evolution of Kohat and Potwar fold thrust belt in Pakistan

    Science.gov (United States)

    Ghani, Humaad; Zeilinger, Gerold; Sobel, Edward; Heidarzadeh, Ghasem

    2016-04-01

    The Kohat and Potwar fold thrust belts in Pakistan represent the outermost external zone of the Himalayan fold and thrust system. The Main Boundary thrust marks their northern extent, showing that they are genetically linked; however, both exhibit a distinct contrast between the structural style at the surface and subsurface. This contrast becomes more conspicuous at the leading edge of the thrust belt where the Potwar allochothon extends further south, linked to Kohat in the north via an active strike-slip fault. Previous workers explained the structural evolution of the two belts separately, disregarding the influence of similar fold and thrusts developed in both belts. This research focuses on the preparation of a 3D structural model at the boundary of the two thrust belts to understand similarities and differences in their structural style and evolution. The model is constrained by integrating field, seismic and well data for better subsurface interpretation. Cross sections show that Potwar evolved on thrust faults originating from a basal detachment in Precambrian (pC) salt and terminating in Miocene Molasse forming duplexes of pre Himalayan strata. To the south, the Potwar allochothon is glided over a salt detachment with rare internal deformation toward its leading edge, forming fault bend fold thrust structure known as Salt range. The structural evolution towards the west in Kohat results from deformation on multiple detachment horizons at the pC salt, Eocene evaporites and Miocene Molasse. Disharmonic folding over Eocene evaporites is evident from their presence in the cores of outcropping folds. In the subsurface, closely spaced thrusts cut up section from basal detachment terminates in Eocene evaporites forming duplex in northern part of area. In south change of lithological facies from evaporites to limestone shift detachment level upward in to molasse strata which resemble structural style in northern Potwar. Thrusts at the surface evolved from the

  10. Stress determination in active thrust belts: An alternative leak-off pressure interpretation

    Science.gov (United States)

    Couzens-Schultz, Brent A.; Chan, Alvin W.

    2010-08-01

    In thrust belts, fluid flow through critically stressed fractures will occur at pressures less than the overburden stress, which is the minimum stress. We propose that low leak-off pressures obtained in active thrust belts may result from this mechanism, leading workers to infer that apparent minimum stresses are 30-60% less than the overburden stress in some compressional settings. Traditionally, leak-off pressure data have been used to constrain the magnitude of minimum stress, assuming that the rock is dilating against the minimum stress during a leak-off test. In our new interpretation, we constrain the stress state by assuming that the leak-off test causes shear failure along pre-existing weaknesses rather than tensile opening. While this mechanism has been discussed in a small number of borehole stability and hydraulic fracture papers, it has not been directly applied to leak-off tests. We considered this interpretation because we observed that some leak-off tests imply an apparent contradiction between the stress states from the standard interpretation of leak-off tests versus the stress state inferred from geologic and geophysical evidence in tectonically active thrust belts. We present two examples with one in an onshore fold-thrust belt and one in a deepwater fold-thrust belt. Our new interpretation of stresses based on shear failure resolves the contradiction and also provides a constraint on the maximum horizontal stress in the fold-thrust belts.

  11. Cenozoic structural evolution, thermal history, and erosion of the Ukrainian Carpathians fold-thrust belt

    Science.gov (United States)

    Nakapelyukh, Mykhaylo; Bubniak, Ihor; Bubniak, Andriy; Jonckheere, Raymond; Ratschbacher, Lothar

    2018-01-01

    The Carpathians are part of the Alpine-Carpathian-Dinaridic orogen surrounding the Pannonian basin. Their Ukrainian part constitutes an ancient subduction-accretion complex that evolved into a foreland fold-thrust belt with a shortening history that was perpendicular to the orogenic strike. Herein, we constrain the evolution of the Ukrainian part of the Carpathian fold-thrust belt by apatite fission-track dating of sedimentary and volcanic samples and cross-section balancing and restoration. The apatite fission-track ages are uniform in the inner―southwestern part of the fold-thrust belt, implying post-shortening erosion since 12-10 Ma. The ages in the leading and trailing edges record provenance, i.e., sources in the Trans-European suture zone and the Inner Carpathians, respectively, and show that these parts of the fold-thrust were not heated to more than 100 °C. Syn-orogenic strata show sediment recycling: in the interior of the fold-thrust belt―the most thickened and most deeply eroded nappes―the apatite ages were reset, eroded, and redeposited in the syn-orogenic strata closer to the fore- and hinterland; the lag times are only a few million years. Two balanced cross sections, one constructed for this study and based on field and subsurface data, reveal an architecture characterized by nappe stacks separated by high-displacement thrusts; they record 340-390 km shortening. A kinematic forward model highlights the fold-thrust belt evolution from the pre-contractional configuration over the intermediate geometries during folding and thrusting and the post-shortening, erosional-unloading configuration at 12-10 Ma to the present-day geometry. Average shortening rates between 32-20 Ma and 20-12 Ma amounted to 13 and 21 km/Ma, respectively, implying a two-phased deformation of the Ukrainian fold-thrust belt.

  12. Structural framework of the Zagros Fold-Thrust Belt, Iran

    Energy Technology Data Exchange (ETDEWEB)

    Sepehr, M.; Cosgrove, J.W. [Imperial College, London (United Kingdom). Royal School of Mines

    2004-08-01

    Data gleaned from the literature on the Zagros have been compiled and used in conjunction with new interpretations to provide a better picture of the structures, sedimentation history and deformation of this hydrocarbon rich Mountain Belt. The belt parallel Mountain Front, the N-S trending Kazerun, lzeh and E-W trending Bala Rud Fault Zones are defined as the master structural elements of the Belt. These fault zones divide the Zagros basin into zones with different stratigraphic successions and different rheological profiles. This resulted in different structural styles developing along the belt during the subsequent collision. The Kazerun and lzeh Fault Zones acted as the depositional system transition zone between the Lurestan and Fars regions in Jurassic-Cretaceous time and partly controlled the distribution of the Kazhdumi Formation (one of the major source rocks). By the end of the Cretaceous the NW-SE trending Mountain Front Fault divided the present Folded Belt of the Zagros into a major foreland basin to the southwest, and a piggyback basin to the northeast. Activity along other major (transfer) fault zones including the lzeh, Kazerun and Bala Rud Fault zones occurred at this time and controlled the sedimentation and subsidence of the Dezful Embayment the main target region for hydrocarbon exploration. These fault zones controlled the thickness of the Asmari Formation (one of the main reservoirs) and also the considerable thickness and facies changes of the Gachsaran Formation (the major seal to the Asmari Formation). The present morphology of the mountain belt is interpreted as being mainly related to the pinning of the Mountain Front Fault to the northwest of the Dezful Embayment and to the north of the Strait of Hormuz. (author)

  13. Palinspastic reconstruction of the Alpine thrust belt at the Alpine-Carpathian transition - A geological Sudoku

    Science.gov (United States)

    Beidinger, A.; Decker, K.; Zamolyi, A.; Hölzel, M.; Hoprich, M.; Strauss, P.

    2009-04-01

    The palinspastic reconstruction of the Austroalpine thrust belt is part of the project Karpatian Tectonics, which is funded by OMV Austria. The objective is to reconstruct the evolution of the thrust belt through the Early to Middle Miocene in order to obtain information on the palaeogeographic position of the Northern Calcareous Alps (NCA) in the region of the present Vienna Basin. A particular goal of the study is to constrain the position of reservoir rocks within the Rhenodanubic Flysch units and the NCA with respect to the autochthonous Malmian source rocks overlying the European basement below the Alpine-Carpathian thrust wedge, and to constrain the burial history of these source rocks. Reconstruction uses regional 2D seismic lines crossing from the European foreland into the fold-thrust belt, 3D seismic data covering the external thrust sheets, and lithostratigraphic data from a total of 51 selected wells, which were drilled and provided by OMV Austria. The main criterion, whether a well was suitable for palinspastic reconstruction or not, was its penetration of Alpine thrust sheets down to the Autochthonous Molasse of the foreland. Additional wells, which do not penetrate the entire Alpine thrust complex but include the Allochthonous Molasse or the external Alpine-Carpathian nappes (Waschberg and Roseldorf thrust unit, Rhenodanubic Flysch nappes) in their well path, were also taken into account. The well data in particular comprise stratigraphic information on the youngest overthrust sediments of the different thrust units and the underlying Autochthonous foreland Molasse. These data allow constraining the timing of thrust events in the allochthonous thrust units and overthrusting of the Autochthonous Molasse. In the particular case of overthrust Autochthonous Molasse, additionally to the timing of overthrusting, which can be derived from the youngest overthrust sediments, the palaeogeographic position of the Alpine Carpathian thrust front could directly be

  14. The Influence of Frontal and Lateral Ramps in Fold Thrust Belts on Structural Architecture and Erosion

    Science.gov (United States)

    Robinson, D. M.; McQuarrie, N.

    2016-12-01

    In fold thrust belts, horizontal and vertical motions (or flow) define the path that a particular rock or mineral takes to the surface of the Earth, which is dictated by the location of frontal and lateral ramps. Horizontal flow occurs between ramp locations while the vertical component of motion (or flow) dominates when rocks are traveling over the ramps. Frontal ramps are common features near the front (foreland) of a fold thrust belt. Foreland frontal ramps are the easiest to obtain data for, and from these data predict ramp geometry, because they are shallow and the ramp geometry is commonly expressed as changes in the dip of strata in the mapped geology. Less constrainable are the frontal ramps at depth in the hinterland of a fold thrust belt. However, these deep frontal ramps control the architecture of a fold thrust belt, influence the mapped surface geology, control active uplift and thus, are locations of focused erosion. We show kinematic models from Nepal that illustrate how the architecture (geometry of structures, dips of strata) changes in the fold thrust belt when the location of a frontal ramp is moved and how both thermochronologic data and accurate mapping limit the possibilities for the location of these hinterland frontal ramps. Lateral ramps at depth provide limits on the width of horizontal flow paths and encourage vertical flow paths that have orientations strongly oblique to the strike of the orogen. A challenge in fold thrust belts is to determine the most logical location for lateral ramps. We use examples from Nepal that highlight characteristics that can be used to define the location of lateral ramps. Both lateral and frontal ramps produce significant structural elevation and changes in topographic elevation and thus, are locations of focused erosion through time. Additionally, because material is moving both laterally and vertically in a brittle fold thrust belt, frontal and lateral ramps can control the origin of earthquakes as well

  15. Morphotectonics of the central Muertos thrust belt and Muertos Trough (northeastern Caribbean)

    Science.gov (United States)

    Granja, Bruna J.L.; ten Brink, Uri S.; Carbó-Gorosabel, Andrés; Muñoz-Martín, A.; Gomez, Ballesteros M.

    2009-01-01

    Multibeam bathymetry data acquired during the 2005 Spanish R/V Hesp??rides cruise and reprocessed multichannel seismic profiles provide the basis for the analysis of the morphology and deformation in the central Muertos Trough and Muertos thrust belt. The Muertos Trough is an elongated basin developed where the Venezuelan Basin crust is thrusted under the Muertos fold-and-thrust belt. Structural variations along the Muertos Trough are suggested to be a consequence of the overburden of the asymmetrical thrust belt and by the variable nature of the Venezuelan Basin crust along the margin. The insular slope can be divided into three east-west trending slope provinces with high lateral variability which correspond to different accretion stages: 1) The lower slope is composed of an active sequence of imbricate thrust slices and closed fold axes, which form short and narrow accretionary ridges and elongated slope basins; 2) The middle slope shows a less active imbricate structure resulting in lower superficial deformation and bigger slope basins; 3) The upper slope comprises the talus region and extended terraces burying an island arc basement and an inactive imbricate structure. The talus region is characterized by a dense drainage network that transports turbidite flows from the islands and their surrounding carbonate platform areas to the slope basins and sometimes to the trough. In the survey area the accommodation of the ongoing east-west differential motion between the Hispaniola and the Puerto Rico-Virgin Islands blocks takes place by means of diffuse deformation. The asymmetrical development of the thrust belt is not related to the geological conditions in the foreland, but rather may be caused by variations in the geometry and movement of the backstop. The map-view curves of the thrust belt and the symmetry of the recesses suggest a main north-south convergence along the Muertos margin. The western end of the Investigator Fault Zone comprises a broad band of

  16. A workflow for 3D model building in fold-thrust belts

    Science.gov (United States)

    Watkins, Hannah; Bond, Clare; Butler, Rob

    2016-04-01

    3D geological models can be used in fold-thrust belts for many purposes such as analysing geometric variation in folds, kinematic modelling to restore fold surfaces, generating strain distribution maps and predicting fracture network distribution. We present a workflow for 3D model building using outcrop bedding data, geological maps, Digital Terrain Models (DTM's), air photos and field photographs. We discuss the challenges of software limitations for 3D kinematic restoration and forward modelling in fold-thrust belt settings. We then discuss the sensitivity of model building approaches to the application of 3D geological models in fold-thrust belts for further analysis e.g. changes in along strike fold geometry, restoration using kinematic and geomechanical modelling, strain prediction and Discrete Fracture Network (DFN) modelling. To create 3D models geological maps and bedding data are digitised using Move software; digitised maps and data are then draped onto DTM's. A series of closely spaced cross section lines are selected; the orientation of these is calculated by determining the average orientation of bedding dip direction. Fault and horizon line intersections, along with bedding data from within a narrow margin of the section lines are projected onto each cross section. Field photographs and sketches are integrated into the cross sections to determine thrust angles at the surface. Horizon lines are then constructed using bedding data. Displacement profiles for thrusts are plotted to ensure thrust displacements are valid with respect to neighbouring cross section interpretations; any discrepancies are alleviated by making minor adjustments to horizon and thrust lines, while ensuring that resultant cross section geometries still adhere to bedding data and other field observations. Once the cross sections have been finalised, 3D surfaces are created using the horizon and thrust line interpretations on each cross section. The simple curvature of 3D surfaces

  17. Estimates of trapped radiation encountered on low-thrust trajectories through the Van Allen belts

    Science.gov (United States)

    Karp, I. M.

    1973-01-01

    Estimates were made of the number of trapped protons and electrons encountered by vehicles on low-thrust trajectories through the Van Allen belts. The estimates serve as a first step in assessing whether these radiations present a problem to on-board sensitive components and payload. The integrated proton spectra and electron spectra are presented for the case of a trajectory described by a vehicle with a constant-thrust acceleration A sub c equal to 0.001 meter/sq sec. This value of acceleration corresponds to a trip time of about 54 days from low earth orbit to synchronous orbit. It is shown that the time spent in the belts and hence the radiation encountered vary nearly inversely with the value of thrust acceleration. Thus, the integrated spectral values presented for the case of A sub c = 0.001 meter/sq sec can be generalized for any other value of thrust acceleration by multiplying them by the factor 0.001/A sub c.

  18. Cenozoic thrust emplacement of a Devonian batholith, northeastern Brooks Range: Involvement of crystalline rocks in a foreland fold-and-thrust belt

    Energy Technology Data Exchange (ETDEWEB)

    Wallace, W.K.; Hanks, C.L. (Univ. of Alaska, Fairbanks (USA))

    1990-05-01

    Involvement of crystalline rocks in thrusting near the foreland basin of a fold-and-thrust belt is relatively uncommon. In the northeastern Brooks Range, the Devonian Okpilak batholith was thrust northward and structurally elevated above adjacent foreland basin deposits during Cenozoic fold-and-thrust deformation. The batholith may have acted initially as a regional structural buttress, but a drop in the basal detachment surface to greater depth south of the batholith resulted in northward transport of the batholith. Shortening within the batholith was accommodated by (1) the development of discrete thrust slices bounded by ductile shear zones, (2) simple shear and development of penetrative mesoscopic and microscopic fabrics throughout the batholith, or both. The Mississippian Kayak Shale, a regional detachment horizon at the base of the overlying cover sequence, is depositionally thin or absent adjacent to the batholith. Thus, most of the cover sequence remained structurally coupled to the batholith during thrusting and was shortened by the development of penetrative structures.

  19. Low-angle normal faults in the south-central Brooks Range fold and thrust belt, Alaska

    Energy Technology Data Exchange (ETDEWEB)

    Gottschalk, R.R.; Oldow, J.S.

    1988-05-01

    A north-south structural transect through the south-central Brooks Range, Alaska, exposes three lithologically distinct, fault-bounded packages of rock, all regionally metamorphosed during the Late Jurassic to Early Cretaceous contractional deformation that formed much of the Brooks Range fold and thrust belt. These are, from south to north and structurally highest to lowest, (1) the prehnite-pumpellyite facies ophiolitic rocks of the Angayucham terrane, (2) the low-grade metasedimentary rocks of the Rosie Creek allochthon, and (3) pumpellyite-actinolite to glaucophane-epidote facies metamorphic rocks of the schist belt. The presence of rocks metamorphosed and deformed at shallow levels of the fold and thrust belt (the Angayucham terrane and Rosie Creek allochthon) lying structurally above rocks representing the deepest exposed levels of the fold and thrust belt (the schist belt) indicates that the imbricate stack is disrupted by south-dipping, low-angle normal faults along the southern margin of the Brooks Range. The authors propose that normal faults developed in response to the uplift of the schist belt and the overlying metasedimentary and ophiolitic allochthons by north-directed thrusting in the late Early Cretaceous. Thrusting resulting in the oversteepening of the imbricate stack, causing compensatory normal faulting along the southern flank of the ramp structure. Normal faults may have provided at least local structural control of the locus of Albian and younger sedimentation in the Koyukuk basin. 34 references.

  20. Kinematic Analysis of the Almora Klippe: Testing Tectonic Models of the Himalayan Thrust Belt

    Science.gov (United States)

    Bosu, S.; Robinson, D. M.; Mamtani, M. A.; Bhattacharya, G.

    2016-12-01

    The Almora klippe is located in the Kumaun Himalaya, northwest India and continues east in the western Nepal as the Dadeldhura klippe. Rocks in the Almora klippe have a similar detrital zircon population and ɛ-Nd values to the Greater Himalayan rock north of the Main Central thrust and are either from the same thrust sheet or part of a similar Greater Himalayan thrust belt. During the development of the Lesser Himalayan duplex, this thrust sheet was folded by an antiformal duplex, leaving the klippe as an erosional outlier of Greater Himalayan rock. In this hypothesis, the fault on the north side of the klippe is a thrust. However, a recent study from the Dadeldhura klippe in western Nepal identified two separate shear zones north of the klippe. The shear zone to the south has top-to-the-north sense of shear and the shear zone to the north has top-to-the-south sense of shear. To determine which model is more accurate, we conducted field work and sampled north of the Almora klippe and towards east in the Dadeldhura klippe to identify the presence of shear zone(s) and the sense of shear. Only one shear zone was identified in the field in 3 transects north of the Almora klippe and 1 transect north of the Dadeldhura klippe. Shear sense indicators in outcrop and microscopic scales show top-to-the-south sense of shear, which matches with the general shear sense of the Main Central thrust. Electron Back-scatter Diffraction (EBSD) analysis is in progress to identify crystallographic deformation and compare that with microstructures.

  1. Evolution and Dynamics of a Fold-Thrust Belt: The Sulaiman Range of Pakistan

    Science.gov (United States)

    Reynolds, K.; Copley, A.; Hussain, E.

    2014-12-01

    Plan-view curvature of geological structures and range-front topography has long been a recognized and debated feature of both ancient and active fold-thrust belts. As part of the largest active mountain range on Earth, much of the body of work surrounding this topic has focused on the Tibetan Plateau. A lack of published data, extremely limited geodetic coverage and difficulty of access mean there have been relatively few studies of the western part of the India-Asia collision zone, where the Himalaya curve to the southwest into the lobate fold-thrust belts of Pakistan. The widest of these, the Sulaiman Range, forms a strongly curved lobe with ~300km across-strike width. We present observations and models of the Sulaiman Range of western Pakistan that shed new light on the evolution and deformation of fold-thrust belts. Earthquake source inversions show that the seismic deformation in the range is concentrated in the thick pile of sediments overlying the underthrusting lithosphere of the Indian subcontinent. The slip vectors of the earthquakes vary in strike around the margin of the range, in tandem with the shape of the topography, suggesting that gravitational driving forces arising from the topography play an important role in governing the deformation of the region. Numerical models suggest that the active deformation, and extreme plan-view curvature of the range, are governed by the presence of weak sediments in a pre-existing basin on the underthrusting Indian plate. These sediments affect the stress-state in the over-riding mountain range and allow for the rapid propagation of the nose of the range and the development of extreme curvature and laterally-varying surface gradients.

  2. Geodetic measurement of tectonic deformation in the Santa Maria Fold and Thrust Belt, California

    Science.gov (United States)

    Feigl, Kurt L.; King, Robert W.; Jordan, Thomas H.

    1990-01-01

    Geodetic observations taken over the last 100 years were analyzed to quantify active tectonic deformations in the Santa Maria Fold and Thrust Belt (SMFTB), California. Three different types of data were combined to estimate two-dimensioanl station positions and strain rate parameters simultaneously: (1) historical triangulation from the 1880s, 1920s, and 1950s; (2) electronic distance measurement trilateration from 1971 and 1985; and (3) GPS observations from 1986 and 1987. Results imply that the SMFTB is the primary active element in transforming motion from the Coast Ranges to the western Transverse Ranges and the Santa Barbara Channel.

  3. Shear zones of the Verkhoyansk fold-and-thrust belt, Northeast Russia

    Science.gov (United States)

    Fridovsky, Valery; Polufuntikova, Lena

    2017-04-01

    The Verkhoyansk fold-and-thrust belt is situated on the submerged eastern margin of the North Asian craton, and is largely composed of the Ediacaran - Middle Paleozoic carbonate and the Upper Paleozoic-Mesozoic terrigenous rocks. The Upper Carboniferous - Jurassic sediments constitute the Verkhoyansk terrigenous complex containing economically viable orogenic gold deposits. The structure of the belt is mainly controlled by thrusts and associated diagonal strike slips. Linear concentric folds are common all over the area of the belt. Shear zones with associated similar folds are confined to long narrow areas. Shear zones were formed during the early stages of the Oxfordian-Kimmeridgian collisional and accretionary events prior to the emplacement of large orogenic granitoid plutons. The main ore-controlling structures are shear zones associated with slaty cleavage, shear folds, mullion- and boudinage-structures, and transposition features. The shear zones are listric-type, and represent branches of a detachment structure, which is assumed to be present at the base of the Verkhoyansk fold-and-thrust belt. A vertical zonation of shear zones is correlated with the distance to the detachment. Changes in the dip angle of the shear zones (as indicated mainly by cleavage), structural paragenesis, the degree of microdeformation of the host rocks, and the type of ore-controlling structures can be clearly observed in the direction away from the detachment. Structural zoning is evidenced, among other things, by changing morphologic types of microstructures and by strain-indicators of the degree of rock metamorphism. Four morphologic types of microstructures are identified. The first platy-shear type is characterized by aggregate cleavage and the coefficient of deformation (Cd) of single grains from 1.0 to 2.0. Irregular angular fragments of variously oriented grains can be observed in thin sections. The second shear-cataclastic morphologic type (Cd from 2.0 to 3.0) exhibits

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

    Science.gov (United States)

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

    2010-05-01

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

  5. Structural model of the eastern Achara-Trialeti fold and thrust belt using seismic reflection profiles

    Science.gov (United States)

    Alania, Victor; Chabukiani, Alexander; Enukidze, Onise; Razmadze, Alexander; Sosson, Marc; Tsereteli, Nino; Varazanashvili, Otar

    2017-04-01

    Our study focused on the structural geometry at the eastern Achara-Trialeti fold and thrust belt (ATFTB) located at the retro-wedge of the Lesser Caucasus orogen (Alania et al., 2016a). Our interpretation has integrated seismic reflection profiles, several oil-wells, and the surface geology data to reveal structural characteristics of the eastern ATFTB. Fault-related folding theories were used to seismic interpretation (Shaw et al., 2004). Seismic reflection data reveal the presence of basement structural wedge, south-vergent backthrust, north-vergent forethrust and some structural wedges (or duplex). The rocks are involved in the deformation range from Paleozoic basement rocks to Tertiary strata. Building of thick-skinned structures of eastern Achara-Trialeti was formed by basement wedges propagated from south to north along detachment horizons within the cover generating thin-skinned structures. The kinematic evolution of the south-vergent backthrust zone with respect to the northward propagating structural wedge (or duplexes). The main style of deformation within the backthrust belt is a series of fault-propagation folds. Frontal part of eastern ATFTB are represent by triangle zone (Alania et al., 2016b; Sosson et al., 2016). A detailed study was done for Tbilisi area: seismic refection profiles, serial balanced cross-sections, and earthquakes reveal the presence of an active blind thrust fault beneath Tbilisi. 2 & 3-D structural models show that 2002 Mw 4.5 Tbilisi earthquake related to a north-vergent blind thrust. Empirical relations between blind fault rupture area and magnitude suggest that these fault segments could generate earthquakes of Mw 6.5. The growth fault-propagation fold has been observed near Tbilisi in the frontal part of eastern ATFTB. Seismic reflection profile through Ormoiani syncline shows that south-vergent growth fault-propagation fold related to out-of-the-syncline thrust. The outcrop of fault-propagation fold shown the geometry of the

  6. Comparison of fault-related folding algorithms to restore a fold-and-thrust-belt

    Science.gov (United States)

    Brandes, Christian; Tanner, David

    2017-04-01

    Fault-related folding means the contemporaneous evolution of folds as a consequence of fault movement. It is a common deformation process in the upper crust that occurs worldwide in accretionary wedges, fold-and-thrust belts, and intra-plate settings, in either strike-slip, compressional, or extensional regimes. Over the last 30 years different algorithms have been developed to simulate the kinematic evolution of fault-related folds. All these models of fault-related folding include similar simplifications and limitations and use the same kinematic behaviour throughout the model (Brandes & Tanner, 2014). We used a natural example of fault-related folding from the Limón fold-and-thrust belt in eastern Costa Rica to test two different algorithms and to compare the resulting geometries. A thrust fault and its hanging-wall anticline were restored using both the trishear method (Allmendinger, 1998; Zehnder & Allmendinger, 2000) and the fault-parallel flow approach (Ziesch et al. 2014); both methods are widely used in academia and industry. The resulting hanging-wall folds above the thrust fault are restored in substantially different fashions. This is largely a function of the propagation-to-slip ratio of the thrust, which controls the geometry of the related anticline. Understanding the controlling factors for anticline evolution is important for the evaluation of potential hydrocarbon reservoirs and the characterization of fault processes. References: Allmendinger, R.W., 1998. Inverse and forward numerical modeling of trishear fault propagation folds. Tectonics, 17, 640-656. Brandes, C., Tanner, D.C. 2014. Fault-related folding: a review of kinematic models and their application. Earth Science Reviews, 138, 352-370. Zehnder, A.T., Allmendinger, R.W., 2000. Velocity field for the trishear model. Journal of Structural Geology, 22, 1009-1014. Ziesch, J., Tanner, D.C., Krawczyk, C.M. 2014. Strain associated with the fault-parallel flow algorithm during kinematic fault

  7. Two stages of deformation and fluid migration in the central Brooks Range fold-and-thrust belt

    Science.gov (United States)

    Moore, Thomas E.; Potter, Christopher J.; O'Sullivan, Paul B.; Shelton, Kevin L.; Underwood, Michael B.

    2004-01-01

    The Brooks Range is a north-directed fold and thrust belt that forms the southern boundary of the North Slope petroleum province in northern Alaska. Field-based studies have long recognized that large-magnitude, thin-skinned folding and thrusting in the Brooks Range occurred during arc-continent collision in the Middle Jurassic to Early Cretaceous (Neocomian). Folds and thrusts, however, also deform middle and Upper Cretaceous strata of the Colville foreland basin and thus record a younger phase of deformation that apatite fission-track data have shown to occur primarily during the early Tertiary (~60 and ~45 Ma). A structural and kinematic model that reconciles these observations is critical to understanding the petroleum system of the Brooks Range fold and thrust belt.

  8. Exhuming retroarc fold-and-thrust belts: a comparison between the southern Patagonian Andes and the Argentine Precordillera

    Science.gov (United States)

    Fosdick, J. C.

    2014-12-01

    Detailed constraints on erosional flux are critical for understanding how exhumational processes control and respond to tectonic events in orogenic belts. This work compares the thermochronologic record and erosional behavior of retroarc thrust belts at two latitudes in the Andes with contrasting Cenozoic climate and deformational records: the glaciated southern Patagonian Andes and the semiarid Argentine Precordillera of the Central Andes. Both regions have undergone crustal shortening during Andean growth and have been affected by thermotectonic processes associated with subduction of oceanic ridges; the Chile Ridge spreading center and Juan Fernández Ridge, respectively. In Patagonia, deep erosion occurred during Miocene retroarc deformation. Zircon He thermochronology documents regional cooling and unroofing of the thrust belt ~22-17 Ma. This behavior likely reflects an upper plate manifestation of incipient subduction of the Chile Ridge spreading center and enhanced unroofing during thermally driven regional uplift. Late Cenozoic expansion of the Patagonian icesheet led to further excavation of the thrust belt, indicating a strong climatic overprinting on thrust belt erosional behavior. In contrast, less overall Cenozoic exhumation is observed in the Argentine Precordillera, despite high strain and crustal thickening. Pre-Jurassic zircon He dates from the Paleozoic strata within thrust sheets suggest Cenozoic Andean deformation was insufficient to exhume rocks from beneath the zircon He closure depth. The apatite He record shows a close correlation between thrust faulting and locus of erosion, and document eastward in-sequence rock cooling from 16 to 2 Ma across the Precordillera tracking with the progressive faulting of the Blanca, San Roque, and Niquivil thrust faults during this time. Pliocene apatite He dates located along the external margins of the Precordillera suggest that the most recent cooling and unroofing is associated with both out

  9. Geodetic measurement of tectonic deformation in the Santa Maria Fold and Thrust Belt, California

    Energy Technology Data Exchange (ETDEWEB)

    Feigl, K.L.; King, R.W.; Jordan, T.H. (Massachusetts Inst. of Tech., Cambridge (United States))

    1990-03-10

    The authors have analyzed geodetic observations to resolve tectonic deformation across the Belt, northwest of Santa Barbara, California. The data include (1) historical triangulation from the 1880s, 1920s and 1950s; (2) electronic distance measurement trilateration from 1971 and 1985; and (3) Global Positioning System observations from 1986 and 1987. They combine the three different types of data to estimate two-dimensional station positions and strain rate parameters simultaneously. Using a model which constrains the relative velocity field to be linear in space and constant in time, they find significant strain rates. The maximum compressive strain is oriented N17{degree}E {plus minus} 5{degree}E, and the compressive strain rate in this direction is 0.13 {plus minus} 0.03 {mu}strain/yr. Under the assumption that the unresolved rotational component of the velocity field is zero, they estimate that the integrated rate of deformation across the basin is 7 {plus minus} 1 mm/yr oriented at N 03{degree}E {plus minus} 13{degree}. This vector can be decomposed into 6 {plus minus} 2 mm/yr of crustal shortening on the general structural trend of N 30{degree}E and 3 {plus minus} 1 mm/yr of right-lateral shear across this axis. On the basis of these values and earthquake focal mechanisms in the area, they infer that the deformation occurs on northwest trending folds and thrusts within the belt. These results are consistent with the rate and direction of deformation across the central California Coast Ranges inferred by balancing Pacific-North America plate motion against San Andreas slip and Basin and Range extension. They imply that the Santa Maria Fold and Thrust Belt is the primary active element in transforming motion from the Coast Ranges to the western Transverse Ranges and the Santa Barbara Channel.

  10. Geometry and Kinematics of Tumuxiuke Fold and Thrust Belt in Bachu Uplift, Tarim Basin

    Science.gov (United States)

    Song, Z.; Tang, L.

    2016-12-01

    Bachu uplift, mainly characterized by a series of out-of-sequence basement involved structures, is a large scale Cenozoic structural unit located in the west of Tarim basin. The NW-SE oriented, arc shaped Tumuxiuke fold and thrust belt (TFTB), which is roughly 200km in length, constrains the northern boundary of Bachu uplift. Based on multiple 2D seismic reflection profiles, we analysed the differences in structural styles along the strike of TFTB. It is mainly consist of several basement involved thrust faults and associated folds (or monoclines). The western segment of TFTB is characterized by a single basement involved structure; as to the middle segment, there is also backthrust branching from the main basement involved structure; in contrast, the eastern segment is consist of basement involved contractional wedge structures. According to the analysis of stratigraphy involved in deformation, fault slip and growth strata, we summarized that the TFTB mainly constructed by the compressional stress during late Miocene Himalayan orogency. Then, we analyzed the kinematics of TFTB with trishear fault propagation folding model. It is suggested that the initial fault tip that located below the basement-cover contact began to propagate during the late Miocene epoch and the propagation to slip ratio (P/S) also changes along strike. At the early stage of compression, the P/S was low and sedimentary cover mainly folded; then, the thrust faults of western segment and middle segment propagated rapidly with high P/S ratio and broke through early formed folds into Neogene strata; but in the eastern segment, the main thrust fault pinch out in the thick gypsum salt layer of middle Cambrian and the sedimentary cover decoupled from basement. About the genesis of basement-involved structures of TFTB in the intracontinent circumstance, we consider the effect of positive inversion of late Proterozoic-early Palaeozoic rift which requires further evidences.

  11. The Formation of a Retroarc Fold-Thrust Belt by the Closure and Inversion of a Back-Arc Basin; Patagonian-Fuegian Fold-Thrust Belt, Chile

    Science.gov (United States)

    Betka, P.; Klepeis, K. A.; Mosher, S.

    2012-12-01

    The Late Cretaceous closure and inversion of the Late Jurassic Rocas Verdes back-arc basin (RVB) defines the onset of the Andean orogeny and the development of the Patagonian retroarc fold-thrust belt (FTB) between 50°-54.5° S. Back-arc extension in the RVB led to the generation of new oceanic crust that was coeval with the deposition of syn-rift silicic volcanoclastic rocks on the continental margin. A > 500 m thick succession of mudstone and distal turbidite deposits accumulated in the RVB (post-rift). New maps and line-balanced cross-sections from three transects across the FTB show a transition through time from thin-to thick-skinned structural styles that is controlled by the inherited stratigraphic architecture and structure of the RVB. The closure of the RVB and development of the FTB occurred in two stages. During the initial stage, mafic schist, gabbro, basalt, and hemipelagic mudstone of the RVB floor were imbricated and thrust onto the continental margin resulting in the formation of the Magallanes foreland basin and underthrusting of the continental crust to depths of ~ 35 km. Displacement from the obduction of the RVB was transferred along two decollement levels into the FTB by ~85 Ma. Each decollement level formed at a rheological boundary within the syn- and post-rift stratigraphy. The lower decollement formed in quartz-chlorite schist (basement) > 1 km beneath the top-basement contact with relatively strong syn-rift volcanoclastic deposits. The lower decollement is defined by a ~1 km thick ductile shear zone. C-S fabrics, C-C' shear bands and prominent SW plunging quartz stretching lineations that occur within the shear zone indicate a top-NE transport direction. Isoclinal recumbent F2 folds and inclined tight F3 folds refold the S1/L1 surface. The decollement cuts up-section through the syn-rift volcanoclastic deposits to join a structurally higher decollement that formed within weak, post-rift mudstone and turbidite deposits on the continental

  12. Style, magnitude, and timing of shortening at the eastern end of Kura fold-thrust belt, Azerbaijan

    Science.gov (United States)

    Forte, A. M.; Cowgill, E.; Murtuzayev, I.

    2010-12-01

    Although the Greater Caucasus forms the northern edge of the Arabia-Eurasia collision, the main locus of shortening has shifted south since 5 Ma, producing the Kura fold-thrust belt in Georgia and Azerbaijan. Eastward-decreasing structural complexity and depth of exposure within the thrust belt suggest eastward propagation of faulting. Two topographic features define the eastern termination of the Kura fold-thrust belt at ~48°E: a southern range front exposing south-directed, closely spaced (back thrust. To determine the style, magnitude, and timing of shortening at the east end of the fold-thrust belt, we conducted 1:100K-scale structural mapping covering ~1000 ~km^2 of this region. Along-strike changes in structural geometry divide the map area into two structural domains, the Surxayxan in the west and the Qaramaryam to the east. The Surxayxan domain (47.5°E to 47.8°E) is characterized by two main, north-dipping thrusts, the Savalan to the north and Agcayazi ~4-6 km to the S. At maximum displacement the Savalan thrust places Apsheron sediments over Baku-Khazar deposits, repeating ~2 km of section. The hanging wall anticline of the Savalan thrust is poorly preserved, but a footwall syncline occurs along its full length. The Agcayazi thrust defines the southern range front in this domain, characterized by exposures of Apsheron sediments with the overturned forelimb of the hanging wall anticline preserved in limited areas, but no definitive exposure of the thrust. The Qaramaryam structural domain (47.8°E to 48.3°E) is characterized by the eastwards termination of the Agcayazi thrust and transfer of slip to the north-dipping Padar and Inca thrusts to the south, which together form the Qaramaryam anticline. The latter two thrusts are separated by ~4 km and expose the top of the Apsheron at their maximum displacements but mostly deform Baku-Khazar sediments. In both domains, fold geometries are consistent with a trishear model. Preliminary balanced cross sections

  13. Comment on "Sandbox modeling of evolving thrust wedges with different preexisting topographic relief: Implications for the longmen Shan thrust belt, eastern Tibet" by C. Sun et al.

    Science.gov (United States)

    Tan, Xibin; Xu, Xiwei; Lu, Renqi

    2017-02-01

    Sun et al.'s (2016) sandbox modeling takes preexisting topographic relief into account for faulting activity at the compressional orogenic belt, which promotes better understanding of Longmenshan thrust belt's (LTB) orogenic process and faulting behavior. However, topographic relief in sandbox modeling is contradictory to central LTB's actual topographic relief, and as a result, both the comparison between sandbox modeling and actual tectonics and topography and the conclusion that Xiaoyudong Fault is a tear fault should be reconsidered. Actually, based on Sun et al.'s (2016) sandbox modeling, the Xiaoyudong Fault cannot be treated as a tear fault.

  14. Assessment of undiscovered conventional oil and gas resources in the Wyoming Thrust Belt Province, Wyoming, Idaho, and Utah, 2017

    Science.gov (United States)

    Schenk, Christopher J.; Mercier, Tracey J.; Tennyson, Marilyn E.; Woodall, Cheryl A.; Brownfield, Michael E.; Le, Phuong A.; Klett, Timothy R.; Gaswirth, Stephanie B.; Finn, Thomas M.; Marra, Kristen R.; Leathers-Miller, Heidi M.

    2018-02-16

    Using a geology-based assessment methodology, the U.S. Geological Survey estimated mean undiscovered, technically recoverable resources of 26 million barrels of oil and 700 billion cubic feet of gas in the Wyoming Thrust Belt Province, Wyoming, Idaho, and Utah.

  15. The contribution of 3D restoration for the reconstruction of pre-thrusting basin geometries in fold-and-thrust belts

    Science.gov (United States)

    Aquè, R.; Tavarnelli, E.

    2012-04-01

    The three-dimensional (3D) reconstruction of complex geological settings and of original, pre-thrusting basin geometry is one of the challenges for modern structural geology. It has indeed a critical role in many industrial applications, such as in the hydrocarbon exploration. By using commercial specific softwares to produce balanced cross-sections and inferred 3D reconstructions (2DMove™, Gocad™), we modelled a portion of the Umbria-Marche fold-and-thrust belt, in the outer zones of the Northern Apennines of Italy, in order to infer the pre-thrusting geometry of the Mesozoic-Cenozoic extensional basins and to test the applicability of existing computer tools in areas that have experienced the effects of positive tectonic inversion. In the study area, the accurate reconstruction of the structural setting, cross-cut relationships and timing of the deformation, was inferred by using field data, map analysis and cross-section balancing techniques. The structural overprinting relationships among the investigated thrusts made it possible to infer a general piggy-back thrusting sequence, with new thrust faults to the East, developed in the footwall of formerly emplaced thrust sheets, in the West. This allowed to sequentially remove the effects of the deformation for progressively older structures, and to back-strip the thrust sheets in sequential evolutionary steps, in order to reconstruct a viable pre-thrusting template. Four balanced cross-sections have been drawn, providing the initial skeleton for 3D modelling, together with the map trace of the major tectonic features. The cross-sections and the geological map have been digitized and geo-referred in 2D-Move™. Starting from the inferred geometries, a coherent 3D model was built in Gocad™. The surfaces represent post-thrust normal faults, thrust planes, and pre-thrust normal faults, and five key stratigraphic surfaces, from bottom; the base and top of the Calcare Massiccio fm. (Lower Liassic), the base of the

  16. Mechanical analysis of fault activation in southern Longmen Shan fold-and- thrust belt

    Science.gov (United States)

    Zhang, Zhen; Zhang, Huai; Wang, Liangshu; Shi, Yaolin; Leroy, Yves M.

    2017-04-01

    A mixed fault activation mode with obvious hinterland rupture in the southern Longmen Shan, the eastern margin of Tibetan Plateau, is revealed by recent 2008 Mw7.9 Wenchuan and 2013 Mw6.6 Lushan earthquakes together with GPS measurements. How to systematically understand the coexistence and competition mechanisms of fault activation, especially the principal-subordinate relationship on deformation absorption, in essence, involves mechanical onset analysis of this fold- and-thrust belt. However, due to the two-décollement- level thrust system with active 'flat-ramp- flat' geometry décollement, the predication of fault activation in the LMS has beyond the scope of Critical Coulomb wedge theory, not to mention the synchronous listric-type splay fault rupturing in the Beichuan fault (BCF) and Pengguan fault (PGF). For that purpose, we adopted maximum strength theorem, the kinematic approach of limit analysis, to deal with mechanical analysis of fault activation. Four end-member failure modes, or collapse mechanisms (CMs) in classical limit analysis, are proposed corresponding to the rupture of BCF, PGF, Range Frontal Blind Fault (RFBF) and the rupture of the flat-ramp- flat décollement into Sichuan Basin via RFBF. By selecting the available CMs via finite element limit analysis, the listric geometry of BCF and PGF is demonstrated to the dominant factor in trapping deformation in the hinterland. To activate the high-angle Beichuan splay fault, low cohesion and low friction angle on the BCF are combined effects on the rupturing of BCF. The change in cohesion and friction on BCF eventually forms the transition state between high angle BCF and low-angle PGF. Besides, due to the existence of low frictional upper décollement layer in Sichuan Basin (the Triassic evaporate layer), small amount of deformation is attracted into the Sichuan Basin forming small-scale thrusting folding. Moreover, favorable deformation migration toward Sichuan Basin is jointly influenced by

  17. Comparing spatial patterns of thrust belt architecture and bedrock river morphology across the southern Bolivian Andes

    Science.gov (United States)

    Syrek, J. F.; Barnes, J. B.

    2011-12-01

    Rivers set the pace of mountain landscape evolution, but their ability to incise into rock is often governed by numerous factors. The degree to which variations in lithology, relief, rock uplift rates, and climate may affect the form of channel profiles remain largely open questions. Empirical models of bedrock river incision, such as stream power (E = KAmSn), oversimplify these potentially important factors. For example, the influence of many factors such as channel geometry, hydraulic roughness, sediment flux, and substrate erodibility are combined into the coefficient of erosion, K. Here we investigate the spatial patterns of rock erodibility, bedrock river slope, concavity, and stream power-based estimates of incision across the southern Bolivian Andes. We hypothesize that bedrock river morphology correlates with the thrust-belt geology. For example, channels cutting through the strongest and least fractured rock units will exhibit the highest steepness values. We estimate rock erodibility by measuring (a) compressive rock strength with a Schmidt hammer and (b) fracture density from exposures proximal to river channels at ~80 total sites from all the major rock units exposed throughout the study area. We use a hydrologically-conditioned 90 m digital elevation model to map patterns of channel steepness (ksn) and concavity (θ) indices. Furthermore, we use the stream power model, combined with a previous local calibration of K, to estimate patterns of river incision along the study area rivers. The combined strength and fracture density measurements suggest the Neogene volcanics, Cretaceous sediments, and Devonian metasediments are the least erodible units and the Silurian and Ordovician metasediments are the weakest. In general, changes in channel steepness often correlate with (1) changes in rock erodibility, (2) high rock uplift rates associated with active structures in the Subandes, and (3) the major hinterland structural transition between the Eastern

  18. Deformation of Fold-and-Thrust Belts above a Viscous Detachment: New Insights from Analogue Modelling Experiments

    Science.gov (United States)

    Nogueira, Carlos R.; Marques, Fernando O.

    2015-04-01

    Theoretical and experimental studies on fold-and-thrusts belts (FTB) have shown that, under Coulomb conditions, deformation of brittle thrust wedges above a dry frictional basal contact is characterized by dominant frontward vergent thrusts (forethrusts) with thrust spacing and taper angle being directly influenced by the basal strength (increase in basal strength leading to narrower thrust spacing and higher taper angles); whereas thrust wedges deformed above a weak viscous detachment, such as salt, show a more symmetric thrust style (no prevailing vergence of thrusting) with wider thrust spacing and shallower wedges. However, different deformation patterns can be found on this last group of thrust wedges both in nature and experimentally. Therefore we focused on the strength (friction) of the wedge basal contact, the basal detachment. We used a parallelepiped box with four fixed walls and one mobile that worked as a vertical piston drove by a computer controlled stepping motor. Fine dry sand was used as the analogue of brittle rocks and silicone putty (PDMS) with Newtonian behaviour as analogue of the weak viscous detachment. To investigate the strength of basal contact on thrust wedge deformation, two configurations were used: 1) a horizontal sand pack with a dry frictional basal contact; and 2) a horizontal sand pack above a horizontal PDMS layer, acting as a basal weak viscous contact. Results of the experiments show that: the model with a dry frictional basal detachment support the predictions for the Coulomb wedges, showing a narrow wedge with dominant frontward vergence of thrusting, close spacing between FTs and high taper angle. The model with a weak viscous frictional basal detachment show that: 1) forethrusts (FT) are dominant showing clearly an imbricate asymmetric geometry, with wider spaced thrusts than the dry frictional basal model; 2) after FT initiation, the movement on the thrust can last up to 15% model shortening, leading to great amount of

  19. The effects of plate margin inhomogeneity on the deformation pattern within west-Central Zagros Fold-and-Thrust Belt

    Science.gov (United States)

    Malekzade, Zaman; Bellier, Olivier; Abbassi, Mohammad Reza; Shabanian, Esmaiel; Authemayou, Christine

    2016-12-01

    Zagros Folded and thrust Belt (ZFTB) is a Cenozoic mountain belt in SSW of Iran and northeast of Arabia that resulted from closure of Neo-Tethys and collision between Arabia passive margin and Central Iran active margin. At this tectonic grain of Alp-Himalayan chain, change of the tectonic regime, degree of basement involvement, and character of accommodation of the deformation, in time and space, has been under debate. The results show that the deformation along the Zagros is not uniformly accommodated. Although the researchers have already paid attention to basement involvement in addition to the sedimentary cover rocks, little has been shown on the role of the basement's rigidity and lower crust's rheology on the deformation pattern along and across the belt. This study tries to address these questions in terms of inversion of slip vector of basement earthquakes, measurement of fault-slip data on the cover rocks, geomorphic and field observations, and existing geodetic and gravity data, with especial focus on Dezful embayment and surrounding area. The results show the Dezful embayment plays an indenter role. It, with the other reentrants, changes the obliquity of Arabian plate convergence, facilitates the escape of the upper crust toward free mechanical boundaries in salients, controls the slip-rate of Zagros Main Recent Fault at the rear of the belt and contributes in forming Zagros Fold-and-Thrust Belt as an orocline. The viscous lower crust helps the strain partitioning by providing a ductile shear base under the rigid upper crust.

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

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    A. V. Marinin

    2013-01-01

    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.  

  1. Multi-scale seismic reflection imaging of active fold-and-thrust belts in Niigata backarc basin in central Japan

    Science.gov (United States)

    Ishiyama, T.; Kato, N.; Sato, H.; Takeda, T.; Abe, S.

    2012-04-01

    Structural characters of en echelon, active fold and thrust structures in backarc, thick sedimentary basins and their structural links to deeper structures are commonly complicated, depending on inherited structural and mechanical factors including their kinematic histories, present and past sedimentary environments, volcanisms, fault reactivation, and thermal and/or dynamic subsidence. In this study we present multi-scale seismic reflection profiles across active fold-and-thrust belts in Niigata backarc basin in central Japan to analyze their structures from shallow to otherwise inaccessible deeper levels. Niigata basin is underlain by ca. 8-km-thick Neogene sediments, which are deformed by highly active fold-and-thrust belts, where large devastating earthquakes have occurred in these several hundred years. Deep seismic reflection profile (2010 Mishima-Higashiyama Line) across the 2007 Chuetsu-oki earthquake (M6.8) source region illuminates highly complicated fold-and-thrust structures. Pairs of west-dipping thrusts merge into a shallow, easterly dipping thrust fault, on which the mainshock of the 2007 earthquake was located. In addition, decollement folding enhanced by over-pressured Miocene mudstone on the hangingwall of the deeper thrust also complicates styles of deformation at higher structural levels. In spite of these structural complexities, tight structural and stratigraphic constraints on the seismic reflection profile by rich dataset of industrial boreholes provide west-dipping thrust trajectories sole into the deeper thrust at depth of ca. 10 km. We also collected and processed shallow high-resolution seismic reflection data in order to resolve shallow structures and to understand structural linkage between active faults and folds recognized at ground surface and deeper, complicated fold and thrust structures. We deployed 200 seismic channels, 10-Hz geophones, and mini-vibrator as a seismic source along about 7-km-long seismic line. Common midpoint

  2. Growth stratal records of instantaneous and progressive limb rotation in the Precordillera thrust belt and Bermejo basin, Argentina

    Science.gov (United States)

    Zapata, TomáS. R.; Allmendinger, Richard W.

    1996-10-01

    Analysis of synorogenic deposits preserved near the thrust front zone of the Precordillera fold and thrust belt and in the Bermejo foreland basin in central Argentina documents the evolution of deformation during the last 5 Myr as well as the thrust system kinematics. Seismic lines across the area display examples of progressive and instantaneous limb rotations. The easternmost thrust plate of the Central Precordillera, the Niquivil thrust, experienced episodic motion in two main stages: a first thrust movement as a fault-propagation fold and a second movement as a high-angle anticlinal breakthrough fault after a period of quiescence. Growth strata deposited in the La Pareja intermontane basin and the Las Salinas and Bermejo anticline recorded continuous growth of Eastern Precordilleran structures beginning at ˜2.7 Ma, with uplift rates of ˜0.3 mm/yr for the Niquivil anticline, 1.08 mm/yr for the Las Salinas anticline, and between ˜0.6 and 0.38 mm/yr during the last ˜2 Myr for the Bermejo anticline. Once the Eastern Precordillera began to grow, the propagation of the Niquivil thrust stopped, restricting the deformation to the young Vallecito out-of sequence thrust. The complex geometry of growth strata deposited on the back limb of the Las Salinas anticline can be explained by using a model of a two-step fault propagation fold with constant layer thickness. The Bermejo anticline of the Eastern Precordillera is formed by the simultaneous propagation of a shallow fault, responsible for the fold shape, and a deep fault that produced vertical uplift. A growth triangle that documents instantaneous forelimb rotation for a fault-propagation fold is recorded for the first time in a published seismic line.

  3. Constraining thrust-belt thermal histories from partially reset zircon (U-Th)/He datasets: An "inheritance envelope" approach with examples from the Sevier belt of central Utah

    Science.gov (United States)

    Guenthner, W.; Reiners, P. W.; DeCelles, P. G.; Kendall, J. J.

    2015-12-01

    Low-temperature thermochronology has become an established tool for deciphering the time-temperature (t-T) histories of sedimentary units involved in basin burial and thrust-belt exhumation. However, thermochronologic datasets from detrital samples can be complex and difficult to interpret if these samples contain grains with different pre-depositional t-T histories that are only partially reset. Here, we present an approach for interpreting complex detrital zircon (U-TH)/He datasets to constrain the maximum foreland basin burial temperatures and timing of thrust-belt related exhumation in the Sevier belt of central Utah. Using forward modeling of t-T paths, we combine the radiation-damage based kinetic model for He diffusion in zircon with a series of pre-depositional He ages to construct "inheritance envelopes" that encompass a wide range of age variation. A forward model is successful if an inheritance envelope captures or bounds the observed age variation in a given dataset. We highlight this approach with two datasets collected from sedimentary units in the Oquirrh Mountains and Wasatch Range near Provo, UT. For the Oquirrh Mtns. dataset, large observed age variation is modeled using a maximum burial temperature of ~173 °C, and an initial Sevier-belt related exhumation event at 110 Ma. The Wasatch Range samples are more straight-forward, with a lack of partially reset ages but some observed variation caused by radiation damage effects. For these samples, our model results constrain a maximum burial temperature of ~230 °C, with a subsequent exhumation event at 100 Ma. Combined, these results suggest a steady eastward migration of exhumation in the Sevier belt during the Late Cretaceous and demonstrate that our inheritance envelope approach is most sensitive to maximum burial temperatures and the timing of initial exhumation.

  4. Overburden and physical properties in the Marathon fold and thrust belt, West Texas, using conodont thermal maturity and vitrinite reflectance

    Energy Technology Data Exchange (ETDEWEB)

    Merrifield, G.T. Jr. (Texas A and M Univ., College Station, TX (United States). Center for Tectonophysics and Ocean Drilling Program)

    1992-01-01

    Distribution of Ordovician conodonts used in this study covers the southern two-thirds of the 2,400 km[sup 2] in the exposed thrust belt. Conodont color alteration indices (CAI) vary from 1.5 in the northwest to 3.0 eastward and 4.0--4.5 in the extreme southeast. These variations correlate with the 3 km increase in stratigraphic overburden from west to east in the accretionary rocks (Mississippian to Mid Pennsylvanian). In the western exposures, CAI increase southward to 2.0--2.5 within the Dagger Flat structural culmination and decrease to 1.0--1.5 further southward. Increased overburden due to structural thickening explains the CAI increase within the culmination. In the northern one-third of the exposed thrust belt, CAI from the Dimple formation (Mid Pennsylvanian) decrease northward from 2.5 to 1.0--1.5. Neither restored stratigraphic overburden nor local intrusions explain the elevated CAI value of 2.5. Extrapolation of the vitrinite reflectance gradient to the 0.2% value in a well less than 10 km east of this location indicate that between 2.5 and 4.3 km of overburden has been eroded. Structural thickening accounts for at least some of the elevated thermal maturity in this area. Vitrinite reflectance gradients are greater in the accretionary prism strata than in the older basinal facies (Upper Cambrian to Lower Mississippian). Since both facies are shale-rich, lithology alone plays little role in thermal conductivity and maturity variations. Instead, the age of compaction (and possibly undercompaction) relative to the times of thrusting subaerial exposure and erosion, and preservation of maximum thermal maturity are a more important factor. There is a slight discontinuous increase in the thermal maturity across the basal thrust, which is not explained by lithologic variations. Above and below the basal thrust, vitrinite gradients increase and is best explained by induced fracture permeability and flow of hot fluids.

  5. Deformation along a salient-transverse zone junction: An example from the Leamington transverse zone, Utah, Sevier fold-thrust belt (USA)

    Science.gov (United States)

    Ismat, Zeshan; Toeneboehn, Kevin

    2015-06-01

    Within fold-thrust belts, the junctions between salients and recesses may hold critical clues to the overall kinematic history of fold-thrust belts. The deformation history within these junctions is best preserved in areas where thrust sheets extend from a salient through an adjacent recess. We examine one such junction within the Sevier fold-thrust belt (western United States) along the Leamington transverse zone, northern Utah. The Canyon Range thrust sheet can be traced continuously from the Leamington transverse zone to its adjacent salient to the south, the Central Utah segment. Deformation within the Canyon Range thrust sheet took place by faulting and cataclastic flow. Analyses of these fault networks preserved throughout the Canyon Range thrust sheet are used to develop a kinematic history of the Leamington transverse zone. Field data is supplemented by analog sandbox experiments. This study suggests that, in detail, deformation within the overlying thrust sheet may not directly reflect the underlying basement structure. Moreover, these junctions may contain several types of accommodating structures that helped to maintain critical-taper and that serve as potential targets for natural resource exploration.

  6. Contemporary deformation in the Yakima fold and thrust belt estimated with GPS

    Science.gov (United States)

    McCaffrey, Robert; King, Robert W.; Wells, Ray E.; Lancaster, Matthew; Miller, M. Meghan

    2016-10-01

    Geodetic, geologic and palaeomagnetic data reveal that Oregon (western USA) rotates clockwise at 0.3 to 1.0° Ma-1 (relative to North America) about an axis near the Idaho-Oregon-Washington border, while northeast Washington is relatively fixed. This rotation has been going on for at least 15 Ma. The Yakima fold and thrust belt (YFTB) forms the boundary between northern Oregon and central Washington where convergence of the clockwise-rotating Oregon block is apparently accommodated. North-south shortening across the YFTB has been thought to occur in a fan-like manner, increasing in rate to the west. We obtained high-accuracy, high-density geodetic GPS measurements in 2012-2014 that are used with earlier GPS measurements from the 1990s to characterize YFTB kinematics. The new results show that the deformation associated with the YFTB starts at the Blue Mountains Anticline in northern Oregon and extends north beyond the Frenchman Hills in Washington, past the epicentre of the 1872 Mw 7.0 Entiat earthquake to 49°N. The north-south strain rate across the region is 2 to 3 × 10-9 yr-1 between the volcanic arc and the eastern edge of the YFTB (241.0°E); east of there it drops to about 10-9 yr-1. At the eastern boundary of the YFTB, faults and earthquake activity are truncated by a north-trending, narrow zone of deformation that runs along the Pasco Basin and Moses Lake regions near 240.9°E. This zone, abutting the Department of Energy Hanford Nuclear Reservation, accommodates about 0.5 mm yr-1 of east to northeast shortening. A similar zone of N-trending transpression is seen along 239.9°E where there is a change in the strike of the Yakima folds. The modern deformation of the YFTB is about 600 km wide from south to north and internally may be controlled by pre-existing crustal structure.

  7. Thrust belt advance versus sediment-flux steering - Late Pleistocene river migrations in the southern Caucasus

    Science.gov (United States)

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

    2017-04-01

    One response of rivers toward allogenic controls is 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. Sediment-flux steering, i.e. a lateral shift of rivers against a tectonically driven subsidence trend promoted by transverse sediment discharge exerts such control. Evidence for this mechanism to operate stems from numerous field and experimental studies in extensional settings, characterized by commonly small-sized transverse catchments compared with that of the main river and/or volcaniclastic sedimentation. For the first time, this study investigates sediment-flux steering in a contractional tectonic setting with relatively large-sized transverse catchments compared with that of the main river. Geomorphologic, geochronologic, and heavy mineral provenance analyses were complemented with tectonomorphometric data to investigate late Quaternary channel migrations of the Kura River in the southern foreland basin of the Greater Caucasus. Large-scale migrations of the course of the Kura River during the late Quaternary reflect the interplay between a continuing southwestward advance of the Kura Fold-and-Thrust-Belt, leading to uplift in the NE and by 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 follow its tectonically driven trend toward the southwest. In contrast, during generally colder periods such as the upper late Pleistocene, sediment-flux steering caused by aggradation of the transverse rivers forced the main Kura River to migrate >10 km against that tectonically induced trend toward the northeast. Generally, besides improving our understanding of the coupling between

  8. Implications from deepwater depositional elements in the fold-and-thrust belt of the remnant ocean basin offshore SW Taiwan

    Science.gov (United States)

    Lin, Liang-Fu; Liu, Char-Shine; Chang, Jih-Hshin

    2017-04-01

    The northeastern South China Sea Basin is being closed due to the oblique collision between the Luzon Volcano Arc and the Chinese Continental Margin. The orogen of Taiwan Island situated in the tropical/subtropical zone with a high uplifting rate provides voluminous sediments to the nearby basins. As a remnant ocean basin, the closing basin in offshore southwestern Taiwan has accommodated a large amount of synorogenic sediments. Through multi-channel seismic profiles, several depositional elements in the deepwater fold-and-thrust belt of the lower Gaoping slope have been identified. These sedimentary layers were deposited before deformation and later incorporated into the orogenic wedge. The N-S trend leveed channels developed along the strike of the orogenic wedge and occupied the most area of the lower Gaoping Slope. This channel-levee complex presents the ancient fan which should relate to the Penghu submarine canyon, named "Penghu Turbidite System". In contrast, at the mouth of the middle section of the Gaoping Submarine Canyon, the buried channels trend SW-NE are characterized by massive high amplitude reflection packets (HARPs) which may represent the coarse grain infills. This facies turns to channelized lobes outward that interfinger with the Penghu Turbidite System. Two different characteristics of submarine fans reflect the different natures of Penghu and Gaoping submarine canyons. Since the tectonic convergence approaching, these two canyons rejuvenated and started to erode the aforementioned deposits. The channels become erosional in the fold-and-thrust belt that most of the sediments bypass through the fold-and-thrust belt or spill into the piggyback accommodations. The newly discovered sedimentary records in this study imply how these two sediment dispersal systems work before and after structuring, which is a puzzle for better understanding the sedimentary history of the remnant ocean basin offshore southwestern Taiwan.

  9. Geometric and kinematics of West Segment of South Dabashan Foreland Fold-and-Thrust Belt, Northeast Sichuan Basin, China

    Science.gov (United States)

    He, Dengfa

    2017-04-01

    The west segment of South Daba Shan (WSD) foreland thrust belt is an ideal area to disclose the intra-continental tectonic processes. Based on the latest pre-stack depth migration of 3-D seismic data, 2-D seismic profile, well data and geological outcrop, the paper explore the structural geometric and kinematic features of WSD with the application of fault-related folding theories. WSD is characterized by multi-level detachment deformation due to the three predominant sets of weak layers, Lower Triassic Jialingjiang Formation gypsum interval, Silurian mudstone beds and Cambrian shale zone. It is accordingly subdivided vertically into three tectonic systems. The upper one is above the Jialingjiang Formation gypsolith layer and presents a Jura-like fold-and-thrust belt. The middle one takes Silurian shale as the base and Jialingjiang Formation gypsolith interval as the passive roof, in which imbricate thrusts developed. The lower one is bounded to Cambrian and Silurian detachment layers, in which duplex dominated. The Sinian and Proterozoic basements below Cambrian have not been involved in deformation. WSD underwent four periods of tectonic evolution: Late Jurassic -Cretaceous (150-110Ma); Late Cretaceous (110-70Ma); Latest Cretaceous to Paleogene (70-30Ma); Oligocene to Quaternary (30-0 Ma). The deformation propagated southward as an imbricate style, which results in the passive uplifting of overlying structural layer. WSD exhibits a rather low taper tectonic wedge. According to the magnetotelluric and deep seismic profiles, it is inferred that the WSD tectonic processes is mainly controlled by the Yangtze continental block subduction northward under the Qingling Mountains and the pro-wedge multi-level thrusting during late Jurassic to Cretaceous. The Upper Paleozoic carbonates in the middle tectonic deformation system are favorable for gas exploration in thea area.

  10. K Ar age constraints on the evolution of polydeformed fold thrust belts: The case of the Northern Appalachians (southern Quebec)

    Science.gov (United States)

    Sasseville, C.; Tremblay, A.; Clauer, N.; Liewig, N.

    2008-03-01

    Precise geometric and temporal constraints are essential for understanding the evolution of fold-thrust belts. The lack of isotopic dating for shallow faults in the Northern Appalachian Taconic allochthons limits the interpretation of their structural evolution. New and more precise kinematic constraints have been obtained using a structural study that combined field work with the mineralogical, morphological and K-Ar isotopic analysis of clay-rich fractions (time (ca. 490 Ma) and culminated with the out-of-sequence imbrication of thrust stacks during Middle (ca. 465 Ma) to Late Ordovician time (ca. 450 Ma). The Silurian-Early Devonian subsidence (ca. 410 Ma) of the Appalachian foreland along wrench and normal fault systems occurred simultaneously with D 3 hinterland-directed tectonic transport at the boundary between the external and internal Humber zones. Late Devonian Acadian imbrications (D 4) in the Taconic allochthons of the Quebec Appalachians are reported here for the first time. The combination of a D 4 contractional pulse and Silurian-Early Devonian D 3 back-thrust faulting caused the exhumation of low-grade metamorphic rocks affected by an Early Devonian thermal event. Across the Laurentian margin, the Acadian contraction evolved from Middle Devonian deformation in the internal metamorphic domain to Late Devonian deformation in the allochthons. The relaxation of Acadian tectonic stress is characterized by D 5 normal faults and related hydrothermal activity. The recognition of an Acadian contraction event in the southern Quebec Appalachians challenges the traditional view of a gradual NW-directed progression of faulting in the Taconic thrust belt, and allows for a new reconstruction that bridges the Appalachians of mainland Canada and Newfoundland.

  11. Geometry and Kinematic evolution of the Sikkim Himalaya, India: Implications for the Evolution of the Himalayan Fold-Thrust Belt

    Science.gov (United States)

    Bhattacharyya, K.; Mitra, G.

    2012-04-01

    In the Darjeeling - Sikkim Himalaya the Main Central thrust (MCT) system has translated the Greater Himalayan hanging wall rocks over large distances so that Greater Himalayan rocks are exposed within 7 km of the mountain front. The sub-MCT Lesser Himalayan duplex is composed of two duplex systems and has a more complex geometry than in other parts of the Himalayan fold-thrust belt. Within the duplex, a foreland-dipping component and reactivation of the roof thrust resulted in large southward translation of the overlying MCT sheets in this region. The growth of the duplex resulted in a plunge culmination that manifests itself as a broad N-S trending structural high in this region; this is not a "river anticline" as its trace lies west of the Teesta river. A transport parallel balanced cross section constructed across this region suggests a total minimum shortening of ~502 km (~82%) south of the South Tibetan Detachment system (STDS). The Lesser Himalayan duplex accommodates nearly half of this total shortening. In this region, the average long-term shortening rate is estimated to be ~22 mm/yr. Comparison of available shortening estimates from different parts of the Himalayan arc show regional variations in shortening, but it is difficult to evaluate the primary cause for this variation; however, shortening in the Himalayan fold - thrust belt (FTB) is highest in the middle of the Himalayan arc (western Nepal) and progressively decreases towards the two syntaxes. Although, the width of the Lesser Himalayan belt decreases in the eastern Himalaya, the Lesser Himalayan shortening percentage remains approximately similar to that in both eastern and western Nepal Himalaya, where the belt is widest. In addition, the shortening accommodated within the Lesser Himalayan duplex progressively increases from the western to the eastern Himalaya. Thus, the width of the original Lesser Himalayan basin may have played an important role in partitioning the shortening in the Himalayan

  12. Fluid-Fault rock interaction during progressive deformation in Pelling-Munsiari thrust fault zone: A preliminary study from Darjeeling-Sikkim Himalayan fold thrust belt

    Science.gov (United States)

    Singh, Akanksha; Ghosh, Pritam; Bhattacharyya, Kathakali

    2017-04-01

    In a fold thrust belt,the dominant thrust fault rocks generally record strong overprinting of dislocation-controlled deformation mechanisms by frictional mechanisms during progressive deformation. Fluids play an integral role during evolution of such fault zones by opening channels by fracturing or by sealing existing fractures by forming veins, or by a combination of both. In the Sikkim Himalayan fold thrust belt (FTB), the Pelling-Munsiari thrust (PT) is one of the dominant thrusts that is the roof thrust of the Lesser Himalayan Duplex. Growth of the duplex has folded the overlying PT sheet, exposing it at various structural positions. We focus this study along the hinterlandmost (Mangan) and forelandmost (Suntaleykhola) exposures of the PT zone. We attempt to develop a temporal sequence of fracture growth by studying offsets recorded along fractures of different orientations, and also quantifing the variation in fracture population from hinterland to foreland. Additionally, we probe the role of fluids during the different stages of progressive deformation by studying fractures versus filled in fractures (veins). We examine the sources and temperature of the fluids as a function of the structural position of the exposed PT zones. The PT fault rocks are dominantly quartz-mica mylonite. At the hinterlandmost exposure, three dominant fracture orientations are recorded at 0°-30° ( 46%), 30°-70° ( 37%), and 70°-90° ( 17%) with respect to the mylonitic foliation. Low-angle fractures are offset by the younger, high-angle fractures. Vein population study reveals that the early-formed fractures are filled in by fluids while the later ones are independent of it.The same fault zone records a higher fracture population in the forelandmost exposure with orientations of 0°-30° ( 16%), 30°-70° ( 47%) and 70°-90° ( 37%) with respect to the mylonitic foliation. In this outcrop, fluids are present in both low-angle and high-angle fractures. Based on recrystallized

  13. First thermochronological constraints on the Cenozoic extension along the Balkan fold-thrust belt (Central Stara Planina Mountains, Bulgaria)

    Science.gov (United States)

    Kounov, Alexandre; Gerdjikov, Ianko; Vangelov, Dian; Balkanska, Eleonora; Lazarova, Anna; Georgiev, Stoyan; Blunt, Edward; Stockli, Daniel

    2017-11-01

    The Balkan fold-thrust belt, exposed in Bulgaria and north-east Serbia, is part of the north-east vergent segment of the bi-vergent Eastern Mediterranean Alpine orogen. It was formed during two distinct compressional stages; the first one lasted from the Middle Jurassic to the Early Cretaceous and the second from Late Cretaceous to the Paleogene. Although the compressional tectonic evolution of the Balkan fold-thrust belt since the Middle Jurassic and during most of the Mesozoic is relatively well studied, the final exhumation of the rocks of the belt during the Cenozoic has remained poorly understood. Here, we present the first thermochronological constraints, based on fission-track and [U-Th-(Sm)]/He analysis, showing that along the central part of the belt syn- to post-orogenic extension could have started as early as the middle Eocene. Low-temperature thermochronological analysis of samples collected from three areas reveals at least two phases of increased cooling and exhumation during the Cenozoic. The first exhumation phase took place between 44 and 30 Ma and appears to be related to the syn- to post-orogenic collapse coeval with the earliest Cenozoic extensional stage observed across the southern Balkan Peninsula. A period of relative quiescence (between 30 and 25 Ma) is followed by the next cooling stage, between 25 and 20 Ma, which appears to be related to late Oligocene to early Miocene crustal extension across the Balkan Peninsula. Extension accommodated by the late Miocene to Recent age Sub-Balkan Graben System does not appear to have produced exhumation of rocks from beneath 2-4 km depth, as it was not detected by the low-temperature thermochronological methods applied in this study.

  14. Tectonothermal evolution in the core of an arcuate fold and thrust belt: the south-eastern sector of the Cantabrian Zone (Variscan belt, north-western Spain)

    Science.gov (United States)

    Valín, María Luz; García-López, Susana; Brime, Covadonga; Bastida, Fernando; Aller, Jesús

    2016-07-01

    The tectonothermal evolution of an area located in the core of the Ibero-Armorican Arc (Variscan belt) has been determined by using the conodont colour alteration index (CAI), Kübler index of illite (KI), the Árkai index of chlorite (AI) and the analysis of clay minerals and rock cleavage. The area is part of the Cantabrian Zone (CZ), which represents the foreland fold and thrust belt of the orogen. It has been thrust by several large units of the CZ, what resulted in the generation of a large number of synorogenic Carboniferous sediments. CAI, KI and AI values show an irregular distribution of metamorphic grade, independent of stratigraphic position. Two tectonothermal events have been distinguished in the area. The first one, poorly defined, is mainly located in the northern part. It gave rise to very-low-grade metamorphism in some areas and it was associated with a deformation event that resulted in the emplacement of the last large thrust unit and development of upright folds and associated cleavage (S1). The second tectonothermal event gave rise to low-grade metamorphism and cleavage (S2) crosscutting earlier upright folds in the central, western and southern parts of the study area. The event continued with the intrusion of small igneous rock bodies, which gave rise to contact metamorphism and hydrothermal alteration. This event was linked to an extensional episode due to a gravitational instability at the end of the Variscan deformation. This tectonothermal evolution occurred during the Gzhelian-Sakmarian. Subsequently, several hydrothermal episodes took place and local crenulation cleavage developed during the Alpine deformation.

  15. Kinematic evolution of a regional-scale gravity-driven deepwater fold-and-thrust belt: The Lamu Basin case-history (East Africa)

    Science.gov (United States)

    Cruciani, F.; Barchi, M. R.; Koyi, H. A.; Porreca, M.

    2017-08-01

    The deepwater fold-and-thrust belts (DWFTBs) are geological structures recently explored thanks to advances in offshore seismic imaging by oil industry. In this study we present a kinematic analysis based on three balanced cross-sections of depth-converted, 2-D seismic profiles along the offshore Lamu Basin (East African passive margin). This margin is characterized by a regional-scale DWFTB (> 450 km long), which is the product of gravity-driven contraction on the shelf that exhibits complex structural styles and differing amount of shortening along strike. Net shortening is up to 48 km in the northern wider part of the fold-and-thrust belt (≈ 180 km), diminishing to 95% of net shortening was produced in < 10 Myr (during Paleocene). During this acme phase, which followed a period of high sedimentation rate, thrusts were largely synchronous and the shortening rate reached a maximum value of 5 mm/yr. The kinematic evolution reconstructed in this study suggests that the structural evolution of gravity-driven fold-and-thrust belts differs from the accretionary wedges and the collisional fold-and-thrust belts, where thrusts propagate in-sequence and shortening is uniformly accommodated along dip.

  16. Feedback between erosion and active deformation: geomorphic constraints from the frontal Jura fold-and-thrust belt (eastern France)

    Science.gov (United States)

    Madritsch, Herfried; Fabbri, Olivier; Hagedorn, Eva-Marie; Preusser, Frank; Schmid, Stefan M.; Ziegler, Peter A.

    2010-10-01

    A regional tectono-geomorphic analysis indicates a Pliocene to recent rock uplift of the outermost segment of the Jura fold-and-thrust belt, which spatially coincides with the intra-continental Rhine-Bresse Transfer Zone. Elevated remnants of the partly eroded Middle Pliocene Sundgau-Forêt de Chaux Gravels identified by heavy mineral analyses allow for a paleo-topographic reconstruction that yields minimum regional Latest Pliocene to recent rock uplift rates of 0.05 ± 0.02 mm/year. This uplift also affected the Pleistocene evolution of the Ognon and Doubs drainage basins and is interpreted as being tectonically controlled. While the Ognon River was deflected from the uplifted region the Doubs deeply incised into it. Focused incision of the Doubs possibly sustained ongoing deformation along anticlines which were initiated during the Neogene evolution of the thin-skinned Jura fold-and-thrust belt. At present, this erosion-related active deformation is taking place synchronously with thick-skinned tectonics, controlling the inversion of the Rhine-Bresse Transfer Zone. This suggests local decoupling between seismogenic basement faulting and erosion-related deformation of the Mesozoic cover sequences.

  17. Stratigraphy and structure of the Sevier thrust belt and proximal foreland-basin system in central Utah: A transect from the Sevier Desert to the Wasatch Plateau

    Science.gov (United States)

    Lawton, T.F.; Sprinkel, D.A.; Decelles, P.G.; Mitra, G.; Sussman, A.J.; Weiss, M.P.

    1997-01-01

    The Sevier orogenic belt in central Utah comprises four north-northwest trending thrust plates and two structural culminations that record crustal shortening and uplift in late Mesozoic and early Tertiary time. Synorogenic clastic rocks, mostly conglomerate and sandstone, exposed within the thrust belt were deposited in wedge-top and foredeep depozones within the proximal part of the foreland-basin system. The geologic relations preserved between thrust structures and synorogenic deposits demonstrate a foreland-breaking sequence of thrust deformation that was modified by minor out-of-sequence thrust displacement. Structural culminations in the interior part of the thrust belt deformed and uplifted some of the thrust sheets following their emplacement. Strata in the foreland basin indicate that the thrust sheets of central Utah were emplaced between latest Jurassic and Eocene time. The oldest strata of the foredeep depozone (Cedar Mountain Formation) are Neocomian and were derived from the hanging wall of the Canyon Range thrust. The foredeep depozone subsided most rapidly during Albian through Santonian or early Campanian time and accumulated about 2.5 km of conglomeratic strata (Indianola Group). The overlying North Horn Formation accumulated in a wedge-top basin from the Campanian to the Eocene and records propagation of the Gunnison thrust beneath the former foredeep. The Canyon Range Conglomerate of the Canyon Mountains, equivalent to the Indianola Group and the North Horn Formation, was deposited exclusively in a wedge-top setting on the Canyon Range and Pavant thrust sheets. This field trip, a three day, west-to-east traverse of the Sevier orogenic belt in central Utah, visits localities where timing of thrust structures is demonstrated by geometry of cross-cutting relations, growth strata associated with faults and folds, or deformation of foredeep deposits. Stops in the Canyon Mountains emphasize geometry of late structural culminations and relationships of

  18. The arcuate fold-and-thrust belt of northern Taiwan: Results of a two-stage rotation revealed from a paleomagnetic study

    Science.gov (United States)

    Sonnette, Lionel; Lee, Jian-Cheng; Horng, Chorng-Shern

    2017-10-01

    The Taiwan orogen is the result of the collision of the Luzon Volcanic Arc pushed northwestward by the Philippine Sea Plate against the Chinese Continental Margin since the Late Miocene and is still uplifting nowadays. The fold-and-thrust belt in northern Taiwan shows an arcuate shape from SW to NE: the strike of the main tectonic structures changes from N 0 ° E to N 70 ° E. Such curvature has not yet been properly interpreted so far. In this study we used paleomagnetic analyses to decipher the tectonic evolution along the fold-and-thrust belt in northern Taiwan, which reveals complex magnetization patterns both in ante-folding and post-folding formations. We also interpret that the fold-and-thrust belt in northern Taiwan has experienced two main rotational events: a 30 - 60 ± 14 ° clockwise rotation followed by a 30 ± 7 ° counterclockwise rotation during the ages of 4.6-1.5 Ma.

  19. Implications of heterogeneous fracture distribution on reservoir quality; an analogue from the Torridon Group sandstone, Moine Thrust Belt, NW Scotland

    Science.gov (United States)

    Watkins, Hannah; Healy, David; Bond, Clare E.; Butler, Robert W. H.

    2018-03-01

    Understanding fracture network variation is fundamental in characterising fractured reservoirs. Simple relationships between fractures, stress and strain are commonly assumed in fold-thrust structures, inferring relatively homogeneous fracture patterns. In reality fractures are more complex, commonly appearing as heterogeneous networks at outcrop. We use the Achnashellach Culmination (NW Scotland) as an outcrop analogue to a folded tight sandstone reservoir in a thrust belt. We present fracture data is collected from four fold-thrust structures to determine how fracture connectivity, orientation, permeability anisotropy and fill vary at different structural positions. We use a 3D model of the field area, constructed using field observations and bedding data, and geomechanically restored using Move software, to determine how factors such as fold curvature and strain influence fracture variation. Fracture patterns in the Torridon Group are consistent and predictable in high strain forelimbs, however in low strain backlimbs fracture patterns are inconsistent. Heterogeneities in fracture connectivity and orientation in low strain regions do not correspond to fluctuations in strain or fold curvature. We infer that where strain is low, other factors such as lithology have a greater control on fracture formation. Despite unpredictable fracture attributes in low strain regions, fractured reservoir quality would be highest here because fractures in high strain forelimbs are infilled with quartz. Heterogeneities in fracture attribute data on fold backlimbs mean that fractured reservoir quality and reservoir potential is difficult to predict.

  20. Variable shortening rates in the Bhutan thrust belt: implications for strain partitioning in the eastern Himalayan-Tibetan orogenic system

    Science.gov (United States)

    Long, S. P.; McQuarrie, N.; Tobgay, T.; Coutand, I.; Cooper, F. J.; Reiners, P. W.; Wartho, J.; Hodges, K.

    2012-12-01

    We present data on the burial, displacement and exhumation history of the Himalayan fold-thrust belt in eastern Bhutan, which highlight temporal variability in shortening rates. 8 new 40Ar/39Ar ages from white mica (MAr), 32 new zircon (U-Th)/He ages (ZHe), 7 new apatite fission-track (AFT) ages, and one new U-Pb zircon (LA-MC-ICP-MS) metamorphic rim growth age are combined with published cooling ages and deformation temperatures, and incremental restorations of two published balanced cross-sections, to constrain a four-part record of shortening rates from ~23 Ma to the present. Previous work indicates that the Main Central thrust (MCT) sheet was emplaced between ~23-18 Ma, and that proximal Lesser Himalayan (LH) rocks were buried under the MCT sheet at ~20 Ma. After burial, LH rocks were deformed in two duplex systems, the lower LH duplex, with the MCT acting as the roof thrust and the Shumar thrust (ST) acting as the floor thrust, and the upper LH duplex, with the ST acting as the roof thrust. U-Pb zircon rim growth as young as ~15 Ma and a ~15 Ma MAr neoblastic mica growth age from rocks beneath the ST are interpreted as prograde metamorphism due to thrust burial via displacement on the ST. These data bracket construction of the lower LH duplex between 20-15 Ma. Thrust sheets of the lower LH duplex yield MAr ages (325-400°C) between 13-8 Ma, ZHe ages (185-195°C) between 6-10 Ma, and AFT ages (120-130°C) between 3-5 Ma, which are interpreted as the result of passive transport, uplift and erosion during translation over a subsurface footwall ramp and younger deformation of upper LH rocks. Exhumation rates for lower LH rocks were as high as 1.3-2.6 mm/yr, and slowed to 0.4-0.9 mm/yr after passing over the footwall ramp. Thrust sheets of the upper LH duplex were exhumed from peak temperatures of 350-400°C to 185-195°C between 15 and ~9.5-10.5 Ma (ZHe ages). We attribute this pulse of rapid cooling, which corresponds to exhumation rates of 1.1-1.7 mm/yr, to

  1. Seismic profile analysis of the Kangra and Dehradun re-entrant of NW Himalayan Foreland thrust belt, India: A new approach to delineate subsurface geometry

    Science.gov (United States)

    Dey, Joyjit; Perumal, R. Jayangonda; Sarkar, Subham; Bhowmik, Anamitra

    2017-08-01

    In the NW Sub-Himalayan frontal thrust belt in India, seismic interpretation of subsurface geometry of the Kangra and Dehradun re-entrant mismatch with the previously proposed models. These procedures lack direct quantitative measurement on the seismic profile required for subsurface structural architecture. Here we use a predictive angular function for establishing quantitative geometric relationships between fault and fold shapes with `Distance-displacement method' (D-d method). It is a prognostic straightforward mechanism to probe the possible structural network from a seismic profile. Two seismic profiles Kangra-2 and Kangra-4 of Kangra re-entrant, Himachal Pradesh (India), are investigated for the fault-related folds associated with the Balh and Paror anticlines. For Paror anticline, the final cut-off angle β =35{°} was obtained by transforming the seismic time profile into depth profile to corroborate the interpreted structures. Also, the estimated shortening along the Jawalamukhi Thrust and Jhor Fault, lying between the Himalayan Frontal Thrust (HFT) and the Main Boundary Thrust (MBT) in the frontal fold-thrust belt, were found to be 6.06 and 0.25 km, respectively. Lastly, the geometric method of fold-fault relationship has been exercised to document the existence of a fault-bend fold above the Himalayan Frontal Thrust (HFT). Measurement of shortening along the fault plane is employed as an ancillary tool to prove the multi-bending geometry of the blind thrust of the Dehradun re-entrant.

  2. Late Cretaceous-Cenozoic Evolution of the Central Andean Foreland Basin System in the Eastern Cordillera to Subandean Zone, Southern Bolivia

    Science.gov (United States)

    Calle, A.; Horton, B. K.; Anderson, R. B.; Long, S. P.

    2015-12-01

    Evaluation of foreland basin deposystems and provenance across southern Bolivia reveals punctuated growth of the central Andean orogenic wedge. New and published sedimentology, provenance data, stratigraphy, subcrop mapping, and apatite (U-Th)/He thermochronometry along two transects (19.5, 21°S) from the easternmost Eastern Cordillera (EC) to the western Subandean Zone (SAZ) shed light on Late Cretaceous-Miocene thrust belt and foreland basin dynamics. Sediment dispersal patterns are constrained by paleocurrents, detrital zircon U-Pb geochronology, sandstone petrography, and conglomerate clast compositions. Spatial and temporal changes in the Andean thrust belt are recorded in asymmetric foreland basin thicknesses, facies distributions, and provenance within the EC (Incapampa and Camargo synclines) and SAZ (El Rosal and Entre Rios synclines). The >4 km uppermost Cretaceous-lower Miocene EC succession and ~2.5 km upper Oligocene-Miocene SAZ clastic successions record a shift from fluvial backbulge to pedogenic forebulge deposition. Braided, meandering, and lacustrine foredeep deposition records the most-rapid subsidence, with a later shift to progradational braided and alluvial fan deposition in the wedge-top zone. Growth strata preserved in EC and SAZ wedge-top deposits suggest unsteady eastward advance of the deformation front. Distal foreland deposits show west-directed paleocurrents with >1 Ga detrital zircon populations. Emerging Andean sources are indicated by east-directed paleocurrents, 36-25 Ma), Interandean Zone (IAZ, ~22-7 Ma) and SAZ (<6 Ma) can be linked to eastward passage of a flexural forebulge, recorded as a 50-200 m thick condensed zone in EC and SAZ basin fill. Integrated assessment of basin architecture, provenance, and exhumation highlights the potential influence of pre-Cenozoic IAZ heterogeneities on orogenic wedge growth.

  3. Cleavage development within a foreland fold and thrust belt, southern Pyrenees, Spain

    Science.gov (United States)

    Holl, James E.; Anastasio, David J.

    1995-03-01

    In the southern Pyrenees lithologically distinct cleavage fronts are each parallel to bedding and dip ˜20° towards the foreland. Pressure solution was the dominant mechanism of cleavage development. The mudstone cleavage front is coincident with the ˜195°C paleoisotherm and is associated with a pressure solution strain of ˜5%, a mechanical twin strain of ˜4%, and a deviatoric stress magnitude of ˜65 MPa. Illite crystallinity measurements define a geothermal gradient of 15°C km -1 and indicate that the paleoisotherms are bedding-parallel. Deviatoric stress magnitudes, from calcite twins, were regionally constant at ˜65 MPa and principal stress axes were perpendicular to cleavage. Temperature was the primary control on deformation micromechanisms and the position and orientation of the cleavage front within the foreland thrust wedge. Deformation below the cleavage front occurs predominantly by pressure solution, which in conjunction with mechanical twinning and microfracturing produces a quasi-plastic rheology. Stress magnitudes determined from mechanical twinning of carbonate grains and long-term (10 6-10 76 y) strain rates determined for regional folds and faults suggest an apparent macroscopic viscosity of 9.8 × 10 18 to 7.2 × 10 19 Pa s for the lower thrust wedge. Above the cleavage front temperature, pressure solution strain, total strain, and mesoscale deformation diminish. The region of the thrust wedge above the ˜100°C paleoisotherm is characterized by large brittle faults with cataclastic fault zones and negligible grain-scale deformation indicating an elastico-frictional rheology.

  4. Structure and tectonics of the Sierra Madre oriental fold-thrust belt near Monterrey, northeastern Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, C.A.; Gray, G.G.; Goldhammer, R. (Exxon Production Research Co., Houston, TX (United States))

    1991-03-01

    The Monterrey salient was examined using Landsat TM and MSS images to determine factors controlling the development, distribution, and exposure of Laramide structures. Lateral Mesozoic facies changes influence structural styles and distribution. Exposure of deep foreland structures north of Monterrey is partly related to the location of the Cupido reef trend. Structure along the front of the salient changes abruptly from tectonic wedging to normal overthrusting where deltaic clastics of the Difunta Group grade into incompetent Mendez shale. Salt thickness is an important factor controlling structural development. Areas without evaporites are usually persistent basement highs characterized by less severe deformation. Areas with thin evaporites have complex structural styles, depending on stratigraphy, depth of exposure, and distance from the Sierra Madre thrust front. Thick salt, apparently in a Jurassic rift beneath the salient, facilitated the northward transport of thrust sheets. Late Cretaceous salt movement influenced stratigraphy in La Popa basin where limestone lenses developed in the clastic Difunta Group. Basement topography is the major factor controlling development, style, distribution of structures, and areal distribution of salt and lateral facies changes. The authors propose a tectonic model that explains the large scale structural styles in the region. The Coahuila basement-high block acted as a buttress during Laramide shortening, limiting northward progression of deformation west of Saltillo. East, in the Monterrey salient, the effect of deeper basement and thick salt permitted thrusts to transport material much farther north, resulting in development of a north-south zone of distributed left-lateral shear in the region of Saltillo.

  5. Variable shortening rates in the eastern Himalayan thrust belt, Bhutan: Insights from multiple thermochronologic and geochronologic data sets tied to kinematic reconstructions

    Science.gov (United States)

    Long, Sean P.; McQuarrie, Nadine; Tobgay, Tobgay; Coutand, Isabelle; Cooper, Frances J.; Reiners, Peter W.; Wartho, Jo-Anne; Hodges, Kip V.

    2012-10-01

    We present data on the burial, displacement and exhumation history of the Himalayan fold-thrust belt in eastern Bhutan. These data document the magnitude and timing of displacement of large, discrete structures and highlight temporal variability in shortening rates. Eight new40Ar/39Ar ages from white mica, 32 new zircon (U-Th)/He ages, 7 new apatite fission track ages, and 1 new U-Pb zircon (LA-MC-ICP-MS) metamorphic rim growth age are combined with published cooling ages and deformation temperatures, and incremental shortening magnitudes from restorations of two published balanced cross sections, to illustrate the kinematic and temporal development of the Bhutan thrust belt. Integrating these data from ˜23 Ma to the present illustrates rapid horizontal shortening rates (28-35 mm/yr) between 23-20 Ma and 15-10 Ma, separated by more moderate rates (10-23 mm/yr). Shortening rates decrease significantly to 7-10 mm/yr (and possibly as low as 3-4 mm/yr) from 10 to 0 Ma. This decrease is interpreted to represent the onset of strain partitioning in the eastern part of the Himalayan-Tibetan orogenic system, between shortening in the Bhutan thrust belt, uplift of the Shillong Plateau, and deformation and outward growth of the northern and eastern Tibetan Plateau. Within estimated error, horizontal shortening rates during emplacement of the Main Central thrust sheet and during construction of the upper Lesser Himalayan duplex approached India-Asia tectonic velocities. Thus, for periods of time between ˜23-20 Ma and ˜15-10 Ma, the Bhutan thrust belt may have absorbed nearly all India-Asian convergence at this longitude.

  6. Control of Cambrian evaporites on fracturing in fault-related anticlines in the Zagros fold-and-thrust belt

    Science.gov (United States)

    Carminati, Eugenio; Aldega, Luca; Bigi, Sabina; Corrado, Sveva; D'Ambrogi, Chiara; Mohammadi, Peyman; Shaban, Ali; Sherkati, Shahram

    2013-07-01

    Orientation and distribution of fractures in the Oligocene-Early Miocene Asmari Formation (a major reservoir rock of the Zagros petroleum system) were investigated in two anticlines of the Zagros fold-and-thrust belt. The Sim and Kuh-e-Asmari anticlines developed in the areas of the Zagros characterized by the occurrence and absence of Cambrian evaporites at the bottom of the stratigraphic pile, respectively. The aim was to outline major differences in terms of fracture spacing and saturation. Organic matter maturity and clay minerals-based geothermometers suggest that the depth of deformation for the top of the Asmari Formation in the Kuh-e-Asmari anticline was in the range of 1.5-2.7 km assuming a geothermal gradient of 22.5 °C/km. The Asmari Formation in the Sim anticline probably experienced a slightly deeper sedimentary burial (maximum 3 km) with a geothermal gradient of 20 °C/km. The spacing of fractures is generally 2-3 times larger (i.e., strain accommodated by fracturing is smaller) in the Sim anticline than in the Kuh-e-Asmari anticline. This is consistent with regional geological studies, analogue, and numerical models that suggest that thrust faults geometry and related folds are markedly different in the absence or presence of a weak decòllement (evaporites). The larger spacing in the Sim anticline is also consistent with higher temperature predicted for the Asmari Formation in this area. By contrast, the orientation of fractures with respect to the fold axes is the same in both anticlines. The fracture systems are rather immature in both anticlines. The amount and density of fractures in the twofolds are controlled by regional (occurrence/absence of salt and probably different burial), rather than local features (fold geometry).

  7. Deciphering nature's chaos: University-Industry Consortium unraveling complexities of fold-thrust belts

    Energy Technology Data Exchange (ETDEWEB)

    Smith, M.

    2002-03-01

    The Fold-Fault Research Project (FRP) at the University of Calgary, in collaboration with Queen's University in Kingston, Ontario, and 23 oil and gas industry sponsors aim to find hydrocarbons within the convoluted folds and faults of the Rocky Mountains Foothills. Using tools ranging from simple plasticine to advanced supercomputers, more than two dozen researchers are combining expertise in a number of disciplines to unravel the region's complexity and thereby significantly reduce exploration risks. Key to the project's success are the integration of geology and geophysics, small-scale modelling of complex structures, a pooling of companies' seismic data and dramatic improvements in seismic imaging. Anisotropic pre-stack depth migration, which compensates for the variations in seismic waves when they penetrate certain rock layers that have been heaved into folds and thrusts was one of the major breakthroughs. Significant advances have also been made in the better understanding of the processes that went into the formation of thrust belts. These advances have been achieved by studying seismic and well data, surface geology mapping, and radar and aeromagnetic data, fleshed out by reconstruction software and forward modelling. New methods of estimating anisotropic parameters from seismic data, deal primarily with dipping shale sequences that cause structures to appear laterally shifted and shifted up-dip from where they really are. Considerable effort is also being expended on finding type locations up and down the Cordillera in a project designed to track changes in structural style. Brief descriptions of these and other phenomena under investigation by the FRP team are provided.

  8. The variety of subaerial active salt deformations in the Kuqa fold-thrust belt (China) constrained by InSAR

    Science.gov (United States)

    Colón, Cindy; Webb, A. Alexander G.; Lasserre, Cécile; Doin, Marie-Pierre; Renard, François; Lohman, Rowena; Li, Jianghai; Baudoin, Patrick F.

    2016-09-01

    Surface salt bodies in the western Kuqa fold-thrust belt of northwestern China allow study of subaerial salt kinematics and its possible correlations with weather variations. Ephemeral subaerial salt exposure during the evolution of a salt structure can greatly impact the subsequent development and deformation of its tectonic setting. Here, we present a quantitative time-lapse survey of surface salt deformation measured from interferometric synthetic aperture radar (InSAR) using Envisat radar imagery acquired between 2003 and 2010. Time series analysis and inspection of individual interferograms confirm that the majority of the salt bodies in western Kuqa are active, with significant InSAR observable displacements at 3 of 4 structures studied in the region. Subaerial salt motion toward and away from the satellite at rates up to 5 mm/yr with respect to local references. Rainfall measurements from the Tropical Rainfall Measuring Mission (TRMM) and temperature from a local weather station are used to test the relationship between seasonality and surface salt motion. We observe decoupling between surface salt motion and seasonality and interpret these observations to indicate that regional and local structural regimes exert primary control on surface salt displacement rates.

  9. Role of tectonic inheritance in the instauration of Tunisian Atlassic fold-and-thrust belt: Case of Bouhedma - Boudouaou structures

    Science.gov (United States)

    Ghanmi, Mohamed Abdelhamid; Ghanmi, Mohamed; Aridhi, Sabri; Ben Salem, Mohamed Sadok; Zargouni, Fouad

    2016-07-01

    Tectonic inversion in the Bouhedma-Boudouaou Mountains was investigated through recent field work and seismic lines interpretation calibrated with petroleum well data. Located to the Central-Southern Atlas of Tunisia, this area signed shortened intra-continental fold-and-thrust belts. Two dissymmetric anticlines characterize Bouhedma - Boudouaou major fold. These structures show a strong virgation respectively from E-W to NNE-SSW as a response to the interference between both tectonic inversion and tectonic inheritance. This complex geometry is driven by Mesozoic rifting, which marked an extensional inherited regime. A set of late Triassic-Early Jurassic E-W and NW-SE normal faults dipping respectively to the North and to the East seems to widely affect the overall geodynamic evolution of this domain. They result in major thickness changes across the hanging wall and the footwall blocks in response with the rifting activity. Tectonic inversion is inferred from convergence between African and European plates since late Cretaceous. During Serravalian - Tortonian event, NW-SE trending paroxysm led to: 1) folding of pre-inversion and syn-inversion strata, 2) reactivation of pre-existing normal faults to reverse ones and 3) orogeny of the main structures with NE-SW and E-W trending. The compressional feature still remains active during Quaternary event (Post-Villafranchian) with N-S trending compression. Contraction during inversion generates folding and internal deformation as well as Fault-Propagation-Fold and folding related strike.

  10. Structural evolution of the Namakdan salt diapir in the Zagros fold-thrust belt: The Persian Gulf, Iran

    Science.gov (United States)

    Shahpasandzadeh, Majid; Hashemifar, Ghasem; Shafiei Bafti, Amir

    2016-04-01

    Intersalt and host roch structures of the the Namakdan diapir were studied and compared with available 14C and OSL dated sediments to determine the structural evolution and uplift pattern of the diapir. The Namakdan salt diapir is situated on Qeshm Island in the east of the Zagros fold-thrust belt of Iran, north of the Persian Gulf. This nearly circular diapir with ~ 7 km diameter penetrates the crest of Salkh anticline and is embedded by steep-dip bedding of the Miocene Mishan and Aghajari Formations, which demonstrates the concentric internal structure of the diapir. The intraformational unconformities of country rocks were developed due to the Zagros shortening and salt diapirism, which demonstrate their syn-tectonic sedimentation. In addition, the dip of these unconfromities and also bedding of the country rocks decrease upward. The Namakdan diapir is partly covered by gypsum/anhydrite residuals, dolomite, marine limestone, and tilted marine terraces. The salt belong to the Hormuz Complex, consisted of predominantly halite, gypsum, anhydrite, dolomite, shale, sandstone, and volcanic-volanoclastic blocks, which was deposited in the Late Proterozoic-Middle Cambrian evaporitic rift basins. The Hormuz Complex is not only the cause of many salt diapir oil/gas fields but is also considered to have been a major source rock for generation of younger reservoirs. Thus, the salt diapirs of the Zagros play an important role in generation of the oil/gas reservoirs in this strategic area, so determination of structural style and evolution of the salt diapirs are vital in oil/gas exploration and development. The upright folds are developed in the salt beds due to upward movement and minor extrusion of the salt rocks due to its low viscosity. The dip of country rock beds increase toward to the diapir rim, so that the beds shows a vertical and even overturned attitude in vicinity of the diapir. Differential uplift pattern of the diapir was deduced in rim-to-center profiles by

  11. Tectonics in the Cuddapah fold-thrust belt in the Indian shield, Andhra Pradesh, India and its implication on the crustal amalgamation of India and Rayner craton of Antarctica during Neoproterozoic orogenesis

    Science.gov (United States)

    Matin, Abdul

    2014-01-01

    Neoproterozoic orogenesis in East Antarctica and India led to the amalgamation of northern Prince Charles Mountains-Rayner complex of Antarctica with the Krishna Province of India along the present eastern coast of India with the development of ~990-900 Ma old fold-thrust belt. The frontal part of the fold-thrust belt [henceforth called the Cuddapah fold-thrust belt (CFTB)], recognized in the intercratonic, Palaeoproterozoic-Neoproterozoic Cuddapah Basin, includes two frontal thrust sheets carried by the eastern Velikonda and the western Nallamalai thrusts, along with a part of the undeformed foreland, constituting frontal part of a larger fold-thrust belt now fragmented and separated in different continents of Gondwanaland. Therefore, the intercratonic deformation now preserved in the Palaeoproterozoic-Neoproterozoic Cuddapah Basin is related to the collision of the Indian shield to the Antarctic block during the amalgamation of the Rodinia Supercontinent. CFTB is dominated by quasi-plastic deformational structures, representing exhumed deeper level fault-propagation folding related to the Velikonda thrust, while the Nallamalai thrust represents the forelandward thrust of the CFTB dominated by elastico-frictional deformation structures.

  12. A cross section of the Los Angeles Area: Seismically active fold and thrust belt, The 1987 Whittier Narrows earthquake, and earthquake hazard

    Science.gov (United States)

    Davis, Thomas L.; Namson, Jay; Yerkes, Robert F.

    1989-07-01

    Retrodeformable cross sections across the Los Angeles area interpret the Pliocene to Quaternary deformation to be a developing basement-involved fold and thrust belt. The fold and thrust belt is seismically active as evidenced by the 1987 Whittier Narrows earthquake (ML = 5.9) and the 1971 San Fernando earthquake (MW = 6.6). The structural geology of the Los Angeles area is dominated by three major compressional uplift trends: (1) the Palos Verdes anticlinorium and western shelf, (2) the Santa Monica Mountains anticlinorium, and (3) the Verdugo Mountains-San Rafael Hills and the San Gabriel Mountains. These trends result from major thrust ramps off a detachment(s) at 10-15 km depth. Thrusts of the Verdugo Mountains-San Rafael Hills and the San Gabriel Mountains reach the surface; the other two uplifts are associated with blind thrusts. Compressional seismicity is concentrated along these thrust ramps. The 1987 Whittier Narrows earthquake probably occurred on the Elysian Park thrust which underlies the Santa Monica Mountains anticlinorium. The thrust interpretation accounts for the geometry of the anticlinorium, the seismological characteristics of the earthquake, and the geometry of coseismic uplift. The earthquake and aftershocks occurred within a structurally complex, narrow zone of Miocene and Pliocene northwest trending faults that cross the anticlinorium at a high angle. These northwest trending faults are interpreted to be reactivated faults now behaving as tears in the Elysian Park thrust and not the result of active right-lateral deformation extending into the Whittier Narrows area. Our analysis suggests the Whittier Narrows earthquake sequence occurred within a structurally weakened zone along the Elysian Park thrust. We also suggest that the Whittier fault is not an important Quaternary structure and may not be seismogenic. The regional cross section is a nonunique solution, and other possible solutions are considered. Multiple solutions arise from the

  13. Epiphytic diversity patterns in lowland and subandean forests

    Directory of Open Access Journals (Sweden)

    Luis Francisco Henao-Diaz

    2012-12-01

    Full Text Available Tropical rainforests are the most diverse ecosystems on the planet. Although many theories have been proposed to explain their richness we currently know little about their relative importance. This diversity is threatened by anthropogenic disturbances such as fragmentation and forest degradation. In this study we compared epiphytic plant diversity patterns in lowland and subandean forests. More epiphytic diversity was found in subandean (PNN Cueva de los Guácharos compared to lowland forest (Palmarí Reserve. In addition a higher abundance of epiphytes was found in conserved forest. Tree host diversity was higher in lowland forests than in subandean forests, so we can reject the possibility that differences between the patterns of epiphytic diversity are caused by regional effects of plant diversity. Our results suggest that humidity seems to be the most important environmental filter explaining epiphyte diversity.

  14. Modelling "reality" in tectonics: Simulation of the mechanical evolution of the Jura Mountains-Molasse Basin system, and routes to forward-inverse modelling of fold thrust belts.

    Science.gov (United States)

    Hindle, David; Kley, Jonas

    2016-04-01

    The ultimate validation of any numerical model of any geological process comes when it can accurately forward model a case study from the geological record. However, as the example of the Jura-Molasse fold thrust belt demonstrates, geological information on even the most basic aspects of the present day state of such systems is highly incomplete and usually known only with large uncertainties. Fold thrust-belts are studied and understood by geologists in an iterative process of constructing their subsurface geometries and structures (folds, faults, bedding etc) based on limited subsurface information from boreholes, tunnels or seismic data where available, and surface information on outcrops of different layers and their dips. This data is usually processed through geometric models which involve conservation of line length of different beds over the length of an entire cross section. Constructing such sections is the art of cross section balancing. A balanced cross section can be easily restored to its pre-deformation state, assuming (usually) originally horizontal bedding to remove the effects of folding and faulting. Such a pre-deformation state can then form an initial condition for a forward mechanical model of the section. A mechanical model introduces new parameters into the system such as rock elasticity, cohesion, and frictional properties. However, a forward mechanical model can also potentially show the continuous evolution of a fold thrust belt, including dynamic quantities like stress. Moreover, a forward mechanical model, if correct in most aspects, should match in its final state, the present day geological cross section it is simulating. However, when attempting to achieve a match between geometric and mechanical models, it becomes clear that many more aspects of the geodynamic history of a fold thrust belt have to be taken into account. Erosion of the uppermost layers of an evolving thrust belt is the most obvious one of these. This can potentially

  15. Rotation of the Pacific Northwest and Deformation Across the Yakima Fold and Thrust Belt Estimated with GPS

    Science.gov (United States)

    McCaffrey, R.; King, R. W.; Lancaster, M.; Miller, M. M.; Wells, R. E.

    2015-12-01

    Geodetic, geologic and paleomagnetic data reveal that Oregon and parts of California, Nevada and Idaho rotate clockwise at 0.3 to 1.0 deg/Ma (relative to North America) about an axis near the Idaho-Oregon-Washington border, while northeast Washington is relatively fixed to North America. This rotation has been going on for at least 15 Ma. The spatial termination of the rotation requires shortening between Oregon and Washington. The Yakima fold and thrust belt (YFTB) lies along the boundary between northern Oregon and central Washington where convergence of the clockwise-rotating Oregon block is apparently accommodated. Shortening across the YFTB is thought to occur in a fan-like manner, increasing to the west. We obtained high-accuracy, high-density geodetic GPS measurements in 2012 and 2013 that are used with earlier measurements to characterize YFTB kinematics. Deformation associated with the YFTB starts in the south at the Blue Mountains Anticline in northern Oregon and extends northward to Frenchman Hills in Washington. To the east, the faulting and earthquake activity of the YFTB are truncated by a NNW-trending, narrow zone of deformation that runs along the Pasco Basin and Moses Lake region. It accommodates about 0.5 to 1.0 mm/yr of east to northeast shortening along the eastern boundary of the Department of Energy Hanford Site. The deforming zone aligns with recent seismicity in the Ice Harbor dike swarm, a relatively young ~ 8.5 Ma vent complex. West of the Cascade arc, shortening is accommodated by a series of east-trending faults, starting at the Doty fault in central coastal Washington and extending through Seattle up to the Canadian border. South of the Doty fault, other faults may take up some motion but may be too slow to resolve with GPS.

  16. Along-dip variations of structural style in the Somali Basin deep-water fold and thrust belt (East Africa)

    Science.gov (United States)

    Cruciani, Francesco; Rinaldo Barchi, Massimiliano

    2014-05-01

    Continental passive margins are place of extended slope-failure phenomena, which can lead to the formation of gravity-driven deep-water fold and thrust belts (DW-FTBs), in regions where no far-field compressional stress is active. These giant geological features, which are confined to the sedimentary section, consist of extensional-compressional linked systems detached over a common décollement, generally salt or shales. The continental passive margin of northern Kenya and southern Somalia is an excellent and relatively unexplored site for recognizing and understanding the DW-FTBs originated over a regional shale décollement. In this study we have interpreted a 2D seismic data-set of the 1980s, hosted by Marine Geoscience Data System at Lamont-Doherty Earth Observatory of Columbia University (http://www.marine-geo.org), and recently reprocessed by ENI, in order to investigate the structural style of a DW-FTB developed offshore of northern Kenya and southern Somalia (Somali Basin). This region records the oldest sedimentary section of the Indian Ocean since the breakup of Gondwana began in the Middle-Lower Jurassic separating Madagascar from Africa. From the Upper Cretaceous to at least the Lower Miocene, the margin has been characterized by gravitational collapse leading to the formation of a DW-FTB extending more than 400 km along-strike. The northern portion of the DW-FTB is about 150 km wide, whilst in the southern portion is few tens of km wide. We analysed the northern portion along a regional seismic section. Our study represents the first detailed structural interpretation of this DW-FTB since its discovery in the 1980s. The good quality of the available reprocessed seismic data has allowed us to identify remarkable along-dip variations in the structural style. The basal detachment constantly deepens landward, in agreement with a prevailing gravity-spreading deformation process (as in the case of the Niger Delta). On the seismic data are not visible, as

  17. Layer-parallel shortening across the Sevier fold-thrust belt and Laramide foreland of Wyoming: spatial and temporal evolution of a complex geodynamic system

    Science.gov (United States)

    Weil, Arlo Brandon; Yonkee, W. Adolph

    2012-12-01

    Varying patterns of layer-parallel shortening (LPS) and vertical-axis rotations from the thin-skin Sevier fold-thrust belt to the thick-skin Laramide foreland of Wyoming are quantified from integrated structural, anisotropy of magnetic susceptibility (AMS), and paleomagnetic analyses. Within the Sevier belt, widespread early LPS was accommodated by spaced cleavage, fracture sets, minor folds, and minor faults. LPS directions are subperpendicular to structural trends of systematically curved thrust sheets of the Wyoming salient, reflecting a combination of primary dispersion and secondary rotation during thrusting. Within the Laramide foreland, limited LPS was accommodated mostly by minor faults with conjugate wedge and strike-slip geometries. LPS directions in gentler fold limbs vary from perpendicular to acute with structural trends of variably oriented, anastomosing basement-cored arches. Steep forelimbs display more complex relations, including younger fault sets that developed during evolving stress states and localized vertical-axis rotations. Although internal strain is limited, weak AMS lineations defined by kinked and rotated phyllosilicates are widely developed and consistently oriented perpendicular to measured LPS directions. Palinspastically restored LPS directions, corrected for paleomagnetically determined vertical-axis rotations, vary on average from W-E in the Sevier belt to WSW-ENE in the Laramide foreland. In detail, LPS directions display deflections related to primary sedimentary wedge geometry and basement fabrics. LPS in the Sevier belt is interpreted to partly reflect stress transmitted from the hinterland through the growing orogenic wedge and topographic stress along the front of the wedge. LPS in the Laramide foreland is interpreted to partly reflect basal traction during flat-slab subduction beneath thick cratonic lithosphere, with spatial-temporal variations in stress trajectories related to basement heterogeneities and evolving fault

  18. Upper crustal shortening and forward modeling of the Himalayan thrust belt along the Budhi-Gandaki River, central Nepal

    Science.gov (United States)

    Khanal, Subodha; Robinson, Delores M.

    2013-04-01

    A balanced cross-section along the Budhi-Gandaki River in central Nepal between the Main Central thrust, including displacement on that fault, and the Main Frontal thrust reveals a minimum total shortening of 400 km. Minimum displacement on major orogen-scale structures include 116 km on the Main Central thrust, 110 km on the Ramgarh thrust, 95 km on the Trishuli thrust, and 56 km in the Lesser Himalayan duplex. The balanced cross-section was also incrementally forward modeled assuming a generally forward-breaking sequence of thrusting, where early faults and hanging-wall structures are passively carried from the hinterland toward the foreland. The approximate correspondence of the forward modeled result to observe present day geometries suggest that the section interpretation is viable and admissible. In the balanced cross-section, the Trishuli thrust is the roof thrust for the Lesser Himalayan duplex. The forward model and reconstruction emphasize that the Lesser Himalayan duplex grew by incorporating rock from the footwall and transferring it to the hanging wall along the Main Himalayan thrust. As the duplex developed, the Lesser Himalayan ramp migrated southward. The movement of Lesser Himalayan thrust sheets over the ramp pushed the Lesser Himalayan rock and the overburdens of the Greater and Tibetan Himalayan rock toward the erosional surface. This vertical structural movement caused by footwall collapse and duplexing, in combination with erosion, exhumed the Lesser Himalaya.

  19. Sediment provenance in contractional orogens: The detrital zircon record from modern rivers in the Andean fold-thrust belt and foreland basin of western Argentina

    Science.gov (United States)

    Capaldi, Tomas N.; Horton, Brian K.; McKenzie, N. Ryan; Stockli, Daniel F.; Odlum, Margaret L.

    2017-12-01

    This study analyzes detrital zircon U-Pb age populations from Andean rivers to assess whether active synorogenic sedimentation accurately records proportional contributions from varied bedrock source units across different drainage areas. Samples of modern river sand were collected from west-central Argentina (28-33°S), where the Andes are characterized by active uplift and deposition in diverse contractional provinces, including (1) hinterland, (2) wedge-top, (3) proximal foreland, and (4) distal broken foreland basin settings. Potential controls on sediment provenance were evaluated by comparing river U-Pb age distributions with predicted age spectra generated by a sediment mixing model weighted by relative catchment exposure (outcrop) areas for different source units. Several statistical measures (similarity, likeness, and cross-correlation) are employed to compare how well the area-weighted model predicts modern river age populations. (1) Hinterland basin provenance is influenced by local relief generated along thrust-bounded ranges and high zircon fertility of exposed crystalline basement. (2) Wedge-top (piggyback) basin provenance is controlled by variable lithologic durability among thrust-belt bedrock sources and recycled basin sediments. (3) Proximal foreland (foredeep) basin provenance of rivers and fluvial megafans accurately reflect regional bedrock distributions, with limited effects of zircon fertility and lithologic durability in large (>20,000 km2) second-order drainage systems. (4) In distal broken segments of the foreland basin, regional provenance signatures from thrust-belt and hinterland areas are diluted by local contributions from foreland basement-cored uplifts.

  20. Variation of depositional environment during the evolution of deepwater fold-and-thrust belt in the Frontal Ridge area offshore SW Taiwan

    Science.gov (United States)

    Lin, L. F.; Liu, C. S.; Lin, C. C.; Hsu, H. H.; Chang, J. H.; Chen, S. C.; Wang, Y.; Chung, S. H.

    2014-12-01

    The area offshore SW Taiwan is an active margin where the accretionary prism of the Luzon arc-trench system has obliquely overridden the continental margin of the South China Sea (SCS). Located by the Penghu Submarine Canyon, the Frontal Ridge is the westernmost structural relief of the orogenic wedge which is separated from the SCS continental margin by a deformation front. The Penghu submarine canyon, which starts from the China continental shelf and cuts across the fold-and-thrust belt, may plays an important role for transporting orogenic sediments from on shore Taiwan to the deep sea South China Sea basin. In this study, high-resolution seismic data collected in the Frontal Ridge area have been analyzed, a significant variation of stratigraphic architectures with time were identified by detailed analyzing both structural and depositional characteristics. Seismic facies analysis shows that the older parallel strata were eroded and superimposed by a series of lobe-channel-levee complex, interpreted as the fan deposits of the paleo Penghu Submarine Canyon. These deposits were later deformed by a multi-stage frontal thrusting. We propose a model to show how tectonic processes change the depositional environment. During the evolution of fold-and-thrust belt, the slope gradient and sedimentation rate changed. The Frontal Ridge area was at the abyssal plain, and then changed to the continental rise environment. Finally, convergent tectonics changed this area to be part of the orogenic wedge, and frontal fold developed.

  1. Fault fluid evolution at the outermost edges of the southern Apennines fold-and-thrust belt, Italy

    Science.gov (United States)

    Agosta, Fabrizio; Belviso, Claudia; Cavalcante, Francesco; Vita Petrullo, Angela

    2017-04-01

    This work focuses on the structural architecture and mineralization of a high-angle, extensional fault zone that crosscuts the Middle Pleistocene tuffs and pyroclastites of the Vulture Volcano, southern Italy. This fault zone is topped by a few m-thick travertine deposit formed by precipitation, in a typical lacustrine depositional environment, from a fault fluid that included a mixed, biogenic- and mantle-derived CO2. The detailed analysis of its different mineralization can shed new lights into the shallow crustal fluid flow that took place during deformation of the outer edge of the southern Apennines fold-and-thrust belt. In fact, the study fault zone is interpreted as a shallow-seated, tear fault associated with a shallow thrust fault displacing the most inner portion of the Bradano foredeep basin infill, and was thus active during the latest stages of contractional deformation. Far from the fault zone, the fracture network is made up of three high-angle joint sets striking N-S, E-W and NW-SE, respectively. The former two sets can be interpreted as the older structural elements that pre-dated the latter one, which is likely due to the current stress state that affects the whole Italian peninsula. In the vicinity of the fault zone, a fourth joint high-angle set striking NE-SW is also present, which becomes the most dominant fracture set within the study footwall fault damage zone. Detailed X-ray diffraction analysis of the powder obtained from hand specimens representative of the multiple mineralization present within the fault zone, and in the surrounding volcanites, are consistent with circulation of a fault fluid that modified its composition with time during the latest stages of volcanic activity and contractional deformation. Specifically, veins infilled with and slickenside coated by jarosite, Opal A and/or goethite are found in the footwall fault damage zone. Based upon the relative timing of formation of the aforementioned joint sets, deciphered after

  2. An alternative interpretation for the map expression of “abrupt” changes in lateral stratigraphic level near transverse zones in fold-thrust belts

    Directory of Open Access Journals (Sweden)

    Sanghoon Kwon

    2012-07-01

    Full Text Available The map expression of “abrupt” changes in lateral stratigraphic level of a thrust fault has been traditionally interpreted to be a result of the presence of (1 a lateral (or oblique thrust-ramp, or (2 a frontal ramp with displacement gradient, and/or (3 a combination of these geometries. These geometries have been used to interpret the structures near transverse zones in fold-thrust belts (FTB. This contribution outlines an alternative explanation that can result in the same map pattern by lateral variations in stratigraphy along the strike of a low angle thrust fault. We describe the natural example of the Leamington transverse zone, which marks the southern margin of the Pennsylvanian–Permian Oquirrh basin with genetically related lateral stratigraphic variations in the North American Sevier FTB. Thus, the observed map pattern at this zone is closely related to lateral stratigraphic variations along the strike of a horizontal fault. Even though the present-day erosional level shows the map pattern that could be interpreted as a lateral ramp, the observed structures along the Leamington zone most likely share the effects of the presence of a lateral (or oblique ramp, lateral stratigraphic variations along the fault trace, and the displacement gradient.

  3. Timing of Deformation in the Central Metasedimentary Belt Boundary Thrust Zone (CMBbtz), southern Ontario, Canada, from Electron Microprobe Dating of Monazite

    Science.gov (United States)

    Markley, M. J.; Dunn, S. R.; Peck, W. H.; Jercinovic, M. J.; Williams, M. L.

    2015-12-01

    In the Grenville Province of Southern Ontario, the Central Metasedimentary Belt boundary thrust zone (CMBbtz) is a crustal-scale tectonic boundary between the older, granulite-facies Central Gneiss Belt to the NW and the younger, amphibolite-facies Central Metasedimentary Belt to the SE. Although there are a range of tectonic models for the CMBbtz, most workers agree it is a major tectonic boundary that accommodated ductile thrusting and crustal shortening during the Ottawan phase of the Grenville Orogeny (~1080-1020 Ma). Some studies suggest that ductile thrusting in the CMBbtz was roughly synchronous with synorogenic extensional collapse below an orogenic lid. Previous geochronological studies also provide evidence of earlier deformation and/or metamorphic events in the CMBbtz, although the relation between deformation in the CMBbtz to the Elzeviran (~1230 Ma) and Shawinigan (~1180 Ma) orogenies is unclear. Our study is the first to report in situ electron microprobe monazite (mnz) dates from amphibolite-grade ortho- and para-gneisses of the CMBbtz. Our results are broadly consistent with other chronometers. We present dates from 132 age-domains within 83 mnz grains in 14 samples. Although our data provide strong evidence for deformation and metamorphism along the length of the CMBbtz during the Ottawan (1080-1020 Ma), we also report two other clusters of ages: 1140-1110 Ma and 1230-1170 Ma. The latter cluster falls between the widely accepted ranges for the Elzeviran and Shawinigan orogenies. In addition, some individual outcrops, particularly those in Killaloe and Minden, show mnz ages spanning over 200 m.y., and the setting and compositions of individual monazite domains allow us to link mnz growth to episodes of garnet growth during multiple events. Together these data indicate an unexpectedly continuous and long-lived period of deformation and metamorphism in the CMBbtz.

  4. Lateral structural variations and drainage response along the Misikantage anticline in the western Kuqa fold-and-thrust belt, southern Tianshan, NW China

    Science.gov (United States)

    Tang, Pengcheng; Rao, Gang; Li, Shiqin; Yu, Yangli; Pei, Yangwen; Wang, Xin; Shen, Zhongyue; Chen, Ninghua; Zhao, Bo

    2017-11-01

    The Cenozoic Kuqa fold-and-thrust belt (KFTB) along the southern piedmont of the Tianshan Mountains (NW China) provides excellent chances for investigating active deformation and its controls on landscape topography. In contrast to the well-imaged eastern KFTB, the structural deformation in the western part complicated by the development of early-stage salt structures still has not been well investigated. On the basis of seismic reflection profiles, well data and surface geology, combined with previously determined paleomagnetic ages, this study focuses on the deformation style, onset and average shortening rate of the Misikantage anticline in the western KFTB. Together with the morphometric analysis of satellite images and digital elevation models (DEMs), we have demonstrated that: 1) the Misikantage anticline is an asymmetric detachment fold, where the fold geometry, amounts of shortening, outcropping strata and channel network patterns vary along strike; 2) syntectonic growth strata recognized from seismic profiles combined with paleomagnetic ages indicate that the folding started at 2.4 Ma and resulted in 0.3-0.9 km of shortening, yielding an average shortening rate of 0.12-0.38 mm/yr; 3) the landscape topography and drainage networks markedly change in response to lateral structural variations. These findings would provide a basis for further comparisons of compressional structures between the eastern and western KFTB, which are also helpful in better understanding active folding in fold-and-thrust belts particularly where thick salt is involved in deformation.

  5. Impact of an interbedded viscous décollement on the structural and kinematic coupling in fold-and-thrust belts: Insights from analogue modeling

    Science.gov (United States)

    Borderie, Sandra; Graveleau, Fabien; Witt, César; Vendeville, Bruno C.

    2018-01-01

    Fold-and-thrust belts (FTBs) can be segmented both across and along strike because of various factors including tectonic and stratigraphic inheritance. In this study, we investigated along/across-strike structural interactions in a FTB propagating toward a foreland which displays contrasted lithological sequences. A set of analogue models was performed in a compressional box where a single viscous level of varying width was interbedded within a frictional series. The tectonic interaction between the viscous and the frictional provinces was tested both along and across strike. Results indicate that a frictional province influences the along-strike tectonic evolution of an adjacent viscous province. This influence decreases when the width of the viscous province increases. The frictional provinces control the taper, structural style, obliquity of the structures' trend and kinematics of the shallow deformation front of the viscous province. Results evidence how far a frictional province can impact the deformation of an adjacent viscous province. For frictional-viscous wedges, it appears that the critical taper theory, which is generally applied in 2-D, should be likely considered in terms of 3-D. Moreover, the kinematics of the deep deformation front shows mutual influences between the adjacent viscous and frictional provinces. Experimental results are compared to natural examples in the Kuqa Basin (Southern Tian Shan, China) and the Salt Range (Pakistan), and give an insight to a better understanding of the dynamics of fold-and-thrust belts bearing a viscous décollement, such as salt.

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

    Science.gov (United States)

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

    2014-12-01

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

  7. Five Earthquakes In The Last 50 Ka In The Northwestern Yakima Fold And Thrust Belt, Central Washington

    Science.gov (United States)

    Sherrod, B. L.; Blakely, R. J.; Barnett, E. A.; Foit, F. F.; Weaver, C. S.

    2011-12-01

    Stratigraphic and structural relationships revealed in paleoseismic trenches suggest at least five earthquakes occurred in the last 50 ka along two prominent anticlines of the Yakima fold and thrust belt (YFTB). The YFTB is a series of northwest- and west-trending anticlinal ridges and synclinal valleys formed during and after emplacement of Miocene flood basalts of the Columbia River Basalt Group (CRBG). Here we focus on scarps along Umtanum and Boylston Ridges. Air photos and LiDAR show an E-W trending, up-to-the-north scarp (~8 m high, ~11 km long) lying at the base of the southern limb of the Umtanum Ridge anticline at Wenas Valley, near the city of Yakima. A trench across the scarp exposed volcaniclastic deposits overlain by buried soils and colluvial deposits. Electron microprobe analysis of tephra from the uppermost volcaniclastic layers indicates correlation with Mt. St. Helens Set C (possibly Cy), erupted ~47 ka. Eight normal faults and one possible reverse fault deform the tephra, buried soils, and colluvial deposits above the tephra. Cross cutting relations require at least three earthquakes over the last ~47 ka. We infer bending moment deformation above a buried reverse fault as the most likely cause of surface faulting observed along the Wenas Valley scarp. LiDAR images at Boylston Ridge east of Ellensburg, WA reveal a ~4-km-long, NE-trending, up-to-the-west scarp. Trenches across this scarp showed Miocene basalt overlain by a thin, cobble-rich, colluvial soil at the surface. A single high-angle reverse fault offsets the basalt, and a fissure filled with colluvium separates the fault blocks. Older colluvium and a soil formed in the colluvium are both offset by the fault, suggesting at least two episodes of movement. Inclined striae on the fault plane hint at right-lateral oblique offset. About 1 km to the NE, a 700-m-long stretch of stream floodplain is incised as much as 7 m. Electron microprobe analysis of a tephra layer in the incised floodplain

  8. Late Jurassic to Early Cretaceous sedimentary-tectonic development in the Chengde Basin, Yanshan fold-thrust belt, North China Craton

    Science.gov (United States)

    Liu, Jian; Zhao, Yue; Liu, Ankun; Ye, Hao

    2015-12-01

    The Chengde Basin is located in the central part of the Yanshan fold-thrust belt in the northern North China Craton. The sediments in the Upper Jurassic to Lower Cretaceous Tuchengzi Formation in the Chengde Basin provide a detrital record of basin dynamics and uplift of the basin margins during that time. We analyzed the sedimentary facies, paleocurrents, and provenance of the Tuchengzi Formation in the Chengde Basin for the period of the Late Jurassic and Early Cretaceous shortening in the Yanshan fold-thrust belt. Four sedimentary facies associations have been identified in the Tuchengzi Formation, corresponding to proximal fan, mid-fan, distal alluvial fan, and fluvial facies. The transport and distribution of the Upper Jurassic to Lower Cretaceous sediments in the Chengde Basin was controlled by the faults bounding the basin. Paleocurrent indicators and provenance data of conglomerate clasts reveal that the sediments of the Tuchengzi Formation in the northern part of the Chengde Basin were delivered from source regions to the north of the basin. The early sediments of the Tuchengzi Formation in the southern part of the basin comprise a suite of fluvial deposits, similar to the fluvial sediments in the northern part of the basin, and their paleocurrent data and the compositions of conglomerate clasts also suggest a northern source. However, the subsequent sedimentation in the Tuchengzi Formation in the southern part of the basin changed markedly to proximal fan facies, with sediments being derived from the south of the basin, according to the paleocurrent data and conglomerate clast lithology. The Sandaohe sheet, which is located in the southeast limb of the Chengde syncline, is not a klippe formed as a result of long-distance northward thrusting, but an autochthonous pop-up tectonic wedge generated by N-S shortening during the Early Cretaceous sedimentation of the Tuchengzi Formation. The sedimentation ended before the onset of the Early Cretaceous volcanic

  9. Tectono-sedimentary evolution of salt controlled minibasin in a fold-an-thrust belt setting Example from the Sivas Basin Turkey and physical model.

    Science.gov (United States)

    Kergaravat, Charlie; Ribes, Charlotte; Darnault, Romain; Callot, Jean-Paul; Ringenbach, Jean-Claude

    2017-04-01

    The aim of this study is to present the influence of regional shortening on the evolution of a minibasin province and the associated foldbelt geometry based on a natural example, the Sivas Basin, then compared to a physical experiment. The Sivas Basin in the Central Anatolian Plateau (Turkey) is a foreland fold-and-thrust belt, displaying in the central part a typical wall and basin province characterized by spectacularly exposed minibasins, separated by continuous steep-flanked walls and diapirs over a large area (45x25 km). The advance of the orogenic wedge is expressed within the second generation of minibasins by a shortening-induced squeezing of diapirs. Network of walls and diapirs evolve form polygonal to linear pattern probably induced by the squeezing of pre-existing evaporite walls and diapirs, separating linear primary minibasins. From base to top of secondary minibasins, halokinetic structures seem to evolve from small-scale objects along diapir flanks, showing hook and wedges halokinetic sequences, to large stratigraphic wedging, megaflap and salt sheets. Minibasins show progressively more linear shape at right angle to the regional shortening and present angular unconformities along salt structures related to the rejuvenation of pre-existing salt diapirs and walls probably encouraged by the shortening tectonic regime. The advance of the fold-and-thrust belts during the minibasins emplacement is mainly expressed during the late stage of minibasins development by a complex polygonal network of small- and intermediate-scale tectonic objects: (1) squeezed evaporite walls and diapirs, sometimes thrusted forming oblique or vertical welds, (2) allochthonous evaporite sheets, (3) thrusts and strike-slip faults recording translation and rotation of minibasins about vertical axis. Some minibasins are also tilted, with up to vertical position, associated with both the salt expulsion during minibasins sinking, recorded by large stratigraphic wedge, and the late

  10. Reply to comment by Tan et al. on "Sandbox modeling of evolving thrust wedges with different preexisting topographic relief: Implications for the Longmen Shan thrust belt, eastern Tibet"

    Science.gov (United States)

    Sun, Chuang; Jia, Dong; Yin, Hongwei; Chen, Zhuxin; Li, Zhigang; Li, Shen; Wei, Dongtao; Li, Yiquan; Yan, Bin; Wang, Maomao; Fang, Shaozhi; Cui, Jian

    2017-02-01

    Tan et al. comment that the preexisting topographic relief in our sandbox is opposed to its prototype in the central Longmen Shan. Therefore, the comparison between our sandbox modeling and the natural topography is questionable and does not agree with our conclusion that the Xiaoyudong fault is a tear fault. First, we are grateful to the authors for their approval of our sandbox modeling and its contribution to understanding fault behavior within thrust wedges. However, after reading the comment carefully, we found that they misunderstood the meaning of topographic relief we conveyed. In response, we would like to address the differences between the topography in their comment and the orogen-scale topography we investigated in our modeling to defend our conclusion.

  11. Kinematic reconstruction of a thin-skinned, deep-water fold and thrust belt: the case of the Outer Tuscan Nappe (Umbria, Italy)

    Science.gov (United States)

    Carboni, Filippo; Barchi, Massimiliano; Brozzetti, Francesco; Cruciani, Francesco; Ercoli, Maurizio; Mirabella, Francesco; Porreca, Massimiliano

    2017-04-01

    Fold-and-Thrust Belts occur worldwide in a variety of tectonic settings. Most of them develop in a deepwater environment (Deep Water Fold-and-Thrust Belts, DWFTBs), at both continental passive and active margins, driven by gravity (near-field stresses) and tectonic forces (far-field stresses) respectively. Here we present a multidisciplinary geological study of the Outer Tuscan Nappe (OTN), an imbricate thrust system in the Northern Apennines of Italy, emplaced in Early Miocene times in deep water environment. Despite the wide scientific literature, the geometry and the kinematic evolution of the OTN were never reconstructed in detail. Furthermore, its total amount of shortening and then its shortening rate, were never measured and calculated through proper restoration techniques. The OTN involves a 2000 m thick, Late Cretaceous-Tertiary "Tuscan" succession, consisting of arenaceous turbidites (Macigno Fm.), overlying a thick level of marls and calcarenites (Scaglia Toscana Fm.), which form the major basal décollement of the imbricate system. Along this basal décollement, the OTN overthrusts eastward younger turbidite units (Mt. Rentella and Marnoso-Arenacea successions). In this study we interpreted a set of 2D seismic reflection profiles calibrated with a deep borehole, crossing transversally (WSW-ENE) and longitudinally (NNW-SSE) the OTN. To better constrain the interpretation, selected controls of key outcrops was performed, mainly aimed at reconstructing: i) the actual transport direction during the OTN emplacement; ii) the position of the subsequent, NNW-SSE trending, extensional faults dissecting the tectonic wedge; iii) the role of transversal faults, longitudinally segmenting the thrust system. Combining the aforesaid data, we drew an integrated 20 km long geological cross section showing the internal geometry of the imbricate thrust system, down to the main basal décollement. The integrated section was successively restored in 2D using the software

  12. Regional Differences in Geological Conditions Related to Reservoir-forming in the Foreland Fold and Thrust Belt of Southwest Tarim Basin

    Science.gov (United States)

    Li, Danmei; Tang, Dazhen; Zhang, Shonghang; Lin, Wenji; Tao, Shu; Zhang, Biao; Xin, Weixin

    The foreland fold and thrust belt of southwest Tarim basin can be divided into four structural zones, and different tectonic sectors have quite different geological conditions related to reservoir-forming. Most favorable locations are Pusha-Keliyang zone and Sugaite-Qimugen zone, not only with many fault-propagation folds, triangle-zone structures, and three sets of excellent source rocks including Lower-Middle Cambrian carbonate, Lower Carboniferous-Lower Permian, and Jurassic dark mudstone but also with a series of good petroleum reservoir and seal combinations such as Lower-Cretaceous sandstone reservoirs associated with Paleogene cap rocks, Paleocene carbonate reservoirs, and Miocene sandstone reservoirs associated with their corresponding mudstone cap rocks, respectively. The second favorable location is Hotan thrust nappe zone with some good tectonic traps including traps of par-autochthonous system and in-situ system, and Lower-Permian mudstone as a set of high quality regional cap rocks, but their source and reservoir are relatively bad, that is, Lower-Permian carbonate source rocks just meet the criteria of gas source rocks, and Lower-Permian sandstone or carbonate reservoirs and Lower-Ordovician carbonate reservoirs are all low-porous and low-permeable in spite of Lower-Permian Pusige mudstone as excellent regional cap rocks. The last, Pamir thrust zone might not be favorable for reservoir-forming due to its large-scale nappes and distinctly-exposed thrust faults which result in the lack of good tectonic traps although there are some advantageous petroleum source-reservoir-seal combinations.

  13. Core-Log-Seismic Integrative Study of a Subduction Zone Megasplay Fault -An Example from the Nobeoka Thrust, Shimanto Belt, Southwest Japan

    Science.gov (United States)

    Hamahashi, M.; Tsuji, T.; Saito, S.; Tanikawa, W.; Hamada, Y.; Hashimoto, Y.; Kimura, G.

    2016-12-01

    Investigating the mechanical properties and deformation patterns of megathrusts in subduction zones is important to understand the generation of large earthquakes. The Nobeoka Thrust, a fossilized megasplay fault in Kyushu Shimanto Belt, southwest Japan, exposes foliated fault rocks that were formed under the temperature range of 180-350° (Kondo et al., 2005). During the Nobeoka Thrust Drilling Project (2011), core samples and geophysical logging data were obtained recovering a continuous distribution of multiple fault zones, which provide the opportunity to examine their structure and physical properties in various scales (Hamahashi et al., 2013; 2015). By performing logging data analysis, discrete sample physical property measurements, and synthetic modeling of seismic reflections along the Nobeoka Thrust, we conducted core-log-seismic integrative study to characterize the effects of damage zone architecture and structural anisotropy towards the physical properties of the megasplay. A clear contrast in physical properties across the main fault core and surrounding damage zones were identified, where the fault rocks preserve the porosity of 4.8% in the hanging wall and 7.6% in the footwall, and P-wave velocity of 4.8 km/s and 4.2 km/s, respectively. Multiple sandstone-rich- and shale-rich damage zones were found from the drilled cores, in which velocity decreases significantly in the brecciated zones. The internal structure of these foliated fault rocks consist of heterogeneous lithology and texture, and velocity anisotropy ranges 1-18% (P-wave) and 1.5-80% (S-wave), affected by structural dip angle, foliation density, and sandstone/mudstone ratio. To evaluate the fault properties at the seismogenic depth, we developed velocity/earth models and synthetic modeling of seismic reflection using acoustic logs across the thrust and parameterized lithological and structural elements in the identified multiple damage zones.

  14. Early Cretaceous overprinting of the Mesozoic Daqing Shan fold-and-thrust belt by the Hohhot metamorphic core complex, Inner Mongolia, China

    Directory of Open Access Journals (Sweden)

    Gregory A. Davis

    2010-10-01

    Full Text Available The Early Cretaceous Hohhot metamorphic core complex (mcc of the Daqing Shan (Mtns. of central Inner Mongolia is among the best exposed and most spectacular of the spatially isolated mcc’s that developed within the northern edge of the North China “craton”. All of these mcc’s were formed within the basement of a Late Paleozoic Andean-style arc and across older Mesozoic fold-and-thrust belts of variable age and tectonic vergence. The master Hohhot detachment fault roots southwards within the southern margin of the Daqing Shan for an along-strike distance of at least 120 km. Its geometry in the range to the north is complicated by interference patterns between (1 primary, large-scale NW-SE-trending convex and concave fault corrugations and (2 secondary ENE-WSW-trending antiforms and synforms that folded the detachment in its late kinematic history. As in the Whipple Mtns. of California, the Hohhot master detachment is not of the Wernicke (1981 simple rooted type; instead, it was spawned from a mid-crustal shear zone, the top of which is preserved as a mylonitic front within Carboniferous metasedimentary rocks in its exhumed lower plate. 40Ar–39Ar dating of siliceous volcanic rocks in basal sections of now isolated supradetachment basins suggest that crustal extension began at ca. 127 Ma, although lower-plate mylonitic rocks were not exposed to erosion until after ca. 119 Ma. Essentially synchronous cooling of hornblende, biotite, and muscovite in footwall mylonitic gneisses indicates very rapid exhumation and at ca. 122–120 Ma. Contrary to several recent reports, the master detachment clearly cuts across and dismembers older, north-directed thrust sheets of the Daqing Shan foreland fold-and-thrust belt. Folded and thrust-faulted basalts within its foredeep strata are as young as 132.6 ± 2.4 Ma, thus defining within 5–6 Ma the regional tectonic transition between crustal contraction and profound crustal extension.

  15. Balancing cross-sections combining field work and remote sensing data using LithoTect software in the Zagros fold-and-thrust belt, N Iraq.

    Science.gov (United States)

    Reif, Daniel; Grasemann, Bernhard; Lockhart, Duncan

    2010-05-01

    The Zagros fold-and-thrust belt has formed in detached Phanerozoic sedimentary cover rocks above a shortened crystalline Precambrian basement and evolved through the Late Cretaceous to Miocene collision between the Arabian and Eurasian plate, during which the Neotethys oceanic basin was closed. Deformation is partitioned in SW directed folding and thrusting of the sediments and NW-SE to N-S trending dextral strike slip faults. The sub-cylindrical doubly-plunging fold trains with wavelengths of 5 - 10 km host more than half of the world's hydrocarbon reserves in mostly anticlinal traps. Generally the Zagros is divided into three NW-SE striking tectonic units: the Zagros Imbricate Zone, the Zagros Simply Folded Belt and the Zagros Foredeep. This work presents a balanced cross-section through the Simply Folded Belt, NE of the city of Erbil (Kurdistan, Iraq). The regional stratigraphy comprises mainly Cretaceous to Cenozoic folded sediments consisting of massive, carbonate rocks (limestones, dolomites), reacting as competent layers during folding compared to the incompetent behavior of interlayered siltstones, claystones and marls. Although the overall security situation in Kurdistan is much better than in the rest of Iraq, structural field mapping was restricted to asphalt streets, mainly because of the contamination of the area with landmines and unexploded ordnance. In order to extend the structural measurements statistically over the investigated area, we used a newly developed software tool (www.terramath.com) for interactive structural mapping of spatial orientations (i.e. dip direction and dip angles) of the sedimentary beddings from digital elevation models. Structural field data and computed measurements where integrated and projected in NE-SW striking balanced cross-sections perpendicular to the regional trend of the fold axes. We used the software LithoTect (www.geologicsystems.com) for the restoration of the cross-sections. Depending on the interpretation

  16. Geometry and kinematics of the fold-thrust belt and structural evolution of the major Himalayan fault zones in the Darjeeling -- Sikkim Himalaya, India

    Science.gov (United States)

    Bhattacharyya, Kathakali

    The Darjeeling-Sikkim Himalaya lies in the eastern part of the Himalayan fold-thrust belt (FTB) in a zone of high arc-perpendicular convergence between the Indian and Eurasian plates. In this region two distinct faults form the Main Central thrust (MCT), the structurally higher MCT1 and the lower MCT2; both these faults have translated the Greater Himalayan hanging wall rocks farther towards the foreland than in the western Himalaya. The width of the sub-MCT Lesser Himalayan rocks progressively decreases from the western Himalaya to this part of the eastern Himalaya, and as a result, the width of the FTB is narrower in this region compared to the western Himalaya. Our structural analysis shows that in the Darjeeling-Sikkim Himalaya the sub-MCT Lesser Himalayan duplex is composed of two duplex systems and has a more complex geometry than in the rest of the Himalayan fold-thrust belt. The structurally higher Dating duplex is a hinterland-dipping duplex; the structurally lower Rangit duplex varies in geometry from a hinterland-dipping duplex in the north to an antiformal stack in the middle and a foreland-dipping duplex in the south. The MCT2 is the roof thrust of the Daling duplex and the Ramgarh thrust is the roof thrust of the Rangit duplex. In this region, the Ramgarh thrust has a complex structural history with continued reactivation during footwall imbrication. The foreland-dipping component of the Rangit duplex, along with the large displacement associated with the reactivation of the Ramgarh thrust accounts for the large translation of the MCT sheets in the Darjeeling-Sikkim Himalaya. The growth of the Lesser Himalayan duplex modified the final geometry of the overlying MCT sheets, resulting in a plunge culmination that manifests itself as a broad N-S trending "anticline" in the Darjeeling-Sikkim Himalaya. This is not a "river anticline" as its trace lies west of the Teesta river. A transport parallel balanced cross section across this region has accommodated

  17. Uncoupled vs. coupled thrust belt-foreland deformation: a model for northern Patagonia inferred from U-Th/He and apatite fission track dating

    Science.gov (United States)

    Savignano, Elisa; Mazzoli, Stefano; Zattin, Massimiliano; Gautheron, Cécile; Franchini, Marta

    2017-04-01

    The study of the Cretaceous - Cenozoic evolution of the Patagonian Andes represents a great opportunity to investigate the effects of coupling between deep lithospheric processes and near-surface deformation. Low-temperature thermochronological systems are ideally suited for detecting events involving rocks in the uppermost part of the crust because they record time and rates of cooling related to exhumation of the top few kilometers of the crust. The Patagonia region, although characterized by a general continuity of the Andean orogen along its strike, shows an appreciable internal tectonic segmentation (marked by a variable position of the magmatic arc and of the deformation front in the retroarc area) at various latitudes. This complex structural architecture has been interpreted as the result of different processes acting since the Late Cretaceous. The present-day configuration of the southern Andes is interpreted to have been controlled by alternating stages of flat- and steep-slab subduction, which produced shortening and upper plate extension episodes,, respectively. Furthermore, the deformation in this whole retroarc sector varied not only in time (i.e. with major 'cycles' of mountain building and orogenic collapse), but also in space, due to the variable transmission of horizontal compressive stress away from the orogen, that produced an irregular unroofing pattern. In this study, we have integrated field structural observations with new apatite (U-Th)/He data (AHe) and apatite fission-track (AFT) ages in the north Patagonia region (at latitudes between 40° and 44°S) in order to analyse and compare the exhumation patterns from the frontal part of the orogen and from the adjacent foreland sector, as well as to gain new insights into the timing and modes of coupling vs. uncoupling of the deformation between the northern Patagonian fold and thrust belt and its foreland. The obtained data indicate a markedly different unroofing pattern between the 'broken

  18. Pre-folding fracture development in the Lurestan region of the Zagros Fold and Thrust Belt: constraints from early fracture sets in the Shabazan and Asmari Formations

    Science.gov (United States)

    Corradetti, Amerigo; Tavani, Stefano; D'Assisi Tramparulo, Francesco; Prinzi, Ernesto Paolo; Vitale, Stefano; Parente, Mariano; Morsalnejad, Davoud; Mazzoli, Stefano

    2017-04-01

    In the Zagros Fold and Thrust Belt (FTB), the timing of fracture development with respect to folding is debated. Multiple fracture systems occur in the area. These include "typical" fracture systems that are oriented parallel and orthogonal to the NW-SE strike of the belt, as well as sets oriented N-S and E-W. The interpretation of the N-S and E-W sets is controversial. Despite the general consensus about the first-order relationship between these fractures and inherited N-S striking basement faults, their timing and kinematic significance is not yet fully understood. The ambiguous crosscutting/abutting relationships with the NE-SW and NW-SE sets, together with the difficulty of framing them into the classical scenario of fracturing in foreland basin systems, has led to the development of different hypotheses about the timing of N-S and E-W sets. For the generation of these structures, both pre- and syn-thrusting interpretations have been proposed. In this work, we report on the occurrence of bed-perpendicular fracture sets in the upper part of the Shabazan (Eocene) and in the Asmari (Oligo-Miocene) Formations of the Zagros FTB. These fractures have the peculiarity of being filled with karst material. Such filled fractures are preserved in beds showing variable angles of dip, ranging from horizontal to vertical. Their homogeneous distribution in variably dipping beds around folds undoubtedly point to an origin of these fracture sets predating the tilting of the strata in which they are contained. Therefore, fracture development and related infilling occurred at an early stage, in still flat lying strata, following the deposition of the top Shabazan and Asmari Formations. Such a deposition took place within the general framework of ongoing shortening in the Zagros. This process, occurring since the Late Cretaceous, progressively led to folding of the syn-orogenic Shabazan and Asmari Formations subsequently to the development of the studied filled fractures.

  19. Applying the anisotropy of magnetic susceptibility technique to the study of the tectonic evolution of the West Spitsbergen Fold-and-Thrust Belt

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    Katarzyna Dudzisz

    2016-12-01

    Full Text Available We demonstrate the use of the anisotropy of magnetic susceptibility (AMS method to determine the orientation of the principal tectonic strain directions developed during the formation of the West Spitsbergen Fold-and-Thrust Belt (WSFTB. The AMS measurements and extensive rock-magnetic studies of the Lower Triassic rocks reported here were focused on the recognition of the magnetic fabric, the identification of ferromagnetic minerals and an estimation of the influence of ferro- and paramagnetic minerals on magnetic susceptibility. At most sites, the paramagnetic minerals controlled the magnetic susceptibility, and at only one site the impact of ferromagnetic minerals was higher. The AMS technique documented the presence of different types of magnetic fabrics within the sampled sites. At two sites, a normal (Kmin perpendicular to the bedding magnetic fabric of sedimentary origin was detected. This was associated with a good clustering of the maximum AMS axes imposed by tectonic strain. The Kmax magnetic lineation directions obtained here parallel the general NNW–SSE trend of the WSFTB fold axial traces and thrust fronts. The two other investigated sites possessed mixed and inverted fabrics, the latter of which appear to reflect the presence of iron-bearing carbonates.

  20. Late Paleozoic low-angle southward-dipping thrust in the Züünharaa area, Mongolia: tectonic implications for the geological structures in the Sayan-Baikal and Hangai-Daur belts

    Science.gov (United States)

    Onon, Gantumur; Tsukada, Kazuhiro

    2017-10-01

    The Central Asian Orogenic Belt (CAOB) is key to understanding the Paleozoic-Mesozoic geodynamics of Eurasian continent. The geological structure of the Middle-to-Late Paleozoic rock units in the North Mongolia-West Transbaikal region is critical in revealing development process of CAOB. The region is largely comprised of rocks from the continental affinity and accretionary complexes which form the Sayan-Baikal (SB) and Hangai-Daur (HD) belts. This paper describes the lithology, stratigraphy, geological structure, and U-Pb age of the rocks in the Züünharaa area, which is located within the Haraa terrane of the HD belt in Mongolia. We identified a regional low-angle southward-dipping thrust in this area. The tectonic implication of the low-angle south-dipping thrust is discussed within the North Mongolia-West Transbaikal region. The study area exposes metamorphosed clastic rocks of the Haraa Group intruded by Ordovician-Silurian granitic rocks, Devonian felsic volcanic rocks of the Ulaan Öndör Formation, and Visean clastic rocks of the Örmögtei Formation in ascending order. The Haraa Group, granitic rock, and Ulaan Öndör Formation are cut by the low-angle southward-dipping thrust throughout this area. The rocks along the thrust are fractured to form cataclasite zone up to 40 m wide. The thrust includes granite-rhyolite clast of 450-420 Ma, and is unconformably covered by Visean Örmögtei Formation. Therefore, thrusting occurred after Ordovician-Silurian and before Visean. Late Paleozoic low-angle southward-dipping thrusts, similar to the present study, are widely distributed in the Haraa terrane of the Hangai-Daur belt and in terranes of the Sayan-Baikal belt. Whereas, the contemporaneous southeast-verging composite folds and northward-dipping thrusts are developed in the accretionary complexes, which are exposed at south of the Haraa terrane. These contrasting structures suggest a couple of "landward-verging" and "oceanward-verging" structures and may

  1. Thick-skinned tectonics within the intracontinental easternmost Atlas foreland-and-thrust belt (Tunisia): Meso-Cenozoic kinematics and implications for regional geodynamics

    Science.gov (United States)

    Belkhiria, W.; Boussiga, H.; Inoubli, M. H.

    2017-05-01

    The transition zone between western and central Mediterranean domains presents a key area to investigate kinematic interactions within the adjacent orogen systems such as the easternmost Atlas foreland-and-thrust belt. Gravity and seismic data revealed a highly structured basement, characterizing a series of structural highs and lows delimited by high-angle N-S, E-W, and NW-SE extensional faults. This basement architecture is inherited from successive extensional events related to the openings of the Triassic-Early Cretaceous Tethys oceans (i.e., Alpine Tethys, Ligurian Tethys, and Mesogea). Throughout this period, this mosaic of continental blocks significantly controlled the thickness and facies distributions. Early stages of diapirism took place along these basement faults and allowed maximum subsidence in minibasins revealed by the development of growth strata. In response to the Late Cretaceous-Eocene shortenings, these extensional faults have been reactivated as trasnpressional shear zones, giving rise to narrow pop-up structures. In addition, gravity modeling indicates crustal thinning and deep-rooted faults affecting the crust south of the Zaghouan Thrust and along E-W transfer zones. From the late Miocene, a drastic change in the stress regime is attributed to the effect of the adjacent Sicily channel on the study area. This promotes crustal thinning, basin subsidence, and channeling up of mantle-derived helium along lithospheric-scale weak zones. Our results give rise to new insights into the reactivation of inherited weakness zones of southern Tethys margin in response to the complex interaction between African and Eurasian plates accommodated by subduction, rollback, collision, and slab segmentation.

  2. Controls on size and occurrence of the largest sub-aerial landslide on Earth: Seymareh (Saidmarreh) landslide, Zagros fold-thrust belt, Iran

    Science.gov (United States)

    Roberts, N. J.; Evans, S. G.

    2009-12-01

    Gigantic (> 1 Gm3) landslides are high-magnitude, low-frequency extremes of mass movements. They are important factors in topographic evolution and hazard in mountain regions due to their magnitude. However, few examples exist for study because of their infrequency. Consequently, controls on the location and size gigantic landslides remain poorly understood. Re-examination of the Seymareh (Saidmarreh) rock avalanche, Zagros fold-thrust belt, shows it to be the largest sub-aerial landslide on Earth (initial failure volume 38 Gm3), thus representing the upper magnitude limit for terrestrial landslides. Detailed examination of the source area (including orbital remote sensing, geotechnical investigation and structural mapping) provides new insights into controls on the size and mobility of gigantic landslides. The gigantic Early Holocene rockslide initiated on the northeast limb of Kabir Kuh, the largest anticline in the Zagros fold-thrust belt, and involved the simultaneous failure of a rock mass measuring 15 km along strike. The rockslide transformed into a rock avalanche that ran-out 19.0 km, filling two adjacent valleys and overtopping an intervening low mountain ridge. The failure involved 220 m of competent jointed limestone (Asmari Formation) underlain by 580 m of weaker mudrock-dominated units. Geologic structure, geomechanical strength and topography of the source slope strongly controlled failure initiation. Extreme landslide dimensions resulted in part from extensive uniform pre-failure stability, produced by structural and topographic features related to the large scale of the Kabir Kuh anticline. High continuity bedding planes determined the large lateral extent along strike. Bedding normal joints, the breached nature of the anticline and fluvial undercutting at the slope toe accommodated expansive lateral, headscarp and toe release, respectively, necessary for extensive failure. Geomechanically weak units at depth aided the penetration of the failure

  3. High mobility of mud-core anticline responsible for anomalous high deformation rate in fold-and-thrust belt of southwestern Taiwan

    Science.gov (United States)

    Hu, Jyr-Ching; Kuo, Ying-Ping; Tan, Eh

    2017-04-01

    Anomalous high strain accommodation across the fold-and-thrust belt in SW Taiwan are revealed by the Continuous GPS, precise leveling and SAR interferometry. It is surprising to notice that the footwall of Longchuan reverse fault demonstrates a high uplift rate of 20-30 mm/yr in interseismic period. This anomalous deformation rate might part be related with a ramp duplex located in the footwall of the Longchuan reverse fault and the triggered slip of moderate earthquake in nearby area. A clear evidence of multiple fault slip along a fold-and-thrust belt at 5-10 km depth was triggered by the 2016 Mw 6.4 Meinong earthquake at 15-20 km depth. We hypothesize that the surface coseismic deformation is mainly controlled by a structure related to the shallow detachment at around 5-10 km depth, which a proposed duplex in a region of high pressure and high interseismic uplift rate might be sensitive to stress perturbations induced by moderate lower crustal earthquake. In addition, the mechanical heterogeneity of mudstone in the Gutingkang formation might play a crucial role of anomalous deformation. Consequently, we use an Efficient Unstructured Finite Element method (DynearthSol2D) to simulate and discuss the contrast of viscosity in mudstone and sandstone contributed in deformation pattern and upward mobility. We also want to check the previous hypothesis of mud diapirism and incorporate a new mud-cored anticline model for mechanic explanation of anomalous interseismic deformation occurred in SW Taiwan. The numerical predicts an uplift rate of 10 mm/yr of active folding related to ramp duplex in the footwall of the Longchuan reverse fault. The uplift rate could reach to 20 mm/yr with incorporating the high pressure zone in the ramp duplex and a backthrust of the in the footwall of the Longchuan reverse fault, which is in good agreement with the uplift rate from precise leveling. Thus we conclude that the high mobility of mud-core anticline responsible for anomalous high

  4. Kinematic Evolution of fold-and-thrust Belts in the Yubei Area: Implications for the Tectonic Events of Ordovician at the Southern Tarim Basin

    Science.gov (United States)

    Zhang, Y.

    2015-12-01

    As a response to tecto-orogenic processes of the South Altun and the West Kunlun (Monlar P, 1975; He Bizhu, 2011), early Paleozoic tectonic evolution of the southern Tarim craton was distinctively one of the extensions and was followed by compression (Morris W.Leighton, 1990; Gao Zhiqian, 2015). From the late Ordovician, the Yubei area developed distinctively NE-SW trending fold-and-thrust belts in rows which were eroded and deformed through multiphase tectonic movement (Dengfa He, 2007), with similarities and dissimilarities between each other rows in many aspects, at the Southern Tarim inner basin (Fig. 1). The northern of Hetian paleo-uplift and the northwestern of NE-trending folds zone on Caledonian in Tangguzibasi depression should be favorable to the potential exploration area for the first large-scale period of hydrocarbon migration and accumulation (Brown LF, 1979). In this contribution, based on geophysical log, core and 2D/3D seismic data, we constructed its tectonic geometry morphology, controlled by detailed chronostratigraphic framework. According to the fault-related fold theory, rows of asymmetric fault-propagation folds grew in the Yubei area during the late Caledonian period, with the evidence of interpreted growth strata from the high resolution 3D seismic data (Suppe J et al., 1990). That intercontinental tecto-orogenic events from southern Tarim basin, leading to the transformation of its margins, affected inner basin at that time, modified the basin into the Tarim metacraton (Jean-Paul Liégeois, 2013; Zieglar P.A., 1998). Correlating the four tectonic groups of the identified with the axis variation of strata and fold amplitude distribution showed that fault evolution progressed in several superimposed stages: Precambrian, late Ordovician to early Carboniferous (Zhao Zongju, 2009), Carboniferous to Permian, Cenozoic. Analyzing the sedimentary development and structure evolution the tectonic paleo-geographic setting is reconstructed, providing

  5. Age and evolution of thin-skinned deformation in Zacatecas, Mexico: Sevier orogeny evidence in the Mexican Fold-Thrust Belt

    Science.gov (United States)

    Ramírez-Peña, César Francisco; Chávez-Cabello, Gabriel

    2017-07-01

    Integrating U-Pb ages from zircons of syn- and postectonic intrusives emplaced in folded pre- and synorogenic marine sedimentary rocks, it is proposed that thin-skinned deformation in the Concepción del Oro salient of the Mexican Fold Thrust Belt in northern Zacatecas, Mexico, was active between 92 and 71.6 Ma. The intrusives Pico de Teyra and El Peñuelo (U-Pb zircon ages: 76.9 and 72.5 Ma) show internal tectonic foliations and horizontal shear zones that cut off aplitic veins, which apparently developed syntectonically to thin-skinned deformation. Other intrusives like Saltillito (71.6 Ma) and Concepción del Oro are clearly postectonic because they are undeformed internally, cut regional structures and are younger than syntectonic plutons. Biostratigraphic ages reported for synorogenic sediments (Concepción del Oro and Parras formations) indicate that regional thin-skinned deformation was active between Early Turonian and Late Campanian, which is in agreement with syn and postectonic intrusive emplacement ages in the area. Nevertheless, the thin-skinned structures are disrupted by a younger NNW-SSE high angle reverse and normal faults that uplifts the San Julián Block in the west and truncate the Concepción del Oro salient, suggesting a post-Paleocene thick-skinned stage of deformation. In this work, we propose that style and age of thin-skinned deformation is similar to the Sevier orogeny in the Rocky Mountains.

  6. Structural style and evolution of the triangle zone and external Foothills, southwestern Alberta: Implications for thin-skinned thrust-and-fold belt mechanics

    Energy Technology Data Exchange (ETDEWEB)

    Stockmal, G. S.; McMechan, M E. [Geological Survey of Canada, Calgary, AB (Canada); Lebel, D. [Geological Survey of Canada, Sainte-Foy, PQ (Canada); MacKay, P. A. [Paul MacKay Geoconsultants Ltd., Calgary, AB (Canada)

    2001-12-01

    A thin-skinned NNW-striking, structural triangular zone and steep, imbricate, dominantly foreland-vergent thrusts characterize the eastern margin of the Rocky Mountain Foothills belt in southwestern Alberta. Recent and systematic 1:50,000 scale bedrock mapping by the GSC in Alberta has added considerably to our understanding of the structural geometry and kinematics of the triangle zone and the Foothills. This paper presents observations and interpretations in the northern portion of the study area and discusses along-strike variations in structural style, with a view to a qualitative interpretation of the mechanics. In this round of GSC mapping advantage was taken of important changes in our understanding of Foothills structural style and stratigraphy. Most importantly, the structures associated with the triangle zone were explicitly mapped, a concept not developed at the time of previous mapping in 1950. Also, portions of the Cretaceous stratigraphy were subdivided into new mappable units, along with more detailed structural mapping than was possible previously. Cross sections information from reflection seismic data and exploration wells was also added. 72 refs., 32 figs.

  7. Assessment of undiscovered oil and gas resources of the East Coast Mesozoic basins of the Piedmont, Blue Ridge Thrust Belt, Atlantic Coastal Plain, and New England Provinces, 2011

    Science.gov (United States)

    Milici, Robert C.; Coleman, James L.; Rowan, Elisabeth L.; Cook, Troy A.; Charpentier, Ronald R.; Kirschbaum, Mark A.; Klett, Timothy R.; Pollastro, Richard M.; Schenk, Christopher J.

    2012-01-01

    During the early opening of the Atlantic Ocean in the Mesozoic Era, numerous extensional basins formed along the eastern margin of the North American continent from Florida northward to New England and parts of adjacent Canada. The basins extend generally from the offshore Atlantic continental margin westward beneath the Atlantic Coastal Plain to the Appalachian Mountains. Using a geology-based assessment method, the U.S. Geological Survey estimated a mean undiscovered natural gas resource of 3,860 billion cubic feet and a mean undiscovered natural gas liquids resource of 135 million barrels in continuous accumulations within five of the East Coast Mesozoic basins: the Deep River, Dan River-Danville, and Richmond basins, which are within the Piedmont Province of North Carolina and Virginia; the Taylorsville basin, which is almost entirely within the Atlantic Coastal Plain Province of Virginia and Maryland; and the southern part of the Newark basin (herein referred to as the South Newark basin), which is within the Blue Ridge Thrust Belt Province of New Jersey. The provinces, which contain these extensional basins, extend across parts of Georgia, South Carolina, North Carolina, Virginia, Maryland, Delaware, Pennsylvania, New Jersey, New York, Connecticut, and Massachusetts.

  8. Influence of thrust belt geometry and shortening rate on thermochronometer cooling ages: Insights from thermokinematic and erosion modeling of the Bhutan Himalaya

    Science.gov (United States)

    McQuarrie, Nadine; Ehlers, Todd A.

    2015-06-01

    Advancements in thermochronology and numerical modeling offer the potential to associate the age of thermochronometric samples to both exhumational and deformational processes. However, understanding how these components are related in compressional systems requires linking the geometry and magnitude of fault slip to the distribution and amount of erosion. To address this, we apply a 2-D thermokinematic model to a forward modeled balanced cross section to quantify the cooling history in fold-thrust belt settings. The restored cross section provides a kinematic path of rocks and structures necessary to reproduce the surface geology. By assigning ages to displacement amounts, we produced a range of potential velocity vectors used to calculate heat transport, erosion, and rock cooling. We test the predicted ages against a suite of previously published thermochronometric data from the Bhutan Himalaya to explore the utility of the data to constrain the timing, rate, and geometry of fault motion as well as variations in the exhumation rate. We evaluate the cooling history associated with a constant rate of shortening of 18 mm/yr, rates that are 2.0, 1.5, 0.75, and 0.5 times the constant rate, and rates that vary with time to determine which kinematic history best matches the measured cooling ages. The combination of relatively old apatite fission track and zircon (U-Th)/He measured ages and younger (15-9 Ma) 40Ar/39Ar ages from white mica is best matched with faster rates (relative to constant rates) between 11.5 and 8 Ma and slower than constant rates from 17 to 11.5 Ma and 8 Ma to present.

  9. The fracture network, a proxy for mesoscale deformation: Constraints on layer parallel shortening history from the Malargüe fold and thrust belt, Argentina

    Science.gov (United States)

    Branellec, M.; Callot, J. P.; Nivière, B.; Ringenbach, J. C.

    2015-04-01

    An analysis was performed of the fracture networks in the N-S trending thick-skinned Malargüe fold and thrust belt (MFTB). A total of 2000 planar structures including joints and veins were measured in different structural domains ranging from surficial thin-skinned systems detached in the cover to large-scale structures such as basement-cored folds. The investigated stratigraphic section ranges from the Middle Jurassic (Cuyo Group) to the Paleocene (Malargüe Group), including sandstones, siltstones, shales, and limestones. Four main fracture sets are identified trending, E-W, NW-SE, NE-SW, and N-S. The abutting relationships provide a reliable chronology between the four fracture sets which are ubiquitously found in the MFTB throughout the various structural domains. Due to this observation, we assume the fracture signal to be regional and developed in response to both large-scale processes and folding. In particular, based on a fold test and the characteristics of data dispersion, the fracture sets I, II, and III exhibit a prefolding origin, while set IV shows a synfolding origin. A regional interpretation of the various fractures is proposed, involving several stages of fracture formation from compaction to folding, including prefolding layer parallel shortening. The fracture signal yields useful insights about the structural history of the MFTB and the spatiotemporal evolution of the foreland tectonic regime since Late Cretaceous times. We then place the various identified fracture sets into the known pattern of geodynamic evolution since the Late Cretaceous.

  10. Polyphase deformation and metamorphism of the Cuiabá group in the Poconé region (MT, Paraguay Fold and Thrust Belt: kinematic and tectonic implications

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    Bruno Rodrigo Vasconcelos

    Full Text Available Several deformation models have been proposed for the Paraguay Belt, which primarily differ in the number of phases of deformation, direction of vergence and tectonic style. Structural features presented in this work indicate that the tectonics was dominated by low dip thrust sheets in an initial phase, followed by two progressive deformation phases. The first phase of deformation is characterized by a slate cleavage and axial plane of isoclinal recumbent folds with a NE axial direction, with a recrystallization of the minerals in the greenschist facies associated with horizontal shear zones with a top-to-the-SE sense of movement. The second stage shows vergence towards the NW, characterized by crenulation cleavage axial plane to F2 open folds over S0 and S1, locally associated with reverse faults. The third phase of deformation is characterized by subvertical faults and fractures with a NW direction showing sinistral movement, which are commonly filled by quartz veins. The collection of tectonic structures and metamorphic paragenesis described indicate that the most intense deformation at the deeper crustal level, greenschistfacies, occurred during F1, which accommodated significant crustal shortening through isoclinal recumbent folds and shear zones with low dip angles and hangwall movement to the SE, in a thin-skinned tectonic regime. The F2 deformation phase was less intense and had a brittle to ductile behavior that accommodated a slight shortening through normal open subvertical folds, and reverse faults developed in shallower crustal level, with vergence towards the Amazonian Craton. The third phase was less pervasive, and the shortening was accommodated by relief subvertical sinistral faults.

  11. Mechanical study of the Chartreuse Fold-and-Thrust Belt: relationships between fluids overpressure and decollement within the Toarcian source-rock

    Science.gov (United States)

    Berthelon, Josselin; Sassi, William; Burov, Evgueni

    2016-04-01

    Many source-rocks are shale and constitute potential detachment levels in Fold-and-Thrust Belts (FTB): the toarcian Schistes-Cartons in the French Chartreuse FTB for example. Their mechanical properties can change during their burial and thermal maturation, as for example when large amount of hydrocarbon fluids are generated. A structural reconstruction of the Chartreuse FTB geo-history places the Toarcian Formation as the major decollement horizon. In this work, a mechanical analysis integrating the fluids overpressuring development is proposed to discuss on the validity of the structural interpretation. At first, an analogue of the Chartreuse Toarcian Fm, the albanian Posidonia Schist, is documented as it can provide insights on its initial properties and composition of its kerogen content. Laboratory characterisation documents the vertical evolution of the mineralogical, geochemical and mechanical parameters of this potential decollement layer. These physical parameters (i.e. Total Organic Carbon (TOC), porosity/permeability relationship, friction coefficient) are used to address overpressure buildup in the frontal part of the Chartreuse FTB with TEMISFlow Arctem Basin modelling approach (Faille et al, 2014) and the structural emplacement of the Chartreuse thrust units using the FLAMAR thermo-mechanical model (Burov et al, 2014). The hydro-mechanical modeling results highlight the calendar, distribution and magnitude of the overpressure that developed within the source-rock in the footwall of a simple fault-bend fold structure localized in the frontal part of the Chartreuse FTB. Several key geological conditions are required to create an overpressure able to fracture the shale-rocks and induce a significant change in the rheological behaviour: high TOC, low permeability, favourable structural evolution. These models highlight the importance of modeling the impact of a diffuse natural hydraulic fracturing to explain fluids propagation toward the foreland within

  12. Combining paleomagnetism and structural geology to better understand complex orogenic systems: development of a robust kinematic model for Sevier fold-thrust belt and Laramide foreland of Wyoming, U.S.A.

    Science.gov (United States)

    Weil, Arlo; Yonkee, Adolph

    2013-04-01

    Varying patterns of layer-parallel shortening (LPS) and vertical-axis rotations from the thin-skin Sevier fold-thrust belt to the thick-skin Laramide foreland of Wyoming are quantified from integrated structural, anisotropy of magnetic susceptibility (AMS), and paleomagnetic analyses. Within the Sevier belt, widespread early LPS was accommodated by spaced cleavage, fracture sets, minor folds, and minor faults. LPS directions are subperpendicular to structural trends of systematically curved thrust sheets of the Wyoming salient, reflecting a combination of primary dispersion and secondary rotation during thrusting. Within the Laramide foreland, limited LPS was accommodated mostly by minor faults with conjugate wedge and strike-slip geometries. LPS directions in gentler fold limbs vary from perpendicular to acute with structural trends of variably oriented, anastomosing basement-cored arches. Steep forelimbs display more complex relations, including younger fault sets that developed during evolving stress states and localized vertical-axis rotations. Although internal strain is limited, weak AMS lineations defined by kinked and rotated phyllosilicates are widely developed and consistently oriented perpendicular to measured LPS directions. Palinspastically restored LPS directions, corrected for paleomagnetically determined vertical-axis rotations, vary on average from W-E in the Sevier belt to WSW-ENE in the Laramide foreland. In detail, LPS directions display deflections related to primary sedimentary wedge geometry and basement fabrics. LPS in the Sevier belt is interpreted to partly reflect stress transmitted from the hinterland through the growing orogenic wedge and topographic stress along the front of the wedge. LPS in the Laramide foreland is interpreted to partly reflect basal traction during flat-slab subduction beneath thick cratonic lithosphere, with spatial-temporal variations in stress trajectories related to basement heterogeneities and evolving fault

  13. Deep Structure of the Fold-and-Thrust Belt in the Tenpoku Area, Northern Hokkaido Island, Japan, Revealed by Reprocessing of Seismic Reflection Data From the 1990 MITI Geophysical Explorations.

    Science.gov (United States)

    Yokokura, T.; Miyazaki, T.; Kano, N.

    2005-12-01

    The Tenpoku area, the northern part of Hokkaido island, Japan, is believed to have hydrocarbon potential in the thick Cretaceous-Tertiary sediments. Ministry of International Trade and Industry (MITI, present Ministry of Economy, Trade and Industry) and some private companies have conducted many geological and geophysical explorations and test drillings in this area. These surveys have revealed that some anticlines (e.g. Horonobe and Toyotomi anticlines) and faults (e.g. Ohmagari and Horonobe faults) exist in the mountainous area and that a large sedimentary basin extends from the west of the mountainous area to the Japan Sea. The area shows a fold-and-thrust belt structure of west vergence. There is an active Sarobetsu flexural zone in the eastern end of the sedimentary basin. The flexural zone is believed to have become active since the middle Pliocene. In this way, overall geological structure down to around 5km in depth is well known, while there is few information about the deeper part. Japan National Oil Corporation (present Japan Oil, Gas and Metals National Corporation (JOGMEC)) conducted seismic reflection surveys in this area in 1990 on consignment from MITI. Part of the seismic reflection data was acquired by using dynamite and has long two-way traveltime of 18sec. As the seismic data may provide us deeper information on this fold-and-thrust belt, we tried to reprocess the data with permission by JOGMEC. As a result, we found that two low-angle east-dipping thrusts extend to around 10km in depth, which are related to the Ohmagari fault and Sarobetsu flexural zone. Beneath these thrusts, some other east-dipping thrusts also exist which may be related to micro-earthquake activity of this area.

  14. Stratigraphy and Folding in the Cenozoic Cover of a Fold-Thrust Belt in the Nallıhan Region (Ankara, Central Turkey)

    Science.gov (United States)

    Karaaǧaç, Serdal; Koral, Hayrettin

    2017-04-01

    This study investigates stratigraphy and structural features in the Cenozoic sedimentary sequence of the fold-thrust belt of the Nallıhan-Ankara region, located to the north of the İzmir-Ankara-Erzincan Suture Zone. Permian-Triassic age marble intercalated with schist-phyllites, the upper Jurassic-lower Cretaceous age limestone and the upper Cretaceous age sandstone-shale alternation compose the basement in the study area. These rocks are unconformably overlain by the Cenozoic age terrestrial sedimentary and volcanic units. The Cenozoic stratigraphy begins with the Paleocene-Eocene age coal-bearing, at times, volcanic intercalated conglomerate-sandstone-mudstone alternation of alluvial-fluvial origins (Aksaklar Formation) and the tuff intercalated with lacustrine limestone, bituminous limestone (Kabalar Formation). These units are conformably overlain by the Eocene age basalt-andesite and pyroclastic rocks (Meyildere volcanics). The Paleocene-Eocene aged units are unconformably overlain by the conglomerate-sandstone-mudstone-marl of a lower-middle Miocene lacustrine environment (Hançili Formation). The terrestrial conglomerate-sandstone alternation (Örencik Formation) is the youngest unit in the Cenozoic stratigraphy, and is assumed to be of Pliocene age based its stratigraphic position on older units. Field study shows existence of both folds and faults in the sedimentary cover. Stereographic projections of bedding measured in the field shows N25W/45NW and N60W/4SE-oriented fold axes in the Paleocene-Eocene age units. There are also N76W/12SE and N88E/8NE-oriented folds. The difference in fold-axis orientations suggests that some folds may have been rotated in blocks bound by faults during the post-Paleocene/Eocene period. Whereas, the lower-middle Miocene units manifest N88W/13SE-oriented fold axes. It is thus proposed that the observed difference in the azimuth of fold axes represent two different folding phases, one with NE-SW and the other with N

  15. Sedimentation in an Active Fold and Thrust Belt, Santa Barbara Basin, CA: Spatial and Temporal Evolution from 1.0 Ma to Present

    Science.gov (United States)

    Marshall, C. J.; Sorlien, C. C.; Nicholson, C.; Behl, R. J.; Kennett, J.

    2009-12-01

    The east-west-trending Santa Barbara Basin is part of an active fold and thrust belt within the Western Transverse Ranges province related to block rotation and north-south transpression associated with a continental transform plate boundary. This setting provides an excellent opportunity to study the relation between tectonics and sedimentation within a dynamic margin setting. Isochore maps derived from high-quality grids of seismic reflection profiles document dramatic shifts in location, shape, and accumulation rate of sedimentary depocenters in Santa Barbara Basin during the last 1 Myr. Isochore maps are defined by distinctive sequence boundaries and other stratigraphic horizons identified on deep-penetration industry multichannel seismic (MCS) data, and high-resolution MCS and USGS towed chirp data acquired during 2005 and 2008 research cruises. Horizon ages were assigned based on correlation to well-dated ODP Site 893, a previously recognized 1-Ma horizon derived from industry well logs, and interpolation between dated tephra layers, biostratigraphic markers, and MIS climate transitions identified from oxygen isotopic analysis of recovered cores that sample strata back to ~700 ka. Horizons were interpreted and correlated across the eastern and central basin, extending beyond ODP Site 893, then gridded. Isochore thickness maps were created from the gridded horizons, first in two-way travel time, then converted to depth and volume. Over much of the basin, average sediment accumulation rates (uncorrected for compaction) since 1 Ma are remarkably high (~1.0 to 1.5 m/kyr) and the spatial pattern is relatively constant. Rates were highest between 1 Ma and ~500 ka in the central portion of the Santa Barbara Channel (near ODP Site 893), but then decreased owing possibly to diversion of sediment into Santa Monica Bay with the initiation of the Hueneme fan. Since ~710 ka, most basin sedimentation has been focused within a WNW-ESE-trending offshore trough located

  16. A REMARKABLE CLADONIACEAE FLORA AT SUBANDEAN REGION IN CHÁMEZA (CASANARE, COLOMBIA

    Directory of Open Access Journals (Sweden)

    LADY JOHANNA HERRERA VARGAS

    2014-12-01

    Full Text Available A remarkable Cladoniaceae flora was discovered in the subandean region of Chámeza, ( Casanare, Colombia at 1200 meters above sea level. Four species of the genus Cladonia (Cladoniaceae, Lichenized Fungi are new records for Colombia : Cladonia macilentoides, C. scabriuscula, C. sipmanii and C. subdelicatula. This shows the importance of increasing diversity studies at mid elevations where suitable habitats for species of Cladonia occur.

  17. Large-scale thrusting at the northern Junggar Basin since Cretaceous and its implications for the rejuvenation of the Central Asian Orogenic Belt

    Directory of Open Access Journals (Sweden)

    Jieyun Tang

    2015-03-01

    Full Text Available The Wulungu Depression is the northernmost first-order tectonic unit in the Junggar Basin. It can be divided into three sub-units: the Hongyan step-fault zone, the Suosuoquan sag and the Wulungu south slope. The Cenozoic strata in the basin are intact and Mesozoic–Cenozoic deformation can be observed in the Wulungu step-fault zone, so this is an ideal place to study the Mesozoic–Cenozoic deformation. By integration of fault-related folding theories, regional geology and drilling data, the strata of the Cretaceous–Paleogene systems are divided into small layers which are selected as the subjects of this research. The combination of the developing unconformity with existing growth strata makes it conceivable that faults on the step-fault zone have experienced different degrees of reactivation of movement since the Cretaceous. Evolutionary analyses of the small layers using 2D-Move software showed certain differences in the reactivation of different segments of the Wulungu Depression such as the timing of reactivation of thrusting, for which the reactivity time of the eastern segment was late compared with those of the western and middle segments. In addition the resurrection strength was similarly slightly different, with the shortening rate being higher in the western segment than in the other segments. Moreover, the thrust fault mechanism is basement-involved combined with triangle shear fold, for which a forward evolution model was proposed.

  18. Anomalous high deformation rate in mudstone of fold-and-thrust belt in southwestern Taiwan: mud diapirism or mud-core anticline?

    Science.gov (United States)

    Kuo, Ying-Ping; Tung, Hsin; Hu, Jyr-Ching; Tan, Eh

    2016-04-01

    The southwestern Taiwan is located in the transition zone of an active accretionary wedge and the northern end of the Manila trench, where the thrust sheets demonstrate a distinctive deformation pattern. To characterize the deformation pattern, we use the PSInSAR technique with constrains by precise leveling and GPS measurements to derive the line of sight (LOS) velocities of the study area. From different periods of SAR images of various wavelengths and different periods (e.g. ERS, Envisat and ALOS satellites), we noticed that the boundary between the subsidence and the uplift area roughly aligns with the deformation front. The main subsidence area is in the Chianan coastal plain with a LOS velocity of ~ 30 mm/yr relative to a continuous GPS station LIKN as a local reference point. The maximum LOS velocities of ~ 20 - 30 mm/yr is recorded on an active fault-related folding in Tainan tableland and the footwall of Longchuan reverse fault in Gutingkang mudstone formation. From PSInSAR and GPS measurements, the northern segment of the Longchuan fault shows a high LOS velocity gradient of ~ 10 - 15 mm/yr with a right-lateral component of 4 mm/yr across the fault. However, it demonstrates a reverse fault with a left-lateral component of about 10 mm/yr at the middle segment, while it turns back to a reverse fault with a right-lateral component at the southern segment. Based on precise leveling data, the footwall of Longchuan reverse fault demonstrates a very high uplift rate of ~ 20 - 30 mm/yr, which is unusual for a reverse fault. The anomalous deformation rate might part be related with a ramp duplex located in the footwall and the triggered slip of moderate earthquake in nearby area. In addition, high uplift rate of footwall can be also observed in the surrounding area (Chishan fault), and it might be due to the mechanical heterogeneity of mudstone in the Gutingkang formation. Consequently, we use DynearthSol3D, an efficient unstructured finite element code, to

  19. Late Dolomitization in Basinal Limestones of the Southern Apennines Fold and Thrust Belt (Italy Dolomitisation tardo-diagénétique dans les calcaires de bassins triassiques de l’Apennin Méridionale (Italie

    Directory of Open Access Journals (Sweden)

    Iannace A.

    2012-02-01

    Full Text Available The Triassic pelagic carbonates of the Lagonegro Units from the southern Apennines fold and thrust belt host discordant bodies of dolostone. These rocks show textural features typical of zebra or saddle dolomites. In this contribution, the results of field observations, petrography and geochemical analyzes performed on samples from three different outcrops are presented. Field data indicate that the peculiar zebra-type rock and brecciated fabrics were controlled by regular bedding of the micritic, pelagic limestones. The dolomitization resulted in the replacement of the host limestones and subsequent void-filling precipitation of dolomite in a dilatational stress field. Homogenization temperatures (Th are in the range 80-120°C, with a clear mode of 95 ÷ 10°C. When corrected for maximum pressure, they indicate an upper limit for dolomite formation around 110-115°C. Melting temperatures of ice (Tmi point to salinities in the range 2-6 wt% NaCl eq, with a mean of 4.2%. δ13C values overlap those of the Upper Triassic seawater, whereas the δ18O values are significantly depleted compared to the coeval seawater. 87Sr/86Sr values are higher with respect to Upper Triassic seawater, and partially overlap Middle-Upper Miocene values. The performed analyzes indicate a dolomitization process driven by warm fluids (110-115°C with a salinity close to that of seawater and O-isotope ratios comprised between seawater and formation waters. It is suggested that the dolomitization was accomplished by formation waters squeezed out or from surrounding lithologies or from the underlying mélange units. Integration with available thermal data on the collisional history of the belt suggests that the fluid-flow took place after maximum burial, in the early stages of exhumation, in the assumption of a fluid in thermal equilibrium with the host rocks. According to literature data, the dolomitization event was quite widespread. It can be argued that it was part of a

  20. Geologic framework for the national assessment of carbon dioxide storage resources: Greater Green River Basin, Wyoming, Colorado, and Utah, and Wyoming-Idaho-Utah Thrust Belt: Chapter E in Geologic framework for the national assessment of carbon dioxide storage resources

    Science.gov (United States)

    Buursink, Marc L.; Slucher, Ernie R.; Brennan, Sean T.; Doolan, Colin A.; Drake II, Ronald M.; Merrill, Matthew D.; Warwick, Peter D.; Blondes, Madalyn S.; Freeman, P.A.; Cahan, Steven M.; DeVera, Christina A.; Lohr, Celeste D.

    2014-01-01

    The 2007 Energy Independence and Security Act (Public Law 110–140) directs the U.S. Geological Survey (USGS) to conduct a national assessment of potential geologic storage resources for carbon dioxide (CO2). The methodology used by the USGS for the national CO2 assessment follows up on previous USGS work. The methodology is non-economic and intended to be used at regional to subbasinal scales. This report identifies and contains geologic descriptions of 14 storage assessment units (SAUs) in Ordovician to Upper Cretaceous sedimentary rocks within the Greater Green River Basin (GGRB) of Wyoming, Colorado, and Utah, and eight SAUs in Ordovician to Upper Cretaceous sedimentary rocks within the Wyoming-Idaho-Utah Thrust Belt (WIUTB). The GGRB and WIUTB are contiguous with nearly identical geologic units; however, the GGRB is larger in size, whereas the WIUTB is more structurally complex. This report focuses on the characteristics, specified in the methodology, that influence the potential CO2 storage resource in the SAUs. Specific descriptions of the SAU boundaries, as well as their sealing and reservoir units, are included. Properties for each SAU, such as depth to top, gross thickness, porosity, permeability, groundwater quality, and structural reservoir traps, are typically provided to illustrate geologic factors critical to the assessment. This geologic information was employed, as specified in the USGS methodology, to calculate a probabilistic distribution of potential storage resources in each SAU. Figures in this report show SAU boundaries and cell maps of well penetrations through sealing units into the top of the storage formations. The cell maps show the number of penetrating wells within one square mile and are derived from interpretations of variably attributed well data and a digital compilation that is known not to include all drilling.

  1. Incadendron : a new genus of Euphorbiaceae tribe Hippomaneae from the sub-Andean cordilleras of Ecuador and Peru

    Directory of Open Access Journals (Sweden)

    Kenneth J. Wurdack

    2017-08-01

    Full Text Available Incadendron esseri K.Wurdack & Farfan, gen. & sp. nov., from the wet sub-Andean cordilleras of Ecuador (Cordillera del Cóndor and Peru (Cusco, Oxapampa is described and illustrated. This recently discovered large canopy tree with a narrow elevational range presents an unusual combination of rare morphological characters in Hippomaneae including mucilage-secreting sheathing stipules, conduplicate ptyxis, and large, woody fruits. The broader significance of these characters in Hippomaneae is discussed. The morphology and anatomy of Incadendron were investigated, highlighting its fruit similarities with Guiana Shield endemic Senefelderopsis, and the systematics value of ptyxis variation, which remains poorly studied for the family.

  2. Blueschist-facies metamorphism related to regional thrust faulting

    Science.gov (United States)

    Blake, M.C.; Irwin, W.P.; Coleman, R.G.

    1969-01-01

    Rocks of the blueschist (glaucophane schist) facies occur throughout the world in narrow tectonic belts associated with ultramafic rocks. In the Coast Range province of California, blueschist rocks are devloped in the eugeosynclinal Franciscan Formation of Late Mesozoic age. The blueschist rocks form a narrow belt for more than 800 km along the eastern margin of this province and commonly are separated from rocks of an overlying thrust plate by serpentinite. Increasing metamorphism upward toward the thrust fault is indicated mineralogically by a transition from pumpellyite to lawsonite and texturally by a transition from metagraywacke to schist. The blueschist metamorphism probably occurred during thrusting in a zone of anomalously high water pressure in the lower plate along the sole of the thrust fault. This tectonic mode of origin for blueschist differs from the generally accepted hypothesis involving extreme depth of burial. Other belts of blueschist-facies rocks, including the Sanbagawa belt of Japan, the marginal synclinal belt of New Zealand, and the blueschist-ultramafic belts of Venezuela, Kamchatka, Ural mountains, and New Caledonia have similar geologic relations and might be explained in the same manner. ?? 1969.

  3. The Overthrust Belt of Western North America

    Energy Technology Data Exchange (ETDEWEB)

    Verrall, P.

    1993-02-01

    The Overthrust Belt extends for 5000 mi (8000 km) from the Brooks Range in Alaska to the Sierra Madre Oriental in Mexico. It consists of northeastward vergent thrust and fold structures involving late Precambrian to early Tertiary sedimentary section. These sediments represent deposition off the western rift margin, formed in late Precambrian time, of the North American Precambrian craton. The northeastward thrusting continued throughout the Mesozoic as a response to the convergence of the East Pacific Plate with the North American Plate. This convergence resulted in subduction beneath the North American Plate except at the northwest end (the Brooks Range) where the result was obduction. Convergence ceased when the west edge of the East Pacific Plate reached the subduction zone. The sedimentary section involved in the Thrust Belt contains good Devonian to Cretaceous hydrocarbon source rocks, and Ordovician to traps related to the thrusting (simple thrust sheets, imbricate thrust sheets, folded thrust sheets, step anticlines, footwall cutoffs, footwall anticlines, etc.). Field methods involved in exploration for hydrocarbons include field geological mapping, remote sensing (aerial photography and Landsat imagery), various seismic refraction and seismic reflection techniques (including modern detailed three dimension surveys) and potential field methods such as gravity and magnetic surveying. Studies of the field data include paleontology, source rock and hydrocarbon migration studies, structural and stratigraphic analyses, and the processing of geophysical data. This work has succeeded in two major areas: the Western Canadian Rocky Mountain Foothills, a major gas province producing mainly from Paleozoic reservoirs; and the Wyoming-Idaho-Utah portion of the thrust belt, also a major gas producer from Paleozoic reservoirs and, in addition, a major oil producer from the Jurassic Nugget Sandstone.

  4. Molecular belts.

    Science.gov (United States)

    Evans, Paul J; Jasti, Ramesh

    2014-01-01

    Rigid hydrocarbon macrocycles with radially-oriented π-systems and continuous conjugation have attracted great interest in recent years. These molecular belts have novel optoelectronic properties and host-guest behavior. Certain belts may also ultimately lead to a rational synthesis of carbon nanotubes. The high strain associated with the nonplanar, conjugated backbones requires the development of new synthetic methods, and clever synthetic design. Herein we describe the synthetic history and properties of these structurally simple but synthetically challenging molecules.

  5. Variable thrust cartridge

    Science.gov (United States)

    Taleyarkhan, Rusi P.

    2000-11-07

    The present invention is a variable thrust cartridge comprising a water-molten aluminum reaction chamber from which a slug is propelled. The cartridge comprises a firing system that initiates a controlled explosion from the reaction chamber. The explosive force provides a thrust to a slug, preferably contained within the cartridge.

  6. Analecta of structures formed during the 28 June 1992 Landers-Big Bear, California earthquake sequence (including maps of shear zones, belts of shear zones, tectonic ridge, duplex en echelon fault, fault elements, and thrusts in restraining steps)

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, A.M.; Johnson, N.A.; Johnson, K.M.; Wei, W. [Purdue Univ., West Lafayette, IN (United States). Dept. of Earth and Atmospheric Sciences; Fleming, R.W. [Geological Survey, Denver, CO (United States); Cruikshank, K.M. [Portland State Univ., OR (United States). Dept. of Geology; Martosudarmo, S.Y. [BPP Technologi, Jakarta (Indonesia)

    1997-12-31

    The June 28, 1992, M{sub s} 7.5 earthquake at Landers, California, which occurred about 10 km north of the community of Yucca Valley, California, produced spectacular ground rupturing more than 80 km in length (Hough and others, 1993). The ground rupturing, which was dominated by right-lateral shearing, extended along at least four distinct faults arranged broadly en echelon. The faults were connected through wide transfer zones by stepovers, consisting of right-lateral fault zones and tension cracks. The Landers earthquakes occurred in the desert of southeastern California, where details of ruptures were well preserved, and patterns of rupturing were generally unaffected by urbanization. The structures were varied and well-displayed and, because the differential displacements were so large, spectacular. The scarcity of vegetation, the aridity of the area, the compactness of the alluvium and bedrock, and the relative isotropy and brittleness of surficial materials collaborated to provide a marvelous visual record of the character of the deformation zones. The authors present a series of analecta -- that is, verbal clips or snippets -- dealing with a variety of structures, including belts of shear zones, segmentation of ruptures, rotating fault block, en echelon fault zones, releasing duplex structures, spines, and ramps. All of these structures are documented with detailed maps in text figures or in plates (in pocket). The purpose is to describe the structures and to present an understanding of the mechanics of their formation. Hence, most descriptions focus on structures where the authors have information on differential displacements as well as spatial data on the position and orientation of fractures.

  7. Great Belt

    DEFF Research Database (Denmark)

    Sørensen, Carsten S.; Kristensen, Per S.; Erichsen, Lars

    1992-01-01

    This paper describes aspects of the soil investigations and geotechnical evaluations for the foundation design of the 6.6 km long Great Belt West Bridge. The gravity foundations rest predominantly on glacial tills and pre-quaternary limestone. Special investigations for assessment of the soil...

  8. Bivergent thrust wedges surrounding oceanic island arcs: Insight from observations and sandbox models of the northeastern caribbean plate

    Science.gov (United States)

    ten Brink, Uri S.; Marshak, S.; Granja, Bruna J. L.

    2009-01-01

    At several localities around the world, thrust belts have developed on both sides of oceanic island arcs (e.g., Java-Timor, Panama, Vanuatu, and the northeastern Caribbean). In these localities, the overall vergence of the backarc thrust belt is opposite to that of the forearc thrust belt. For example, in the northeastern Caribbean, a north-verging accretionary prism lies to the north of the Eastern Greater Antilles arc (Hispaniola and Puerto Rico), whereas a south-verging thrust belt called the Muertos thrust belt lies to the south. Researchers have attributed such bivergent geometry to several processes, including: reversal of subduction polarity; subduction-driven mantle flow; stress transmission across the arc; gravitational spreading of the arc; and magmatic inflation within the arc. New observations of deformational features in the Muertos thrust belt and of fault geometries produced in sandbox kinematic models, along with examination of published studies of island arcs, lead to the conclusion that the bivergence of thrusting in island arcs can develop without reversal of subduction polarity, without subarc mantle flow, and without magmatic inflation. We suggest that the Eastern Greater Antilles arc and comparable arcs are simply crustalscale bivergent (or "doubly vergent") thrust wedges formed during unidirectional subduction. Sandbox kinematic modeling suggests, in addition, that a broad retrowedge containing an imbricate fan of thrusts develops only where the arc behaves relatively rigidly. In such cases, the arc acts as a backstop that transmits compressive stress into the backarc region. Further, modeling shows that when arcs behave as rigid blocks, the strike-slip component of oblique convergence is accommodated entirely within the prowedge and the arc-the retrowedge hosts only dip-slip faulting ("frontal thrusting"). The existence of large retrowedges and the distribution of faulting in an island arc may, therefore, be evidence that the arc is

  9. Upslope-verging back thrusts developed during downslope-directed slumping of mass transport deposits

    Science.gov (United States)

    Alsop, G. I.; Marco, S.; Weinberger, R.; Levi, T.

    2017-07-01

    While much research has recently been focussed on downslope-verging systems of gravity-driven fold and thrust belts within mass transport deposits (MTDs), rather less attention has been paid to back thrusts, which are defined as displaying the opposite vergence to the main transport direction in thrust systems. A fundamental question arises over whether back thrusts in downslope-verging MTDs record actual movement back upslope. In order to address this issue, we have examined exceptional outcrops of Pleistocene fold and thrust systems developed in MTDs around the Dead Sea Basin. Back thrusts can be interpreted in terms of a 'downslope-directed underthrust model', where material moves down slope and is driven into the footwall of the back thrust, resulting in the 'jacking up' of the largely passive hangingwall. Our data support this underthrust model and include the observation that stratigraphic units may be markedly thickened (up to 250%) in the footwall of back thrusts. This thickening is a consequence of pure shear lateral compaction as the 'wedge' of sediment is driven into the footwall to create an underthrust. In addition, back thrusts may be rotated as new back thrusts form in their footwalls, ultimately resulting in overturned thrusts. The observation that steeper back thrusts typically accommodate less displacement than gently-dipping back thrusts suggests that steepening occurred during back thrusting, and is therefore a consequence of 'footwall wedging'. Contrary to some recent interpretations, we demonstrate that back thrusts can develop in gravity-driven systems and cannot therefore be used to distinguish different emplacement mechanisms for MTDs.

  10. Recommended Practices in Thrust Measurements

    Science.gov (United States)

    2013-10-01

    thruster is an important measurement parameter. For instance, the thrusters for the ST7/ LISA Pathfinder mission had to demonstrate a thrust noise level...Ceccanti, F., Priami, L., and Paita, L., “Direct Thrust and Thrust Noise Measurements on the LISA Pathfinder Field Emission Thruster IEPC-2009-183

  11. Mechanical power, thrust power

    OpenAIRE

    Gatta, Giorgio; Cortesi, Matteo; Swaine, Ian; Zamparo, Paola

    2017-01-01

    The purpose of this study was to explore the relationships between mechanical power, thrust power, propelling efficiency and sprint performance in elite swimmers. Mechanical power was measured in 12 elite sprint male swimmers: i) in the laboratory, by using a whole body swimming ergometer (W’TOT); and ii) in the pool, by measuring full tethered swimming force (FT) and maximal swimming velocity (Vmax): W’T = FT .Vmax. Propelling efficiency ( P) was estimated based on the “paddle wheel model“ a...

  12. Laterally bendable belt conveyor

    Science.gov (United States)

    Peterson, William J.

    1985-01-01

    An endless, laterally flexible and bendable belt conveyor particularly adapted for coal mining applications in facilitating the transport of the extracted coal up- or downslope and around corners in a continuous manner is disclosed. The conveying means includes a flat rubber belt reinforced along the middle portion thereof along which the major portion of the belt tension is directed so as to cause rotation of the tubular shaped belt when trammed around lateral turns thus preventing excessive belt bulging distortion between adjacent belt supports which would inhibit belt transport. Pretension induced into the fabric reinforced flat rubber belt by conventional belt take-up means supports the load conveyed when the belt conveyor is making lateral turns. The carrying and return portions of the belt are supported and formed into a tubular shape by a plurality of shapers positioned along its length. Each shaper is supported from above by a monorail and includes clusters of idler rollers which support the belt. Additional cluster rollers in each shaper permit the belt supporting roller clusters to rotate in response to the belt's operating tension imposed upon the cluster rollers by induced lateral belt friction forces. The freely rotating roller clusters thus permit the belt to twist on lateral curves without damage to itself while precluding escape of the conveyed material by effectively enclosing it in the tube-shaped, inner belt transport length.

  13. Basement involved thrusts from Northwestern Maracaibo Basin

    Energy Technology Data Exchange (ETDEWEB)

    Audemard, F. (Intevep, S.A., Caracas (Venezuela))

    1993-02-01

    The interpretation of seismic reflection profiles from northwestern Maracaibo Basin, north of the Palmar River, suggests a late Neogene age for all the structures located within the north-northeast trends of anticlinal belts. These folded structures appear to be ramp anticlines generated from basement involved thrusts. Such detachments are intercepted by conjugate systems of low-angle decollements decoupled from the thick shaly intervals of Cretaceous and Eocene age. The resulting configuration of these fault systems are related to a mechanic of deformation referred as [open quotes]fish tail[close quotes]. This structural style favors the superposition of structural traps at different levels. The superposed reservoirs from La Paz, Mara, Sibucara, Mara Oeste, and Ensenada among others constitute superb examples of this style of deformation. Similar anticlinal structures are also observed to the southeast of the Basin in the Ceuta-Tomoporo area.

  14. Seat belt reminders.

    NARCIS (Netherlands)

    2008-01-01

    Seat belts are an effective way of reducing the number or road deaths and severe road injuries in crashes. Seat belt reminders warn car drivers and passengers if the seat belt is not fastened. This can be done by a visual signal or an acoustic signal or by a combination of the two. Seat belt

  15. The role of pre-existing thrust ramps on the evolution of a differently oriented thrust systems

    Science.gov (United States)

    Bonini, Lorenzo; Pini, Gian Andrea; Ponton, Maurizio; Del Ben, Anna

    2017-04-01

    In the accretionary wedges, as well as in fold-and-thrust belts, shortening is mostly accommodated by fault-related folding. This kind of structures are sensitive both to internal factors such as the mechanical characteristics of the rocks involved in contractional processes, and to external ones such as erosion or syn-kinematics sedimentation. Notwithstanding such diversity, the resulting geometries are commonly composed by faults with flat and ramp trajectory and their related folds. The above mentioned factors may directly affect both the geometry and the kinematics of a fault-related folding, for instance, the location, the number, and the frictional properties of weak horizons lead the location and the extent of the flat portion of the thrust systems. The mechanical properties of the rocks involved in the contractional phase impacts on the location and geometry of the thrust ramp. Thus, the stratigraphic and tectonic architecture of an area is central to predict or study the evolution of a contractional system. Among different factors, we select to test the role of pre-existing thrust ramp on the subsequent evolution on differently oriented thrust ramp. As a method we use analogue modeling and as an analogue material we use wet clay (kaolin). We reproduce different setups varying the initial orientation of the pre-existing thrust ramp with respect to the new ramp that we force to nucleate in the same region of the experiment box. The tested angles vary from 0°, i.e. the two ramps are parallel, to 90°, i.e. the two ramps are perpendicular. Our results show that the angle between the two systems directly impact on the degree of development of new ramps. When the angle between new and pre-existing thrust ramps is low, e.g. <30°, the reactivation of the pre-existing ramp prevail on the development of a new ramp. Conversely, high angles promote the development of new thrust ramps optimally oriented with respect to the imposed stress field. Our results are

  16. Lateral dampers for thrust bearings

    Science.gov (United States)

    Hibner, D. H.; Szafir, D. R.

    1985-01-01

    The development of lateral damping schemes for thrust bearings was examined, ranking their applicability to various engine classes, selecting the best concept for each engine class and performing an in-depth evaluation. Five major engine classes were considered: large transport, military, small general aviation, turboshaft, and non-manrated. Damper concepts developed for evaluation were: curved beam, constrained and unconstrained elastomer, hybrid boost bearing, hydraulic thrust piston, conical squeeze film, and rolling element thrust face.

  17. Thrust modeling for hypersonic engines

    Science.gov (United States)

    Riggins, D. W.; Mcclinton, C. R.

    1995-01-01

    Expressions for the thrust losses of a scramjet engine are developed in terms of irreversible entropy increases and the degree of incomplete combustion. A method is developed which allows the calculation of the lost vehicle thrust due to different loss mechanisms within a given flow-field. This analysis demonstrates clearly the trade-off between mixing enhancement and resultant increased flow losses in scramjet combustors. An engine effectiveness parameter is defined in terms of thrust loss. Exergy and the thrust-potential method are related and compared.

  18. Seafloor expression and shallow structure of a fold-and-thrust system, Isfjorden, west Spitsbergen

    Directory of Open Access Journals (Sweden)

    Maria Blinova

    2012-09-01

    Full Text Available A detailed map of the structure of the west Spitsbergen fold-and-thrust belt in the Isfjorden area, Spitsbergen, is presented. The map was constructed from a dense grid of two-dimensional multichannel reflection seismic and bathymetric data. Joint interpretation of two data sets allowed a comparison of tectonic structures detected along the uppermost parts of the seismic sections and those reflected in the morphology of the seafloor. Three major, predominantly north-west–south-east striking faults were identified. The westernmost fault (T1 is a hinterland-directed (most likely out of sequence thrust, while the central and easternmost faults (T2 and T3 are foreland-directed (in-sequence thrusts. The thrusts divide Isfjorden into three subareas. Subarea 1 is bounded by thrust faults T1 and T2 and comprises Tertiary rocks surrounded by Jurassic–Cretaceous strata. The structural signature of Subarea 1 is that of a system of hinterland- and foreland-directed thrust faults, resulting in a seafloor relief characterized by parallel ridges and troughs. Subarea 2 is limited by thrust faults T2 and T3 and shows Jurassic–Cretaceous outcrops on the seafloor. Subarea 3 is situated east of the main thrust fault T3 and mainly involves outcrops of Triassic–Jurassic rocks. Together, Subareas 2 and 3 are dominated by foreland-directed, north-west–south-east and NNW–SSE-striking thrusts that are hardly detectable in bathymetric data.

  19. Differential displacement and rotation in thrust fronts: A magnetic, calcite twinning and palinspastic study of the Jones Valley thrust, Alabama, US Appalachians

    Science.gov (United States)

    Hnat, James S.; van der Pluijm, Ben A.; Van der Voo, Rob; Thomas, William A.

    2008-06-01

    To test whether a displacement gradient along a curved fault structure requires rotation, we studied the northeast-striking, northwest-verging, large-displacement Jones Valley thrust fault of the Appalachian thrust belt in Alabama. Paleomagnetism, anisotropy of magnetic susceptibility (AMS) and calcite twinning analysis, complemented by balanced cross-sections, were used to evaluate the presence and magnitude of any rotation. Remanence directions from the Silurian Red Mountain Formation reveal a prefolding magnetization acquired in the Pennsylvanian, whereas magnetic analysis shows a strong, bedding-parallel compaction fabric with a tectonic lineation. Paleomagnetic directions and magnetic lineations reveal no relative rotation between the hanging wall and footwall of the thrust fault. Rather than rotation, therefore, we interpret the Jones Valley thrust sheet as a structure that developed in a self-similar fashion, with lateral growth of the fault surface occurring coincident with growth into the foreland.

  20. Scale independence of décollement thrusting

    Science.gov (United States)

    McBride, John H.; Pugin, Andre J.M.; Hatcher, Robert D.

    2007-01-01

    Orogen-scale décollements (detachment surfaces) are an enduring subject of investigation by geoscientists. Uncertainties remain as to how crustal convergence processes maintain the stresses necessary for development of low-angle fault surfaces above which huge slabs of rock are transported horizontally for tens to hundreds of kilometers. Seismic reflection profiles from the southern Appalachian crystalline core and several foreland fold-and-thrust belts provide useful comparisons with high-resolution shallow-penetration seismic reflection profiles acquired over the frontal zone of the Michigan lobe of the Wisconsinan ice sheet northwest of Chicago, Illinois. These profiles provide images of subhorizontal and overlapping dipping reflections that reveal a ramp-and-flat thrust system developed in poorly consolidated glacial till. The system is rooted in a master décollement at the top of bedrock. These 2–3 km long images contain analogs of images observed in seismic reflection profiles from orogenic belts, except that the scale of observation in the profiles in glacial materials is two orders of magnitude less. Whereas the décollement beneath the ice lobe thrust belt lies ∼70 m below thrusted anticlines having wavelengths of tens of meters driven by an advancing ice sheet, seismic images from overthrust terranes are related to lithospheric convergence that produces décollements traceable for thousands of kilometers at depths ranging from a few to over 10 km. Dual vergence or reversals in vergence (retrocharriage) that developed over abrupt changes in depth to the décollement can be observed at all scales. The strikingly similar images, despite the contrast in scale and driving mechanism, suggest a scale- and driving mechanism–independent behavior for décollement thrust systems. All these systems initially had the mechanical properties needed to produce very similar geometries with a compressional driving mechanism directed subparallel to Earth's surface

  1. Low-thrust rocket trajectories

    Energy Technology Data Exchange (ETDEWEB)

    Keaton, P.W.

    1987-03-01

    The development of low-thrust propulsion systems to complement chemical propulsion systems will greatly enhance the evolution of future space programs. Two advantages of low-thrust rockets are stressed: first, in a strong gravitational field, such as occurs near the Earth, freighter missions with low-thrust engines require one-tenth as much propellant as do chemical engines. Second, in a weak gravitational field, such as occurs in the region between Venus and Mars, low-thrust rockets are faster than chemical rockets with comparable propellant mass. The purpose here is to address the physics of low-thrust trajectories and to interpret the results with two simple models. Analytic analyses are used where possible - otherwise, the results of numerical calculations are presented in graphs. The author has attempted to make this a self-contained report.

  2. Low-thrust rocket trajectories

    Energy Technology Data Exchange (ETDEWEB)

    Keaton, P.W.

    1986-01-01

    The development of low-thrust propulsion systems to complement chemical propulsion systems will greatly enhance the evolution of future space programs. Two advantages of low-thrust rockets are stressed: first, in a strong gravitational field, such as occurs near the Earth, freighter missions with low-thrust engines require one-tenth as much propellant as do chemical engines. Second, in a weak gravitational field, such as occurs in the region between Venus and Mars, low-thrust rockets are faster than chemical rockets with comparable propellant mass. The purpose here is to address the physics of low-thrust trajectories and to interpret the results with two simple models. Analytic analyses are used where possible - otherwise, the results of numerical calculations are presented in graphs. The author has attempted to make this a self-contained report. 57 refs., 10 figs.

  3. Lap belts and three-point belts.

    NARCIS (Netherlands)

    Kampen, L.T.B. van & Edelman, A.

    1975-01-01

    Results of the swov-accident investigation prove that if there are any differences in the effectiveness of lap belts and three-point belts, these are so small that they cannot form a basis for giving preference to one type over the other. Furthermore, in spite of the results of this investigation

  4. Synaptic ribbon. Conveyor belt or safety belt?

    Science.gov (United States)

    Parsons, T D; Sterling, P

    2003-02-06

    The synaptic ribbon in neurons that release transmitter via graded potentials has been considered as a conveyor belt that actively moves vesicles toward their release sites. But evidence has accumulated to the contrary, and it now seems plausible that the ribbon serves instead as a safety belt to tether vesicles stably in mutual contact and thus facilitate multivesicular release by compound exocytosis.

  5. Belt Aligning Revisited

    Directory of Open Access Journals (Sweden)

    Yurchenko Vadim

    2017-01-01

    parts of the conveyor, the sides of the belt wear intensively. This results in reducing the life of the belt. The reasons for this phenomenon are well investigated, but the difficulty lies in the fact that they all act simultaneously. The belt misalignment prevention can be carried out in two ways: by minimizing the effect of causes and by aligning the belt. The construction of aligning devices and errors encountered in practice are considered in this paper. Self-aligning roller supports rotational in plan view are recommended as a means of combating the belt misalignment.

  6. Belt Aligning Revisited

    Science.gov (United States)

    Yurchenko, Vadim

    2017-11-01

    The misalignment causes the greatest damage to the conveyor belt. As a result of the interaction of the moving belt with the stationary parts of the conveyor, the sides of the belt wear intensively. This results in reducing the life of the belt. The reasons for this phenomenon are well investigated, but the difficulty lies in the fact that they all act simultaneously. The belt misalignment prevention can be carried out in two ways: by minimizing the effect of causes and by aligning the belt. The construction of aligning devices and errors encountered in practice are considered in this paper. Self-aligning roller supports rotational in plan view are recommended as a means of combating the belt misalignment.

  7. Aircraft Horizontal Thrust Measurement Facility

    Data.gov (United States)

    Federal Laboratory Consortium — This facility is designed to support the DoD mission by providing unique air vehicle installed engine performance (thrust output) measurements. This system consists...

  8. Entering and exiting behaviour of the phlebotomine sand fly Lutzomyia longiflocosa (Diptera: Psychodidae in rural houses of the sub-Andean region of Colombia

    Directory of Open Access Journals (Sweden)

    Raúl Hernando Pardo

    Full Text Available The present study identified the entering and exiting sites for Lutzomyia longiflocosa in rural houses of the sub-Andean region in Colombia. Entering sites were identified with sticky traps set up outside the bedrooms, around the eave openings, and with cage traps enclosing the slits in the doors and windows inside the bedrooms. Exiting sites were identified by releasing groups of females indoors. These females were blood fed and marked with fluorescent powders. Females were recaptured with the trap placement described above but set up on the opposite sides of the openings. In the entering experiment, a significantly higher number of females were captured in the sticky traps at the zone nearest the eave openings (n = 142 than those captured in the other zones of the trap (n = 52; similarly, a higher number of females were captured on the front side of the house (n = 105 than at the rear side (n = 37. Only two females were collected in the cage trap. In the exiting experiment, at the ceiling, the highest percentage (86.2% of females was recaptured with sticky traps nearest the eave openings and on the front side of the house (70.0%. Seven females were collected in the cage trap. Lu. longiflocosa entered and exited houses primarily through the eave openings in a non-random pattern in relation to the sides of the house.

  9. Tardigrada from a sub-Andean forest in the Sierra Nevada de Santa Marta (Colombia) with the description of Itaquascon pilatoi sp. nov.

    Science.gov (United States)

    Lisi, Oscar; Londoño, Rosana; Quiroga, Sigmer

    2014-07-29

    Currently only 32 species of limno-terrestrial tardigrades have been reported in the literature for Colombia. Our study focused on both heterotardigrades and eutardigrades, which were extracted from eight samples of bryophytes and lichens collected in a sub-Andean forest transect in the Sierra Nevada de Santa Marta, Colombia. Fourteen species were found, six of which are new records for Colombia: Echiniscus madonnae Michalczyk & Kaczmarek, 2006, Echiniscus virginicus Riggin, 1962, Milnesium krzysztofi Kaczmarek & Michalczyk, 2007, Doryphoribius amazzonicus Lisi, 2011, Isohypsibius sattleri (Richters, 1902) and Diphascon higginsi Binda, 1971; and one new to science. Itaquascon pilatoi sp. nov., is characterized by having smooth cuticle, no eyes, buccal tube almost as long as the pharyngeal tube, well developed, obvious stylet furcae with long branches, slender claws, no lunules and no cuticular bars on the legs. The new species differs from I. umbellinae Barros, 1939, the most similar species, in having the stylet supports inserted precisely at the border between buccal and pharyngeal tube, more slender claws and more pronounced length differential between the external and internal claws of each leg. The total number of Colombian limno-terrestrial tardigrade species is raised to 37. 

  10. Entering and exiting behaviour of the phlebotomine sand fly Lutzomyia longiflocosa (Diptera: Psychodidae) in rural houses of the sub-Andean region of Colombia.

    Science.gov (United States)

    Pardo, Raúl Hernando; Santamaría, Erika; Cabrera, Olga Lucia

    2017-01-01

    The present study identified the entering and exiting sites for Lutzomyia longiflocosa in rural houses of the sub-Andean region in Colombia. Entering sites were identified with sticky traps set up outside the bedrooms, around the eave openings, and with cage traps enclosing the slits in the doors and windows inside the bedrooms. Exiting sites were identified by releasing groups of females indoors. These females were blood fed and marked with fluorescent powders. Females were recaptured with the trap placement described above but set up on the opposite sides of the openings. In the entering experiment, a significantly higher number of females were captured in the sticky traps at the zone nearest the eave openings (n = 142) than those captured in the other zones of the trap (n = 52); similarly, a higher number of females were captured on the front side of the house (n = 105) than at the rear side (n = 37). Only two females were collected in the cage trap. In the exiting experiment, at the ceiling, the highest percentage (86.2%) of females was recaptured with sticky traps nearest the eave openings and on the front side of the house (70.0%). Seven females were collected in the cage trap. Lu. longiflocosa entered and exited houses primarily through the eave openings in a non-random pattern in relation to the sides of the house.

  11. Belt drive construction improvement

    Directory of Open Access Journals (Sweden)

    I.Yu. Khomenko

    2012-08-01

    Full Text Available The possibility of the traction capacity increase of the belt drive TRK is examined. This was done for the purpose of air conditioning system of passenger car with double-generator system energy supplying. Belts XPC (made by the German firm «Continental ContiTech» testing were conducted. The results confirmed the possibility of their usage in order to improve belt drive TRK characteristics.

  12. Geological mapping of the Schuppen belt of north-east India using geospatial technology

    Science.gov (United States)

    Ghosh, Tanaya; Basu, Surajit; Hazra, Sugata

    2014-01-01

    A revised geologic map of the Schuppen belt of northeast India has been prepared based on interpretation of digitally enhanced satellite images. The satellite image interpretation is supported by limited field work and existing geologic maps. Available geological maps of this fold thrust belt are discontinuous and multi-scaled. The authors are of multiple opinions regarding the trajectory of formation boundaries and fault contacts. Digital image processing of satellite images and limited field surveys have been used to reinterpret and modify the existing geological maps of this fold thrust belt. Optical data of Landsat Thematic Mapper, Enhanced Thematic Mapper and elevation data of ASTER have been used to prepare this revised geological map. The study area extends from Hajadisa in south to Digboi oilfield in north, bounded by Naga thrust in the west and Disang thrust in the east. PCA, Image fusion, Linear Contrast stretch, Histogram Equalization and Painted relief algorithms have been used for the delineation of major geological lineaments like lithological boundary, thrust and strike slip faults. Digital elevation maps have enabled in the discrimination between thrust contacts and lithological boundaries, with the former being located mostly in the valleys. Textural enhancements of PCA, colour composites and Painted relief algorithm have been used to discriminate between different rock types. Few geological concepts about the terrain have been revisited and modified. It is assumed that this revised map should be of practical use as this terrain promises unexploited hydrocarbon reserves.

  13. Lower Miocene coeval thrusting and strike-slip faulting in the Western Betics

    Science.gov (United States)

    Frasca, Gianluca; Gueydan, Frédéric; Brun, Jean-Pierre

    2015-04-01

    In the framework of the Africa-Europe convergence, the Mediterranean system presents a complex interaction between subduction rollback and upper subduction plate deformation since 30 Ma. The western end of the system shows an arcuate geometry across the Gibraltar arc, the Betico-Rifean belt, in which the relationship between slab dynamics and onshore tectonics is poorly constrained. The present study focuses on the Western Betics, which is characterized by two major thrusts: 1/ the Alboran Front limits the metamorphic domain (Alboran Domain) from the fold-and-thrust belts involving the Mesozoic cover of the Iberian margin (Subbetics Domain); 2/ the Alboran Internal Thrust allows the juxtaposition of a strongly attenuated lithosphere section, containing the large Ronda subcontinental mantle bodies, on top of crustal rocks. New structural data show that two major E-W strike-slip corridors controlled the deformation pattern of the Alboran Domain, in which E-W dextral strike-slip faults, N60° thrusts and N140° normal faults developed simultaneously during dextral strike-slip simple shear. The Alozaina piggy-back Basin, mainly formed by olistotromic deposits of Lower Miocene age, provides an age estimate for the continuous westward translation of the Alboran Domain, with reference to Iberia, that is accommodated mainly by an E-W lateral strike-slip ramp and a N60° frontal thrust ramp. In this context, a thrust sequence led to the piling up of thrust units in the Western Betics and to the crustal emplacement of the Ronda Peridotites bodies.

  14. Another Look at Rocket Thrust

    Science.gov (United States)

    Hester, Brooke; Burris, Jennifer

    2012-01-01

    Rocket propulsion is often introduced as an example of Newton's third law. The rocket exerts a force on the exhaust gas being ejected; the gas exerts an equal and opposite force--the thrust--on the rocket. Equivalently, in the absence of a net external force, the total momentum of the system, rocket plus ejected gas, remains constant. The law of…

  15. High Thrust-Density Electrostaic Engines Project

    Data.gov (United States)

    National Aeronautics and Space Administration — These issues are addressable by: increasing the thrust, power, and thrust-to-power ratio capability of EP systems; reducing the non-recurring engineering systems...

  16. Kuiper Belt Objects

    Science.gov (United States)

    Jewitt, David

    The region of the solar system immediately beyond Neptune's orbit is densely populated with small bodies. This region, known as the Kuiper Belt, consists of objects that may predate Neptune, the orbits of which provide a fossil record of processes operative in the young solar system. The Kuiper Belt contains some of the Solar System's most primitive, least thermally processed matter. It is probably the source of the short-period comets and Centaurs, and may also supply collisionally generated interplanetary dust. I discuss the properties of the Kuiper Belt and provide an overview of the outstanding scientific issues.

  17. Nonlinear dynamics of a vectored thrust aircraft

    DEFF Research Database (Denmark)

    Sørensen, C.B; Mosekilde, Erik

    1996-01-01

    With realistic relations for the aerodynamic coefficients, numerical simulations are applied to study the longitudional dynamics of a thrust vectored aircraft. As function of the thrust magnitude and the thrust vectoring angle the equilibrium state exhibits two saddle-node bifurcations and three...

  18. Ore-controlling thrust faults at the Bazovskoe gold-ore deposit (Eastern Yakutia)

    Science.gov (United States)

    Fridovsky, V. Yu.; Polufuntikova, L. I.; Goryachev, N. A.; Kudrin, M. V.

    2017-06-01

    This work presents results of structural analysis of the orogenic Bazovskoe gold-ore deposit, the structure of which is controlled by an imbricate fan with frontal succession of ore-controlling thrust faults and conjugated thrust ramps. It was established that linear and stratified stockworks and their combinations are formed by several systems of quartz veins and veinlets, regularly related to thrusting along the ore-controlling zones and interlayer shears. In addition, superimposed shear deformations are widely distributed. The features revealed of the geological structure of the Bazovskoe gold-ore deposit allow us to refine the prospecting and searching pattern developed for gold-ore deposits of the Verkhoyansk-Kolyma fold belt.

  19. Conveyor belt service machine

    National Research Council Canada - National Science Library

    1984-01-01

    ... in. and thicker that could reduce the time, cost and injury potential inherent in extending and retracting mine wide section belt conveyors while eliminating the need to use additional machinery in accomplishing such moves...

  20. Radiation Belt Dynamics

    Science.gov (United States)

    2015-12-27

    Distributions Recent analysis of Van Allen Probes observations has forced a reevaluation of models and our understanding of the inner electron radiation belt ...challenge” studies of four chosen recent events well-observed by the Van Allen Probes satellites, with participation by the radiation belt research...work, recently augmented by observations made by the currently orbiting NASA Van Allen Probes satellites, has revealed unexpected behavior and

  1. Galactic Radiation Belts.

    Science.gov (United States)

    1982-01-15

    was formulated by Ortwein et al. 13for analysis of the Jovian radio emission. These authors de- rived their results for an arbitrary dipole-axis...galactic radio sources with the Jovian radiation-belt source, 17suggests a=. intriguing similarity. The related questions of why galactic radiation belts...Space Sciences Laboratory: Atmospheric and ionospheric physics, radiation from the atmosphere, densfty and composition of the upper atmosphere, aurorae

  2. Thrust sensing for small UAVs

    Science.gov (United States)

    Marchman, Christopher Scott

    Unmanned aerial vehicles (UAVs) have become prevalent in both military and civilian applications. UAVs have many size categories from large-scale aircraft to micro air vehicles. The performance, health, and efficiency for UAVs of smaller sizes can be difficult to assess and few associated instrumentation systems have been developed. Thrust measurements on the ground can characterize systems especially when combined with simultaneous motor power measurements. This thesis demonstrates the use of strain measurements to measure the thrust produced by motor/propeller combinations for such small UAVs. A full-bridge Wheatstone circuit and electrical resistance strain gauges were used in conjunction with constant-stress cantilever beams for static tests and dynamic wind tunnel tests. An associated instrumentation module monitored power from the electric motor. Monitoring the thrust data over time can provide insights into optimal propeller and motor selection and early detection of problems such as component failure. The approach provides a system for laboratory or field measurements that can be scaled for a wide range of small UAVs.

  3. Belt conveyor apparatus

    Science.gov (United States)

    Oakley, David J.; Bogart, Rex L.

    1987-01-01

    A belt conveyor apparatus according to this invention defines a conveyance path including a first pulley and at least a second pulley. An endless belt member is adapted for continuous travel about the pulleys and comprises a lower portion which engages the pulleys and an integral upper portion adapted to receive objects therein at a first location on said conveyance path and transport the objects to a second location for discharge. The upper belt portion includes an opposed pair of longitudinally disposed crest-like members, biased towards each other in a substantially abutting relationship. The crest-like members define therebetween a continuous, normally biased closed, channel along the upper belt portion. Means are disposed at the first and second locations and operatively associated with the belt member for urging the normally biased together crest-like members apart in order to provide access to the continuous channel whereby objects can be received into, or discharged from the channel. Motors are in communication with the conveyance path for effecting the travel of the endless belt member about the conveyance path. The conveyance path can be configured to include travel through two or more elevations and one or more directional changes in order to convey objects above, below and/or around existing structures.

  4. On the Sample Return From Vesta by Low-Thrust Spacecraft

    Science.gov (United States)

    Akhmetshin, R. Z.; Eneev, T. M.; Efimov, G. B.

    1996-01-01

    It is well known that there would be tremendous scientific value in a sample-return mission to a main-belt asteroid such as Vesta. The sample return from Vesta by traditional high-thrust vehicles is impossible at the present time. Combining high- and low-thrust propulsion (electric propulsion with energy supply by solar arrays) would permit the solution of this problem. At first, the spacecraft would be boosted by the high-thrust engine to the hyperbolic velocity. The rendezvous with the asteroid would then be performed using the low-thrust engine. Flight time to asteroids such as Vesta or Fortune is 2-3 yr. The resulting payload would prove sufficient to solve the problem of the sample return (depending essentially on the parameters of the rocket and the space systems). After the rendezvous with the asteroid, in the case of return with the high-thrust engine, the landing module could land on the asteroid and then return to Earth. In the case of the low-thrust return, the distant sample grab is used. The hyperbolic velocity surplus of returning capsules can be diminished by means of an appropriate entrance into the Earth's atmosphere. If the Soyuz rocket is used, the payload mass near Vesta is equal to 700 kg (except EP and solar array mass). In this case the return with high thrust is possible. For a conversional rocket, there would be 400 kg of payload mass. This would allow landing of the scientific apparatus on the surface or to make a distant grab, with its low thrust returning to the Earth. The total expedition time depends on the combination of dates of the rendezvous with the asteroid and the return to Earth, and would be 4-5 yr for an asteroid such as Vesta. These mission variants suppose use of the new technology, in large part tested during flight, such as EP SPT, ESA-XX, "Super ULP" solar arrays, etc.

  5. The crustal structure of Ellesmere Island, Arctic Canada—teleseismic mapping across a remote intraplate orogenic belt

    DEFF Research Database (Denmark)

    Schiffer, Christian; Stephenson, Randell Alexander; Oakey, Gordon

    2016-01-01

    in the Eurekan fold and thrust belt (∼79.7°–80.6°N) to ∼16–20 km in the Hazen Stable Block (HSB; ∼80.6°–81.4°N) and is covered by a thick succession of metasediments. A deep crustal root (∼48 km) at ∼79.6°N is interpreted as cratonic crust flexed beneath the Eurekan fold and thrust belt. The Carboniferous...

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

    Science.gov (United States)

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

    2016-04-01

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

  7. Thrust augmentation for a small turbojet engine

    OpenAIRE

    Hackaday, Gary L.

    1999-01-01

    Approved for public release; distribution is unlimited A Sophia J450 (nine pounds of thrust) gas turbine engine was used first to examine the thrust augmentation generated using an ejector shroud. Experimental results obtained with and without the ejector were compared with performance predicted using an engine code and a one-dimensional ejector analysis. The engine code was revised to incorporate a radial turbine and the correct compressor map. Thrust augmentation of 3-10% was measured an...

  8. Reconstructing the kinematics of thrust sheet rotation in the Wyoming Salient: a paleomagnetic study of Triassic redbeds

    Science.gov (United States)

    Weil, A. B.; Adolph, Y.; Sussman, A.

    2007-12-01

    Understanding the kinematics and mechanics of orogenic curvature are long standing questions within the structural geology and tectonics community. At the root of these questions is when and how orogens acquire curvature relative to protracted deformation histories. In an effort to describe the kinematic history of the Wyoming salient of the Sevier fold-thrust belt a collaborative effort is underway to determine the three main displacement field components (translation, rotation and strain). Paleomagnetic data are reported here from 164 sites collected from redbeds of the Triassic Ankareh Fm. from throughout the Wyoming salient. Sampled redbeds carry three distinct remanent magnetizations distinguished by field tests and magnetic behavior: 1) a recent viscous magnetization that is usually removed by 250° C, but is sometimes stable through typical hematite unblocking temperatures, 2) a Cretaceous chemical remagnetization (32 sites), and 3) a near-primary Triassic magnetization that is carried by hematite and is stable up to 680° C (92 sites). Site mean directions have a high degree of scatter from the reference Triassic and Cretaceous directions in both site declination and inclination, suggesting significant local rotation and tilt subsequent to magnetization acquisition. Palenspastic structural restoration of individual site means reveals local rotation, significant regional orogenic rotation, and differentiable thrust sheet rotation patterns that are all consistent with overall trends of structures found around the belt. Rotations are more pronounced in the northern and southern sections of the belt, near the intersection of the fold-thrust front with the Teton/Gros Ventre and Uinta Mountain uplifts. Statistical analysis of the rotations within and between individual thrust sheets suggests that between 70 and 80% of present-day curvature of the salient is secondary and must be accounted for in any kinematic model of thrust-belt evolution. Analysis of data for

  9. Dielectric Barrier Discharge (DBD) Plasma Actuators Thrust-Measurement Methodology Incorporating New Anti-Thrust Hypothesis

    Science.gov (United States)

    Ashpis, David E.; Laun, Matthew C.

    2014-01-01

    We discuss thrust measurements of Dielectric Barrier Discharge (DBD) plasma actuators devices used for aerodynamic active flow control. After a review of our experience with conventional thrust measurement and significant non-repeatability of the results, we devised a suspended actuator test setup, and now present a methodology of thrust measurements with decreased uncertainty. The methodology consists of frequency scans at constant voltages. The procedure consists of increasing the frequency in a step-wise fashion from several Hz to the maximum frequency of several kHz, followed by frequency decrease back down to the start frequency of several Hz. This sequence is performed first at the highest voltage of interest, then repeated at lower voltages. The data in the descending frequency direction is more consistent and selected for reporting. Sample results show strong dependence of thrust on humidity which also affects the consistency and fluctuations of the measurements. We also observed negative values of thrust or "anti-thrust", at low frequencies between 4 Hz and up to 64 Hz. The anti-thrust is proportional to the mean-squared voltage and is frequency independent. Departures from the parabolic anti-thrust curve are correlated with appearance of visible plasma discharges. We propose the anti-thrust hypothesis. It states that the measured thrust is a sum of plasma thrust and anti-thrust, and assumes that the anti-thrust exists at all frequencies and voltages. The anti-thrust depends on actuator geometry and materials and on the test installation. It enables the separation of the plasma thrust from the measured total thrust. This approach enables more meaningful comparisons between actuators at different installations and laboratories. The dependence on test installation was validated by surrounding the actuator with a large diameter, grounded, metal sleeve.

  10. Deformation and kinematics of the central Kirthar Fold Belt, Pakistan

    Science.gov (United States)

    Hinsch, Ralph; Hagedorn, Peter; Asmar, Chloé; Nasim, Muhammad; Aamir Rasheed, Muhammad; Kiely, James M.

    2017-04-01

    The Kirthar Fold Belt is part of the lateral mountain belts in Pakistan linking the Himalaya orogeny with the Makran accretionary wedge. This region is deforming very oblique/nearly parallel to the regional plate motion vector. The study area is situated between the prominent Chaman strike-slip fault in the West and the un-deformed foreland (Kirthar Foredeep/Middle Indus Basin) in the East. The Kirthar Fold Belt is subdivided into several crustal blocks/units based on structural orientation and deformation style (e.g. Kallat, Khuzdar, frontal Kirthar). This study uses newly acquired and depth-migrated 2D seismic lines, surface geology observations and Google Earth assessments to construct three balanced cross sections for the frontal part of the fold belt. Further work was done in order to insure the coherency of the built cross-sections by taking a closer look at the regional context inferred from published data, simple analogue modelling, and constructed regional sketch sections. The Khuzdar area and the frontal Kirthar Fold Belt are dominated by folding. Large thrusts with major stratigraphic repetitions are not observed. Furthermore, strike-slip faults in the Khuzdar area are scarce and not observed in the frontal Kirthar Fold Belt. The regional structural elevation rises from the foreland across the Kirthar Fold Belt towards the hinterland (Khuzdar area). These observations indicate that basement-involved deformation is present at depth. The domination of folding indicates a weak decollement below the folds (soft-linked deformation). The fold pattern in the Khuzdar area is complex, whereas the large folds of the central Kirthar Fold Belt trend SSW-NNE to N-S and are best described as large detachment folds that have been slightly uplifted by basement involved transpressive deformation underneath. Towards the foreland, the deformation is apparently more hard-linked and involves fault-propagation folding and a small triangle zone in Cretaceous sediments

  11. MARA GREENSTONE BELT

    African Journals Online (AJOL)

    Mgina

    negative anomalies of Nb and Ti relative to adjacent elements in multi-element spidergrams. ... that Fe-rich tholeiites associated with rare ..... metabasalts from the Southern Musoma –Mara greenstone belt … 78. *Zimbabwe. *Canada. Simba Sirori Mg-rich metabasalts. Komatiite. Kom. Basalt. Komatiite Kom Basalt. Pb. 7. 5.

  12. Measuring Model Rocket Engine Thrust Curves

    Science.gov (United States)

    Penn, Kim; Slaton, William V.

    2010-01-01

    This paper describes a method and setup to quickly and easily measure a model rocket engine's thrust curve using a computer data logger and force probe. Horst describes using Vernier's LabPro and force probe to measure the rocket engine's thrust curve; however, the method of attaching the rocket to the force probe is not discussed. We show how a…

  13. The empty primordial asteroid belt.

    Science.gov (United States)

    Raymond, Sean N; Izidoro, Andre

    2017-09-01

    The asteroid belt contains less than a thousandth of Earth's mass and is radially segregated, with S-types dominating the inner belt and C-types the outer belt. It is generally assumed that the belt formed with far more mass and was later strongly depleted. We show that the present-day asteroid belt is consistent with having formed empty, without any planetesimals between Mars and Jupiter's present-day orbits. This is consistent with models in which drifting dust is concentrated into an isolated annulus of terrestrial planetesimals. Gravitational scattering during terrestrial planet formation causes radial spreading, transporting planetesimals from inside 1 to 1.5 astronomical units out to the belt. Several times the total current mass in S-types is implanted, with a preference for the inner main belt. C-types are implanted from the outside, as the giant planets' gas accretion destabilizes nearby planetesimals and injects a fraction into the asteroid belt, preferentially in the outer main belt. These implantation mechanisms are simple by-products of terrestrial and giant planet formation. The asteroid belt may thus represent a repository for planetary leftovers that accreted across the solar system but not in the belt itself.

  14. A Fold Province in the Hinterland of the Sevier Orogenic Belt in Eastern Nevada: A Valley and Ridge in the Basin and Range

    Science.gov (United States)

    Long, S. P.

    2014-12-01

    The overprinting effects of Cenozoic extensional tectonism hinder analysis of the style, geometry, and timing of Cordilleran contractional deformation in the hinterland of the Sevier fold-thrust belt in Nevada. To address this problem, a 1:250,000-scale paleogeologic map of eastern Nevada, showing spatial distributions of Paleozoic-Mesozoic rocks exposed beneath a Paleogene unconformity, divided out at the formation scale, is integrated with maps of dip magnitude for Paleozoic-Mesozoic and Tertiary rocks, published sedimentary thickness records, and a published reconstruction of Basin and Range extension, in order to define and regionally-correlate thrust faults and folds, and estimate the pre-extensional amplitude, wavelength, and limb dips of folds. A new structural province, the Eastern Nevada fold belt (ENFB) is defined, and consists of a 100-150 km-wide region containing as many as five 1st-order, N-trending folds that can be traced for map distances between 100-250 km, have amplitudes between 2-4 km, wavelengths between 20-40 km, pre-extensional limb dips typically between 10-30˚, and deform rocks as young as Jurassic and Early Cretaceous. No regional-scale thrust faults or decollemont horizons breach modern exposure levels in the ENFB. ENFB folds are interpreted to have formed above a deep (≥10 km below the Paleogene unconformity), blind decollemont or shear zone, perhaps the westward projection of the master decollemont of the Sevier fold-thrust belt. Two additional structural provinces of the Sevier hinterland, the Central Nevada thrust belt (CNTB) and Western Utah thrust belt (WUTB), represent zones of N-striking, E-vergent thrust faults and folds that each accommodated ca. 10 km of shortening. Both thrust belts branch northward off of the Sevier thrust belt, and are interpreted to represent contemporary, interior components of the Sevier thrust system. The CNTB, WUTB, and the intervening ENFB collectively record low-magnitude (a few 10's of km) upper

  15. Deconstructing the conveyor belt.

    Science.gov (United States)

    Lozier, M Susan

    2010-06-18

    For the past several decades, oceanographers have embraced the dominant paradigm that the ocean's meridional overturning circulation operates like a conveyor belt, transporting cold waters equatorward at depth and warm waters poleward at the surface. Within this paradigm, the conveyor, driven by changes in deepwater production at high latitudes, moves deep waters and their attendant properties continuously along western boundary currents and returns surface waters unimpeded to deepwater formation sites. A number of studies conducted over the past few years have challenged this paradigm by revealing the vital role of the ocean's eddy and wind fields in establishing the structure and variability of the ocean's overturning. Here, we review those studies and discuss how they have collectively changed our view of the simple conveyor-belt model.

  16. Metamorphic belts of Anatolia

    Science.gov (United States)

    Oberhänsli, Roland; Prouteau, Amaury; Candan, Osman; Bousquet, Romain

    2015-04-01

    Investigating metamorphic rocks from high-pressure/low-temperature (HP/LT) belts that formed during the closure of several oceanic branches, building up the present Anatolia continental micro-plate gives insight to the palaeogeography of the Neotethys Ocean in Anatolia. Two coherent HP/LT metamorphic belts, the Tavşanlı Zone (distal Gondwana margin) and the Ören-Afyon-Bolkardağ Zone (proximal Gondwana margin), parallel their non-metamorphosed equivalent (the Tauride Carbonate Platform) from the Aegean coast in NW Anatolia to southern Central Anatolia. P-T conditions and timing of metamorphism in the Ören-Afyon-Bolkardağ Zone (>70?-65 Ma; 0.8-1.2 GPa/330-420°C) contrast those published for the overlying Tavşanlı Zone (88-78 Ma; 2.4 GPa/500 °C). These belts trace the southern Neotethys suture connecting the Vardar suture in the Hellenides to the Inner Tauride suture along the southern border of the Kirşehir Complex in Central Anatolia. Eastwards, these belts are capped by the Oligo-Miocene Sivas Basin. Another HP/LT metamorphic belt, in the Alanya and Bitlis regions, outlines the southern flank of the Tauride Carbonate Platform. In the Alanya Nappes, south of the Taurides, eclogites and blueschists yielded metamorphic ages around 82-80 Ma (zircon U-Pb and phengite Ar-Ar data). The Alanya-Bitlis HP belt testifies an additional suture not comparable to the northerly Tavşanlı and Ören-Afyon belts, thus implying an additional oceanic branch of the Neotethys. The most likely eastern lateral continuation of this HP belt is the Bitlis Massif, in SE Turkey. There, eclogites (1.9-2.4 GPa/480-540°C) occur within calc-arenitic meta-sediments and in gneisses of the metamorphic (Barrovian-type) basement. Zircon U-Pb ages revealed 84.4-82.4 Ma for peak metamorphism. Carpholite-bearing HP/LT metasediments representing the stratigraphic cover of the Bitlis Massif underwent 0.8-1.2 GPa/340-400°C at 79-74 Ma (Ar-Ar on white mica). These conditions compares to the Tav

  17. MARA GREENSTONE BELT

    African Journals Online (AJOL)

    Mgina

    nearly flat (La/SmCN = 0.71 – 1.08) and light REE enriched (La/SmCN = 2.89). They also show negative anomalies of ..... Jahrb. B72: 109-229. Borg G and Krogh T 1999 Isotopic age data of single zircons from the Archaean. Sukumalnd Greenstone belt, Tanzania. J. Afr. Earth Sci. 29: 301-312. Borg G and Shackleton RM ...

  18. Low thrust chemical rocket technology

    Science.gov (United States)

    Schneider, Steven J.

    1992-01-01

    An on-going technology program to improve the performance of low thrust chemical rockets for spacecraft on-board propulsion applications is reviewed. Improved performance and lifetime is sought by the development of new predictive tools to understand the combustion and flow physics, introduction of high temperature materials and improved component designs to optimize performance, and use of higher performance propellants. Improved predictive technology is sought through the comparison of both local and global predictions with experimental data. Predictions are based on both the RPLUS Navier-Stokes code with finite rate kinetics and the JANNAF methodology. Data were obtained with laser-based diagnostics along with global performance measurements. Results indicate that the modeling of the injector and the combustion process needs improvement in these codes and flow visualization with a technique such as 2-D laser induced fluorescence (LIF) would aid in resolving issues of flow symmetry and shear layer combustion processes. High temperature material fabrication processes are under development and small rockets are being designed, fabricated, and tested using these new materials. Rhenium coated with iridium for oxidation protection was produced by the Chemical Vapor Deposition (CVD) process and enabled an 800 K increase in rocket operating temperature. Performance gains with this material in rockets using Earth storable propellants (nitrogen tetroxide and monomethylhydrazine or hydrazine) were obtained through component redesign to eliminate fuel film cooling and its associated combustion inefficiency while managing head end thermal soakback. Material interdiffusion and oxidation characteristics indicated that the requisite lifetimes of tens of hours were available for thruster applications. Rockets were designed, fabricated, and tested with thrusts of 22, 62, 440 and 550 N. Performance improvements of 10 to 20 seconds specific impulse were demonstrated. Higher

  19. Pulsed Ejector Thrust Amplification Tested and Modeled

    Science.gov (United States)

    Wilson, Jack

    2004-01-01

    There is currently much interest in pulsed detonation engines for aeronautical propulsion. This, in turn, has sparked renewed interest in pulsed ejectors to increase the thrust of such engines, since previous, though limited, research had indicated that pulsed ejectors could double the thrust in a short device. An experiment has been run at the NASA Glenn Research Center, using a shrouded Hartmann-Sprenger tube as a source of pulsed flow, to measure the thrust augmentation of a statistically designed set of ejectors. A Hartmann- Sprenger tube directs the flow from a supersonic nozzle (Mach 2 in the present experiment) into a closed tube. Under appropriate conditions, an oscillation is set up in which the jet flow alternately fills the tube and then spills around flow emerging from the tube. The tube length determines the frequency of oscillation. By shrouding the tube, the flow was directed out of the shroud as an axial stream. The set of ejectors comprised three different ejector lengths, three ejector diameters, and three nose radii. The thrust of the jet alone, and then of the jet plus ejector, was measured using a thrust plate. The arrangement is shown in this photograph. Thrust augmentation is defined as the thrust of the jet with an ejector divided by the thrust of the jet alone. The experiments exhibited an optimum ejector diameter and length for maximizing the thrust augmentation, but little dependence on nose radius. Different frequencies were produced by changing the length of the Hartmann-Sprenger tube, and the experiment was run at a total of four frequencies. Additional measurements showed that the major feature of the pulsed jet was a starting vortex ring. The size of the vortex ring depended on the frequency, as did the optimum ejector diameter.

  20. Sedimentary Records of Paleogene (Eocene to Lowermost Miocene Deformations near the Contact between the Carpathian Thrust Belt and Moesia Enregistrements sédimentaires des déformations d’âge Éocène à Miocène inférieur dans la zone de contact du front des Carpathes et de la plateforme moésienne

    Directory of Open Access Journals (Sweden)

    Rabagia T.

    2012-01-01

    Full Text Available The kinematic models proposed for the Tertiary evolution of the Romanian Carpathians explain its arcuate shape by the progressive displacement of the upper plate (Tisza-Dacia block around the western margin and then along the northern margin of Moesia, the latter representing the stable foreland autochthon. The main tectonic events took place in the Eocene when a former nappe pile, formed by the end of the Cretaceous and representing the actual Southern Carpathians, underwent extension. This episode was followed by dextral wrenching that was accompanied by the opening of the Getic Depression as a pull-apart basin along the northern Moesian margin, at the current location of the Southern Carpathian foothills. This deformation operated from Oligocene to Lower Miocene times. Although from the Lower Miocene onwards the progressive eastwards motion of the Tisza-Dacia block accounted for well-defined accommodating structures in both the frontal (Eastern Carpathians and lateral (Getic Depression sides of the accretionary wedge, the Eocene to Lower Miocene tectonics left apparently no imprint upon the outer thin-skinned belt. We have looked for the sedimentary records of these tectonic events by building and integrating several detailed sedimentary logs near the contact between the Outer Carpathians and Moesia. Two main facies associations were defined in terms of basin energy, i.e. proximal high-energy prograding associations, represented by coarser sedimentary units and distal variable-energy aggrading associations. Based on the wide incision observed at the base of the high-energy units and on the clast provenance, we assume a tectonic origin for the vertical changes observed in the dipping attitude of the beds, which account for angular unconformities. Importantly, the regional correlation of the Eocene-Lowermost Miocene formations points to a progressive migration in time and space of the high-energy sedimentary units, which get younger eastwards

  1. Lap belt injuries in children.

    LENUS (Irish Health Repository)

    McGrath, N

    2010-07-01

    The use of adult seat belts without booster seats in young children may lead to severe abdominal, lumbar or cervical spine and head and neck injuries. We describe four characteristic cases of lap belt injuries presenting to a tertiary children\\'s hospital over the past year in addition to a review of the current literature. These four cases of spinal cord injury, resulting in significant long-term morbidity in the two survivors and death in one child, arose as a result of lap belt injury. These complex injuries are caused by rapid deceleration characteristic of high impact crashes, resulting in sudden flexion of the upper body around the fixed lap belt, and consequent compression of the abdominal viscera between the lap belt and spine. This report highlights the dangers of using lap belts only without shoulder straps. Age-appropriate child restraint in cars will prevent these injuries.

  2. 30 CFR 77.406 - Drive belts.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Drive belts. 77.406 Section 77.406 Mineral... Mechanical Equipment § 77.406 Drive belts. (a) Drive belts shall not be shifted while in motion unless the machines are provided with mechanical shifters. (b) Belt dressing shall not be applied while belts are in...

  3. Deformation history from microstructures: an example from Ramgarh Thrust Sheet, Eastern Himalaya

    Science.gov (United States)

    Banerjee, S.; Matin, A.; Mukul, M.; Mukherjee, A.

    2011-12-01

    The emplacement of thrust sheets in a fold and thrust belt is an integral part in the evolution of orogenic belts. The signatures of deformation present in a thrust sheet is often very useful to elucidate the history of deformation and also to understand the mechanisms of deformation that operates in stages during the emplacement of thrust sheets. The Himalayan orogenic belt has experienced multiple stages of thrusting and duplex formation. Ramgarh thrust sheet (RTS), one of the major thrust sheets bounded by the Main Central Thrust to the North and Ramgarh thrust (RT) in the south, is studied in the eastern Himalaya to understand its emplacement history and formation of microstructures in response to the deformation. The RTS consists dominantly of metapelitic sequence with intercalated quartzite bands. The present study attempts to understand the deformation history and mechanisms of deformation from microstructures developed in Daling group of rocks of the RTS, in the immediate northern side outside the Rangit window, Sikkim Himalaya. Three stages of cleavage formation in phyllite have been identified. The cleavages of the early stages are transposed to the present stage through the process of shearing adjacent to the RT fault zone as deformation progresses. The remnants of earlier cleavages are present as obliterated relict structures within the dominant last stage fabric. The evidence of shearing is present in both quartz-poor as well as in quartz-rich sericite schist. Schistosity plane is sheared to form S-C structure along with the development of pressure solution planes usually parallel to C-plane. Shear band cleavage is a common micro-scale structure in the deformed schistose rocks. Quartz grains in quartz mylonite have undergone crystal-plastic deformation and exhibit sweeping undulatory extinction, deformation bands, sub-grain formation and incipient to almost complete recrystallization of original grains. In phyllosilicate grains, undulatory extinction

  4. High Performance Methane Thrust Chamber (HPMTC) Project

    Data.gov (United States)

    National Aeronautics and Space Administration — ORBITEC proposes to develop a High-Performance Methane Thrust Chamber (HPMRE) to meet the demands of advanced chemical propulsion systems for deep-space mission...

  5. SLH Timing Belt Powertrain

    Energy Technology Data Exchange (ETDEWEB)

    Schneider, Abe

    2014-04-09

    The main goal of this proposal was to develop and test a novel powertrain solution for the SLH hydroEngine, a low-cost, efficient low-head hydropower technology. Nearly two-thirds of U.S. renewable electricity is produced by hydropower (EIA 2010). According to the U.S. Department of Energy; this amount could be increased by 50% with small hydropower plants, often using already-existing dams (Hall 2004). There are more than 80,000 existing dams, and of these, less than 4% generate power (Blankinship 2009). In addition, there are over 800 irrigation districts in the U.S., many with multiple, non-power, low-head drops. These existing, non-power dams and irrigation drops could be retrofitted to produce distributed, baseload, renewable energy with appropriate technology. The problem is that most existing dams are low-head, or less than 30 feet in height (Ragon 2009). Only about 2% of the available low-head hydropower resource in the U.S. has been developed, leaving more than 70 GW of annual mean potential low-head capacity untapped (Hall 2004). Natel Energy, Inc. is developing a low-head hydropower turbine that operates efficiently at heads less than 6 meters and is cost-effective for deployment across multiple low-head structures. Because of the unique racetrack-like path taken by the prime-movers in the SLH, a flexible powertrain is required. Historically, the only viable technological solution was roller chain. Despite the having the ability to easily attach blades, roller chain is characterized by significant drawbacks, including high cost, wear, and vibration from chordal action. Advanced carbon- fiber-reinforced timing belts have been recently developed which, coupled with a novel belt attachment system developed by Natel Energy, result in a large reduction in moving parts, reduced mass and cost, and elimination of chordal action for increased fatigue life. The work done in this project affirmatively addressed each of the following 3 major uncertainties concerning

  6. Optimal low thrust-based rendezvous maneuvers

    OpenAIRE

    Gonzalo Gomez, Juan Luis; Bombardelli, Claudio

    2015-01-01

    The minimum-time, low-constant-thrust, same circular orbit rendezvous problem is studied using a relative motion description of the system dynamics. The resulting Optimal Control Problem in the thrust orientation angle is formulated using both the Direct and Indirect methods. An extensive set of test cases is numerically solved with the former, while perturbation techniques applied to the later allow to obtain several approximate solutions and provide a greater insight on the underlying physi...

  7. PROFILE DESIGN OF NONCIRCULAR BELT PULLEYS

    OpenAIRE

    Krawiec, Piotr; Marlewski, Adam

    2017-01-01

    During design of the envelope of a noncircular belt pulley one should take into account several conditions resulting from kinematics and geometry of the uneven-running strand transmission. Design of proper values of pitches for a belt pulley, which enable good cooperation between the belt pulley and the belt, should be carefully done. In available Polish literature and catalogues offered by belt manufacturers, one can find only detailed dimensions of belts with a trapezoidal profile. Informat...

  8. Geography of the asteroid belt

    Science.gov (United States)

    Zellner, B. H.

    1978-01-01

    The CSM classification serves as the starting point on the geography of the asteroid belt. Raw data on asteroid types are corrected for observational biases (against dark objects, for instance) to derive the distribution of types throughout the belt. Recent work on family members indicates that dynamical families have a true physical relationship, presumably indicating common origin in the breakup of a parent asteroid.

  9. Middle Proterozoic thrusting in central New Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Grambling, J.A.; Thompson, A.G. (Univ. of New Mexico, Albuquerque, NM (United States). Dept. of Earth and Planetary Sciences); Dallmeyer, R.D. (Univ. of Georgia, Athens, GA (United States). Dept. of Geology)

    1992-01-01

    Ductile thrust faults truncate contact-metamorphic aureoles surrounding two 1.4 Ga plutons in central New Mexico. The Priest quartz monzonite (1440 Ma) and Sandia granite (1420 Ma) are 50 km apart in the continuous Sandia/Manzano mountain chain. Thermobarometry and phase relations demonstrate that country-rock temperatures rose from 700 C toward the pluton, at pressure near 4 kb. The northern edge of this aureole is cut by the southeast-dipping ductile Monte Largo thrust fault. Prograde, greenschist-facies metamorphism of footwall rocks accompanied local retrogression of hangingwall rocks during thrusting. This second metamorphism took place at P-T conditions of 2-3 kb and 450-475 C. Another contact aureole surrounds the Sandia granite. Mafic rocks near the granite reflect amphibolite-facies conditions, whereas pelites display low-pressure contact assemblages. Quantitative temperatures increase from 500--750 C toward the granite, at pressures of 2.5--3.5 kb. The shallowly southeast-dipping Vincent Moore fault truncates the Sandia granite and the southern portion of its contact aureole. This ductile shear zone emplaced greenschist-facies rocks northwestward above the Sandia contact aureole. Footwall rocks were retrograded to the greenschist facies within 100 m of this fault; the retrograde phases are aligned parallel to the trace of the thrust. Metamorphic temperatures in hangingwall rocks (during thrusting ) were 400-475 C at pressures above 2.75 kb. Additional northwest-vergent ductile thrusts are found elsewhere in the mountain chain. This may represent the age of thrusting and of the related greenschist and the related greenschist-facies metamorphic overprint.

  10. Thrust distribution for attitude control in a variable thrust propulsion system with four ACS nozzles

    Science.gov (United States)

    Lim, Yeerang; Lee, Wonsuk; Bang, Hyochoong; Lee, Hosung

    2017-04-01

    A thrust distribution approach is proposed in this paper for a variable thrust solid propulsion system with an attitude control system (ACS) that uses a reduced number of nozzles for a three-axis attitude maneuver. Although a conventional variable thrust solid propulsion system needs six ACS nozzles, this paper proposes a thrust system with four ACS nozzles to reduce the complexity and mass of the system. The performance of the new system was analyzed with numerical simulations, and the results show that the performance of the system with four ACS nozzles was similar to the original system while the mass of the whole system was simultaneously reduced. Moreover, a feasibility analysis was performed to determine whether a thrust system with three ACS nozzles is possible.

  11. Thrust Augmentation with Mixer/Ejector Systems

    Science.gov (United States)

    Presz, Walter M., Jr.; Reynolds, Gary; Hunter, Craig

    2002-01-01

    Older commercial aircraft often exceed FAA (Federal Aviation Administration) sideline noise regulations. The major problem is the jet noise associated with the high exhaust velocities of the low bypass ratio engines on such aircraft. Mixer/ejector exhaust systems can provide a simple means of reducing the jet noise on these aircraft by mixing cool ambient air with the high velocity engine gases before they are exhausted to ambient. This paper presents new information on thrust performance predictions, and thrust augmentation capabilities of mixer/ejectors. Results are presented from the recent development program of the patented Alternating Lobe Mixer Ejector Concept (ALMEC) suppressor system for the Gulfstream GII, GIIB and GIII aircraft. Mixer/ejector performance procedures are presented which include classical control volume analyses, compound compressible flow theory, lobed nozzle loss correlations and state of the art computational fluid dynamic predictions. The mixer/ejector thrust predictions are compared to subscale wind tunnel test model data and actual aircraft flight test measurements. The results demonstrate that a properly designed mixer/ejector noise suppressor can increase effective engine bypass ratio and generate large thrust gains at takeoff conditions with little or no thrust loss at cruise conditions. The cruise performance obtained for such noise suppressor systems is shown to be a strong function of installation effects on the aircraft.

  12. The Port Isabel Fold Belt: Salt enhanced Neogene Gravitational Spreading in the East Breaks, Western Gulf of Mexico

    Science.gov (United States)

    Lebit, Hermann; Clavaud, Marie; Whitehead, Sam; Opdyke, Scott; Luneburg, Catalina

    2017-04-01

    The Port Isabel fold belt is situated at the northwestern corner of the deep water Gulf of Mexico where the regional E-W trending Texas-Louisiana shelf bends into the NNE-SSW trend of the East Mexico Shelf. The fold belt forms an allochthonous wedge that ramps up from West to East with its front occupied by shallow salt complexes (local canopies). It is assumed that the belt predominantly comprises Oligocene siliciclastic sequences which reveal eastward facing folds and thrusts with a NE-SW regional trend. The structural architecture of the fold belt is very well imaged on recently processed 3D seismic volumes. Crystal III is a wide-azimuth survey acquired in 2011 and reprocessed in 2016 leveraging newly developed state-of-the-art technology. 3D deghosting, directional designature and multi-model 3D SRME resulted in broader frequency spectrum. The new image benefits from unique implementation of FWI, combined with classic tomographic updates. Seismically transparent zones indicating over-pressured shales are limited to the core of anticlines or to the footwall of internal thrust. Mobile shales associated with diapirs are absent in the study area. In contrast, salt is mobile and apparently forms the major decollement of the PIFB as indicated by remnant salt preferentially located in triangles along the major thrusts and fault intersections or at the core of anticlines. Shallow salt diapirs seam to root in the fold belt, while lacking evidence for salt feeders being connected to the deep salt underlying the Mesozoic to Paleogene substratum of the fold belt. Towards the WNW the fold belt is transient into a extensional regime, characterized by roll-over structures associated with deep reaching normal faults which form ultra-deep mini basins filled with Neogene deposits. Kinematic restorations confirm the simultaneous evolution of the deep mini basins and the outboard fold belt. This resembles a gravitational spreading system with the extensional tectonics of the deep

  13. Evaluation of the static belt fit provided by belt-positioning booster seats.

    Science.gov (United States)

    Reed, Matthew P; Ebert, Sheila M; Sherwood, Christopher P; Klinich, Kathleen D; Manary, Miriam A

    2009-05-01

    Belt-positioning booster seats are recommended for children who use vehicle seat belts as primary restraints but who are too small to obtain good belt fit. Previous research has shown that belt-positioning boosters reduce injury risk, but the belt fit produced by the wide range of boosters in the US market has not previously been assessed. The present study describes the development of a method for quantifying static belt fit with a Hybrid-III 6-year-old test dummy. The measurement method was applied in a laboratory seat mockup to 31 boosters (10 in both backless and highback modes) across a range of belt geometries obtained from in-vehicle measurements. Belt fit varied widely across boosters. Backless boosters generally produced better lap belt fit than highback boosters, largely because adding the back component moved the dummy forward with respect to the lap belt routing guides. However, highback boosters produced more consistent shoulder belt fit because of the presence of belt routing guides near the shoulder. Some boosters performed well on both lap belt and shoulder belt fit. Lap belt fit in dedicated boosters was generally better than in combination restraints that also can be used with an integrated harness. Results demonstrate that certain booster design features produce better belt fit across a wide range of belt geometries. Lap belt guides that hold the belt down, rather than up, and shoulder belt guides integrated into the booster backrest provided better belt fit.

  14. Role of wing morphing in thrust generation

    Directory of Open Access Journals (Sweden)

    Mehdi Ghommem

    2014-01-01

    Full Text Available In this paper, we investigate the role of morphing on flight dynamics of two birds by simulating the flow over rigid and morphing wings that have the characteristics of two different birds, namely the Giant Petrel and Dove Prion. The simulation of a flapping rigid wing shows that the root of the wing should be placed at a specific angle of attack in order to generate enough lift to balance the weight of the bird. However, in this case the generated thrust is either very small, or even negative, depending on the wing shape. Further, results show that morphing of the wing enables a significant increase in the thrust and propulsive efficiency. This indicates that the birds actually utilize some sort of active wing twisting and bending to produce enough thrust. This study should facilitate better guidance for the design of flapping air vehicles.

  15. Quadcopter thrust optimization with ducted-propeller

    Directory of Open Access Journals (Sweden)

    Kuantama Endrowednes

    2017-01-01

    Full Text Available In relation to quadcopter body frame model, propeller can be categorized into propeller with ducted and without ducted. This study present differences between those two using CFD (Computational Fluid Dynamics method. Both categories utilize two blade-propeller with diameter of 406 (mm. Propeller rotation generates acceleration per time unit on the volume of air. Based on the behavior of generated air velocity, ducted propeller can be modeled into three versions. The generated thrust and performance on each model were calculated to determine the best model. The use of ducted propeller increases the total weight of quadcopter and also total thrust. The influence of this modeling were analyzed in detail with variation of angular velocity propeller from 1000 (rpm to 9000 (rpm. Besides the distance between propeller tip and ducted barrier, the size of ducted is also an important part in thrust optimization and total weight minimization of quadcopter.

  16. National Assessment of Oil and Gas Project - Wyoming Thrust Belt Province (036) Boundary

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The USGS Central Region Energy Team assesses oil and gas resources of the United States. The onshore and State water areas of the United States comprise 71...

  17. National Assessment of Oil and Gas Project - Montana Thrust Belt Province (027) Boundary

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The USGS Central Region Energy Team assesses oil and gas resources of the United States. The onshore and State water areas of the United States comprise 71...

  18. National Assessment of Oil and Gas Project - Wyoming Thrust Belt (036) Quarter-Mile Cells

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Cell maps for each oil and gas assessment unit were created by the USGS as a method for illustrating the degree of exploration, type of production, and distribution...

  19. National Assessment of Oil and Gas Project - Montana Thrust Belt Province (027) Assessment Units

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The Assessment Unit is the fundamental unit used in the National Assessment Project for the assessment of undiscovered oil and gas resources. The Assessment Unit is...

  20. National Assessment of Oil and Gas Project - Wyoming Thrust Belt Province (036) Total Petroleum Systems

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The Total Petroleum System is used in the National Assessment Project and incorporates the Assessment Unit, which is the fundamental geologic unit used for the...

  1. National Assessment of Oil and Gas Project - Montana Thrust Belt Province (027) Quarter-Mile Cells

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Cell maps for each oil and gas assessment unit were created by the USGS as a method for illustrating the degree of exploration, type of production, and distribution...

  2. National Assessment of Oil and Gas Project - Wyoming Thrust Belt Province (036) Assessment Units

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The Assessment Unit is the fundamental unit used in the National Assessment Project for the assessment of undiscovered oil and gas resources. The Assessment Unit is...

  3. Chaos on the conveyor belt

    OpenAIRE

    Sándor, Bulcsú; Járai-Szabó, Ferenc; Tél, Tamás; Néda, Zoltán

    2013-01-01

    The dynamics of a spring-block train placed on a moving conveyor belt is investigated both by simple experiments and computer simulations. The first block is connected by spring to an external static point, and due to the dragging effect of the belt the blocks undergo complex stick-slip dynamics. A qualitative agreement with the experimental results can only be achieved by taking into account the spatial inhomogeneity of the friction force on the belt's surface, modeled as noise. As a functio...

  4. AUTOMATION OF CONVEYOR BELT TRANSPORT

    Directory of Open Access Journals (Sweden)

    Nenad Marinović

    1990-12-01

    Full Text Available Belt conveyor transport, although one of the most economical mining transport system, introduce many problems to mantain the continuity of the operation. Every stop causes economical loses. Optimal operation require correct tension of the belt, correct belt position and velocity and faultless rolls, which are together input conditions for automation. Detection and position selection of the faults are essential for safety to eliminate fire hazard and for efficient maintenance. Detection and location of idler roll faults are still open problem and up to now not solved successfully (the paper is published in Croatian.

  5. Thrust allocation for DP in ice

    OpenAIRE

    Wold, Henrik Emil

    2013-01-01

    The commercial industry has initiated work on how to make it feasible to enter the Arctic seas. Ice loads affects most aspects of the Arctic operation, and the marine crafts must be able to handle them all. The DP control system, and thus the thrust allocation, is not designed to handle ice loads and will not work properly \\cite{Moran}. The main purpose of this master thesis is to enhance the thrust allocation for handling ice loads. This is done by including thruster dynamics and adding thru...

  6. 30 CFR 75.1727 - Drive belts.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Drive belts. 75.1727 Section 75.1727 Mineral... SAFETY STANDARDS-UNDERGROUND COAL MINES Miscellaneous § 75.1727 Drive belts. (a) Drive belts shall not be shifted while in motion unless the machines are provided with mechanical shifters. (b) Belt dressing shall...

  7. Northeastern Brooks Range, Alaska: new evidence for complex thin-skinned thrusting

    Energy Technology Data Exchange (ETDEWEB)

    Rattey, R.P.

    1985-04-01

    Extensive fieldwork has shed new light on the style of deformation in the Franklin, Ramanzof, and British Mountains of the northeastern Brooks Range. Bedding-parallel thrusting controls the structure, and two major decollements are recognized. In the mountain belt, the lower one lies in the Lower Carboniferous Kayak Formation but often steps down to the base of the Upper Devonian Kanayut or Lower Carboniferous Kekiktuk Conglomerates. Near the Sadlerochit and Shublik Mountains, it steps down to its deepest level to the base of the Cambrian to Middle Devonian Katakturuk Dolomite. The upper decollement is poorly exposed in the mountains and lies in the Jurassic Kingak Shale. Locally, these are removed by Early Cretaceous erosion and the decollement steps unsequence. The two decollements separate three tectonic sequences that deform differently. First, basement below the lower decollement deforms into a set of thrust duplexes. The core of these is well exposed in the Franklin Mountains. The Sagavanirktok sidewall ramp is a major basement structure that causes the northern swing in the mountain front between the central and northeastern Brooks Range. Second, the lower cover between the two decollements deforms more complexly than basement by both passive drape over the underlying duplexes and by active thrust stacking. Large-scale buckle folding occurs in a shear zone above the Sagavanirktok sidewall ramp. Third, the upper cover above the upper decollement is poorly preserved in the mountains as allochthonous klippe in depressions in the basement and lower cover duplexes.

  8. 30 CFR 75.1731 - Maintenance of belt conveyors and belt conveyor entries.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Maintenance of belt conveyors and belt conveyor....1731 Maintenance of belt conveyors and belt conveyor entries. (a) Damaged rollers, or other damaged belt conveyor components, which pose a fire hazard must be immediately repaired or replaced. All other...

  9. A thrust-ridge paleodepositional model for the Upper Freeport coal bed and associated clastic facies, Upper Potomac coal field, Appalachian basin, U.S.A.

    Science.gov (United States)

    Belt, E.S.; Lyons, P.C.

    1989-01-01

    A blind-thrust-ridge model is proposed to explain the lack of coarse clastic material in the vast minable Upper Freeport coal bed (UF). This coal bed contains only fine elastic partings and is overlain by regionally extensive, closely spaced channel-belt deposits in the Upper Potomac coal field of the Appalachian basin. A blind-thrust ridge may have formed a sediment trap and prevented c coarse fluvial sediments from entering the swamp during a period (Westphalian D) when the thick Upper Freeport peat accumulated. Anticlinal thrust ridges and associated depressions may have existed uninterrupted for about 40 km parallel to the Appalachian orogen. Sediment shed from the breached anticlinal ridges accumulated in the sediment trap and was carried out of the ends of the trap by streams that occupied the shear zone at the ends of the blind-thrust ridge. The extent, parallel to the orogen, of thick, areally extensive UF is related to the length of the blind-thrust ridge that, in turn, controlled the spacing of the river-derived coarse clastic sediments that entered the main basin from the east. The thrust plane eventually emerged to the surface of the blind-thrust ridge and peat accumulation was terminated when the ridge became eroded and the sediment trapped behind it was released. The peat was buried by abundant coarse clastic sediment, which formed closely spaced channel belts and intervening flood basins. This model has implications for widespread peat deposits (now coal) that developed in tropical regions a few hundred kilometers from the sea in a tectonically active foreland basin. ?? 1989.

  10. (U-Th)/He and U-Pb double dating constraints on the interplay between thrust deformation and basin development, Sevier foreland basin, Utah

    Science.gov (United States)

    Pujols, E.; Stockli, D. F.; Horton, B. K.; Steel, R. J.; Constenius, K. N.

    2015-12-01

    The degree of connectivity between thrust-belt deformation and foreland basin evolution has been a matter of debate for decades. This is in part due to the lack of temporal constraints on the relationship between thrust-belt deformation and associated deposition. New high-resolution zircon (U-Th)-(Pb-He) double dating of pre- and syn-tectonic sedimentary strata along the Sevier thrust front and basin provide an unprecedented geochronological framework to temporally and spatially link the Sevier foreland basin stratigraphy to deforming hinterland sources. Results improve constraints on timing and magnitude of deformation, depositional ages, sediment dispersal and sources. In Late Cretaceous proximal deposits of the Indianola Group (IG) and Canyon Range Conglomerates (CRC), detrital zircon U-Pb (zUPb) and (U-Th)/He ages (ZHe) chronicle the sequential unroofing of the Charlestone-Nebo Salient (CNS) and Canyon Range (CR) duplexes. Furthermore, short ZHe depositional lag-times indicate rapid hinterland exhumation (>1km/my) associated with active thrusting during Cenomanian and Coniacian-Santonian times as supported by bedrock ZHe ages in the CNS and CR thrust sheets. Detrital zircon analyses on the Late Cretaceous marine Book Cliffs strata suggest a more complex source-to-sink evolution compared to the time-equivalent IG and CRC proximal strata due to mixing of multi-source detrital zircons, sediment recycling and more prominent volcanic input. Nonetheless, the overall cooling history recorded in the Book Cliffs clearly reflects three hinterland exhumational phases, an early phase derived from the frontal thrusts and two additional phases with more integrated hinterland ZHe signatures. These three short lag-time phases correlate with fast clastic progradational wedges in the Sevier foreland. These results strengthen the role played by hinterland deformation on clastic progradation and elucidate the temporal relationship between thrusting and foreland basin architecture.

  11. Chaos on the conveyor belt

    Science.gov (United States)

    Sándor, Bulcsú; Járai-Szabó, Ferenc; Tél, Tamás; Néda, Zoltán

    2013-04-01

    The dynamics of a spring-block train placed on a moving conveyor belt is investigated both by simple experiments and computer simulations. The first block is connected by a spring to an external static point and, due to the dragging effect of the belt, the blocks undergo complex stick-slip dynamics. A qualitative agreement with the experimental results can be achieved only by taking into account the spatial inhomogeneity of the friction force on the belt's surface, modeled as noise. As a function of the velocity of the conveyor belt and the noise strength, the system exhibits complex, self-organized critical, sometimes chaotic, dynamics and phase transition-like behavior. Noise-induced chaos and intermittency is also observed. Simulations suggest that the maximum complexity of the dynamical states is achieved for a relatively small number of blocks (around five).

  12. Chaos on the conveyor belt.

    Science.gov (United States)

    Sándor, Bulcsú; Járai-Szabó, Ferenc; Tél, Tamás; Néda, Zoltán

    2013-04-01

    The dynamics of a spring-block train placed on a moving conveyor belt is investigated both by simple experiments and computer simulations. The first block is connected by a spring to an external static point and, due to the dragging effect of the belt, the blocks undergo complex stick-slip dynamics. A qualitative agreement with the experimental results can be achieved only by taking into account the spatial inhomogeneity of the friction force on the belt's surface, modeled as noise. As a function of the velocity of the conveyor belt and the noise strength, the system exhibits complex, self-organized critical, sometimes chaotic, dynamics and phase transition-like behavior. Noise-induced chaos and intermittency is also observed. Simulations suggest that the maximum complexity of the dynamical states is achieved for a relatively small number of blocks (around five).

  13. Reverse Core Engine with Thrust Reverser

    Science.gov (United States)

    Suciu, Gabriel L. (Inventor); Chandler, Jesse M. (Inventor)

    2017-01-01

    An engine system has a gas generator, a bi-fi wall surrounding at least a portion of the gas generator, a casing surrounding a fan, and the casing having first and second thrust reverser doors which in a deployed position abut each other and the bi-fi wall.

  14. Pilot tests of a seat belt gearshift delay on the belt use of commercial fleet drivers.

    Science.gov (United States)

    2009-12-01

    the seat belt was buckled. Participants, commercial drivers from the United States and Canada who did not consistently wear their seat belts, could avoid the delay by fastening their seat belts. Unbelted participants experienced a delay of either a c...

  15. Proterozoic orogenic belts and rifting of Indian cratons: Geophysical constraints

    Directory of Open Access Journals (Sweden)

    D.C. Mishra

    2014-01-01

    Full Text Available The Aravalli–Delhi and Satpura Mobile Belts (ADMB and SMB and the Eastern Ghat Mobile Belt (EGMB in India form major Proterozoic mobile belts with adjoining cratons and contemporary basins. The most convincing features of the ADMB and the SMB have been the crustal layers dipping from both sides in opposite directions, crustal thickening (∼45 km and high density and high conductivity rocks in upper/lower crust associated with faults/thrusts. These observations indicate convergence while domal type reflectors in the lower crust suggest an extensional rifting phase. In case of the SMB, even the remnant of the subducting slab characterized by high conductive and low density slab in lithospheric mantle up to ∼120 km across the Purna–Godavari river faults has been traced which may be caused by fluids due to metamorphism. Subduction related intrusives of the SMB south of it and the ADMB west of it suggest N–S and E–W directed convergence and subduction during Meso–Neoproterozoic convergence. The simultaneous E–W convergence between the Bundelkhand craton and Marwar craton (Western Rajasthan across the ADMB and the N–S convergence between the Bundelkhand craton and the Bhandara and Dharwar cratons across the SMB suggest that the forces of convergence might have been in a NE–SW direction with E–W and N–S components in the two cases, respectively. This explains the arcuate shaped collision zone of the ADMB and the SMB which are connected in their western part. The Eastern Ghat Mobile Belt (EGMB also shows signatures of E–W directed Meso–Neoproterozoic convergence with East Antarctica similar to ADMB in north India. Foreland basins such as Vindhyan (ADMB–SMB, and Kurnool (EGMB Supergroups of rocks were formed during this convergence. Older rocks such as Aravalli (ADMB, Mahakoshal–Bijawar (SMB, and Cuddapah (EGMB Supergroups of rocks with several basic/ultrabasic intrusives along these mobile belts, plausibly formed during

  16. Precise Thrust Actuation by a Micro RF Ion Engine Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Busek proposes to develop a radio-frequency discharge, gridded micro ion engine that produces 5N level of thrust precisely adjustable over a wide dynamic thrust...

  17. Duration of inverted metamorphic sequence formation across the Himalayan Main Central Thrust (MCT), Sikkim

    Science.gov (United States)

    Cioldi, Stefania; Moulas, Evangelos; Tajcmanová, Lucie; Burg, Jean-Pierre

    2016-04-01

    Collision between the Indian and Eurasian plates since the Eocene (50 Ma) caused the closure of the Neo-Tethys and the underthrusting of India beneath the Tibetan Plateau, generating the 2500 km extended Himalayan belt. The Main Central Thrust (MCT) marks the boundary of the underlying Midland Lower Himalaya metasediments zone (LH) in the south from the overlying high grade metamorphic Higher Himalaya (HH) in the north. Several models considering petrochronology, geothermobarometry and structural geology have been discussed to explain the inverted metamorphic gradient in the LH metasediments without reaching a common agreement. This study investigates the tectonic setting and the timescale of inverted isograds related to crustal-scale thrusting at the MCT in the Sikkim region, northeast India. The aim is to contribute to the understanding of the link between mechanical and thermal evolution of major thrust zones and to clarify the nature and the origin of orogenic heat applying garnet geospeedometry. Garnets provide a sensitive record of metamorphic conditions and are potential chronometer. Their compositional zoning is used as a gauge for rate estimates of element diffusion within the mineral and allows estimating the absolute time of the thermal evolution. Inverse-fitting numerical model considering FRactIonation and Diffusion in GarnEt (FRIDGE) calculates garnet composition profiles by introducing P-T-t paths and bulk-rock composition of a specific sample. P-T conditions were estimated by convectional geothermobarometry supported by phase equilibria modelling and measured garnet chemical compositions. Simulation were compared with measured garnet profiles. Simple step function and FRIDGE preliminary results of Fe-Mg - Ca - Mn garnet fractionation-diffusion modelling indicate very short timescale (between 3 and 6 Ma) for peak metamorphic conditions in the northeast Himalayan collisional system. This duration does not allow thermal re-equilibration. It is an

  18. 3D Fault modeling of the active Chittagong-Myanmar fold belt, Bangladesh

    Science.gov (United States)

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

    2013-12-01

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

  19. High temperature thrust chamber for spacecraft

    Science.gov (United States)

    Chazen, Melvin L. (Inventor); Mueller, Thomas J. (Inventor); Kruse, William D. (Inventor)

    1998-01-01

    A high temperature thrust chamber for spacecraft (20) is provided herein. The high temperature thrust chamber comprises a hollow body member (12) having an outer surface and an internal surface (16) defining the high temperature chamber (10). The body member (12) is made substantially of rhenium. An alloy (18) consisting of iridium and at least alloying metal selected of the group consisting of rhodium, platinum and palladium is deposited on at least a portion of the internal surface (16) of the body member (12). The iridium and the alloying metal are electrodeposited onto the body member (12). A HIP cycle is performed upon the body member (12) to cause the coating of iridium and the alloying metal to form the alloy (18) which protects the body member (12) from oxidation.

  20. Midterm results of "thrust plate" prosthesis.

    Science.gov (United States)

    Fink, Bernd; Wessel, Stephanie; Deuretzbacher, Georg; Protzen, Michael; Ruther, Wolfgang

    2007-08-01

    The aim of this investigation was to analyze the midterm results obtained with the metaphyseal fixation principle of the thrust plate prosthesis (TPP). Survival of 214 implants in 204 patients was analyzed. Clinical (Harris hip score) and radiologic examinations were carried out on 157 of 190 TPP with a postimplantation follow-up period of at least 5 years. Failure rate was 7.0% (9 aseptic and 6 septic loosening). Harris hip score increased from 36.9 +/- 13.5 points preoperatively to 91.2 +/- 13.1 points at follow-up. Eleven TPPs showed radiolucent lines not indicating prosthetic loosening. Thrust plate prosthesis is not an alternative to stemmed endoprostheses. It may be rarely indicated in very young patients where, because of their age, several revision operations can be expected.

  1. Thrust production by a mechanical swimming lamprey

    Science.gov (United States)

    Leftwich, M. C.; Smits, A. J.

    2011-05-01

    To develop a comprehensive model of lamprey locomotion, we use a robotic lamprey to investigate the formation of the wake structure, the shedding vorticity from the body, and the relationship between thrust production and pressure on the surface of the robot. The robot mimics the motion of living lamprey in steady swimming by using a programmable microcomputer to actuate 13 servomotors that produce a traveling wave along the length of the lamprey body. The amplitude of the phase-averaged surface pressure distribution along the centerline of the robot increases toward the tail, which is consistent with previous momentum balance experiments. This indicates that thrust is produced mainly at the tail. The phase relationship between the pressure signal and the vortex shedding from the tail is also examined, showing a clear connection between the location of vortex structures and the fluctuations of the pressure signal.

  2. NATURAL BARRIERS TARGETED THRUST FY 2004 PROJECTS

    Energy Technology Data Exchange (ETDEWEB)

    NA

    2005-07-27

    This booklet contains project descriptions of work performed by the Department of Energy (DOE), Office of Civilian Radioactive Waste Management (OCRWM), Office of Science and Technology and International's (OST&I) Natural Barriers Targeted Thrust during Fiscal Year (FY) 2004. The Natural Barriers Targeted Thrust is part of OST&I's Science and Technology Program which supports the OCRWM mission to manage and dispose of high-level radioactive waste and spent nuclear fuel in a manner that protects health, safety, and the environment; enhances national and energy security; and merits public confidence. In general, the projects described will continue beyond FY 2004 assuming that the technical work remains relevant to the proposed Yucca Mountain Repository and sufficient funding is made available to the Science and Technology Program.

  3. MATERIALS PERFORMANCE TARGETED THRUST FY 2004 PROJECTS

    Energy Technology Data Exchange (ETDEWEB)

    DOE

    2005-09-13

    The Yucca Mountain site was recommended by the President to be a geological repository for commercial spent nuclear fuel and high-level radioactive waste. The multi-barrier approach was adopted for assessing and predicting system behavior, including both natural barriers and engineered barriers. A major component of the long-term strategy for safe disposal of nuclear waste is first to completely isolate the radionuclides in waste packages for long times and then to greatly retard the egress and transport of radionuclides from penetrated packages. The goal of the Materials Performance Targeted Thrust program is to further enhance the understanding of the role of engineered barriers in waste isolation. In addition, the Thrust will explore technical enhancements and seek to offer improvements in materials costs and reliability.

  4. Several topics on orbital dynamics of consecutive, low-thrust, accelerated spacecraft trajectories

    OpenAIRE

    Yamakawa, Hiroshi; 山川 宏

    2008-01-01

    Orbital dynamics of consecutive, low-thrust trajectories is overviewed. Focusing on the thrust direction constraints (e.g., transversal and radial thrust direction constraints), various trajectory design strategies of low-thrust missions are summarized with concrete examples.

  5. Effect of the brittle-ductile transition on the topography of compressive mountain belts on Earth and Venus

    Energy Technology Data Exchange (ETDEWEB)

    Williams, C.A.; Connors, C.; Dahlen, F.A.; Price, E.J.; Suppe, J. [Princeton Univ., NJ (United States)

    1994-10-10

    The Coulomb critical taper model has been very successful in explaining the large-scale topography of a number of terrestrial accretionary wedges; however, this model is limited to cases of purely brittle frictional deformation. In this paper the authors extend the range of applicability of the critical taper model by explicitly including the effects of temperature-dependent ductile deformation. The new model includes temperature-dependent power law flow, an assumed velocity field, and linear thermal gradients in the atmosphere and within the crust. Flexural isostasy is also incorporated so that the decollement geometry is computed as a response to the applied load of the wedge material. They assume that ductile deformation within the decollement zone is controlled by dislocation creep. The topographic profiles predicted by the model are very similar to those of a number of fold-and-thrust belts on both Earth and Venus. A typical wedge and the decollement zone deforms in a brittle-frictional manner; a region of relatively steep slope, where the wedge base deforms ductilely and the decollement zone are deforming by ductile flow. The authors have applied the model to two-fold-and-thrust belts on Venus (Maxwell Montes and Uorsar Rupes) and to the Andes on Earth, and they find good agreement between observed and predicted topography using reasonable parameter values. The model accounts for the observed positive correlation between relief and evaluation of Venusian fold-and-thrust belts on the basis of different thermal environments at different elevations. It is also able to explain the first-order differences between and Venusian fold-and thrust belts; fundamentally, this difference is due to a combination of the lower temperatures and the presence of water on Earth. 54 refs., 20 figs., 3 tabs.

  6. Calculating track thrust with track functions

    Science.gov (United States)

    Chang, Hsi-Ming; Procura, Massimiliano; Thaler, Jesse; Waalewijn, Wouter J.

    2013-08-01

    In e+e- event shapes studies at LEP, two different measurements were sometimes performed: a “calorimetric” measurement using both charged and neutral particles and a “track-based” measurement using just charged particles. Whereas calorimetric measurements are infrared and collinear safe, and therefore calculable in perturbative QCD, track-based measurements necessarily depend on nonperturbative hadronization effects. On the other hand, track-based measurements typically have smaller experimental uncertainties. In this paper, we present the first calculation of the event shape “track thrust” and compare to measurements performed at ALEPH and DELPHI. This calculation is made possible through the recently developed formalism of track functions, which are nonperturbative objects describing how energetic partons fragment into charged hadrons. By incorporating track functions into soft-collinear effective theory, we calculate the distribution for track thrust with next-to-leading logarithmic resummation. Due to a partial cancellation between nonperturbative parameters, the distributions for calorimeter thrust and track thrust are remarkably similar, a feature also seen in LEP data.

  7. MHD thrust vectoring of a rocket engine

    Science.gov (United States)

    Labaune, Julien; Packan, Denis; Tholin, Fabien; Chemartin, Laurent; Stillace, Thierry; Masson, Frederic

    2016-09-01

    In this work, the possibility to use MagnetoHydroDynamics (MHD) to vectorize the thrust of a solid propellant rocket engine exhaust is investigated. Using a magnetic field for vectoring offers a mass gain and a reusability advantage compared to standard gimbaled, elastomer-joint systems. Analytical and numerical models were used to evaluate the flow deviation with a 1 Tesla magnetic field inside the nozzle. The fluid flow in the resistive MHD approximation is calculated using the KRONOS code from ONERA, coupling the hypersonic CFD platform CEDRE and the electrical code SATURNE from EDF. A critical parameter of these simulations is the electrical conductivity, which was evaluated using a set of equilibrium calculations with 25 species. Two models were used: local thermodynamic equilibrium and frozen flow. In both cases, chlorine captures a large fraction of free electrons, limiting the electrical conductivity to a value inadequate for thrust vectoring applications. However, when using chlorine-free propergols with 1% in mass of alkali, an MHD thrust vectoring of several degrees was obtained.

  8. Aircraft Engine Thrust Estimator Design Based on GSA-LSSVM

    Science.gov (United States)

    Sheng, Hanlin; Zhang, Tianhong

    2017-08-01

    In view of the necessity of highly precise and reliable thrust estimator to achieve direct thrust control of aircraft engine, based on support vector regression (SVR), as well as least square support vector machine (LSSVM) and a new optimization algorithm - gravitational search algorithm (GSA), by performing integrated modelling and parameter optimization, a GSA-LSSVM-based thrust estimator design solution is proposed. The results show that compared to particle swarm optimization (PSO) algorithm, GSA can find unknown optimization parameter better and enables the model developed with better prediction and generalization ability. The model can better predict aircraft engine thrust and thus fulfills the need of direct thrust control of aircraft engine.

  9. The Eoalpine High Pressure Belt west of the Tauern Window

    Science.gov (United States)

    Pomella, Hannah; Flöss, David; Speckbacher, Romed; Tropper, Peter; Fügenschuh, Bernhard

    2015-04-01

    Eclogites in the Texel Unit (Eastern Alps; South Tyrol, Italy) represent the westernmost outcrops of the E-W striking Eoalpine High Pressure Belt (EHB), a key feature of the Eastern Alps. The EHB forms part of a Cretaceous intra-continental, south(east) dipping subduction/collision zone as visible east of the Tauern window. West of the Tauern window the same nappe stack displays a northwest dip giving rise for discussion on the general setting. Based on own observations and literature data we present a new and coherent tectonic model for the eastern end of the EHB: Despite at present the major structures dip to northwest the subduction was originally directed to south(east). Due to the special situation of this area at the tip of the Southalpine indenter the originally south(east) dipping structures became overturned and former thrusts appear as normal faults (e.g. Schneeberg fault zone) while former normal faults presently display thrust geometries (e.g. Jaufen fault). Two crustal-scale cross-sections together with an evolution model are presented to illustrate the model.

  10. Thrust Performance Evaluation of a Turbofan Engine Based on Exergetic Approach and Thrust Management in Aircraft

    Science.gov (United States)

    Yalcin, Enver

    2017-05-01

    The environmental parameters such as temperature and air pressure which are changing depending on altitudes are effective on thrust and fuel consumption of aircraft engines. In flights with long routes, thrust management function in airplane information system has a structure that ensures altitude and performance management. This study focused on thrust changes throughout all flight were examined by taking into consideration their energy and exergy performances for fuel consumption of an aircraft engine used in flight with long route were taken as reference. The energetic and exergetic performance evaluations were made under the various altitude conditions. The thrust changes for different altitude conditions were obtained to be at 86.53 % in descending direction and at 142.58 % in ascending direction while the energy and exergy efficiency changes for the referenced engine were found to be at 80.77 % and 84.45 %, respectively. The results revealed here can be helpful to manage thrust and reduce fuel consumption, but engine performance will be in accordance with operation requirements.

  11. 49 CFR 393.93 - Seats, seat belt assemblies, and seat belt assembly anchorages.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 5 2010-10-01 2010-10-01 false Seats, seat belt assemblies, and seat belt... § 393.93 Seats, seat belt assemblies, and seat belt assembly anchorages. (a) Buses—(1) Buses... on or after January 1, 1965, and before July 1, 1971, must be equipped with a Type 1 or Type 2 seat...

  12. French experience in seat belt use.

    NARCIS (Netherlands)

    Lassarre, S. & Page, Y.

    1992-01-01

    This paper concerns the French experience in seat belt use. As well as the seat belt regulations, the strategies employed to reinforce the wearing of seat belts by using information and encouragement campaigns and checks by the police and gendarmerie are described here along with their timetables

  13. 36 CFR 4.15 - Safety belts.

    Science.gov (United States)

    2010-07-01

    ... 36 Parks, Forests, and Public Property 1 2010-07-01 2010-07-01 false Safety belts. 4.15 Section 4... TRAFFIC SAFETY § 4.15 Safety belts. (a) Each operator and passenger occupying any seating position of a motor vehicle in a park area will have the safety belt or child restraint system properly fastened at...

  14. 36 CFR 1004.15 - Safety belts.

    Science.gov (United States)

    2010-07-01

    ... 36 Parks, Forests, and Public Property 3 2010-07-01 2010-07-01 false Safety belts. 1004.15 Section... belts. (a) Each operator and passenger occupying any seating position of a motor vehicle in the area administered by the Presidio Trust will have the safety belt or child restraint system properly fastened at all...

  15. 46 CFR 169.723 - Safety belts.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Safety belts. 169.723 Section 169.723 Shipping COAST... Control, Miscellaneous Systems, and Equipment § 169.723 Safety belts. Each vessel must carry a harness type safety belt conforming to Offshore Racing Council (ORC) standards for each person on watch or...

  16. 14 CFR 27.1413 - Safety belts.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Safety belts. 27.1413 Section 27.1413 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: NORMAL CATEGORY ROTORCRAFT Equipment Safety Equipment § 27.1413 Safety belts. Each safety belt...

  17. 30 CFR 77.1107 - Belt conveyors.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Belt conveyors. 77.1107 Section 77.1107 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR COAL MINE SAFETY AND HEALTH MANDATORY... § 77.1107 Belt conveyors. Belt conveyors in locations where fire would create a hazard to personnel...

  18. Kuiper belts around nearby stars

    NARCIS (Netherlands)

    Nilsson, R.; Liseau, R.; Brandeker, A.; Olofsson, G.; Pilbratt, G. L.; Risacher, C.; Rodmann, J.; Augereau, J-C.; Bergman, P.; Eiroa, C.; Fridlund, M.; Thebault, P.; White, G. J.

    2010-01-01

    Context. The existence of dusty debris disks around a large fraction of solar type main-sequence stars, inferred from excess far-IR and submillimetre emission compared to that expected from stellar photospheres, suggests that leftover planetesimal belts analogous to the asteroid-and comet reservoirs

  19. Seat Belts: 1949-1956

    Science.gov (United States)

    1979-04-01

    The study assesses the impact of the consumer misconceptions, the lack of a seat belt standard, corporate attitudes towards safety, and the role of safety advocates. In addition, the study assesses the validity of the oft-stated hypothesis "safety do...

  20. Fluid mixing and recycling during Pyrenean thrusting: evidence from fluid inclusion halogen ratios

    Science.gov (United States)

    McCaig, A. M.; Tritlla, J.; Banks, D. A.

    2000-10-01

    Syntectonic fluids have been sampled through fluid inclusion microthermometry and crush-leach analyses (cations and halogens) from a 50 km N-S transect through the central-southern Pyrenees. The fluid inclusions are contained in syntectonic quartz veins in Triassic redbeds, Cretaceous carbonates and Hercynian basement rocks, with some calcite and dolomite data from limestones and evaporites in more external parts of the belt. The main datasets come from (1) Alpine shear zones cutting the Néouvielle granodiorite in the Hercynian Axial Zone at the north end of the transect; (2) An imbricate zone beneath the Alpine Gavarnie Thrust at the Pic de Port Vieux; (3) Several localities in the footwall and hangingwall of the Gavarnie Thrust on the southern margin of the Axial Zone. The inclusion fluids generally decrease in salinity from 27-35% at the northern end of the transect to 7-22% on the southern margin of the Axial Zone. The majority of the inclusions have Cl/Br ratios lower than seawater and are interpreted as relict fluids after seawater evaporation and halite precipitation in the upper Trias. This interpretation is supported by Cl-Br-Na systematics, which are consistent with a change from halite to halite + sylvite precipitation with progressive evaporation. Fluids in the basement shear zones are interpreted to have essentially the same evaporitic origin as those still contained in sedimentary formations, although it is possible that final concentration of brines in the Néouvielle Massif involved retrograde hydration reactions with removal of water by precipitation of hydrous minerals. The fluids are also very similar in salinity and halogen chemistry to those found in veins associated with Mesozoic Pb-Zn-F deposits which predate the thrusting. The lower salinities seen at the southern margin of the Axial Zone are interpreted to reflect mixing of the brines with a higher level fluid (connate or meteoric water) circulating within the Mesozoic carbonates of the

  1. Time and space variability of thin-skinned and thick-skinned thrust tectonics in the Appennines (Italy)

    Energy Technology Data Exchange (ETDEWEB)

    Mazzoli, S. [Urbino Univ., Urbino (IT). Dipt. Dinamica Ambientale] [and others

    2000-07-01

    In the Apennine fold and thrust belt of Italy, thin skinned (i.e. detachment-dominated) and thick-skinned (i.e. crustal ramp-dominated) structures coexist, but with marked differences in both time and space. The external part of the northern Apennines and the deeper and younger portions (buried Apulian carbonates) of the thrust belt in the central and southern Apennines show limited amounts of shortening (in the range of 5-14 km). These results from similar deformation styles, involving the occurrence of relatively low-displacement, thick-skinned thrust ramps. The latter represents, at least in the northern Apennines, preexisting basement structures reactivated and inverted during contractional deformation. Interposed between the northern and southern parts of the fold and thrust belt, the central Apennines appears to constitute a transitional area in which strike-slip tectonics is relevant and carbonate platform units become predominant over pelagic basin ones, whereas the overall structure of the thrust belt becomes similar to that of the southern Apennines. In the latter, a peculiar structural style is revealed by the integrated analysis of surface and subsurface data. Structurally, the upper part of the thrust belt consists of allochthonous units made of Mesozoic peritidal carbonate platform. Based on available seismic data, the latter appears to be involved, together with the underlying Permo-Triassic clastics and also the basement, in relatively low displacement, thick-skinned structures. Therefore, in southern Apennines, a transition from thin- to thick-skinned tectonics appears to have occurred through time. Thin-skinned structures characterise the shallower - and older - part of the thrust belt made recent accretion. The present boundary between two different, superposed portions of thrust belt consists of a low-angle, large-displacement thrust fault penetrated by numerous oil wells. Different styles and modes of contractional deformation in the

  2. Space geodetic observations of nazca-south america convergence across the central andes

    Science.gov (United States)

    Norabuena; Leffler-Griffin; Mao; Dixon; Stein; Sacks; Ocola; Ellis

    1998-01-16

    Space geodetic data recorded rates and directions of motion across the convergent boundary zone between the oceanic Nazca and continental South American plates in Peru and Bolivia. Roughly half of the overall convergence, about 30 to 40 millimeters per year, accumulated on the locked plate interface and can be released in future earthquakes. About 10 to 15 millimeters per year of crustal shortening occurred inland at the sub-Andean foreland fold and thrust belt, indicating that the Andes are continuing to build. Little (5 to 10 millimeters per year) along-trench motion of coastal forearc slivers was observed, despite the oblique convergence.

  3. Versatile and Extensible, Continuous-Thrust Trajectory Optimization Tool Project

    Data.gov (United States)

    National Aeronautics and Space Administration — We propose to develop an innovative, versatile and extensible, continuous-thrust trajectory optimization tool for planetary mission design and optimization of...

  4. Improved Propulsion Modeling for Low-Thrust Trajectory Optimization

    Science.gov (United States)

    Knittel, Jeremy M.; Englander, Jacob A.; Ozimek, Martin T.; Atchison, Justin A.; Gould, Julian J.

    2017-01-01

    Low-thrust trajectory design is tightly coupled with spacecraft systems design. In particular, the propulsion and power characteristics of a low-thrust spacecraft are major drivers in the design of the optimal trajectory. Accurate modeling of the power and propulsion behavior is essential for meaningful low-thrust trajectory optimization. In this work, we discuss new techniques to improve the accuracy of propulsion modeling in low-thrust trajectory optimization while maintaining the smooth derivatives that are necessary for a gradient-based optimizer. The resulting model is significantly more realistic than the industry standard and performs well inside an optimizer. A variety of deep-space trajectory examples are presented.

  5. Ring current and radiation belts

    Science.gov (United States)

    Williams, D. J.

    1987-01-01

    Studies performed during 1983-1986 on the ring current, the injection boundary model, and the radiation belts are discussed. The results of these studies yielded the first observations on the composition and charge state of the ring current throughout the ring-current energy range, and strong observational support for an injection-boundary model accounting for the origins of radiation-belt particles, the ring current, and substorm particles observed at R less than about 7 earth radii. In addition, the results have demonstrated that the detection of energetic neutral atoms generated by charge-exchange interactions between the ring current and the hydrogen geocorona can provide global images of the earth's ring current and its spatial and temporal evolution.

  6. Saturation of Van Allen's belts

    CERN Document Server

    Le Bel, E

    2002-01-01

    The maximum number of electrons that can be trapped in van Allen's belts has been evaluated at CEA-DAM more precisely than that commonly used in the space community. The modelization that we have developed allows to understand the disagreement (factor 50) observed between the measured and predicted electrons flux by US satellites and theory. This saturation level allows sizing-up of the protection on a satellite in case of energetic events. (authors)

  7. Use of seatbelts in cars with automatic belts.

    OpenAIRE

    Williams, A F; Wells, J K; Lund, A K; Teed, N J

    1992-01-01

    Use of seatbelts in late model cars with automatic or manual belt systems was observed in suburban Washington, DC, Chicago, Los Angeles, and Philadelphia. In cars with automatic two-point belt systems, the use of shoulder belts by drivers was substantially higher than in the same model cars with manual three-point belts. This finding was true in varying degrees whatever the type of automatic belt, including cars with detachable nonmotorized belts, cars with detachable motorized belts, and esp...

  8. Experimental Investigation of Thrust Fault Rupture Mechanics

    Science.gov (United States)

    Gabuchian, Vahe

    Thrust fault earthquakes are investigated in the laboratory by generating dynamic shear ruptures along pre-existing frictional faults in rectangular plates. A considerable body of evidence suggests that dip-slip earthquakes exhibit enhanced ground motions in the acute hanging wall wedge as an outcome of broken symmetry between hanging and foot wall plates with respect to the earth surface. To understand the physical behavior of thrust fault earthquakes, particularly ground motions near the earth surface, ruptures are nucleated in analog laboratory experiments and guided up-dip towards the simulated earth surface. The transient slip event and emitted radiation mimic a natural thrust earthquake. High-speed photography and laser velocimeters capture the rupture evolution, outputting a full-field view of photo-elastic fringe contours proportional to maximum shearing stresses as well as continuous ground motion velocity records at discrete points on the specimen. Earth surface-normal measurements validate selective enhancement of hanging wall ground motions for both sub-Rayleigh and super-shear rupture speeds. The earth surface breaks upon rupture tip arrival to the fault trace, generating prominent Rayleigh surface waves. A rupture wave is sensed in the hanging wall but is, however, absent from the foot wall plate: a direct consequence of proximity from fault to seismometer. Signatures in earth surface-normal records attenuate with distance from the fault trace. Super-shear earthquakes feature greater amplitudes of ground shaking profiles, as expected from the increased tectonic pressures required to induce super-shear transition. Paired stations measure fault parallel and fault normal ground motions at various depths, which yield slip and opening rates through direct subtraction of like components. Peak fault slip and opening rates associated with the rupture tip increase with proximity to the fault trace, a result of selective ground motion amplification in the

  9. Structural evidence for the allochthonous nature of the Bulbul terrane in southern Ethiopia: A west-verging thrust nappe

    Science.gov (United States)

    Yihunie, Tadesse; Tesfaye, Melaku

    2002-02-01

    The Neoproterozoic basement of southern Ethiopia links the low-grade Pan-African province of the Arabian-Nubian Shield to the high-grade Mozambique Belt to the south. In this intervening area, a northward terminating low-grade metavolcano-sedimentary and mafic-ultramafic sequence of the Bulbul terrane gently overlies moderately to steeply dipping granitic migmatites of the Alghe gneissic terrane. The contact between the two terranes is a right lateral thrust. In the Bulbul terrane, rocks are part of an overturned sequence with a gently east-dipping composite D1/D2 foliation containing downdip and NE-plunging stretching lineations and westerly verging intrafolial folds. These structures are interpreted to have been developed during westward thrusting. The Bulbul sequence was therefore detached and tectonically transported to the west as a thrust nappe of which the lower inverted limb is still preserved. Structural evidence suggest yet another smaller nappe sequence (terrane) is present in southern Ethiopia and further suggest that Neoproterozoic obducted crust of the Arabian-Nubian Shield in eastern Ethiopia may be located beneath Phanerozoic cover.

  10. Thrust Production in a Mechanical Swimming Lamprey

    Science.gov (United States)

    Leftwich, Megan; Smits, Alexander

    2008-11-01

    To develop a comprehensive model of lamprey locomotion, we use a robotic lamprey as a means of investigating the surface pressure and wake structure during swimming. A programmable microcomputer actuates 11 servomotors that produce a traveling wave along the length of the lamprey body. The waveform is based on the motion of the American eel (Anguilla rostrata), as described by Tytell and Lauder (2004) and kinematic studies of living lamprey. The amplitude of the phase-averaged surface pressure distribution along the centerline of the robot increases toward the tail, which is consistent with previous momentum balance experiments indicating that thrust is produced mainly at the tail. The phase relationship between the pressure signal and the vortex shedding from the tail is also examined. The project is supported by NIH CNRS Grant 1R01NS054271.

  11. Secondary production of massive quarks in thrust

    Energy Technology Data Exchange (ETDEWEB)

    Hoang, André H. [University of Vienna, Faculty of Physics, Boltzmanngasse 5, A-1090 Wien (Austria); Erwin Schrödinger International Institute for Mathematical Physics, University of Vienna, Boltzmanngasse 9, A-1090 Vienna (Austria); Mateu, Vicent [University of Vienna, Faculty of Physics, Boltzmanngasse 5, A-1090 Wien (Austria); Pietrulewicz, Piotr [Theory Group, Deutsches Elektronen-Synchrotron (DESY), D-22607 Hamburg (Germany)

    2016-01-22

    We present a factorization framework that takes into account the production of heavy quarks through gluon splitting in the thrust distribution for e{sup +}e{sup −} → hadrons. The explicit factorization theorems and some numerical results are displayed in the dijet region where the kinematic scales are widely separated, which can be extended systematically to the whole spectrum. We account for the necessary two-loop matrix elements, threshold corrections, and include resummation up to N{sup 3}LL order. We include nonperturbative power corrections through a field theoretical shape function, and remove the O(Λ{sub QCD}) renormalon in the partonic soft function by appropriate mass-dependent subtractions. Our results hold for any value of the quark mass, from an infinitesimally small (merging to the known massless result) to an infinitely large one (achieving the decoupling limit). This is the first example of an application of a variable flavor number scheme to final state jets.

  12. Investigating the kinematics of local thrust sheet rotation in the limb of an orocline: a paleomagnetic and structural analysis of the Esla tectonic unit, Cantabrian-Asturian Arc, NW Iberia

    Science.gov (United States)

    Weil, Arlo Brandon; Gutiérrez-Alonso, Gabriel; Wicks, David

    2013-01-01

    The Esla tectonic unit lies along the southern boundary of the Cantabrian-Asturian Arc, a highly curved foreland fold-thrust belt that was deformed during the final amalgamation of the Pangea supercontinent. Previous structural and paleomagnetic analyses of the Cantabrian-Asturian Arc suggest a two-stage tectonic history in which an originally linear belt was bent into its present configuration, creating an orocline. The Esla tectonic unit is a particularly complex region due to the interaction of rotating thrust sheets from the southern limb of the arc and the southward-directed thrusts of the Picos de Europa tectonic domain during late-stage north-south shortening and oroclinal bending. These structural interactions resulted in intense modification of early-phase thin-skinned tectonic structures that were previously affected by a deeper out-of-sequence antiformal stack that passively deformed the early thrust stack. A total of 75 paleomagnetic sites were collected from the Portilla and Santa Lucia formations, two carbonate passive-margin reef platform units from the middle Devonian. Similar to other regions of the Cantabrian-Asturian Arc, Esla Unit samples carry a secondary remanent magnetization that was acquired after initial thrusting and folding of Variscan deformation in the late Carboniferous. Protracted deformation during late-stage oroclinal bending caused reactivation of existing thrust sheets that include the Esla and younger Corniero and Valbuena thrusts. When combined with existing structural data and interpretations, these data indicate that the present-day sinuosity of the Esla Unit is the consequence of both secondary rotation of originally linear features in the western Esla exposures (e.g., frontal thrusts), and secondary modification and tightening of originally curvilinear features in the eastern Esla exposures (e.g., hanging-wall lateral/oblique ramps). Differences in structural style between the Esla and other tectonic units of the arc

  13. Synchronous and Cogged Fan Belt Performance Assessment

    Energy Technology Data Exchange (ETDEWEB)

    Cutler, D.; Dean, J.; Acosta, J.

    2014-02-01

    The GSA Regional GPG Team commissioned the National Renewable Energy Laboratory (NREL) to perform monitoring of cogged V-belts and synchronous belts on both a constant volume and a variable air volume fan at the Byron G. Rodgers Federal Building and U.S. Courthouse in Denver, Colorado. These motor/fan combinations were tested with their original, standard V-belts (appropriately tensioned by an operation and maintenance professional) to obtain a baseline for standard operation. They were then switched to the cogged V-belts, and finally to synchronous belts. The power consumption by the motor was normalized for both fan speed and air density changes. This was necessary to ensure that the power readings were not influenced by a change in rotational fan speed or by the power required to push denser air. Finally, energy savings and operation and maintenance savings were compiled into an economic life-cycle cost analysis of the different belt options.

  14. Dynamic Model for Thrust Generation of Marine Propellers

    DEFF Research Database (Denmark)

    Blanke, Mogens; Lindegaard, Karl-Petter; Fossen, Thor I.

    2000-01-01

    Mathematical models of propeller thrust and torque are traditionally based on steady state thrust and torque characteristics obtained in model basin or cavitation tunnel tests. Experimental results showed that these quasi steady state models do not accurately describe the transient phenomena in a...

  15. Electronics Engineering Department Thrust Area report FY'84

    Energy Technology Data Exchange (ETDEWEB)

    Minichino, C.; Phelps, P.L. (eds.)

    1984-01-01

    This report describes the work of the Electronics Engineering Department Thrust Areas for FY'84: diagnostics and microelectronic engineering; signal and control engineering; microwave and pulsed power engineering; computer-aided engineering; engineering modeling and simulation; and systems engineering. For each Thrust Area, an overview and a description of the goals and achievements of each project is provided.

  16. A model of the secondary radiation belt

    OpenAIRE

    Selesnick, R. S.; Looper, M. D.; Mewaldt, R. A.

    2008-01-01

    Products of nuclear reactions between primary radiation belt protons and constituents of the tenuous upper atmosphere form a collocated secondary radiation belt. A calculation of the time-dependent secondary intensity provides a model specification of this environmental component for low- and medium-altitude satellite orbits. It is based on an earlier model of the radiation belt protons, the novel feature being a determination of the secondary source function from nuclear reaction cross secti...

  17. Tectonic Significance of Intraoceanic Thrusts in the Nankai Trough

    Science.gov (United States)

    Tsuji, T.; Kodaira, S.; Park, J.; Ashi, J.; Fukao, Y.; Moore, G. F.; Matsuoka, T.

    2009-12-01

    The Nankai Trough is a convergent margin where the Philippine Sea plate is subducting beneath southwest Japan. Because this subduction zone has repeatedly generated great earthquakes with Mw>8, seismic reflection studies have been intensively carried out in the whole Nankai Trough region. However, the role of oceanic crust in plate convergent margins was not well understood. Recently, Tsuji et al. [2009] identified intraoceanic thrusts developed as imbricate structures within the subducting Philippine Sea plate off the Kii Peninsula in central Japan manifesting as strong-amplitude reflections observed in an industry-standard 3D seismic reflection data set. In this study, we use other 2D and 3D seismic reflection data acquired in the whole Nankai Trough region and extract geometries of (1) intraoceanic thrusts, (2) surface of oceanic crust and (3) Moho in order to discuss characteristics of intraoceanic thrusts distributed in the whole Nankai Trough region. We mainly use seismic reflection data acquired by JAMSTEC. Seismic profiles demonstrate that intraoceanic faults are densely distributed eastern side of the Cape Shionomisaki (southern edge of the Kii Peninsula). Large displacements of a few major intraoceanic thrusts elevate the crust surface, and the offset due to cumulative displacements reaches >1 km at the sediment-igneous crust interface. A part of Kashinozaki-Knoll is also uplifted by the thrust displacement. These imbricate intraoceanic thrusts cut through the oceanic crust as a discontinuous thrust plane. The intraoceanic thrusts strike nearly parallel to the trend of the trough axis. However the fault traces are bending at the western termination; the fault planes extend upward from side edges of the underlying intraoceanic thrusts and work as lateral faults. The deformation within oceanic crust may have continued until recently with subduction, because the shallow sediment as well as the seafloor is deformed due to the thrust displacement [Kodaira et

  18. Anomalous Thrust Production from an RF Test Device Measured on a Low-Thrust Torsion Pendulum

    Science.gov (United States)

    Brady, David A.; White, Harold G.; March, Paul; Lawrence, James T.; Davies, Frank J.

    2014-01-01

    This paper describes the test campaigns designed to investigate and demonstrate viability of using classical magnetoplasmadynamics to obtain a propulsive momentum transfer via the quantum vacuum virtual plasma. This paper will not address the physics of the quantum vacuum plasma thruster (QVPT), but instead will describe the recent test campaign. In addition, it contains a brief description of the supporting radio frequency (RF) field analysis, lessons learned, and potential applications of the technology to space exploration missions. During the first (Cannae) portion of the campaign, approximately 40 micronewtons of thrust were observed in an RF resonant cavity test article excited at approximately 935 megahertz and 28 watts. During the subsequent (tapered cavity) portion of the campaign, approximately 91 micronewtons of thrust were observed in an RF resonant cavity test article excited at approximately 1933 megahertz and 17 watts. Testing was performed on a low-thrust torsion pendulum that is capable of detecting force at a single-digit micronewton level. Test campaign results indicate that the RF resonant cavity thruster design, which is unique as an electric propulsion device, is producing a force that is not attributable to any classical electromagnetic phenomenon and therefore is potentially demonstrating an interaction with the quantum vacuum virtual plasma.

  19. Thrust Measurements for a Pulse Detonation Engine Driven Ejector

    Science.gov (United States)

    Santoro, Robert J.; Pak, Sibtosh; Shehadeh, R.; Saretto, S. R.; Lee, S.-Y.

    2005-01-01

    Results of an experimental effort on pulse detonation driven ejectors aimed at probing different aspects of PDE ejector processes, are presented and discussed. The PDE was operated using ethylene as the fuel and an equimolar oxygen/nitrogen mixture as the oxidizer at an equivalence ratio of one. The thrust measurements for the PDE alone are in excellent agreement with experimental and modeling results reported in the literature and serve as a Baseline for the ejector studies. These thrust measurements were then used as a basis for quantifying thrust augmentation for various PDE/ejector setups using constant diameter ejector tubes and various detonation tube/ejector tube overlap distances. The results show that for the geometries studied here, a maximum thrust augmentation of 24% is achieved. The thrust augmentation results are complemented by shadowgraph imaging of the flowfield in the ejector tube inlet area and high frequency pressure transducer measurements along the length of the ejector tube.

  20. Condition-Based Conveyor Belt Replacement Strategy in Lignite Mines with Random Belt Deterioration

    Science.gov (United States)

    Blazej, Ryszard; Jurdziak, Leszek

    2017-12-01

    In Polish lignite surface mines, condition-based belt replacement strategies are applied in order to assure profitable refurbishment of worn out belts performed by external firms specializing in belt maintenance. In two of three lignite mines, staff asses belt condition subjectively during visual inspections. Only one mine applies specialized diagnostic device (HRDS) allowing objective magnetic evaluation of belt core condition in order to choose the most profitable moment for the dismantling of worn out belt segments from conveyors and sending them to the maintenance firm which provides their refurbishment. This article describes the advantages of a new diagnostic device called DiagBelt. It was developed at the Faculty of Geoengineering, Mining and Geology, Wroclaw University of Science and Technology. Economic gains from its application are calculated for the lignite mine and for the belt maintenance firm, taking into account random life (durability) of new and reconditioned belts (after the 1st and the 2nd refurbishment). Recursive calculations for following years allow the estimation of the length and costs of replaced, reconditioned and purchased belts on an annual basis, while the use of the Monte Carlo method allows the estimation of their variability caused by random deterioration of belts. Savings are obtained due to better selection of moments (times) for the replacement of belt segments and die to the possibility to qualify worn out belts for refurbishment without the need to remove their covers. In effect, increased belt durability and lowered share of waste belts (which were not qualified for reconditioning) create savings which can quickly cover expenditures on new diagnostic tools and regular belt inspections in the mine.

  1. Early Cenozoic Multiple Thrust in the Tibetan Plateau

    Directory of Open Access Journals (Sweden)

    Zhenhan Wu

    2013-01-01

    Full Text Available Recently completed regional geological mapping at a scale of 1 : 250,000 or larger across all of the Tibetan Plateau coupled with deep seismic surveys reveals for the first time a comprehensive depiction of the major early Cenozoic thrust systems resulting from the northward subduction of the Indian Continental Plate. These systems define a series of overlapping north-dipping thrust sheets that thickened the Tibetan crust and lead to the rise of the plateau. The few south-dipping thrusts present apparently developed within a sheet when the back moved faster than the toe. Many of the thrusts are shown to extend to the middle-lower crustal depths by seismic data. The regional thrust systems are the Main Central, Renbu-Zedong, Gangdese, Central Gangdese, North Gangdese, Bangoin-Nujiang, Qiangtang, Hohxil, and South Kunlun Thrusts. The minimal southward displacements of the South Kunlun, Hohxil, South Qiangtang, and Central Gangdese Thrusts are estimated to be 30 km, 25 km, 150 km and 50 km, respectively. Deep thrusting began in the Himalaya-Tibetan region soon after India-Eurasia continental collision and led to crustal thickening and subsequent uplift of the Tibetan Plateau during Late Eocene-Early Miocene when the systems were mainly active. The major thrust systems ceased moving in Early Miocene and many were soon covered by lacustrine strata. This activity succeeded in the late Cenozoic to crustal extension and strike-slip movement in the central Tibetan Plateau. The revelation of the full array of the early Cenozoic thrust systems provides a much more complete understanding of the tectonic framework of the Tibetan Plateau.

  2. Puzzling Snowballs: Main Belt Comets

    Science.gov (United States)

    Yang, Bin; Meech, Karen

    2015-03-01

    Main belt comets (MBCs) are a class of newly discovered objects that exhibit comet-like appearances and yet are dynamically indistinguishable from ordinary main belt asteroids. The measured size and albedo of MBCs are similar to those of classical comets. At present, six MBCs have been discovered, namely 133P/Elst-Pizarro, 176P/LINEAR, 238P/Read, P/2008 R1, P/La Sagra and P/2006 VW139. The total number of active MBCs is estimated to be at the level of a few hundreds (Hsieh & Jewitt, 2006). Several explanations for the activity of MBCs have been suggested. These include impact ejection, sublimation and rotational instability. However, since renewed activity has been observed in 133P and 238P at successive perihelion passages, the most likely explanation may be a thermally-driven process - e.g sublimation of exposed surface ice. Although the proximity of MBCs to the Sun (r ~ 3 AU) makes the survival of surface ice improbable, thermal models have shown that water ice is thermally stable under a regolith layer a few meters thick. The study of MBCs has recently been complicated by the discoveries of two asteroid collisional events (P/2010 A2 (LINEAR) and (596) Scheila) in 2010, where comet-like dust coma/tail have been attributed to recent impacts. If MBCs are indeed icy, they represent the closest and the third established reservoir of comets (after the Oort cloud and the Kuiper belt). As such, they may have been an important source of water for the Earth's oceans. I will review the current state of MBC studies, present the latest observational results and discuss possible mechanisms that could produce the observed activity. I will also talk about current and future space missions that are dedicated or closely related to MBC studies.

  3. New component of radiation belts

    Energy Technology Data Exchange (ETDEWEB)

    Grigorov, N.L.; Kurnosova, L.V.; Razorenov, L.A.; Remizov, A.S.; Fradkin, M.I. (AN SSSR, Moscow. Fizicheskij Inst.; Moskovskij Gosudarstvennyj Univ. (USSR). Nauchno-Issledovatel' skij Inst. Yadernoj Fiziki)

    1982-09-01

    The mechanism of electron radiation belt filling with high-energy particles is discussed. Experimental data on particle fluxes in the Earth magnetosphere are presented. The experiments are carried out using the Cherenkov scintillation telescope installed on the ''Lightning-1'' satellite. Values of secondary particle flux obtained during the measurement at a height of 500 km and 30-40 th. km. coincide within the limits of errors. It is noted that secondary particle flux, equal to the albedo electron flux, is registered on large heights. This reason indicates the fact of forbidden angle filling with electrons with energies above 10 MeV.

  4. Use of seat belt and enforcement of seat belt laws in Pakistan.

    Science.gov (United States)

    Klair, Ashfaq Ahmad; Arfan, Muhammad

    2014-01-01

    Traffic crashes are a leading cause of deaths and injuries in Pakistan. The World Health Organization (WHO) estimates that approximately 30,131 people die in road crashes annually on Pakistani roads (WHO 2013). The use of seat belts can be effective in reducing road crash fatalities in Pakistan but under existing seat belt laws, seat belt use is mandatory only for drivers and is limited to specific vehicles and roads. Primarily, this study was aimed to measure seat belt use rates among Pakistani vehicle occupants. It was meant to investigate the factors influencing the compliance behavior of seat belt use among vehicle drivers. The second objective was to gauge the enforcement of seat belt laws and their effectiveness in Pakistan. A first ever national survey was conducted for the systematic recording of seat belt use rates among Pakistani drivers and front passengers on 5 different kinds of roads. Factors influencing compliance with seat belt use were gauged through a questionnaire for 5 different kinds of roads. Commitment level of different traffic police organizations to enforce seat belt laws was also measured through their previous year's enforcement data. Average seat belt use rates were 20% with the highest on motorways (53%) and the lowest on rural roads (5%). Unawareness of the law/usefulness, seat belt not fitted, discomfort, forgetfulness, low speed, and careless attitude were major reasons for noncompliance with seat belt laws among Pakistani drivers. Seat belt use rates were directly proportional to law enforcement strength and the National Highways and Motorways Police (NH&MP) showed maximum enforcement on M-2. There is a dire need to revise existing seat belt laws in order to raise seat belt use rates in Pakistan.

  5. Using haptic feedback to increase seat belt use : traffic tech.

    Science.gov (United States)

    2011-07-01

    The legacy of research on increasing seat belt use has : focused on enactment of seat belt legislation, public education, : high-visibility police enforcement, and seat belt : reminder systems. Several behavioral programs have : produced large, susta...

  6. Early history and reactivation of the rand thrust, southern California

    Science.gov (United States)

    Postlethwaite, Clay E.; Jacobson, Carl E.

    The Rand thrust of the Rand Mountains in the northwestern Mojave Desert separates an upper plate of quartz monzonite and quartzofeldspathic to amphibolitic gneiss from a lower plate of metagraywacke and mafic schist (Rand Schist). The Rand thrust is considered part of the regionally extensive Vincent/Chocolate Mountain thrust system, which is commonly believed to represent a Late Cretaceous subduction zone. The initial direction of dip and sense of movement along the Vincent/Chocolate Mountain thrust are controversial. Microfabrics of mylonites and quartzites from the Rand Mountains were analyzed in an attempt to determine transport direction for this region, but the results are ambiguous. In addition, the southwestern portion of the Rand thrust was found to have been reactivated as a low-angle normal fault after subduction. Reactivation might have occurred shortly after subduction, in which case it could account for the preservation of high-pressure mineral assemblages in the Rand Schist, or it could be related to mid-Tertiary extension in the western United States. In either event, the reactivation might be responsible for the complicated nature of the microfabrics. The Rand Schist exhibits an inverted metamorphic zonation. Isograds in the schist are not significantly truncated by the reactivated segment of the Rand thrust. This indicates that other segments of the Vincent/Chocolate Mountain thrust should be re-evaluated for the possibility of late movement, even if they show an apparently undisturbed inverted metamorphic zonation.

  7. Thrust Stand Characterization of the NASA Evolutionary Xenon Thruster (NEXT)

    Science.gov (United States)

    Diamant, Kevin D.; Pollard, James E.; Crofton, Mark W.; Patterson, Michael J.; Soulas, George C.

    2010-01-01

    Direct thrust measurements have been made on the NASA Evolutionary Xenon Thruster (NEXT) ion engine using a standard pendulum style thrust stand constructed specifically for this application. Values have been obtained for the full 40-level throttle table, as well as for a few off-nominal operating conditions. Measurements differ from the nominal NASA throttle table 10 (TT10) values by 3.1 percent at most, while at 30 throttle levels (TLs) the difference is less than 2.0 percent. When measurements are compared to TT10 values that have been corrected using ion beam current density and charge state data obtained at The Aerospace Corporation, they differ by 1.2 percent at most, and by 1.0 percent or less at 37 TLs. Thrust correction factors calculated from direct thrust measurements and from The Aerospace Corporation s plume data agree to within measurement error for all but one TL. Thrust due to cold flow and "discharge only" operation has been measured, and analytical expressions are presented which accurately predict thrust based on thermal thrust generation mechanisms.

  8. Geophysical perspective on the structural interference zone along the Neoproterozoic Brasília and Ribeira fold belts in West Gondwana

    Directory of Open Access Journals (Sweden)

    João Gabriel Motta

    Full Text Available ABSTRACT: The Brasília and Ribeira fold belts have been established in south-southwestern São Francisco Craton during the Brasiliano-Pan African orogeny (0.9-0.5 Ga - Tonian to Cambrian, and played an important role in West Gondwana continent assembly. The region is given by a complex regional fold and thrust belt superposed by shearing during the orogeny late times, with superposing stress fields forming a structural interference zone. These thrust sheets encompasses assemblies from lower- to upper-crust from different major tectonic blocks (Paranapanema, São Francisco, and newly created metamorphic rocks. Re-evaluation of ground gravity datasets in a geologically constrained approach including seismology (CRUST1 model and magnetic data (EMAG2 model unveiled details on the deep- crust settings, and the overall geometry of the structural interference zone. The Simple Bouguer Anomaly map shows heterogeneous density distribution in the area, highlighting the presence of high-density, high metamorphic grade rocks along the Alterosa suture zone in the Socorro-Guaxupé Nappe, lying amid a series of metasedimentary thrust scales in a regional nappe system with important verticalization along regional shear zones. Forward gravity modeling favors interpretations of structural interference up North into Guaxupé Nappe. Comparison to geotectonic models shows similarities with modern accretionary belts, renewing the discussion.

  9. The Administrator's "Handy Dandy" Tool Belt

    Science.gov (United States)

    Anderson, Terry

    2012-01-01

    Every good leader needs a tool belt. Throughout the author's years of building early childhood programs, she has acquired a number of tools for her personal belt. These tools have helped her sharpen her skills in supporting teachers and staff, connecting with families, and educating children. This article focuses on those leadership skills that…

  10. Understanding Quaternions and the Dirac Belt Trick

    Science.gov (United States)

    Staley, Mark

    2010-01-01

    The Dirac belt trick is often employed in physics classrooms to show that a 2n rotation is not topologically equivalent to the absence of rotation whereas a 4n rotation is, mirroring a key property of quaternions and their isomorphic cousins, spinors. The belt trick can leave the student wondering if a real understanding of quaternions and spinors…

  11. Intelligent Belt Conveyor Monitoring and Control

    NARCIS (Netherlands)

    Pang, Y.

    2010-01-01

    Belt conveyors have been used worldwide in continuous material transport for about 250 years. Traditional inspection and monitoring of large-scale belt conveyors focus on individual critical components and response to catastrophic system failures. To prevent operational problems caused by the lack

  12. Combined Radiation Belt - Plasma Sheet System Modeling

    Science.gov (United States)

    Aseev, Nikita; Shprits, Yuri; Kellerman, Adam; Drozdov, Alexander; Zhu, Hui

    2017-04-01

    Recent years have given rise to numerous mathematical models of the Earth's radiation belt dynamics. Driven by observations at geosynchronous orbit (GEO) where satellites (e.g. GOES and LANL) provide extensive in-situ measurements, radiation belt models usually take into account only diffusion processes in the energetic electron belts (100 keV and greater), leaving aside the dynamics of colder source population (tens of keV). Such models are able to reconstruct the radiation belt state, but they are not capable of predicting the electron dynamics at GEO, where many communication and navigation satellites currently operate. In this work we present combined four-dimensional electron radiation belt - plasma sheet model accounting for adiabatic advective transport, radial diffusion due to interaction with ULF waves, local acceleration of electrons, scattering into the atmosphere, magnetopause shadowing, and adiabatic effects due to contraction and expansion of the magnetic field. The developed model is applicable to energetic, relativistic and ultrarelativistic electrons as well as to source electron population. The model provides spatial particle distribution allowing us to compare and validate the model with multiple satellite measurements at different MLT sectors (e.g. Van Allen Probes, GOES, LANL, THEMIS). The model can be helpful for the prediction of crucial for satellite operators geosynchronous electron fluxes and electron radiation belt dynamics including the heart of the outer belt, slot region and inner belt.

  13. Powered Descent Guidance with General Thrust-Pointing Constraints

    Science.gov (United States)

    Carson, John M., III; Acikmese, Behcet; Blackmore, Lars

    2013-01-01

    The Powered Descent Guidance (PDG) algorithm and software for generating Mars pinpoint or precision landing guidance profiles has been enhanced to incorporate thrust-pointing constraints. Pointing constraints would typically be needed for onboard sensor and navigation systems that have specific field-of-view requirements to generate valid ground proximity and terrain-relative state measurements. The original PDG algorithm was designed to enforce both control and state constraints, including maximum and minimum thrust bounds, avoidance of the ground or descent within a glide slope cone, and maximum speed limits. The thrust-bound and thrust-pointing constraints within PDG are non-convex, which in general requires nonlinear optimization methods to generate solutions. The short duration of Mars powered descent requires guaranteed PDG convergence to a solution within a finite time; however, nonlinear optimization methods have no guarantees of convergence to the global optimal or convergence within finite computation time. A lossless convexification developed for the original PDG algorithm relaxed the non-convex thrust bound constraints. This relaxation was theoretically proven to provide valid and optimal solutions for the original, non-convex problem within a convex framework. As with the thrust bound constraint, a relaxation of the thrust-pointing constraint also provides a lossless convexification that ensures the enhanced relaxed PDG algorithm remains convex and retains validity for the original nonconvex problem. The enhanced PDG algorithm provides guidance profiles for pinpoint and precision landing that minimize fuel usage, minimize landing error to the target, and ensure satisfaction of all position and control constraints, including thrust bounds and now thrust-pointing constraints.

  14. Electronegative Gas Thruster - Direct Thrust Measurement Project

    Science.gov (United States)

    Dankanich, John (Principal Investigator); Aanesland, Ane; Polzin, Kurt; Walker, Mitchell

    2015-01-01

    This effort is an international collaboration and academic partnership to mature an innovative electric propulsion (EP) thruster concept to TRL 3 through direct thrust measurement. The initial target application is for Small Satellites, but can be extended to higher power. The Plasma propulsion with Electronegative GASES (PEGASES) concept simplifies ion thruster operation, eliminates a neutralizer requirement and should yield longer life capabilities and lower cost implementation over conventional gridded ion engines. The basic proof-of concept has been demonstrated and matured to TRL 2 over the past several years by researchers at the Laboratoire de Physique des Plasma in France. Due to the low maturity of the innovation, there are currently no domestic investments in electronegative gas thrusters anywhere within NASA, industry or academia. The end product of this Center Innovation Fund (CIF) project will be a validation of the proof-of-concept, maturation to TRL 3 and technology assessment report to summarize the potential for the PEGASES concept to supplant the incumbent technology. Information exchange with the foreign national will be one-way with the exception of the test results. Those test results will first go through a standard public release ITAR/export control review, and the results will be presented in a public technical forum, and the results will be presented in a public technical forum.

  15. The South-Western Branch of the Variscan Belt: Evidence from Morocco

    Science.gov (United States)

    Michard, A.; Soulaimani, A.; Hoepffner, C.; Ouanaimi, H.; Baidder, L.; Rjimati, E. C.; Saddiqi, O.

    2010-09-01

    This work is based on the compilation and re-evaluation of the most significant data, either personal or from the literature, concerning the Moroccan Variscides. The latter constitute the only, moderately disturbed or even undisturbed part of the South-Western Branch of the Variscan Belt, facing directly NW Gondwana. They include two orogenic segments, namely the northern Mauritanides and the Meseta Domain exposed in the Saharan and Atlas-Meseta regions respectively, and a foreland belt cropping out essentially in the Anti-Atlas. The eastward thrust units of Saharan Morocco (Oulad Dlim) mostly originate from the West African Craton (WAC) border in an area of thin Palaeozoic sedimentation. Thin-skinned fold-thrust foreland arcs develop progressively northward (Zemmour) at the expense of the increasingly thick Palaeozoic series, whereas thick-skinned deformation characterizes the inverted proximal paleomargin in the Anti-Atlas Domain. As suggested by the Meseta and Anti-Atlas stratigraphic similarities, the Meseta Domain corresponds to a collage of moderately displaced, thinned crustal blocks from the distal Gondwana paleomargin. Variscan deformation is dominated by NW-verging thrusts, and metamorphism developed in the thickened tectonic prism in relation with crustal anatexis at depth. The Meseta-Anti-Atlas boundary is a major, ENE-trending transpressional dextral fault referred to as the South Meseta Fault (SMF). Discussing the correlations between the Variscan segments of Morocco and SW Iberia allows us to suggest that a latitudinal transform zone similar to the SMF separated these segments during the Late Palaeozoic. Subduction of the Rheic Ocean crust would have been directed SE-ward along both the Iberian and Moroccan Meseta, and NW-ward south of the SMF, i.e. along the WAC.

  16. Quaternary Tectonic Evolution of the Coastal Belt Southwest of Los Angeles Basin

    Science.gov (United States)

    Bohannon, R. G.

    2001-12-01

    Modern geologic hazards in the coastal belt southwest of Los Angeles Basin are intimately tied to its Quaternary tectonic evolution. Models describing tectonism during this period fall into at least three classes depending on what type of feature is showcased. 1.) Fold-and-thrust belt models feature blind thrusts, 2.) convergent-flake-tectonic models emphasize rigid upper-crustal blocks that interact above a mobile middle crust, and 3.) strike-slip models center on the interaction of blocks bounded by vertical faults with lateral offsets. High-resolution, multi-channel, seismic-reflection data, collected in a network of lines offshore, image numerous structures and tectonic features that have geometric characteristics that can be used to support each of the models, depending upon where one looks. Numerous folded uplifts and reverse faults are consistent with fold-and-thrust models. Some of the broad, deep basins might be best explained by convergent-flake tectonics. Complex vertical fault zones separating blocks with different seismic stratigraphy suggest strike-slip. In addition, large normal faults and deep fault-bounded basins are widespread, but are not explained well by any of the models. One aspect of local tectonic history, not considered by any models, is a major reversal of the regional physiography that occurred during the Quaternary. Los Angeles Basin (LAB), which is now sub aerial, was mid-bathyal in the Pliocene whereas Santa Monica and San Pedro (SM/SP) Basins, which are presently mid-bathyal, were shallow to sub aerial. The physiographic reversal resulted from a combination of folding and uplift in the Palos Verdes/Santa Monica areas, which impounded sediment causing LAB to fill, and extensional faulting and rapid subsidence nearby in SM/SP Basins. These seemingly opposed tectonic styles can be easily documented with seismic data, but these styles are thought to be incompatible in most models.

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

    Science.gov (United States)

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

    2010-05-01

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

  18. Electromagnetic calibration system for sub-micronewton torsional thrust stand

    Science.gov (United States)

    Lam, J. K.; Koay, S. C.; Cheah, K. H.

    2017-12-01

    It is critical for a micropropulsion system to be evaluated. Thrust stands are widely recognised as the instrument to complete such tasks. This paper presents the development of an alternative electromagnetic calibration technique for thrust stands. Utilising the commercially made voice coils and permanent magnets, the proposed system is able to generate repeatable and also consistent steady-state calibration forces at over four orders of magnitude (30 – 23000 μN). The system is then used to calibrate a custom-designed torsional thrust stand, where its inherent ability in ease of setup is well demonstrated.

  19. Thrust stand for high-power electric propulsion devices

    Science.gov (United States)

    Haag, T. W.

    1991-01-01

    This paper describes a new high-power thrust stand developed for use with high-power (up to 250 kW) magnetoplasmadynamic (MPD) thrusters, which is installed in a high-vacuum MPD facility at Lewis Research Center. The design of the stand is based on inverted pendulum configuration, with the result of large displacements and high resolution. Calibration results showed that thrust measurements were linear and repeatable to within a fraction of 1 percent. The thrust stand was used for testing water-cooled MPD thrusters at power levels up to 125 kW. The thruster, however, is quite well suited for testing other types of electric propulsion devices.

  20. Use of seatbelts in cars with automatic belts.

    Science.gov (United States)

    Williams, A F; Wells, J K; Lund, A K; Teed, N J

    1992-01-01

    Use of seatbelts in late model cars with automatic or manual belt systems was observed in suburban Washington, DC, Chicago, Los Angeles, and Philadelphia. In cars with automatic two-point belt systems, the use of shoulder belts by drivers was substantially higher than in the same model cars with manual three-point belts. This finding was true in varying degrees whatever the type of automatic belt, including cars with detachable nonmotorized belts, cars with detachable motorized belts, and especially cars with nondetachable motorized belts. Most of these automatic shoulder belts systems include manual lap belts. Use of lap belts was lower in cars with automatic two-point belt systems than in the same model cars with manual three-point belts; precisely how much lower could not be reliably estimated in this survey. Use of shoulder and lap belts was slightly higher in General Motors cars with detachable automatic three-point belts compared with the same model cars with manual three-point belts; in Hondas there was no difference in the rates of use of manual three-point belts and the rates of use of automatic three-point belts. PMID:1561301

  1. Out-of-Sequence Thrust in the Higher Himalaya- a Review & Possible Genesis

    Science.gov (United States)

    Mukherjee, S.; Koyi, H. A.; Talbot, C. J.

    2009-04-01

    : evidences from fission track dating. Earth Planetary Science Letters 179, 437-451. Mukherjee, S. 2007. Geodynamics, deformation and mathematical analysis of metamorphic belts of the NW Himalaya. Unpublished Ph.D. thesis. Indian Institute of Technology Roorkee. pp. 1-267. Searle, M.P., 1999. Extensional and compressional faults in the Everest-Lhotse massif, Khumbu Himalaya, Nepal. Journal of Geological Society, London, 156, 227-240. Swapp, S.M., Hollister, L.S., 1991. Inverted metamorphism within the Tibetan slab of Bhutan: evidence for a tectonically transported heat source. Canadian Mineralogist 29, 1019-1041. Vannay, J-C., Hodges, K.V., 1996. Tectonomorphic evolution of the Himalayan metamorphic core between the Annapurna and Dhaulagiri, central Nepal. Journal of Metamorphic Geology 14, 635-656. Wobus, C., Heimsath, A., Whipple, K., Hodges, K., 2005. Active out-of-sequence thrust faulting in the central Nepalese Himalaya. Nature 434, 1008-1011. Yin, A., Dubey, C.S., Kelty, T.K., Gehrels, G.E., Chou, C.Y., Grove, M., Lovera, O., 2006. Structural evolution of the Arunachal Himalaya and implications for asymmetric development Himalayan orogen. Current Science 90, 195-206.

  2. Improved Rhenium Thrust Chambers for In-Space Propulsion Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Radiation-cooled, bipropellant thrust chambers are being considered for the ascent/descent engines and reaction control systems (RCS) for future NASA missions such...

  3. Improved Rhenium Thrust Chambers for In-Space Propulsion Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Radiation-cooled, bipropellant thrust chambers are being considered for the ascent/descent engines and reaction control systems for NASA missions such as Mars Sample...

  4. Back-thrusting in Lesser Himalaya: Evidences from magnetic fabric ...

    Indian Academy of Sciences (India)

    Valdiya 1980;. Robinson ... while the others treat NAT as the thrust con- tact between inner and outer Lesser Himalaya. (Ahmad et .... temperature of the sample was measured with a Pt resistance thermometer, placed within a distance of 1 mm.

  5. Optimal Thrust Vectoring for an Annular Aerospike Nozzle Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Recent success of an annular aerospike flight test by NASA Dryden has prompted keen interest in providing thrust vector capability to the annular aerospike nozzle...

  6. Nitrous Oxide Liquid Injection Thrust Vector Control System Testing Project

    Data.gov (United States)

    National Aeronautics and Space Administration — A Nitrous Oxide-fed Liquid Thrust Vector Control system is proposed as an efficient method for vehicle attitude control during powered flight. Pulled from a N2O main...

  7. Carbonates in thrust faults: High temperature investigations into deformation processes in calcite-dolomite systems

    Science.gov (United States)

    Kushnir, A.; Kennedy, L.; Misra, S.; Benson, P.

    2012-04-01

    The role of dolomite on the strength and evolution of calcite-dolomite fold and thrust belts and nappes (as observed in the Canadian Rockies, the Swiss Alps, the Italian Apennines, and the Naukluft Nappe Complex) is largely unknown. Field investigations indicate that strain in natural systems is localized in calcite, resulting in a ductile response, while dolomite deforms in a dominantly brittle manner. To date, experimental studies on polymineralic carbonate systems are limited to homogeneous, fine-grained, calcite-dolomite composites of relatively low dolomite content. The effect of dolomite on limestone rheology, the onset of crystal-plastic deformation in dolomite in composites, and the potential for strain localization in composites have not yet been fully quantified. Constant displacement rate (3x10-4 s-1and 10-4 s-1), high confining pressure (300 MPa) and high temperature (750° C and 800° C) torsion experiments were conducted to address the role of dolomite on the strength of calcite-dolomite composites. Experiments were performed on samples produced by hot isostatic pressing (HIP) amalgams of a natural, pure dolomite and a reagent, pure calcite. We performed experiments on the following mixtures (given as dolomite%): 25%, 35%, 50%, and 75%. These synthetic HIP products eliminated concerns of mineralogical impurities and textural anomalies due to porosity, structural fabrics (e.g., foliation) and fossil content. The samples were deformed up to a maximum finite shear strain of 5.0 and the experimental set up was unvented to inhibit sample decarbonation. Mechanical data shows a considerable increase in sample yield strength with increasing dolomite content. Experimental products with low starting dolomite content (dol%: 25% and 35%) display macroscopic strain localization along compositionally defined foliation. Experimental products with high dolomite content (dol%: 50% and 75%) demonstrate no macroscopic foliation. Post-deformation microstructure analysis

  8. Quadcopter Attitude and Thrust Simulation Based on Simulink Platform

    Directory of Open Access Journals (Sweden)

    Endrowednes Kuantama

    2015-12-01

    Full Text Available Orientation of quadcopter axes relative to reference line direction of motion will result in attitude and every movement is controlled regulated by each rotor’s thrust. Mathematical equation based on Euler formula and 3D simulation using Matlab/Simulink software platform are used to model quadcopter movement. Change of attitude, position and thrust of each rotor can be seen through this simulation movement.

  9. The calculation of the thrust of a rocket motor

    Directory of Open Access Journals (Sweden)

    J. H. Knoetze

    1993-07-01

    Full Text Available Traditionally the thrust of a rocket motor is calculated by first calculating the thrust coefficient and then multiplying it by the product of the throat area and pressure. The thrust coefficient is calculated using a standard gas dynamics equation. This equation assumes that the combustion products are a single component, non-reacting ideal gas and that the flow through the nozzle is isentropic. The thrust coefficient is a function of the ratio of specific heats, y, the area ratio of the nozzle and the motor and ambient pressures. Standard methods exist for calculating the tosses due to deviations from the assumed flow. The combustion products of modern composite propellants contain a significant portion of condensed species (primarily A1₂O₃, while the composition of the combustion products changes continuously as the products move throught the nozzle. Some uncertainty therefore exists with regard to which value of y to use and how to handle the condensed species. The assumption o f an ideat, non-reacting gas can be el iminated hy as.mming the process to he isentropic and to calculate the thrust hy using the thermodynamic state and composition of the combustion products in the motor and nozzle exit. This can be achieved by using any of the standard thermochemistry programs available in the rocket industry. It is thus possible to use the results of a standard thermochemistry program directly in an alternative method for calculating thrust. Using this method only the mass flow rate (which is a function of pressure, throat area and effective caracteristic velocity and the results from the thermochemistry program are needed to calculate the thrust. The advantages of the alternative method are illustrated by comparing the results of the two methods with a measured thrust curve.

  10. Application of Chaboche Model in Rocket Thrust Chamber Analysis

    Science.gov (United States)

    Asraff, Ahmedul Kabir; Suresh Babu, Sheela; Babu, Aneena; Eapen, Reeba

    2017-06-01

    Liquid Propellant Rocket Engines are commonly used in space technology. Thrust chamber is one of the most important subsystems of a rocket engine. The thrust chamber generates propulsive thrust force for flight of the rocket by ejection of combustion products at supersonic speeds. Often double walled construction is employed for these chambers. The thrust chamber investigated here has its hot inner wall fabricated out of a high thermal conductive material like copper alloy and outer wall made of stainless steel. Inner wall is subjected to high thermal and pressure loads during operation of engine due to which it will be in the plastic regime. Main reasons for the failure of such chambers are fatigue in the plastic range (called as low cycle fatigue since the number of cycles to failure will be low in plastic range), creep and thermal ratcheting. Elasto plastic material models are required to simulate the above effects through a cyclic stress analysis. This paper gives the details of cyclic stress analysis carried out for the thrust chamber using different plasticity model combinations available in ANSYS (Version 15) FE code. The best model among the above is applied in the cyclic stress analysis of two dimensional (plane strain and axisymmetric) and three dimensional finite element models of thrust chamber. Cyclic life of the chamber is calculated from stress-strain graph obtained from above analyses.

  11. From transmission error measurement to Pulley-Belt slip determination in serpentine belt drives : influence of tensioner and belt characteristics

    OpenAIRE

    Manin, Lionel; Michon, Guilhem; Rémond, Didier; Dufour, Regis

    2009-01-01

    Serpentine belt drives are often used in front end accessory drive of automotive engine. The accessories resistant torques are getting higher within new technological innovations as stater-alternator, and belt transmissions are always asked for higher capacity. Two kind of tensioners are used to maintain minimum tension that insure power transmission and minimize slip: dry friction or hydraulic tensioners. An experimental device and a specific transmission error measurement method have been u...

  12. Kink bands in thrust regime: Examples from Srinagar—Garhwal area ...

    Indian Academy of Sciences (India)

    This paper deciphers the late stress systems involved in the development of kink bands in the perspective of thrust regime. In kink bands, the correlation coefficient for - plots is positive near thrusts and negative away from thrusts. The plots show nearly linear relationship near thrusts and non-linear relationship away from ...

  13. Kink bands in thrust regime: Examples from Srinagar–Garhwal area ...

    Indian Academy of Sciences (India)

    This paper deciphers the late stress systems involved in the development of kink bands in the perspec- tive of thrust regime. In kink bands, the correlation coefficient for α–β plots is positive near thrusts and negative away from thrusts. The plots show nearly linear relationship near thrusts and non-linear rela- tionship away ...

  14. 14 CFR Appendix I to Part 25 - Installation of an Automatic Takeoff Thrust Control System (ATTCS)

    Science.gov (United States)

    2010-01-01

    ... Appendix I to Part 25—Installation of an Automatic Takeoff Thrust Control System (ATTCS) I25.1General. (a... crew to increase thrust or power. I25.2Definitions. (a) Automatic Takeoff Thrust Control System (ATTCS... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Installation of an Automatic Takeoff Thrust...

  15. Varying frontal thrust spacing in mono-vergent wedges: An insight ...

    Indian Academy of Sciences (India)

    Sandbox experiments are used to study frontal thrust fault spacing, which is a function of physical properties within the thrust wedge. We consider three styles of thrust progression in mono-vergent wedges: Style I, II and III. In Style I, frontal thrusts progress forelandward, maintaining a constant spacing, whereas Style II and ...

  16. Electromechanical actuation for thrust vector control applications

    Science.gov (United States)

    Roth, Mary Ellen

    At present, actuation systems for the Thrust Vector Control (TVC) for launch vehicles are hydraulic systems. The Advanced Launch System (ALS), a joint initiative between NASA and the Air Force, is a launch vehicle that is designed to be cost effective, highly reliable and operationally efficient with a goal of reducing the cost per pound to orbit. As part of this initiative, an electromechanical actuation system is being developed as an attractive alternative to the hydraulic systems used today. NASA-Lewis is developing and demonstrating an Induction Motor Controller Actuation System with a 40 hp peak rating. The controller will integrate 20 kHz resonant link Power Management and Distribution (PMAD) technology and Pulse Population Modulation (PPM) techniques to implement Field Oriented Vector Control (FOVC) of a new advanced induction motor. Through PPM, multiphase variable frequency, variable voltage waveforms can be synthesized from the 20 kHz source. FOVC shows that varying both the voltage and frequency and their ratio (V/F), permits independent control of both torque and speed while operating at maximum efficiency at any point on the torque-speed curve. The driver and the FOVC will be microprocessor controlled. For increased system reliability, a Built-in Test (BITE) capability will be included. This involves introducing testability into the design of a system such that testing is calibrated and exercised during the design, manufacturing, maintenance and prelaunch activities. An actuator will be integrated with the motor controller for performance testing of the EMA TVC system. The design and fabrication of the motor controller is being done by General Dynamics Space Systems Division. The University of Wisconsin-Madison will assist in the design of the advanced induction motor and in the implementation of the FOVC theory. A 75 hp electronically controlled dynamometer will be used to test the motor controller in all four quadrants of operation using flight type

  17. Evolution of the Puente Hills Thrust Fault

    Science.gov (United States)

    Bergen, K. J.; Shaw, J. H.; Dolan, J. F.

    2013-12-01

    This study aims to assess the evolution of the blind Puente Hills thrust fault system (PHT) by determining its age of initiation, lateral propagation history, and changes in slip rate over time. The PHT presents one of the largest seismic hazards in the United States, given its location beneath downtown Los Angeles. The PHT is comprised of three fault segments: the Los Angeles (LA), Santa Fe Springs (SFS), and Coyote Hills (CH). The LA and SFS segments are characterized by growth stratigraphy where folds formed by uplift on the fault segments have been continually buried by sediment from the Los Angeles and San Gabriel rivers. The CH segment has developed topography and is characterized by onlapping growth stratigraphy. This depositional setting gives us the unique opportunity to measure uplift on the LA and SFS fault segments, and minimum uplift on the CH fault segment, as the difference in sediment thicknesses across the buried folds. We utilize depth converted oil industry seismic reflection data to image the fold geometries. Identifying time-correlative stratigraphic markers for slip rate determination in the basin has been a problem for researchers in the past, however, as the faunal assemblages observed in wells are time-transgressive by nature. To overcome this, we utilize the sequence stratigraphic model and well picks of Ponti et al. (2007) as a basis for mapping time-correlative sequence boundaries throughout our industry seismic reflection data from the present to the Pleistocene. From the Pleistocene to Miocene we identify additional sequence boundaries in our seismic reflection data from imaged sequence geometries and by correlating industry well formation tops. The sequence and formation top picks are then used to build 3-dimensional surfaces in the modeling program Gocad. From these surfaces we measure the change in thicknesses across the folds to obtain uplift rates between each sequence boundary. Our results show three distinct phases of

  18. Compliance with Seat Belt Use in Makurdi, Nigeria: An ...

    African Journals Online (AJOL)

    2011-03-24

    Mar 24, 2011 ... and injuries can be reduced drastically because seat belts retain occupants in ... has been estimated that using seat belts can reduce the risk of fatalities in a ..... were about three times more likely to wear seatbelts than. Table 2: Availability of seat belts in the vehicles. Seat belt available. Car (%). Bus (%).

  19. 30 CFR 56.14108 - Overhead drive belts.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Overhead drive belts. 56.14108 Section 56.14108... Safety Devices and Maintenance Requirements § 56.14108 Overhead drive belts. Overhead drive belts shall be guarded to contain the whipping action of a broken belt if that action could be hazardous to...

  20. 30 CFR 57.14108 - Overhead drive belts.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Overhead drive belts. 57.14108 Section 57.14108... Equipment Safety Devices and Maintenance Requirements § 57.14108 Overhead drive belts. Overhead drive belts shall be guarded to contain the whipping action of a broken belt if that action could be hazardous to...

  1. 29 CFR 1926.104 - Safety belts, lifelines, and lanyards.

    Science.gov (United States)

    2010-07-01

    ... 29 Labor 8 2010-07-01 2010-07-01 false Safety belts, lifelines, and lanyards. 1926.104 Section... Saving Equipment § 1926.104 Safety belts, lifelines, and lanyards. (a) Lifelines, safety belts, and lanyards shall be used only for employee safeguarding. Any lifeline, safety belt, or lanyard actually...

  2. Compliance with Seat Belt Use in Makurdi, Nigeria: An ...

    African Journals Online (AJOL)

    Background: Seat belts are designed to reduce injuries due to road crash among vehicle occupants. Aims: This study aims to determine the availability of seat belt in vehicles and compliance with seat belt use among vehicle occupants. Materials and methods: This was a 24‑h direct observational study of seat belt usage ...

  3. 30 CFR 56.14131 - Seat belts for haulage trucks.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Seat belts for haulage trucks. 56.14131 Section... Equipment Safety Devices and Maintenance Requirements § 56.14131 Seat belts for haulage trucks. (a) Seat belts shall be provided and worn in haulage trucks. (b) Seat belts shall be maintained in functional...

  4. 30 CFR 57.4503 - Conveyor belt slippage.

    Science.gov (United States)

    2010-07-01

    ...) Underground belt conveyors shall be equipped with a detection system capable of automatically stopping the... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Conveyor belt slippage. 57.4503 Section 57.4503... Control Installation/construction/maintenance § 57.4503 Conveyor belt slippage. (a) Surface belt conveyors...

  5. 30 CFR 75.1403-5 - Criteria-Belt conveyors.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Criteria-Belt conveyors. 75.1403-5 Section 75... Criteria—Belt conveyors. (a) Positive-acting stop controls should be installed along all belt conveyors... can be stopped or started at any location. (b) Belt conveyors used for regularly scheduled mantrips...

  6. Thrust calculation of electric solar wind sail by particle-in-cell simulation

    Energy Technology Data Exchange (ETDEWEB)

    Hoshi, Kento [Kyoto Univ. (Japan). Dept. of Electrical Engineering; Kojima, Hirotsugu; Yamakawa, Hiroshi [Kyoto Univ. (Japan). Research Inst. for Sustainable Humanosphere; Muranaka, Takanobu [Chukyo Univ., Nagoya (Japan). Dept. of Electrical Engineering

    2016-07-01

    In this study, thrust characteristics of an electric solar wind sail were numerically evaluated using full threedimensional particle-in-cell (PIC) simulation. The thrust obtained from the PIC simulation was lower than the thrust estimations obtained in previous studies. The PIC simulation indicated that ambient electrons strongly shield the electrostatic potential of the tether of the sail, and the strong shield effect causes a greater thrust reduction than has been obtained in previous studies. Additionally, previous expressions of the thrust estimation were modified by using the shielded potential structure derived from the present simulation results. The modified thrust estimation agreed very well with the thrust obtained from the PIC simulation.

  7. Dynamics Analysis and Modeling of Rubber Belt in Large Mine Belt Conveyors

    OpenAIRE

    Gao Yang

    2014-01-01

    Rubber belt not only is one of the key components of belt conveyor, but also affects the overall performance of the core part. Research on dynamics analysis of large conveyor not only helps to improve the reliability and design level, but also can guide the rational selection of conveyor safety factor, and effectively reduce the cost of the conveyor belt. Based on unique viscoelastic properties of belt conveyor, it was simplified as one-dimensional viscoelastic rod in this study, and then a d...

  8. Handbook Timing Belts Principles, Calculations, Applications

    CERN Document Server

    Perneder, Raimund

    2012-01-01

    Timing belts offer a broad range of innovative drivetrain solutions; they allow low-backlash operation in robot systems, they are widely used in automated processes and industrial handling involving highly dynamic start-up loads, they are low-maintenance solutions for continuous operation applications, and they can guarantee exact positioning at high operating speeds. Based on his years of professional experience, the author has developed concise guidelines for the dimensioning of timing belt drives and presents proven examples from the fields of power transmission, transport and linear transfer technology. He offers definitive support for dealing with and compensating for adverse operating conditions and belt damage, as well as advice on drive optimization and guidelines for the design of drivetrain details and supporting systems. All market-standard timing belts are listed as brand neutral. Readers will discover an extensive bibliography with information on the various manufacturers and their websites. This...

  9. Radiation Belt and Plasma Model Requirements

    Science.gov (United States)

    Barth, Janet L.

    2005-01-01

    Contents include the following: Radiation belt and plasma model environment. Environment hazards for systems and humans. Need for new models. How models are used. Model requirements. How can space weather community help?

  10. Radiation Belt Storm Probe (RBSP) Mission

    Science.gov (United States)

    Sibeck, D. G.; Fox, N.; Grebowsky, J. M.; Mauk, B. H.

    2009-01-01

    Scheduled to launch in May 2012, NASA's dual spacecraft Living With a Star Radiation Belt Storm Probe mission carries the field and particle instrumentation needed to determine the processes that produce enhancements in radiation belt ion and electron fluxes, the dominant mechanisms that cause the loss of relativistic electrons, and the manner by which the ring current and other geomagnetic phenomena affect radiation belt behavior. The two spacecraft will operate in low-inclination elliptical lapping orbits around the Earth, within and immediately exterior to the Van Allen radiation belts. During course of their two year primary mission, they will cover the full range of local times, measuring both AC and DC electric and magnetic fields to 10kHz, as well as ions from 50 eV to 1 GeV and electrons with energies ranging from 50 eV to 10 MeV.

  11. Bilateral and multiple cavitation sounds during upper cervical thrust manipulation

    Directory of Open Access Journals (Sweden)

    Dunning James

    2013-01-01

    Full Text Available Abstract Background The popping produced during high-velocity, low-amplitude (HVLA thrust manipulation is a common sound; however to our knowledge, no study has previously investigated the location of cavitation sounds during manipulation of the upper cervical spine. The primary purpose was to determine which side of the spine cavitates during C1-2 rotatory HVLA thrust manipulation. Secondary aims were to calculate the average number of pops, the duration of upper cervical thrust manipulation, and the duration of a single cavitation. Methods Nineteen asymptomatic participants received two upper cervical thrust manipulations targeting the right and left C1-2 articulation, respectively. Skin mounted microphones were secured bilaterally over the transverse process of C1, and sound wave signals were recorded. Identification of the side, duration, and number of popping sounds were determined by simultaneous analysis of spectrograms with audio feedback using custom software developed in Matlab. Results Bilateral popping sounds were detected in 34 (91.9% of 37 manipulations while unilateral popping sounds were detected in just 3 (8.1% manipulations; that is, cavitation was significantly (P Conclusions Cavitation was significantly more likely to occur bilaterally than unilaterally during upper cervical HVLA thrust manipulation. Most subjects produced 3–4 pops during a single rotatory HVLA thrust manipulation targeting the right or left C1-2 articulation; therefore, practitioners of spinal manipulative therapy should expect multiple popping sounds when performing upper cervical thrust manipulation to the atlanto-axial joint. Furthermore, the traditional manual therapy approach of targeting a single ipsilateral or contralateral facet joint in the upper cervical spine may not be realistic.

  12. Eccentricity distribution in the main asteroid belt

    Science.gov (United States)

    Malhotra, Renu; Wang, Xianyu

    2017-03-01

    The observationally complete sample of the main belt asteroids now spans more than two orders of magnitude in size and numbers more than 64 000 (excluding collisional family members). We undertook an analysis of asteroids' eccentricities and their interpretation with simple physical models. We find that a century old conclusion that the asteroids' eccentricities follow a Rayleigh distribution holds for the osculating eccentricities of large asteroids, but the proper eccentricities deviate from a Rayleigh distribution; there is a deficit of eccentricities smaller than ∼0.1 and an excess of larger eccentricities. We further find that the proper eccentricities do not depend significantly on asteroid size but have strong dependence on heliocentric distance; the outer asteroid belt follows a Rayleigh distribution, but the inner belt is strikingly different. Eccentricities in the inner belt can be modelled as a vector sum of a primordial eccentricity vector of random orientation and magnitude drawn from a Rayleigh distribution of parameter ∼0.06, and an excitation of random phase and magnitude ∼0.13. These results imply that when a late dynamical excitation of the asteroids occurred, it was independent of asteroid size and was stronger in the inner belt than in the outer belt. We discuss implications for the primordial asteroid belt and suggest that the observationally complete sample size of main belt asteroids is large enough that more sophisticated model-fitting of the eccentricities is warranted and could serve to test alternative theoretical models of the dynamical excitation history of asteroids and its links to the migration history of the giant planets.

  13. The Stability of the Conveyor Belt Pontoon

    Directory of Open Access Journals (Sweden)

    Jiří PODEŠVA

    2011-06-01

    Full Text Available To lead the conveyor belt transport cross water area the pontoon are used to support the carrying structure of the belts. The accident can happen when the pontoon turnover. For this reason the pontoon stability is investigated. The stability is described by the Reed’s diagram. This can be constructed analytically or via numerical modeling. Both methods are described in the paper.

  14. The depositional setting of the Late Quaternary sedimentary fill in southern Bannu basin, Northwest Himalayan fold and thrust belt, Pakistan

    KAUST Repository

    Farid, Asam M.

    2014-07-10

    Geostatistical variogram and inversion techniques combined with modern visualization tools have made it possible to re-model one-dimensional electrical resistivity data into two-dimensional (2D) models of the near subsurface. The resultant models are capable of extending the original interpretation of the data to depict alluvium layers as individual lithological units within the 2D space. By tuning the variogram parameters used in this approach, it is then possible to visualize individual lithofacies and geomorphological features for these lithologic units. The study re-examines an electrical resistivity dataset collected as part of a groundwater study in an area of the Bannu basin in Pakistan. Additional lithological logs from boreholes throughout the area have been combined with the existing resistivity data for calibration. Tectonic activity during the Himalayan orogeny uplifted and generated significant faulting in the rocks resulting in the formation of a depression which subsequently has been filled with clay-silt and dirty sand facies typical of lacustrine and flood plain environments. Streams arising from adjacent mountains have reworked these facies which have been eroded and replaced by gravel-sand facies along channels. It is concluded that the sediments have been deposited as prograding fan shaped bodies, flood plain, and lacustrine deposits. Clay-silt facies mark the locations of paleo depressions or lake environments, which have changed position over time due to local tectonic activity and sedimentation. The Lakki plain alluvial system has thus formed as a result of local tectonic activity with fluvial erosion and deposition characterized by coarse sediments with high electrical resistivities near the mountain ranges and fine sediments with medium to low electrical resistivities towards the basin center. © 2014 Springer International Publishing Switzerland.

  15. Rock magnetic expression of fluid infiltration in the Yingxiu-Beichuan fault (Longmen Shan thrust belt, China)

    NARCIS (Netherlands)

    Yang, T.; Yang, Xiaosong; Duan, Qingbao; Chen, J.; Dekkers, M.J.

    Fluid infiltration within fault zones is an important process in earthquake rupture. Magnetic properties of fault rocks convey essential clues pertaining to physicochemical processes in fault zones. In 2011, two shallow holes (134 and 54 m depth, respectively) were drilled into the Yingxiu-Beichuan

  16. Cave development in an uplifting fold-and-thrust belt: case study of the Tatra Mountains, Poland

    National Research Council Canada - National Science Library

    Szczygiel Jacek

    2015-01-01

      Detailed structural analysis and geomorphological observations supplemented by the analysis of the distribution of karst conduit directions have been performed in 23 morphologically diverse caves in the Tatra Mountains...

  17. Enhancement of DLR/GSOC FDS for Low Thrust Orbit Transfer and Control

    OpenAIRE

    Lück, Stefanie; Spiridonova, Sofya; Kirschner, Michael; Kahle, Ralph; Kiehling, Reinhard

    2016-01-01

    On behalf of possible future missions with electric Propulsion (EP) controlled by DLRs German Space Operations Center (DLR/GSOC) the present operational multi-mission Flight Dynamics System (FDS) is enhanced to support the preparation and operations of such types of project. For designing an easily extendable framework, various low-thrust Scenarios were considered. Each low-thrust phase is modelled by a thrust profile comprising non-equidistant thrust vector and constant thrust level. Based o...

  18. Decay rate of the second radiation belt

    Science.gov (United States)

    Badhwar, G. D.; Robbins, D. E.

    1996-01-01

    Variations in the Earth's trapped (Van Allen) belts produced by solar flare particle events are not well understood. Few observations of increases in particle populations have been reported. This is particularly true for effects in low Earth orbit, where manned spaceflights are conducted. This paper reports the existence of a second proton belt and it's subsequent decay as measured by a tissue-equivalent proportional counter and a particle spectrometer on five Space Shuttle flights covering an eighteen-month period. The creation of this second belt is attributed to the injection of particles from a solar particle event which occurred at 2246 UT, March 22, 1991. Comparisons with observations onboard the Russian Mir space station and other unmanned satellites are made. Shuttle measurements and data from other spacecraft are used to determine that the e-folding time of the peak of the second proton belt. It was ten months. Proton populations in the second belt returned to values of quiescent times within eighteen months. The increase in absorbed dose attributed to protons in the second belt was approximately 20%. Passive dosimeter measurements were in good agreement with this value.

  19. Decay rate of the second radiation belt.

    Science.gov (United States)

    Badhwar, G D; Robbins, D E

    1996-01-01

    Variations in the Earth's trapped (Van Allen) belts produced by solar flare particle events are not well understood. Few observations of increases in particle populations have been reported. This is particularly true for effects in low Earth orbit, where manned spaceflights are conducted. This paper reports the existence of a second proton belt and it's subsequent decay as measured by a tissue-equivalent proportional counter and a particle spectrometer on five Space Shuttle flights covering an eighteen-month period. The creation of this second belt is attributed to the injection of particles from a solar particle event which occurred at 2246 UT, March 22, 1991. Comparisons with observations onboard the Russian Mir space station and other unmanned satellites are made. Shuttle measurements and data from other spacecraft are used to determine that the e-folding time of the peak of the second proton belt. It was ten months. Proton populations in the second belt returned to values of quiescent times within eighteen months. The increase in absorbed dose attributed to protons in the second belt was approximately 20%. Passive dosimeter measurements were in good agreement with this value.

  20. Jupiter's magnetosphere and radiation belts

    Science.gov (United States)

    Kennel, C. F.; Coroniti, F. V.

    1979-01-01

    Radioastronomy and Pioneer data reveal the Jovian magnetosphere as a rotating magnetized source of relativistic particles and radio emission, comparable to astrophysical cosmic ray and radio sources, such as pulsars. According to Pioneer data, the magnetic field in the outer magnetosphere is radially extended into a highly time variable disk-shaped configuration which differs fundamentally from the earth's magnetosphere. The outer disk region, and the energetic particles confined in it, are modulated by Jupiter's 10 hr rotation period. The entire outer magnetosphere appears to change drastically on time scales of a few days to a week. In addition to its known modulation of the Jovian decametric radio bursts, Io was found to absorb some radiation belt particles and to accelerate others, and most importantly, to be a source of neutral atoms, and by inference, a heavy ion plasma which may significantly affect the hydrodynamic flow in the magnetosphere. Another important Pioneer finding is that the Jovian outer magnetosphere generates, or permits to escape, fluxes of relativistic electrons of such intensities that Jupiter may be regarded as the dominant source of 1 to 30 MeV cosmic ray electrons in the heliosphere.

  1. Thrust Augmentation Measurements Using a Pulse Detonation Engine Ejector

    Science.gov (United States)

    Santoro, Robert J.; Pal, Sibtosh

    2005-01-01

    Results of an experimental effort on pulse detonation driven ejectors are presented and discussed. The experiments were conducted using a pulse detonation engine (PDE)/ejector setup that was specifically designed for the study and operated at frequencies up to 50 Hz. The results of various experiments designed to probe different aspects of the PDE/ejector setup are reported. The baseline PDE was operated using ethylene (C2H4) as the fuel and an oxygen/nitrogen O2 + N2) mixture at an equivalence ratio of one. The PDE only experiments included propellant mixture characterization using a laser absorption technique, high fidelity thrust measurements using an integrated spring-damper system, and shadowgraph imaging of the detonation/shock wave structure emanating from the tube. The baseline PDE thrust measurement results at each desired frequency agree with experimental and modeling results reported in the literature. These PDE setup results were then used as a basis for quantifying thrust augmentation for various PDE/ejector setups with constant diameter ejector tubes and various ejector lengths, the radius of curvature for the ejector inlets and various detonation tube/ejector tube overlap distances. For the studied experimental matrix, the results showed a maximum thrust augmentation of 106% at an operational frequency of 30 Hz. The thrust augmentation results are complemented by shadowgraph imaging of the flowfield in the ejector tube inlet area and high frequency pressure transducer measurements along the length of the ejector tube.

  2. Thrust Augmentation Measurements for a Pulse Detonation Engine Driven Ejector

    Science.gov (United States)

    Pal, S.; Santoro, Robert J.; Shehadeh, R.; Saretto, S.; Lee, S.-Y.

    2005-01-01

    Thrust augmentation results of an ongoing study of pulse detonation engine driven ejectors are presented and discussed. The experiments were conducted using a pulse detonation engine (PDE) setup with various ejector configurations. The PDE used in these experiments utilizes ethylene (C2H4) as the fuel, and an equi-molar mixture of oxygen and nitrogen as the oxidizer at an equivalence ratio of one. High fidelity thrust measurements were made using an integrated spring damper system. The baseline thrust of the PDE engine was first measured and agrees with experimental and modeling results found in the literature. Thrust augmentation measurements were then made for constant diameter ejectors. The parameter space for the study included ejector length, PDE tube exit to ejector tube inlet overlap distance, and straight versus rounded ejector inlets. The relationship between the thrust augmentation results and various physical phenomena is described. To further understand the flow dynamics, shadow graph images of the exiting shock wave front from the PDE were also made. For the studied parameter space, the results showed a maximum augmentation of 40%. Further increase in augmentation is possible if the geometry of the ejector is tailored, a topic currently studied by numerous groups in the field.

  3. Common Structural Errors in Paleomagnetic Analysis of Fold-And Belts

    Science.gov (United States)

    Pueyo, E.

    2013-05-01

    Paleomagnetism is essential to decipher vertical axis rotations (VAR) in orogens, an elusive variable in tectonic studies. While unraveling the significance of VAR in the internal parts of orogenic belts might be made difficult due to the complex superposition of deformation events, it has provided timely insights into the geometry and kinematics of the external parts; the fold-and-thrust belts (FAT belts). Accurate quantification of VAR demands a reliable recording of the Earth's magnetic field. Inclination flattening or non-dipolar geometries of the geomagnetic field are well known to affect the reliability of paleomagnetic directions. Other factors are related to the geometry and mechanisms of deformation and are often overlooked: 1) Overlapping of vectors has to do with the technical limitation to isolating components in the laboratory. Secondary remagnetizations may be a common post tectonic process. The orientation of the overlapped vector will change along the fold geometry. Their restoration will result in different DEC and INC errors depending upon the degree of overlapping, the fold axis orientation (FAO), dip of the beds and the polarity of the components. 2) Many paleomagnetic studies implicitly assume the rigid-body behavior of rock volumes during deformation (absence of internal strain). However, pure shear may appear at the fold hinges and simple shear is frequent at the fold limbs and around fault planes. The bedding correction (BC) will induce DEC and INC errors controlled by the FAO and shear magnitude. 3) Different stages of folding and thrusting may happen in FAT belts and may be responsible for the superposition of non-coaxial axis of deformation. Besides, folds are not always cylindrical. These factors are responsible for the generation of plunging, conical and superposed folds, etc… The BC, instead of the reverse sequential restoration, will produce declination errors that depend upon the non-coaxility angle and the folding and tilting

  4. Optimization of Flapping Airfoils for Maximum Thrust and Propulsive Efficiency

    Directory of Open Access Journals (Sweden)

    I. H. Tuncer

    2004-01-01

    Full Text Available A numerical optimization algorithm based on the steepest decent along the variation of the optimization function is implemented for maximizing the thrust and/or propulsive efficiency of a single flapping airfoil. Unsteady, low speed laminar flows are computed using a Navier-Stokes solver on moving overset grids. The flapping motion of the airfoil is described by a combined sinusoidal plunge and pitching motion. Optimization parameters are taken to be the amplitudes of the plunge and pitching motions, and the phase shift between them. Computations are performed in parallel in a work station cluster. The numerical simulations show that high thrust values may be obtained at the expense of reduced efficiency. For high efficiency in thrust generation, the induced angle of attack of the airfoil is reduced and large scale vortex formations at the leading edge are prevented. 

  5. Separability of drag and thrust in undulatory animals and machines

    CERN Document Server

    Bale, Rahul; Neveln, Izaak D; Bhalla, Amneet Pal Singh; MacIver, Malcolm A; Patankar, Neelesh A

    2014-01-01

    For nearly a century, researchers have tried to understand the swimming of aquatic animals in terms of a balance between the forward thrust from swimming movements and drag on the body. Prior approaches have failed to provide a separation of these two forces for undulatory swimmers such as lamprey and eels, where most parts of the body are simultaneously generating drag and thrust. We nonetheless show that this separation is possible, and delineate its fundamental basis in undulatory swimmers. Our approach unifies a vast diversity of undulatory aquatic animals (anguilliform, sub-carangiform, gymnotiform, bal- istiform, rajiform) and provides design principles for highly agile bioinspired underwater vehicles. This approach has practical utility within biology as well as engineering. It is a predictive tool for use in understanding the role of the mechanics of movement in the evolutionary emergence of morphological features relating to locomotion. For example, we demonstrate that the drag-thrust separation fram...

  6. Seat belts, airbags and child protection devices. [previously: Seat belts and child restraint seats.

    NARCIS (Netherlands)

    2010-01-01

    In the Netherlands, the use of seat belts results in a yearly reduction of hundreds of fatalities. Seat belts reduce the risk of fatal injury by 37 to 48%, depending on the position in the car. At 50%, the effect of child protection devices is even slightly higher. When last measured (in 2010), 97%

  7. Microfluidic magnetic bead conveyor belt.

    Science.gov (United States)

    van Pelt, Stijn; Frijns, Arjan; den Toonder, Jaap

    2017-11-07

    Magnetic beads play an important role in the miniaturization of clinical diagnostics systems. In lab-on-chip platforms, beads can be made to link to a target species and can then be used for the manipulation and detection of this species. Current bead actuation systems utilize complex on-chip coil systems that offer low field strengths and little versatility. We demonstrate a novel system based on an external rotating magnetic field and on-chip soft-magnetic structures to focus the field locally. These structures were designed and optimized using finite element simulations in order to create a number of local flux density maxima. These maxima, to which the magnetic beads are attracted, move over the chip surface in a continuous way together with the rotation of the external field, resulting in a mechanism similar to that of a conveyor belt. A prototype was fabricated using PDMS molding techniques mixed with iron powder for the magnetic structures. In the subsequent experiments, a quadrupole electromagnet was used to create the rotating external field. We observed that beads formed agglomerates that rolled over the chip surface, just above the magnetic structures. Field rotation frequencies between 0.1-50 Hz were tested resulting in magnetic bead speeds of over 1 mm s -1 for the highest frequency. With this, we have shown that our novel concept works, combining a simple design and simple operation with a powerful and versatile method for bead actuation. This makes it a promising method for further research and utilization in lab-on-chip systems.

  8. Problems of millipound thrust measurement. The "Hansen Suspension"

    Energy Technology Data Exchange (ETDEWEB)

    Carta, David G.

    2014-03-31

    Considered in detail are problems which led to the need and use of the 'Hansen Suspension'. Also discussed are problems which are likely to be encountered in any low level thrust measuring system. The methods of calibration and the accuracies involved are given careful attention. With all parameters optimized and calibration techniques perfected, the system was found capable of a resolution of 10 {mu} lbs. A comparison of thrust measurements made by the 'Hansen Suspension' with measurements of a less sophisticated device leads to some surprising results.

  9. Robotic Pectoral Fin Thrust Vectoring Using Weighted Gait Combinations

    Directory of Open Access Journals (Sweden)

    John S. Palmisano

    2012-01-01

    Full Text Available A method was devised to vector propulsion of a robotic pectoral fin by means of actively controlling fin surface curvature. Separate flapping fin gaits were designed to maximize thrust for each of three different thrust vectors: forward, reverse, and lift. By using weighted combinations of these three pre-determined main gaits, new intermediate hybrid gaits for any desired propulsion vector can be created with smooth transitioning between these gaits. This weighted gait combination (WGC method is applicable to other difficult-to-model actuators. Both 3D unsteady computational fluid dynamics (CFD and experimental results are presented.

  10. Geomorphic signature of active tectonics in the southern Abruzzi Periadriatic hilly belt (Central Italy)

    Science.gov (United States)

    Racano, Simone; Fubelli, Giandomenico; Centamore, Ernesto; Dramis, Francesco

    2016-04-01

    The geo-structural setting of the southern Abruzzi hilly belt that stretches from the northeastern front of the Maiella Massif to the Adriatic coast is characterized by deep-seated northeast verging thrusts masked by a thick cover of Late Pliocene-Middle Pleistocene marine deposits. Most authors consider this area tectonically inactive while only few of them support the hypothesis of its recent activity from the analysis of the river network pattern. Geological and geomorphological investigations carried out in the area have clearly shown the occurrence of surface deformations resulting from the continued activity of compressive tectonics up to recent times. The analysis of the study area by of a 10 m resolution DTM (using the open-source QGIS software) confirmed and supplemented field observations. Particularly significant in this context is the topographic setting of the alluvial strath terraces in the river valleys that develop transversally to the buried thrusts. In correspondence of these structures, topographic highs have grown up displacing the middle-Pleistocene planation surface developed on top of the hilly belt, from the Maiella piedmont to the coastal zone, and diverting laterally the river courses uphill. In the same places, as along the Alento and Foro rivers that cross by antecedence the grown up topographic highs, the long profiles of terraces bend eastward and the height difference between the terrace orders, essentially related all around the area to the Quaternary regional uplift, strongly increases. In some cases, surficial faults have lowered the terraces into graben troughs or have displaced them until assuming an uphill trend. This recent tectonic activity should be taken in account in assessing the seismic hazard of the study area.

  11. Theoretical study of influence of belt tension of intermediate belt conveyor drive on value of zone of relative slip of traction and carrying belts

    Science.gov (United States)

    Goncharov, K. A.; Grishin, A. V.

    2017-10-01

    The issue of the influence of tension of the traction belt of intermediate drive of the multi-drive belt conveyor on the value of zones of relative rest and sliding of the traction and carrying belts is considered. A variety of values of proportional band of tractive effort regulation of the intermediate drive of belt conveyor while it is being controlled by the tensioning device was obtained in percentage terms. Recommendations on the control of the intermediate drive of belt conveyor by means of the tensioning device when starting and productivity changes are provided.

  12. Lubricants for Metal Belt Continuously Variable Transmissions

    Directory of Open Access Journals (Sweden)

    Keiichi Narita

    2014-02-01

    Full Text Available This paper reviews the effects of lubricant additives and base stock used in metal belt continuously variable transmissions (CVT fluids on the CVT transmission torque capacity. Additive formulation composed of phosphorus anti-wear agent, calcium detergent, and dispersant improved the friction coefficient between the metals. The analysis on the post-test surface suggests that the friction behavior strongly depends on the local morphology of the tribofilms derived from lubricant additives. Examining the effect of base stock on the torque capacity in actual belt CVTs revealed that SN (synthetic naphthene exhibited 10% higher torque capacity than that of PAO (polyalphaolefin. It is believed that the difference in the torque capacity is due to the difference in the oil-film shearing force generated by the relative sliding between the belt and pulley.

  13. Structure of the Kuiper Belt Dust Disk

    Science.gov (United States)

    Liou, J.-C.; Kaufmann, D. E.

    An overview of the Kuiper belt dust disk is provided in this chapter. Mutual collisions among Kuiper belt objects should produce a dust disk in the outer solar system similar to the observed circumstellar dust disks. As the Kuiper belt dust particles migrate toward the Sun due to Poynting-Robertson drag, they are perturbed by the giant planets. Mean-motion resonances with Neptune and gravitational scattering by Saturn and Jupiter alter their orbital evolution dramatically. Asa result, large-scale structures are created in the disk. Descriptions of the dynamics involved, and the numerical simulations required to unveil the disk features, are included. Implications for extrasolar planet detection from circumstellar dust disk modeling are also discussed.

  14. Development Status of High-Thrust Density Electrostatic Engines

    Science.gov (United States)

    Patterson, Michael J.; Haag, Thomas W.; Foster, John E.; Young, Jason A.; Crofton, Mark W.

    2017-01-01

    Ion thruster technology offers the highest performance and efficiency of any mature electric propulsion thruster. It has by far the highest demonstrated total impulse of any technology option, demonstrated at input power levels appropriate for primary propulsion. It has also been successfully implemented for primary propulsion in both geocentric and heliocentric environments, with excellent ground/in-space correlation of both its performance and life. Based on these attributes there is compelling reasoning to continue the development of this technology: it is a leading candidate for high power applications; and it provides risk reduction for as-yet unproven alternatives. As such it is important that the operational limitations of ion thruster technology be critically examined and in particular for its application to primary propulsion its capabilities relative to thrust the density and thrust-to-power ratio be understood. This publication briefly addresses some of the considerations relative to achieving high thrust density and maximizing thrust-to-power ratio with ion thruster technology, and discusses the status of development work in this area being executed under a collaborative effort among NASA Glenn Research Center, the Aerospace Corporation, and the University of Michigan.

  15. Engineering Research, Development and Technology, FY95: Thrust area report

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-02-01

    The mission of the Engineering Research, Development, and Technology Program at Lawrence Livermore National Laboratory (LLNL) is to develop the knowledge base, process technologies, specialized equipment, tools and facilities to support current and future LLNL programs. Engineering`s efforts are guided by a strategy that results in dual benefit: first, in support of Department of Energy missions, such as national security through nuclear deterrence; and second, in enhancing the nation`s economic competitiveness through their collaboration with US industry in pursuit of the most cost-effective engineering solutions to LLNL programs. To accomplish this mission, the Engineering Research, Development, and Technology Program has two important goals: (1) identify key technologies relevant to LLNL programs where they can establish unique competencies, and (2) conduct high-quality research and development to enhance their capabilities and establish themselves as the world leaders in these technologies. To focus Engineering`s efforts, technology thrust areas are identified and technical leaders are selected for each area. The thrust areas are comprised of integrated engineering activities, staffed by personnel from the nine electronics and mechanical engineering divisions, and from other LLNL organizations. This annual report, organized by thrust area, describes Engineering`s activities for fiscal year 1995. The report provides timely summaries of objectives methods, and key results from eight thrust areas: computational electronics and electromagnetics; computational mechanics; microtechnology; manufacturing technology; materials science and engineering; power conversion technologies; nondestructive evaluation; and information engineering.

  16. Page 1 Constant thrust programming for a multistage rocket 383 ...

    Indian Academy of Sciences (India)

    maximum payload ratio is due to its equal distribution among all the stages and each partial payload ratio satisfies (57) where r = 1. Case 2: With a given final thrust-to-weight ratio in the rth stage the overall payload ratio for n stages takes up the same form as in the previous case. Now, like the previous case the optimisation ...

  17. Separability of drag and thrust in undulatory animals and machines

    Science.gov (United States)

    Bale, Rahul; Shirgaonkar, Anup A.; Neveln, Izaak D.; Bhalla, Amneet Pal Singh; Maciver, Malcolm A.; Patankar, Neelesh A.

    2014-12-01

    For nearly a century, researchers have tried to understand the swimming of aquatic animals in terms of a balance between the forward thrust from swimming movements and drag on the body. Prior approaches have failed to provide a separation of these two forces for undulatory swimmers such as lamprey and eels, where most parts of the body are simultaneously generating drag and thrust. We nonetheless show that this separation is possible, and delineate its fundamental basis in undulatory swimmers. Our approach unifies a vast diversity of undulatory aquatic animals (anguilliform, sub-carangiform, gymnotiform, bal-istiform, rajiform) and provides design principles for highly agile bioinspired underwater vehicles. This approach has practical utility within biology as well as engineering. It is a predictive tool for use in understanding the role of the mechanics of movement in the evolutionary emergence of morphological features relating to locomotion. For example, we demonstrate that the drag-thrust separation framework helps to predict the observed height of the ribbon fin of electric knifefish, a diverse group of neotropical fish which are an important model system in sensory neurobiology. We also show how drag-thrust separation leads to models that can predict the swimming velocity of an organism or a robotic vehicle.

  18. Effect of Operating Frequency on PDE Driven Ejector Thrust Performance

    Science.gov (United States)

    Santoro, Robert J.; Pal, Sibtosh; Landry, K.; Shehadeh, R.; Bouvet, N.; Lee, S.-Y.

    2005-01-01

    Results of an on-going study of pulse detonation engine driven ejectors are presented and discussed. The experiments were conducted using a pulse detonation engine (PDE) designed to operate at frequencies up to 50 Hz. The PDE used in these experiments utilizes an equi-molar mixture of oxygen and nitrogen as the oxidizer, and ethylene (C2H4) as the fuel, with the propellant mixture having an equivalence ratio of one. A line of sight laser absorption technique was used to determine the time needed for proper filling of the tube. Thrust measurements were made using an integrated spring damper system coupled with a linear variable displacement transducer. The baseline thrust of the PDE was first measured at each desired frequency and agrees with experimental and modeling results found in the literature. Thrust augmentation measurements were then made for constant diameter ejectors. The ejectors had varying lengths, and two different inlet geometries were tested for each ejector configuration. The parameter space for the study included PDE operation frequency, ejector length, overlap distance and the radius of curvature for the ejector inlets. For the studied experimental matrix, the results showed a maximum thrust augmentation of 106% at an operational frequency of 30 Hz.

  19. Evidence for pre-folding vein development in the Oligo-Miocene Asmari Formation in the Central Zagros Fold Belt, Iran

    Science.gov (United States)

    Ahmadhadi, Faram; Daniel, Jean-Marc; Azzizadeh, Mehran; Lacombe, Olivier

    2008-02-01

    In order to understand the interplay between vein development and folding in the carbonates of the Oligo-Miocene Asmari Formation (one of the main hydrocarbon reservoir rocks) in Iran, several anticlines have been investigated in the central part of the Zagros folded belt. Combining observations of relative chronology between veins based on calcite-filling phases and crosscutting/abutting relationships, as well as aerial/satellite image interpretation on several anticlines allowed proposing a tectonic model highlighting the widespread development of veins and other extensional micro/meso-structures in the Central Zagros folded belt. Our data suggest that most of the veins affecting the Asmari formation predated the main Miocene-Pliocene folding episode. An early regional vein set striking N50° marked the onset of collisional stress build-up in the region. Then, N150° and N20° trending vein sets were initiated in response to local extension caused by large-scale flexure/drape folds above N-S and N140° basement faults reactivated under the regional NE compression. At the onset and during Miocene-Pliocene folding of the sedimentary cover, the early formed veins were reactivated (reopened and/or sheared) while duplexes, low angle reverse faults and thrusts formed. Beyond regional implications, this study puts emphasis on the need of carefully considering regional/local vein development predating folding as well as influence of underlying basement faults in models of folded-fractured reservoirs in fold-thrust belts.

  20. Accretionary prisms of the Sikhote-Alin Orogenic Belt: Composition, structure and significance for reconstruction of the geodynamic evolution of the eastern Asian margin

    Science.gov (United States)

    Kemkin, I. V.; Khanchuk, A. I.; Kemkina, R. A.

    2016-12-01

    We present overview for geological studies of the terranes of the Sikhote-Alin orogenic belt in the Russian Far East. The belt is formed by accretionary prisms with alternating tectonic packets of thrust-like slices which consist of complexly deformed marine (pelagic and hemipelagic deposits, as well as oceanic plateau and paleo-guyot fragments), marginal oceanic turbidites and chaotic (subduction mélange) formations. We reconstruct a stepwise history of accretion of paleo-oceanic crustal fragments of different ages, based on detailed lithological-biostratigraphic and structural analysis. We propose geodynamic model for evolution of the eastern margin of the paleo-Asian continent during the Mesozoic time by combining geological observations for the region with geological data for others terranes of the Sikhote-Alin Orogenic Belt. We recognize several principal Mesozoic geological processes that have led to formation of the continental crust at the eastern margin of Asia: (i) accretion of paleo-oceanic fragments to the continent margin during the subduction of the paleo-Pacific plate along the convergent margins, (ii) subsequent intense deformation of rocks of the accretionary prisms of the transform margin including folding and multiple thrusting which led to a multifold increase in thickness of sediments, (iii) formation of granitic-metamorphic complexes due to intrusion of the orogenic granites into the accretionary prisms.

  1. CALCULATION OF TENSION FORCE OF BELT CONVEYOR

    OpenAIRE

    Ismet Ibishi; Ahmet Latifi; Gzim Ibishi; Kadri Sejdiu; Melihate Shala-Galica; Bekim Latifi

    2012-01-01

    In this paper is done the explanation on tension fashion of the belt conveyor which is employed in Kosovo Energy Corporation – KEK, for coal transportation to provide electric power plant. The aim of the paper enables to recognize tension forces not to pass with deformation of belt so that this problem will damage the workingprocess. Work principle is based on initial tension and tension during working process. The fact is known that the tension starts from the carriage on the way to tension ...

  2. Thrust Area Report, Engineering Research, Development and Technology

    Energy Technology Data Exchange (ETDEWEB)

    Langland, R. T.

    1997-02-01

    The mission of the Engineering Research, Development, and Technology Program at Lawrence Livermore National Laboratory (LLNL) is to develop the knowledge base, process technologies, specialized equipment, tools and facilities to support current and future LLNL programs. Engineering`s efforts are guided by a strategy that results in dual benefit: first, in support of Department of Energy missions, such as national security through nuclear deterrence; and second, in enhancing the nation`s economic competitiveness through our collaboration with U.S. industry in pursuit of the most cost- effective engineering solutions to LLNL programs. To accomplish this mission, the Engineering Research, Development, and Technology Program has two important goals: (1) identify key technologies relevant to LLNL programs where we can establish unique competencies, and (2) conduct high-quality research and development to enhance our capabilities and establish ourselves as the world leaders in these technologies. To focus Engineering`s efforts technology {ital thrust areas} are identified and technical leaders are selected for each area. The thrust areas are comprised of integrated engineering activities, staffed by personnel from the nine electronics and mechanical engineering divisions, and from other LLNL organizations. This annual report, organized by thrust area, describes Engineering`s activities for fiscal year 1996. The report provides timely summaries of objectives, methods, and key results from eight thrust areas: Computational Electronics and Electromagnetics; Computational Mechanics; Microtechnology; Manufacturing Technology; Materials Science and Engineering; Power Conversion Technologies; Nondestructive Evaluation; and Information Engineering. Readers desiring more information are encouraged to contact the individual thrust area leaders or authors. 198 refs., 206 figs., 16 tabs.

  3. Structures of Active Blind Thrusts Beneath Tokyo Metropolitan Area

    Science.gov (United States)

    Ishiyama, T.; Sato, H.; Kato, N.; Nakayama, T.; Iwasaki, T.; Abe, S.

    2011-12-01

    We show structural models of active blind thrust faults beneath Tokyo metropolitan area, based on actively deforming landforms, Quaternary stratigraphy, and deep to shallow high-resolution seismic reflection data tied with these stratigraphic constraints, resolving seismic hazards from otherwise elusive active structures beneath highly urbanized areas. At the leading edge of the subducting Philippine Sea plate beneath the Kanto region, most significant active structures are recognized as folding and/or faulting of late Pleistocene and Holocene fluvial and marine deposits. Newly obtained seismic reflection profile and reprocessed sections indicate that these active structures are surface manifestations of emergent splay thrust faults extending from a subduction megathrust that generated the A.D.1923 Kanto earthquake (M7.9). Much slower rates of slip along these structures (~ 4.2 mm/yr) than slip deficits (~ 30 mm/yr) indicate that slip partitioning might have occurred between the subduction megathrust and splay faults. In contrast to these megathrust-related structures, steeply dipping blind thrusts are distributed beneath the Kanto plain underlain by several thousand meters thick Neogene forearc basin and shallow marine to terrestrial sediments (Kazusa and Shimousa Group). Deep seismic reflection profiles corroborate that these blind thrusts are reactivated normal faults originally formed due to early to middle Miocene extensional tectonics. While rates of slip along these structures are commonly slow (~0.1 mm/yr) based on offsets of late Pleistocene terrace deposits, their proximity to the metropolitan area urges more intense efforts to identify their potential seismic hazards including locations, sizes, rates of slip, and geometries of blind thrusts.

  4. Analytic expressions for ULF wave radiation belt radial diffusion coefficients

    National Research Council Canada - National Science Library

    Ozeke, Louis G; Mann, Ian R; Murphy, Kyle R; Jonathan Rae, I; Milling, David K

    2014-01-01

    We present analytic expressions for ULF wave‐derived radiation belt radial diffusion coefficients, as a function of L and Kp , which can easily be incorporated into global radiation belt transport models...

  5. Chain Versus Belt – System Comparison of Future Timing Drives

    National Research Council Canada - National Science Library

    Howlett, Michael; Ausserhofer, Norbert; Schoeffmann, Wolfgang; Truffinet, Caroline; Zurk, Andreas

    2016-01-01

    ... and the quality requirements of timing drives. In the paper the main timing drive concepts, chain drive, dry belt and wet belt were analyzed and rated based on the functional influencing factors as target parameters to allow a scientifically...

  6. Evaluation of safety belt education program for employees

    Science.gov (United States)

    1980-06-01

    This research was designed to determine the effectiveness of a nine-month safety belt educational program, utilizing various informational materials developed by NHTSA, in increasing safety belt usage among corporate employees. The materials used inc...

  7. SMALL MAIN-BELT ASTEROID SPECTROSCOPIC SURVEY, PHASE II

    Data.gov (United States)

    National Aeronautics and Space Administration — This data set contains visible-wavelength (0.435-0.925 micron) spectra for 1341 main-belt asteroids observed during the second phase of the Small Main-belt Asteroid...

  8. Extended performance solar electric propulsion thrust system study. Volume 3: Tradeoff studies of alternate thrust system configurations

    Science.gov (United States)

    Hawthorne, E. I.

    1977-01-01

    Several thrust system design concepts were evaluated and compared using the specifications of the most advanced 30 cm engineering model thruster as the technology base. Emphasis was placed on relatively high power missions. The extensions in thruster performance required for the Halley's comet mission were defined and alternative thrust system concepts were designed in sufficient detail for comparing mass, efficiency, reliability, structure, and thermal characteristics. Confirmation testing and analysis of thruster and power-processing components were performed. A baseline design was selected from the alternatives considered, and the design analysis and documentation were refined. A program development plan was formulated that outlines the work structure considered necessary for developing, qualifying, and fabricating the flight hardware for the baseline thrust system within the time frame of a project to rendezvous with Halley's comet. An assessment was made of the costs and risks associated with a baseline thrust system as provided to the mission project under this plan. Critical procurements and interfaces were identified and defined.

  9. Design of a thrust stand for high power electric propulsion devices

    Science.gov (United States)

    Haag, Thomas W.

    1989-01-01

    A thrust stand for use with high power electric propulsion devices has been designed and tested. The thrust stand was specifically tailored to the needs of a 0.1 to 0.25 MW magnetoplasmadynamic (MPD) thruster program currently in progress at the NASA Lewis Research Center. The thrust stand structure was built as an inverted pendulum arrangement, supported at the base by water-cooled electrical power flexures. Thrust stand tares due to thruster discharge current were demonstrated to be negligible. Tares due to an applied field magnet current, after considerable effort, were reduced to less than 3.0 percent of measured thrust. These tares, however, could be determined independently and subtracted from the indicated thrust measurement. The paper gives a detailed description of the thrust stand design and operation with a 0.1 MW class MPD device. Other thrust stand tares due to vibration and thermal effects are discussed, along with issues of accuracy and repeatability.

  10. Interseismic Strain Accumulation Across Metropolitan Los Angeles: Puente Hills Thrust

    Science.gov (United States)

    Argus, D.; Liu, Z.; Heflin, M. B.; Moore, A. W.; Owen, S. E.; Lundgren, P.; Drake, V. G.; Rodriguez, I. I.

    2012-12-01

    Twelve years of observation of the Southern California Integrated GPS Network (SCIGN) are tightly constraining the distribution of shortening across metropolitan Los Angeles, providing information on strain accumulation across blind thrust faults. Synthetic Aperture Radar Interferometry (InSAR) and water well records are allowing the effects of water and oil management to be distinguished. The Mojave segment of the San Andreas fault is at a 25° angle to Pacific-North America plate motion. GPS shows that NNE-SSW shortening due to this big restraining bend is fastest not immediately south of the San Andreas fault across the San Gabriel mountains, but rather 50 km south of the fault in northern metropolitan Los Angeles. The GPS results we quote next are for a NNE profile through downtown Los Angeles. Just 2 mm/yr of shortening is being taken up across the San Gabriel mountains, 40 km wide (0.05 micro strain/yr); 4 mm/yr of shortening is being taken up between the Sierra Madre fault, at the southern front of the San Gabriel mountains, and South Central Los Angeles, also 40 km wide (0.10 micro strain/yr). We find shortening to be more evenly distributed across metropolitan Los Angeles than we found before [Argus et al. 2005], though within the 95% confidence limits. An elastic models of interseismic strain accumulation is fit to the GPS observations using the Back Slip model of Savage [1983]. Rheology differences between crystalline basement and sedimentary basin rocks are incorporated using the EDGRN/EDCMP algorithm of Wang et al. [2003]. We attempt to place the Back Slip model into the context of the Elastic Subducting Plate Model of Kanda and Simons [2010]. We find, along the NNE profile through downtown, that: (1) The deep Sierra Madre Thrust cannot be slipping faster than 2 mm/yr, and (2) The Puente Hills Thrust and nearby thrust faults (such as the upper Elysian Park Thrust) are slipping at 9 ±2 mm/yr beneath a locking depth of 12 ±5 km (95% confidence limits

  11. A comparison of outer electron radiation belt dropouts during solar ...

    Indian Academy of Sciences (India)

    Energetic electrons are trapped in the Earth's radiation belts which occupy a toroidal region between 3 and 7 RE above the Earth's surface. Rapid loss of electrons from the radiation belts is known as dropouts. The source and loss mechanisms regulating the radiation belts population are not yet understood entirely, ...

  12. 30 CFR 56.14212 - Chains, ropes, and drive belts.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Chains, ropes, and drive belts. 56.14212... Equipment Safety Practices and Operational Procedures § 56.14212 Chains, ropes, and drive belts. Chains, ropes, and drive belts shall be guided mechanically onto moving pulleys, sprockets, or drums except...

  13. 30 CFR 56.15005 - Safety belts and lines.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Safety belts and lines. 56.15005 Section 56.15005 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL... § 56.15005 Safety belts and lines. Safety belts and lines shall be worn when persons work where there...

  14. 33 CFR 142.42 - Safety belts and lifelines.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Safety belts and lifelines. 142... § 142.42 Safety belts and lifelines. (a) Except when moving from one location to another, personnel engaged in an activity where there is a hazard of falling 10 or more feet shall wear a safety belt or...

  15. 49 CFR 392.16 - Use of seat belts.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 5 2010-10-01 2010-10-01 false Use of seat belts. 392.16 Section 392.16... VEHICLES Driving of Commercial Motor Vehicles § 392.16 Use of seat belts. A commercial motor vehicle which has a seat belt assembly installed at the driver's seat shall not be driven unless the driver has...

  16. 30 CFR 57.14212 - Chains, ropes, and drive belts.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Chains, ropes, and drive belts. 57.14212... and Equipment Safety Practices and Operational Procedures § 57.14212 Chains, ropes, and drive belts. Chains, ropes, and drive belts shall be guided mechanically onto moving pulleys, sprockets, or drums...

  17. 30 CFR 57.15005 - Safety belts and lines.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Safety belts and lines. 57.15005 Section 57.15005 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL... Protection Surface and Underground § 57.15005 Safety belts and lines. Safety belts and lines shall be worn...

  18. Seat belts and shoulder harnesses : smart protection in small airplanes.

    Science.gov (United States)

    2004-05-01

    Seat belts alone will protect you only in minor impacts. : Using shoulder belts in small aircraft would reduce major injuries by 88% and fatalities by 20%. Shoulder belt kits are now available for most airplanes. : Proper use and installation of chil...

  19. 30 CFR 57.15020 - Life jackets and belts.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Life jackets and belts. 57.15020 Section 57.15020 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL... Protection Surface Only § 57.15020 Life jackets and belts. Life jackets or belts shall be worn where there is...

  20. 14 CFR 29.1413 - Safety belts: passenger warning device.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Safety belts: passenger warning device. 29....1413 Safety belts: passenger warning device. (a) If there are means to indicate to the passengers when safety belts should be fastened, they must be installed to be operated from either pilot seat. (b) Each...

  1. 30 CFR 56.15020 - Life jackets and belts.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Life jackets and belts. 56.15020 Section 56.15020 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL... § 56.15020 Life jackets and belts. Life jackets or belts shall be worn where there is danger from...

  2. Gravity inferred subsurface structure of Gadwal Schist belt, Andhra ...

    Indian Academy of Sciences (India)

    Detailed gravity data collected across the Gadwal schist belt in the state of Andhra Pradesh show an 8.4 mgal residual gravity anomaly associated with meta-sediments/volcanics of the linear NNW-SSE trending schist belt that shows metamorphism from green schist to amphibolite facies. This schist belt is flanked on either ...

  3. 30 CFR 56.4503 - Conveyor belt slippage.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Conveyor belt slippage. 56.4503 Section 56.4503... Control Installation/construction/maintenance § 56.4503 Conveyor belt slippage. Belt conveyors within... shall be equipped with a detection system capable of automatically stopping the drive pulley. A person...

  4. 30 CFR 57.4263 - Underground belt conveyors.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Underground belt conveyors. 57.4263 Section 57... and Control Firefighting Equipment § 57.4263 Underground belt conveyors. Fire protection shall be provided at the head, tail, drive, and take-up pulleys of underground belt conveyors. Provisions shall be...

  5. 30 CFR 75.1108 - Approved conveyor belts.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Approved conveyor belts. 75.1108 Section 75... Fire-Resistant Hydraulic Fluids on Underground Equipment § 75.1108 Approved conveyor belts. (a) Until December 31, 2009 conveyor belts placed in service in underground coal mines shall be: (1) Approved under...

  6. Green operations of belt conveyors by means of speed control

    NARCIS (Netherlands)

    He, D.; Pang, Y.; Lodewijks, G.

    2017-01-01

    Belt conveyors can be partially loaded due to the variation of bulk material flow loaded onto the conveyor. Speed control attempts to reduce the belt conveyor energy consumption and to enable the green operations of belt conveyors. Current research of speed control rarely takes the conveyor dynamics

  7. Thrust Measurement of Dielectric Barrier Discharge (DBD) Plasma Actuators: New Anti-Thrust Hypothesis, Frequency Sweeps Methodology, Humidity and Enclosure Effects

    Science.gov (United States)

    Ashpis, David E.; Laun, Matthew C.

    2014-01-01

    We discuss thrust measurements of Dielectric Barrier Discharge (DBD) plasma actuators devices used for aerodynamic active flow control. After a review of our experience with conventional thrust measurement and significant non-repeatability of the results, we devised a suspended actuator test setup, and now present a methodology of thrust measurements with decreased uncertainty. The methodology consists of frequency scans at constant voltages. The procedure consists of increasing the frequency in a step-wise fashion from several Hz to the maximum frequency of several kHz, followed by frequency decrease back down to the start frequency of several Hz. This sequence is performed first at the highest voltage of interest, then repeated at lower voltages. The data in the descending frequency direction is more consistent and selected for reporting. Sample results show strong dependence of thrust on humidity which also affects the consistency and fluctuations of the measurements. We also observed negative values of thrust, or "anti-thrust", at low frequencies between 4 Hz and up to 64 Hz. The anti-thrust is proportional to the mean-squared voltage and is frequency independent. Departures from the parabolic anti-thrust curve are correlated with appearance of visible plasma discharges. We propose the anti-thrust hypothesis. It states that the measured thrust is a sum of plasma thrust and anti-thrust, and assumes that the anti-thrust exists at all frequencies and voltages. The anti-thrust depends on actuator geometry and materials and on the test installation. It enables the separation of the plasma thrust from the measured total thrust. This approach enables more meaningful comparisons between actuators at different installations and laboratories. The dependence on test installation was validated by surrounding the actuator with a grounded large-diameter metal sleeve. Strong dependence on humidity is also shown; the thrust significantly increased with decreasing humidity, e

  8. NASA's Radiation Belt Storm Probes (RBSP) Mission

    Science.gov (United States)

    Fox, Nicola; Mauk, Barry; Ukhorskiy, Aleksandr; Takahashi, Kazue; Sibeck, David; Grebowsky, Joseph; Kessel, Ramona

    Understanding of radiation belt physics has matured to the extent that we have identified a set of processes which interplay to cause the creation and variation of radiation populations. These universal processes operate coherently across the planetary radiation belts of the solar system, and have far reaching impacts even beyond. Improvements in our understanding of these processes will substantially enhance our ability to predict radiation dynamics and mitigate the impacts on space assets. An important link in developing fully predictive understanding of such processes is the Radiation Belt Storm Probes mission to be launched into Earth's radiation belts in 2012 as a part of NASA's Living with a Star program. RBSP comprises two spacecraft making in situ measurements for at least 2 years in nearly the same highly elliptical, low inclination orbits (1.1 x 5.8 RE, 10 degrees). The orbits are slightly different so that 1 spacecraft laps the other spacecraft about every 2.5 months, allowing separation of spatial from temporal affects over spatial scales ranging from 0.1 to 5 RE. The unusually comprehensive suite of instruments, identical on the two spacecraft, measures the particle spectra (electrons, ions, ion compositions), fields (E and B), and wave distributions (dE and dB) that are needed to resolve the most critical science questions. Here we describe the RBSP mission characteristics, review the most pressing science issues that need to be resolved to develop predictive understanding, and describe how RBSP will be used to resolve those issues.

  9. 14 CFR 31.63 - Safety belts.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Safety belts. 31.63 Section 31.63 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS..., harness, or other restraining means for each occupant, unless the Administrator finds it unnecessary. If...

  10. Green Belt Europe - borders separate, nature unites

    Science.gov (United States)

    Uwe Friedel

    2015-01-01

    During the period of the Cold War between 1945 and 1989, a "Green Belt" of valuable pristine landscapes developed along the border line between Eastern and Western Europe, the intensively fortified and guarded so called Iron Curtain. Due to the remoteness of the border areas, a high number of national parks and other large conservation areas can be found...

  11. Research on an Active Seat Belt System

    Science.gov (United States)

    Kawashima, Takeshi

    In a car crash, permanent injury can be avoided if deformation of an occupant's rib cage is maintained within the allowable value. In order to realize this condition, the occupant's seat belt tension must be instantaneously adjusted by a feedback control system. In this study, a seat belt tension control system based on the active shock control system is proposed. The semi-active control law used is derived from the sliding mode control method. One advantage of this proposed system is that it does not require a large power actuator because the seat belt tension is controlled by a brake mechanism. The effectiveness is confirmed by numerical simulation using general parameters of a human thorax and a passenger car in a collision scenario with a wall at a velocity of 100 km/h. The feasibility is then confirmed with a control experiment using a scale model of about 1/10 scale. The relative displacement of the thorax model approaches the allowable value smoothly along the control reference and settles near this value. Thus, the proposed seat belt tension control system design is established.

  12. Composite Microdiscs with a Magnetic Belt

    DEFF Research Database (Denmark)

    Knaapila, Matti; Høyer, Henrik; Helgesen, Geir

    2015-01-01

    We describe an emulsion-based preparation of patchy composite particles (diameter of 100-500 mu m) consisting of a disclike epoxy core and a belt of porous polystyrene particles (diameter of 30 mu m) with magnetite within the pores. Compared to the magnetically uniform polystyrene particles, the ...

  13. Design aspects of multiple driven belt conveyors

    NARCIS (Netherlands)

    Nuttall, A.J.G.

    2007-01-01

    Worldwide belt conveyors are used to transport a great variety of bulk solid materials. The desire to carry higher tonnages over longer distances and more diverse routes, while keeping exploitation costs as low as possible, has fuelled many technological advances. An interesting development in the

  14. 14 CFR 25.904 - Automatic takeoff thrust control system (ATTCS).

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Automatic takeoff thrust control system... Automatic takeoff thrust control system (ATTCS). Each applicant seeking approval for installation of an engine power control system that automatically resets the power or thrust on the operating engine(s) when...

  15. Advances in Thrust-Based Emergency Control of an Airplane

    Science.gov (United States)

    Creech, Gray; Burken, John J.; Burcham, Bill

    2003-01-01

    Engineers at NASA's Dryden Flight Research Center have received a patent on an emergency flight-control method implemented by a propulsion-controlled aircraft (PCA) system. Utilizing the preexisting auto-throttle and engine-pressure-ratio trim controls of the airplane, the PCA system provides pitch and roll control for landing an airplane safely without using aerodynamic control surfaces that have ceased to function because of a primary-flight-control-system failure. The installation of the PCA does not entail any changes in pre-existing engine hardware or software. [Aspects of the method and system at previous stages of development were reported in Thrust-Control System for Emergency Control of an Airplane (DRC-96-07), NASA Tech Briefs, Vol. 25, No. 3 (March 2001), page 68 and Emergency Landing Using Thrust Control and Shift of Weight (DRC-96-55), NASA Tech Briefs, Vol. 26, No. 5 (May 2002), page 58.]. Aircraft flight-control systems are designed with extensive redundancy to ensure low probabilities of failure. During recent years, however, several airplanes have exhibited major flight-control-system failures, leaving engine thrust as the last mode of flight control. In some of these emergency situations, engine thrusts were successfully modulated by the pilots to maintain flight paths or pitch angles, but in other situations, lateral control was also needed. In the majority of such control-system failures, crashes resulted and over 1,200 people died. The challenge lay in creating a means of sufficient degree of thrust-modulation control to safely fly and land a stricken airplane. A thrust-modulation control system designed for this purpose was flight-tested in a PCA an MD-11 airplane. The results of the flight test showed that without any operational control surfaces, a pilot can land a crippled airplane (U.S. Patent 5,330,131). The installation of the original PCA system entailed modifications not only of the flight-control computer (FCC) of the airplane but

  16. VERO cells harbor a poly-ADP-ribose belt partnering their epithelial adhesion belt

    Directory of Open Access Journals (Sweden)

    Laura Lafon-Hughes

    2014-10-01

    Full Text Available Poly-ADP-ribose (PAR is a polymer of up to 400 ADP-ribose units synthesized by poly-ADP-ribose-polymerases (PARPs and degraded by poly-ADP-ribose-glycohydrolase (PARG. Nuclear PAR modulates chromatin compaction, affecting nuclear functions (gene expression, DNA repair. Diverse defined PARP cytoplasmic allocation patterns contrast with the yet still imprecise PAR distribution and still unclear functions. Based on previous evidence from other models, we hypothesized that PAR could be present in epithelial cells where cadherin-based adherens junctions are linked with the actin cytoskeleton (constituting the adhesion belt. In the present work, we have examined through immunofluorescence and confocal microscopy, the subcellular localization of PAR in an epithelial monkey kidney cell line (VERO. PAR was distinguished colocalizing with actin and vinculin in the epithelial belt, a location that has not been previously reported. Actin filaments disruption with cytochalasin D was paralleled by PAR belt disruption. Conversely, PARP inhibitors 3-aminobenzamide, PJ34 or XAV 939, affected PAR belt synthesis, actin distribution, cell shape and adhesion. Extracellular calcium chelation displayed similar effects. Our results demonstrate the existence of PAR in a novel subcellular localization. An initial interpretation of all the available evidence points towards TNKS-1 as the most probable PAR belt architect, although TNKS-2 involvement cannot be discarded. Forthcoming research will test this hypothesis as well as explore the existence of the PAR belt in other epithelial cells and deepen into its functional implications.

  17. Development of damage detector for coal conveyor belt; Sekitan conveyor belt sonsho tanchiki no kaihatsu

    Energy Technology Data Exchange (ETDEWEB)

    Oshima, S. [Chubu Electric Power Co. Inc., Nagoya (Japan)

    1996-11-01

    To realize the automatic detection of disconnection of conveyor belt steel cords used at a coal handling facility in thermal power plants, a damage detector for conveyor belt with a non-contact magnetic balance type highly sensitive sensor and a data processing system having real-time display function of detected signals has been developed in a cooperation with Ishikawajima-Harima Heavy Industries (IHI). A detection method of steel cord disconnection has been designed, by which the disconnection can be detected using a detecting coil as a change of magnetic balance with equivalent magnetic fields in opposite direction generated by two magnetic coils. Detecting performance was confirmed by making dummy disconnection with width of 2 mm in the steel cords of conveyor belt at the Numazu large-capacity coal handling and storage demonstration plant of IHI. Joint observation performance using an actually working conveyor belt was also confirmed at the Hekinan Thermal Power Plant of Chubu Electric Power Co., Inc. Through the tests under four different velocities of conveyor belt, it was confirmed that disconnection and belt joints can be detected accurately. 9 figs.

  18. Dynamics Analysis and Modeling of Rubber Belt in Large Mine Belt Conveyors

    Directory of Open Access Journals (Sweden)

    Gao Yang

    2014-10-01

    Full Text Available Rubber belt not only is one of the key components of belt conveyor, but also affects the overall performance of the core part. Research on dynamics analysis of large conveyor not only helps to improve the reliability and design level, but also can guide the rational selection of conveyor safety factor, and effectively reduce the cost of the conveyor belt. Based on unique viscoelastic properties of belt conveyor, it was simplified as one-dimensional viscoelastic rod in this study, and then a discrete element model of conveyor systems was established. The kinetic equations of each discrete unit was derived using kinetic energy, potential energy of driving segment, bearing segment and return segment and equation of energy dissipation and Lagrange equation. Based on Wilson-q algorithm, the kinetic equation of DT1307-type ST2000's conveyor belt was solved by using Matlab to write computer programs. Research on the change rule of conveyor displacement, velocity, acceleration and dynamic tension during the boot process revealed the working mechanism of nonlinear viscoelastic, which lay the theoretical foundation for dynamic performance optimization of large belt conveyor. The calculation results were used to optimize design and analysis of conveyor system, the result showed that it could reduce the driven tension peaks about 12 %, save 5 % of overall manufacturing cost, which bring considerable profits for enterprises.

  19. Determination of relative immobile and sliding areas between carrying and tractive belts in using of belt conveyor intermediate drives

    Directory of Open Access Journals (Sweden)

    Goncharov K.A.

    2015-12-01

    Full Text Available Method of determination of relative immobile and sliding areas between carrying and tractive belts in places of mount-ing of belt conveyor intermediate drives made in the form of tractive contours is proposed. The example shows potential of this method in multidrive belt conveyor design process.

  20. Investigation of Thrust Augmentation of a 1600-pound Thrust Centrifugal-flow-type Turbojet Engine by Injection of Refrigerants at Compressor Inlets

    Science.gov (United States)

    Jones, William L.; Dowman, Harry W.

    1947-01-01

    Investigations were conducted to determine effectiveness of refrigerants in increasing thrust of turbojet engines. Mixtures of water an alcohol were injected for a range of total flows up to 2.2 lb/sec. Kerosene was injected into inlets covering a range of injected flows up to approximately 30% of normal engine fuel flow. Injection of 2.0 lb/sec of water alone produced an increase in thrust of 35.8% of rate engine conditions and kerosene produced a negligible increase in thrust. Carbon dioxide increased thrust 23.5 percent.

  1. Viking Orbiter 1975 thrust vector control system accuracy

    Science.gov (United States)

    Mcglinchey, L. F.

    1974-01-01

    The thrust vector control (TVC) system of the Viking Orbiter 1975 is discussed. The purpose of the TVC system is to point the engine thrust at the vehicle center of mass and to maintain attitude stability during propulsive maneuvers. This is accomplished by mounting the engine in a two-axis gimbal system. The TVC system then controls the pointing of the engine by closed loop control of two linear actuators which extend or retract and rotate the engine in its gimbal system. The effect of the TVC on the velocity vector pointing error incurred during a propulsive maneuver is analyzed. Models for predicting the magnitude of the error for various propulsive maneuvers are developed.

  2. High Thrust-to-Power Annular Engine Technology

    Science.gov (United States)

    Patterson, Michael J.; Thomas, Robert E.; Crofton, Mark W.; Young, Jason A.; Foster, John E.

    2015-01-01

    Gridded ion engines have the highest efficiency and total impulse of any mature electric propulsion technology, and have been successfully implemented for primary propulsion in both geocentric and heliocentric environments with excellent ground/in-space correlation of performance. However, they have not been optimized to maximize thrust-to-power, an important parameter for Earth orbit transfer applications. This publication discusses technology development work intended to maximize this parameter. These activities include investigating the capabilities of a non-conventional design approach, the annular engine, which has the potential of exceeding the thrust-to-power of other EP technologies. This publication discusses the status of this work, including the fabrication and initial tests of a large-area annular engine. This work is being conducted in collaboration among NASA Glenn Research Center, The Aerospace Corporation, and the University of Michigan.

  3. A space tethered towing method using tension and platform thrusts

    Science.gov (United States)

    Meng, Zhongjie; Wang, Bingheng; Huang, Panfeng

    2017-01-01

    Orbit maneuver via tether is a promising countermeasure for space debris removal and satellite orbit transfer. A space tethered towing method is explored that utilizes thrust to fulfill transfer and bounded tension to stabilize tether heading. For this purpose, a time-energy optimal orbit is designed by Gauss pseudospectral method. The theoretical attitude commands are obtained by equilibria analysis. An effective attitude control strategy is presented where the commands are optimized first and then feedback controller is designed. To deal with the underactuated problem with tension constraint, hierarchical sliding mode theory is employed and an adaptive anti-windup module is added to mitigate the actuator saturation. Simulation results show that the target is towed effectively by the thrusts, and a smooth tracking for the commands of tether length and in-plane tether heading is guaranteed by the bounded tension. In addition, the designed controller also presents appreciable robustness to model error and determination error.

  4. Dating of movements along thrusts and faults in the Himalaya

    Energy Technology Data Exchange (ETDEWEB)

    Saini, H.S.

    1982-11-01

    Radiometric dating of movements along the MCT (Vaikrita Thrust), two local but deep seated thrust and the Sumdoh Fault Zone bordering the Kinnar Kailas Granite in the Baspa and Satluj valleys, NE Himachal Himalaya, has been attempted for the first time by fission track method. Garnet and apatite fission track ages suggest the age of the latest phase of movements around 14 and 7 m.y. respectively along the MCT and Sumdoh Fault. The vertical uplift rates along them were 1.1mm/year from 14 to 7 m.y. and 0.6 mm/year from 7 m.y. to recent geologic past respectively, as against the value 0.036 mm/year during the period from 210 to 17 m.y. in the undisturbed area. (author). 11 refs.

  5. Engineering research, development and technology. Thrust area report, FY93

    Energy Technology Data Exchange (ETDEWEB)

    1994-05-01

    The mission of the Engineering Research, Development, and Technology Program at Lawrence Livermore National Laboratory (LLNL) is to develop the technical staff, tools, and facilities needed to support current and future LLNL programs. The efforts are guided by a dual-benefit research and development strategy that supports Department of Energy missions, such as national security through nuclear deterrence and economic competitiveness through partnerships with U.S. industry. This annual report, organized by thrust area, describes the activities for the fiscal year 1993. The report provides timely summaries of objectives, methods, and results from nine thrust areas for this fiscal year: Computational Electronics and Electromagnetics; Computational Mechanics; Diagnostics and Microelectronics; Fabrication Technology; Materials Science and Engineering; Power Conversion Technologies; Nondestructive Evaluation; Remote Sensing, Imaging, and Signal Engineering; and Emerging Technologies. Separate abstracts were prepared for 47 papers in this report.

  6. Condition monitoring of thrust ball bearings using continuous AE

    Czech Academy of Sciences Publication Activity Database

    Chlada, Milan; Nohal, L.; Převorovský, Zdeněk

    2016-01-01

    Roč. 26, č. 2 (2016), A14-A14 ISSN 1213-3825. [Europen Conference on Acoustic Emission Testing /32./. 07.09.2016-09.09.2016, Praha] Grant - others:NETME Centre Plus - národní program udržitelnosti(CZ) LO1202 Institutional support: RVO:61388998 Keywords : continuous acoustic emission * rolling contact fatigue * thrust ball bearing * histogram of counting periods * wavelet analysis Subject RIV: BI - Acoustics

  7. Low-thrust chemical propulsion system pump technology

    Science.gov (United States)

    Meadville, J. W.

    1980-01-01

    A study was conducted within the thrust range 450 to 9000 N (100 to 2000 pounds). Performance analyses were made on centrifugal, pitot, Barske, drag, Tesla, gear, piston, lobe, and vane pumps with liquid hydrogen, liquid methane, and liquid oxygen as propellants. Gaseous methane and hydrogen driven axial impulse turbines, vane expanders, piston expanders, and electric motors were studied as drivers. Data are presented on performance, sizes, weights, and estimated service lives and costs.

  8. Automated low-thrust guidance for the orbital maneuvering vehicle

    Science.gov (United States)

    Rose, Richard E.; Schmeichel, Harry; Shortwell, Charles P.; Werner, Ronald A.

    1988-01-01

    This paper describes the highly autonomous OMV Guidance Navigation and Control system. Emphasis is placed on a key feature of the design, the low thrust guidance algorithm. The two guidance modes, orbit change guidance and rendezvous guidance, are discussed in detail. It is shown how OMV will automatically transfer from its initial orbit to an arbitrary target orbit and reach a specified rendezvous position relative to the target vehicle.

  9. Gravity as Archimedes' thrust and a bifurcation in that theory

    OpenAIRE

    Arminjon, Mayeul

    2004-01-01

    Euler's interpretation of Newton's gravity (NG) as Archimedes' thrust in a fluid ether is presented in some detail. Then a semi-heuristic mechanism for gravity, close to Euler's, is recalled and compared with the latter. None of these two "gravitational ethers" can obey classical mechanics. This is logical since the ether defines the very reference frame, in which mechanics is defined. This concept is used to build a scalar theory of gravity: NG corresponds to an incompressible ether, a compr...

  10. Camera Layout Design for the Upper Stage Thrust Cone

    Science.gov (United States)

    Wooten, Tevin; Fowler, Bart

    2010-01-01

    Engineers in the Integrated Design and Analysis Division (EV30) use a variety of different tools to aid in the design and analysis of the Ares I vehicle. One primary tool in use is Pro-Engineer. Pro-Engineer is a computer-aided design (CAD) software that allows designers to create computer generated structural models of vehicle structures. For the Upper State thrust cone, Pro-Engineer was used to assist in the design of a layout for two camera housings. These cameras observe the separation between the first and second stage of the Ares I vehicle. For the Ares I-X, one standard speed camera was used. The Ares I design calls for two separate housings, three cameras, and a lighting system. With previous design concepts and verification strategies in mind, a new layout for the two camera design concept was developed with members of the EV32 team. With the new design, Pro-Engineer was used to draw the layout to observe how the two camera housings fit with the thrust cone assembly. Future analysis of the camera housing design will verify the stability and clearance of the camera with other hardware present on the thrust cone.

  11. The cislunar low-thrust trajectories via the libration point

    Science.gov (United States)

    Qu, Qingyu; Xu, Ming; Peng, Kun

    2017-05-01

    The low-thrust propulsion will be one of the most important propulsion in the future due to its large specific impulse. Different from traditional low-thrust trajectories (LTTs) yielded by some optimization algorithms, the gradient-based design methodology is investigated for LTTs in this paper with the help of invariant manifolds of LL1 point and Halo orbit near the LL1 point. Their deformations under solar gravitational perturbation are also presented to design LTTs in the restricted four-body model. The perturbed manifolds of LL1 point and its Halo orbit serve as the free-flight phase to reduce the fuel consumptions as much as possible. An open-loop control law is proposed, which is used to guide the spacecraft escaping from Earth or captured by Moon. By using a two-dimensional search strategy, the ON/OFF time of the low-thrust engine in the Earth-escaping and Moon-captured phases can be obtained. The numerical implementations show that the LTTs achieved in this paper are consistent with the one adopted by the SMART-1 mission.

  12. Seat Belt Use Among Adult Workers - 21 States, 2013.

    Science.gov (United States)

    Boal, Winifred L; Li, Jia; Rodriguez-Acosta, Rosa L

    2016-06-17

    Roadway incidents involving motorized vehicles accounted for 24% of fatal occupational injuries in the United States during 2013 and were the leading cause of fatal injuries among workers.* In 2013, workers' compensation costs for serious, nonfatal injuries among work-related roadway incidents involving motorized land vehicles were estimated at $2.96 billion.(†) Seat belt use is a proven method to reduce injuries to motor vehicle occupants (1). Use of lap/shoulder seat belts reduces the risk for fatal injuries to front seat occupants of cars by 45% and the risk to light truck occupants by 60%.(§) To characterize seat belt use among adult workers by occupational group, CDC analyzed data from the 2013 Behavioral Risk Factor Surveillance System (BRFSS) and found that not always using a seat belt was significantly associated with occupational group after controlling for factors known to influence seat belt use. Occupational groups with the highest prevalences of not always using a seat belt included construction and extraction; farming, fishing, and forestry; and installation, maintenance, and repair. To increase seat belt use among persons currently employed, states can enact and enforce primary seat belt laws, employers can set and enforce safety policies requiring seat belt use by all vehicle occupants, and seat belt safety advocates can target interventions to workers in occupational groups with lower reported seat belt use.

  13. Optimal Trajectories For Orbital Transfers Using Low And Medium Thrust Propulsion Systems

    Science.gov (United States)

    Cobb, Shannon S.

    1992-01-01

    For many problems it is reasonable to expect that the minimum time solution is also the minimum fuel solution. However, if one allows the propulsion system to be turned off and back on, it is clear that these two solutions may differ. In general, high thrust transfers resemble the well-known impulsive transfers where the burn arcs are of very short duration. The low and medium thrust transfers differ in that their thrust acceleration levels yield longer burn arcs which will require more revolutions, thus making the low thrust transfer computational intensive. Here, we consider optimal low and medium thrust orbital transfers.

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

    Science.gov (United States)

    Weigel, Jacob F., II

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

  15. Combined high and low-thrust geostationary orbit insertion with radiation constraint

    Science.gov (United States)

    Macdonald, Malcolm; Owens, Steven Robert

    2018-01-01

    The sequential use of an electric propulsion system is considered in combination with a high-thrust propulsion system for application to the propellant-optimal Geostationary Orbit insertion problem, whilst considering both temporal and radiation flux constraints. Such usage is found to offer a combined propellant mass saving when compared with an equivalent high-thrust only transfer. This propellant mass saving is seen to increase as the allowable transfer duration is increased, and as the thrust from the low-thrust system is increased, assuming constant specific impulse. It was found that the required plane change maneuver is most propellant-efficiently performed by the high-thrust system. The propellant optimal trajectory incurs a significantly increased electron flux when compared to an equivalent high-thrust only transfer. However, the electron flux can be reduced to a similar order of magnitude by increasing the high-thrust propellant consumption, whilst still delivering an improved mass fraction.

  16. Near Earth Asteroid Scout Solar Sail Thrust and Torque Model

    Science.gov (United States)

    Heaton, Andy; Ahmad, Naeem; Miller, Kyle

    2017-01-01

    The Near Earth Asteroid (NEA) Scout is a solar sail mission whose objective is to scout at least one Near Earth Asteroid to help prepare for human missions to Near Earth Asteroids. NEA Scout will launch as a secondary payload on the first SLS-Orion mission. NEA Scout will perform a small trim maneuver shortly after deploy from the spent SLS upper stage using a cold gas propulsion system, but from that point on will depend entirely on the solar sail for thrust. As such, it is important to accurately characterize the thrust of the sail in order to achieve mission success. Additionally, the solar sail creates a relatively large solar disturbance torque that must be mitigated. For early mission design studies a flat plate model of the solar sail with a fixed center of pressure was adequate, but as mission concepts and the sail design matured, greater fidelity was required. Here we discuss the progress to a three-dimensional sail model that includes the effects of tension and thermal deformation that has been derived from a large structural Finite Element Model (FEM) developed by the Langley Research Center. We have found that the deformed sail membrane affects torque relatively much more than thrust; a flat plate model could potentially model thrust well enough to close mission design studies, but a three-dimensional solar sail is essential to control system design. The three-dimensional solar sail model revealed that thermal deformations of unshielded booms would create unacceptably large solar disturbance torques. The original large FEM model was used in control and mission simulations, but was resulted in simulations with prohibitive run times. This led us to adapt the Generalized Sail Model (GSM) of Rios-Reyes. A design reference sail model has been baselined for NEA Scout and has been used to design the mission and control system for the sailcraft. Additionally, since NEA Scout uses reaction wheels for attitude pointing and control, the solar torque model is

  17. Active faulting within a megacity: the geometry and slip rate of the Pardisan thrust in central Tehran, Iran

    Science.gov (United States)

    Talebian, M.; Copley, A. C.; Fattahi, M.; Ghorashi, M.; Jackson, J. A.; Nazari, H.; Sloan, R. A.; Walker, R. T.

    2016-12-01

    Tehran, the capital city of Iran with a population of over 12 million, is one of the largest urban centres within the seismically active Alpine-Himalayan orogenic belt. Although several historic earthquakes have affected Tehran, their relation to individual faults is ambiguous for most. This ambiguity is partly due to a lack of knowledge about the locations, geometries and seismic potential of structures that have been obscured by dramatic urban growth over the past three decades, and which have covered most of the young geomorphic markers and natural exposures. Here we use aerial photographs from 1956, combined with an ˜1 m DEM derived from stereo Pleiades satellite imagery to investigate the geomorphology of a growing anticline above a thrust fault-the Pardisan thrust-within central Tehran. The topography across the ridge is consistent with a steep ramp extending from close to the surface to a depth of ˜2 km, where it presumably connects with a shallow-dipping detachment. No primary fault is visible at the surface, and it is possible that the faulting dissipates in the near surface as distributed shearing. We use optically stimulated luminescence to date remnants of uplifted and warped alluvial deposits that are offset vertically across the Pardisan fault, providing minimum uplift and slip-rates of at least 1 mm yr-1. Our study shows that the faults within the Tehran urban region have relatively rapid rates of slip, are important in the regional tectonics, and have a great impact on earthquake hazard assessment of the city and surrounding region.

  18. Geometry of the Main Himalayan Thrust and Moho beneath Satluj valley, northwest Himalaya: Constraints from receiver function analysis

    Science.gov (United States)

    Hazarika, Devajit; Wadhawan, Monika; Paul, Arpita; Kumar, Naresh; Borah, Kajaljyoti

    2017-04-01

    Crustal configuration beneath the Satluj valley region of the northwest Himalaya has been studied with the help of receiver function analysis of teleseismic earthquakes recorded by 18 broadband seismological stations. These stations were located on diverse geotectonic units from the Himalayan foreland basin in the south to the Tethyan Himalaya (TH) in the north. A gentle north dipping structure of the Main Himalayan Thrust (MHT) is imaged between the Sub and Higher Himalaya in contrast to the reported ramp structure of the MHT beneath the Garhwal and Nepal Himalaya. The ramp structure is, however, identified further north, beyond the South Tibetan Detachment in Satluj valley. The depth of the MHT varies from 16 to 27 km across the Sub, Lesser, and Higher Himalaya, and it increases to 38 km beneath the TH forming a ramp. This is significantly a different structure of the MHT beneath the Satluj valley, which is attributed to the effect of underthrusting Delhi-Hardwar Ridge, a transverse structure to the Himalayan arc. Conspicuously, no strong or large earthquake is observed during 1964-2015 in this segment of the Himalayan Seismic Belt. The RF modeling, on the other hand, shows 44 km crustal thickness beneath the Himalayan Frontal Thrust (HFT), and it gradually increases to 62 km beneath the TH. Low shear wave velocity ( 0.8-1.8 km s-1) is observed in the uppermost 3-4 km of the crust beneath the stations near the HFT, which may be the effect of the sedimentary column of the Indo-Gangetic Plain.

  19. Structural observations and U-Pb mineral ages from igneous rocks at the Archaean-Palaeoproterozoic boundary in the Salahmi Schist Belt, central Finland: constraints on tectonic evolution

    Directory of Open Access Journals (Sweden)

    Pietikäinen, K.

    1999-06-01

    Full Text Available The study area in Vieremä, central Finland, contains part of Archaean-Palaeoproterozoic boundary. In the east, the area comprises Archaean gneiss and the Salahmi Schist Belt. The rocks of the schist belt are turbiditic metagreywackes, with well-preserved depositional structures, occurring as Proterozoic wedge-shaped blocks, and staurolite schists, the latter representing higher-strained and metamorphosed equivalents of the metagreywackes. In the west of the area there is an Archaean gneiss block, containing strongly elongated structures, and deformed Svecofennian supracrustal rocks, which are cut by deformed granitoids. These are juxtaposed with the schist belt. The boundaries of these tectonometamorphic blocks are narrow, highly strained mylonites and thrust zones. The metamorphic grade of the supracrustal rocks increases from east to west, the increase being stepwise across the mylonitic block boundaries. The rocks are more deformed from east to west with younger structures overprinting. In the staurolite schists of the Salahmi Schist Belt, the most prominent structure is a lineation (L2 that overprints the bedding and axial plane foliation. In Sorronmäki quarry, at the western boundary of the schist belt, this Palaeoproterozoic lineation dominates all the structures in tonalite gneiss, which gives a U-Pb age of 2731±6 Ma. Southeast of the quarry, at the same boundary, the Salahmi schists have been overturned towards the northeast, suggesting that the Archaean gneiss at Sorronmäki has been thrust towards the northeast over these rocks. In the western part of the study area, the Leppikangas granodiorite that intrudes the Svecofennian supracrustal rocks gives a U-Pb age of 1891+6 Ma. In the granodiorite, a strong lineation formed by the intersection of two foliations, which maybe L2 is associated with thrusting towards the northeast. The monazite age of the Archaean Sorronmäki gneiss is 1817+3 Ma, and the titanite age of the Svecofennian

  20. Thermal barrier coatings (TBC's) for high heat flux thrust chambers

    Science.gov (United States)

    Bradley, Christopher M.

    The last 30 years materials engineers have been under continual pressure to develop materials with a greater temperature potential or to produce configurations that can be effectively cooled or otherwise protected at elevated temperature conditions. Turbines and thrust chambers produce some of the harshest service conditions for materials which lead to the challenges engineers face in order to increase the efficiencies of current technologies due to the energy crisis that the world is facing. The key tasks for the future of gas turbines are to increase overall efficiencies to meet energy demands of a growing world population and reduce the harmful emissions to protect the environment. Airfoils or blades tend to be the limiting factor when it comes to the performance of the turbine because of their complex design making them difficult to cool as well as limitations of their thermal properties. Key tasks for space transportation it to lower costs while increasing operational efficiency and reliability of our space launchers. The important factor to take into consideration is the rocket nozzle design. The design of the rocket nozzle or thrust chamber has to take into account many constraints including external loads, heat transfer, transients, and the fluid dynamics of expanded hot gases. Turbine engines can have increased efficiencies if the inlet temperature for combustion is higher, increased compressor capacity and lighter weight materials. In order to push for higher temperatures, engineers need to come up with a way to compensate for increased temperatures because material systems that are being used are either at or near their useful properties limit. Before thermal barrier coatings were applied to hot-section components, material alloy systems were able to withstand the service conditions necessary. But, with the increased demand for performance, higher temperatures and pressures have become too much for those alloy systems. Controlled chemistry of hot

  1. Ionic composition of the earth's radiation belts

    Science.gov (United States)

    Spjeldvik, W. N.

    1983-01-01

    Several different ion species have been positively identified in the earth's radiation belts. Besides protons, there are substantial fluxes of helium, carbon and oxygen ions, and there are measurable quantities of even heavier ions. European, American and Soviet space experimenters have reported ion composition measurements over wide ranges of energies: at tens of keV (ring-current energies) and below, and at hundreds of keV and above. There is still a gap in the energy coverage from several tens to several hundreds of keV where little observational data are available. In this review emphasis is placed on the radiation belt ionic structure above 100 keV. Both quiet time conditions and geomagnetic storm periods are considered, and comparison of the available space observations is made with theoretical analysis of geomagnetically trapped ion spatial, energy and charge state distributions.

  2. Crustal structure and evolution of the Pyrenean-Cantabrian belt: A review and new interpretations from recent concepts and data

    Science.gov (United States)

    Teixell, A.; Labaume, P.; Ayarza, P.; Espurt, N.; de Saint Blanquat, M.; Lagabrielle, Y.

    2018-01-01

    This paper provides a synthesis of current data and interpretations on the crustal structure of the Pyrenean-Cantabrian orogenic belt, and presents new tectonic models for representative transects. The Pyrenean orogeny lasted from Santonian ( 84 Ma) to early Miocene times ( 20 Ma), and consisted of a spatial and temporal succession of oceanic crust/exhumed mantle subduction, rift inversion and continental collision processes at the Iberia-Eurasia plate boundary. A good coverage by active-source (vertical-incidence and wide-angle reflection) and passive-source (receiver functions) seismic studies, coupled with surface data have led to a reasonable knowledge of the present-day crustal architecture of the Pyrenean-Cantabrian belt, although questions remain. Seismic imaging reveals a persistent structure, from the central Pyrenees to the central Cantabrian Mountains, consisting of a wedge of Eurasian lithosphere indented into the thicker Iberian plate, whose lower crust is detached and plunges northwards into the mantle. For the Pyrenees, a new scheme of relationships between the southern upper crustal thrust sheets and the Axial Zone is here proposed. For the Cantabrian belt, the depth reached by the N-dipping Iberian crust and the structure of the margin are also revised. The common occurrence of lherzolite bodies in the northern Pyrenees and the seismic velocity and potential field record of the Bay of Biscay indicate that the precursor of the Pyrenees was a hyperextended and strongly segmented rift system, where narrow domains of exhumed mantle separated the thinned Iberian and Eurasian continental margins since the Albian-Cenomanian. The exhumed mantle in the Pyrenean rift was largely covered by a Mesozoic sedimentary lid that had locally glided along detachments in Triassic evaporites. Continental margin collision in the Pyrenees was preceded by subduction of the exhumed mantle, accompanied by the pop-up thrust expulsion of the off-scraped sedimentary lid above

  3. The significance of Late Devonian ophiolites in the Variscan orogen: a record from the Vosges Klippen Belt

    Science.gov (United States)

    Skrzypek, E.; Tabaud, A.-S.; Edel, J.-B.; Schulmann, K.; Cocherie, A.; Guerrot, C.; Rossi, P.

    2012-06-01

    The present work examines the lithological, structural, geochemical and geochronological records from the Klippen Belt located in the southern Vosges Mountains (NE France). The Klippen Belt is represented by discontinuous exposures of serpentinized harzburgite, ophicalcite, gabbro, gneiss and polymictic conglomerate overlain by deep marine pelitic sediments. Structural data and Bouguer anomalies reveal that the Klippen Belt coincides with a significant discontinuity now occupied by a granitic ridge. Gabbro geochemistry indicates a MOR-type affinity similar to recent slow-spreading ridges, but positive Ba, Sr, Th or U anomalies do not exclude the influence of fluids expelled from a subduction zone. A Sm-Nd isochron age of 372 ± 18 Ma is thought to reflect gabbro emplacement from a highly depleted mantle source (ɛNd = +11.3), and U-Pb zircon ages from a gneiss sample indicate that the basement found in the Klippen has a Neoproterozoic origin. Combined data indicate the formation of a deep basin during Late Devonian rifting. The Klippen lithologies could testify for the presence of an ocean-continent transition environment subsequently inverted during the Early Carboniferous. Basin inversion during the Middle Visean was probably controlled by rift-related structures, and resulted in folding of the sedimentary successions as well as exhumation along thrust zones of deep parts of the basin represented by the Klippen Belt. Based on correlations with the neighbouring Variscan massifs, it is proposed that the southern Vosges sequences represent a back-arc basin related to the North-directed subduction of the southern Palaeotethys Ocean. This geodynamic reconstruction is tentatively correlated with similar ophiolitic remnants in the northern part of the French Massif Central (Brévenne) and with the evolution of the southern Black Forest. The Late Devonian ophiolites are interpreted as relicts of small back-arc marginal basins developed during general closure of the

  4. Drivers' attitudes toward front or rear child passenger belt use and seat belt reminders at these seating positions.

    Science.gov (United States)

    Kidd, David G; McCartt, Anne T

    2014-01-01

    Passengers, especially those in rear seating positions, use seat belts less frequently than drivers. In-vehicle technology can inform drivers when their passengers are unbuckled and encourage passengers to use belts. The current study collected information about drivers' attitudes toward passenger belt use and belt reminders for front passengers and children in back seats. A national telephone survey of 1218 people 18 and older was conducted, of which 477 respondents were drivers who transport a front seat passenger at least once a week and 254 were drivers who transport an 8- to 15-year-old child in the back seat. Respondents were asked about their attitudes toward belt use by their front passengers or rear child passengers and preferences for different passenger belt reminder features. Ninety percent of drivers who regularly transport front seat passengers said that the passengers always use seat belts. Reported belt use was even higher among 8- to 15-year-old children in the back seat (97%). Among the drivers whose children do not always buckle up, about half said their child unbuckled the belt during the trip. Almost every full-time belt use driver (96%) would encourage front passengers to buckle up if not belted, compared to 57 percent of part-time belt users and nonusers. In contrast, nearly every driver who transports children in the back seat would encourage their belt use, regardless of the driver's belt use habits. Most drivers who transport front passengers wanted passenger belt reminders to encourage passengers to buckle up. Most of these drivers wanted a chime/buzzer or warning light or text display and wanted the reminder to last indefinitely. Most drivers who transport child passengers in the rear seat wanted the vehicle to indicate whether child passengers are unbuckled. A large majority of these drivers wanted notifications via a visual diagram of seating positions and belt use, a chime/buzzer, and a warning light or text display. These drivers

  5. Substyles of belting: phonatory and resonatory characteristics.

    Science.gov (United States)

    Sundberg, Johan; Thalén, Margareta; Popeil, Lisa

    2012-01-01

    Belting has been described as speechlike, yell-like, or shouting voice production commonly used in contemporary commercial music genres and substantially differing from the esthetic of the Western classical voice tradition. This investigation attempts to describe phonation and resonance characteristics of different substyles of belting (heavy, brassy, ringy, nasal, and speechlike) and the classical style. A professional singer and voice teacher, skilled in these genres, served as the single subject. The recorded material was found representative according to a classification test performed by an expert panel. Subglottal pressure was measured as the oral pressure during the occlusion for the consonant /p/. The voice source and formant frequencies were analyzed by inverse filtering the audio signal. The subglottal pressure and measured flow glottogram parameters differed clearly between the styles heavy and classical assuming opposite extremes in most parameters. The formant frequencies, by contrast, showed fewer less systematic differences between the substyles but were clearly separated from the classical style with regard to the first formant. Thus, the differences between the belting substyles mainly concerned the voice source. Copyright © 2012 The Voice Foundation. Published by Mosby, Inc. All rights reserved.

  6. A binary main-belt comet

    Science.gov (United States)

    Agarwal, Jessica; Jewitt, David; Mutchler, Max; Weaver, Harold; Larson, Stephen

    2017-09-01

    Asteroids are primitive Solar System bodies that evolve both collisionally and through disruptions arising from rapid rotation. These processes can lead to the formation of binary asteroids and to the release of dust, both directly and, in some cases, through uncovering frozen volatiles. In a subset of the asteroids called main-belt comets, the sublimation of excavated volatiles causes transient comet-like activity. Torques exerted by sublimation measurably influence the spin rates of active comets and might lead to the splitting of bilobate comet nuclei. The kilometre-sized main-belt asteroid 288P (300163) showed activity for several months around its perihelion 2011 (ref. 11), suspected to be sustained by the sublimation of water ice and supported by rapid rotation, while at least one component rotates slowly with a period of 16 hours (ref. 14). The object 288P is part of a young family of at least 11 asteroids that formed from a precursor about 10 kilometres in diameter during a shattering collision 7.5 million years ago. Here we report that 288P is a binary main-belt comet. It is different from the known asteroid binaries in its combination of wide separation, near-equal component size, high eccentricity and comet-like activity. The observations also provide strong support for sublimation as the driver of activity in 288P and show that sublimation torques may play an important part in binary orbit evolution.

  7. Rapid Rebuilding of the Outer Radiation Belt

    Science.gov (United States)

    Glocer, A.; Fok, M.-C.; Nagai, T.; Toth, G.; Guild, T.; Bkake, J.

    2011-01-01

    Recent observations by the radiation monitor (RDM) on the spacecraft Akebono have shown several cases of greater than 2.5 MeV radiation belt electron enhancements occurring on timescales of less than a few hours. Similar enhancements are also seen in detectors on board the NOAA/POES and TWINS 1 satellites. These intervals are shorter than typical radial diffusion or wave-particle interactions can account for. We choose two so-called "rapid rebuilding" events that occur during high speed streams (4 September 2008 and 22 July 2009) and simulated them with the Space Weather Modeling Framework configured with global magnetosphere, radiation belt, ring current, and ionosphere electrodynamics model. Our simulations produce a weaker and delayed dipolarization as compared to observations, but the associated inductive electric field in the simulations is still strong enough to rapidly transport and accelerate MeV electrons resulting in an energetic electron flux enhancement that is somewhat weaker than is observed. Nevertheless, the calculated flux enhancement and dipolarization is found to be qualitatively consistent with the observations. Taken together, the modeling results and observations support the conclusion that storm-time dipolarization events in the magnetospheric magnetic field result in strong radial transport and energization of radiation belt electrons.

  8. The atmospheric implications of radiation belt remediation

    Directory of Open Access Journals (Sweden)

    C. J. Rodger

    2006-08-01

    Full Text Available High altitude nuclear explosions (HANEs and geomagnetic storms can produce large scale injections of relativistic particles into the inner radiation belts. It is recognised that these large increases in >1 MeV trapped electron fluxes can shorten the operational lifetime of low Earth orbiting satellites, threatening a large, valuable population. Therefore, studies are being undertaken to bring about practical human control of the radiation belts, termed "Radiation Belt Remediation" (RBR. Here we consider the upper atmospheric consequences of an RBR system operating over either 1 or 10 days. The RBR-forced neutral chemistry changes, leading to NOx enhancements and Ox depletions, are significant during the timescale of the precipitation but are generally not long-lasting. The magnitudes, time-scales, and altitudes of these changes are no more significant than those observed during large solar proton events. In contrast, RBR-operation will lead to unusually intense HF blackouts for about the first half of the operation time, producing large scale disruptions to radio communication and navigation systems. While the neutral atmosphere changes are not particularly important, HF disruptions could be an important area for policy makers to consider, particularly for the remediation of natural injections.

  9. The atmospheric implications of radiation belt remediation

    Directory of Open Access Journals (Sweden)

    C. J. Rodger

    2006-08-01

    Full Text Available High altitude nuclear explosions (HANEs and geomagnetic storms can produce large scale injections of relativistic particles into the inner radiation belts. It is recognised that these large increases in >1 MeV trapped electron fluxes can shorten the operational lifetime of low Earth orbiting satellites, threatening a large, valuable population. Therefore, studies are being undertaken to bring about practical human control of the radiation belts, termed "Radiation Belt Remediation" (RBR. Here we consider the upper atmospheric consequences of an RBR system operating over either 1 or 10 days. The RBR-forced neutral chemistry changes, leading to NOx enhancements and Ox depletions, are significant during the timescale of the precipitation but are generally not long-lasting. The magnitudes, time-scales, and altitudes of these changes are no more significant than those observed during large solar proton events. In contrast, RBR-operation will lead to unusually intense HF blackouts for about the first half of the operation time, producing large scale disruptions to radio communication and navigation systems. While the neutral atmosphere changes are not particularly important, HF disruptions could be an important area for policy makers to consider, particularly for the remediation of natural injections.

  10. Why do airlines want and use thrust reversers? A compilation of airline industry responses to a survey regarding the use of thrust reversers on commercial transport airplanes

    Science.gov (United States)

    Yetter, Jeffrey A.

    1995-01-01

    Although thrust reversers are used for only a fraction of the airplane operating time, their impact on nacelle design, weight, airplane cruise performance, and overall airplane operating and maintenance expenses is significant. Why then do the airlines want and use thrust reversers? In an effort to understand the airlines need for thrust reversers, a survey of the airline industry was made to determine why and under what situations thrust reversers are currently used or thought to be needed. The survey was intended to help establish the cost/benefits trades for the use of thrust reversers and airline opinion regarding alternative deceleration devices. A compilation and summary of the responses given to the survey questionnaire is presented.

  11. Investigation of Asymmetric Thrust Detection with Demonstration in a Real-Time Simulation Testbed

    Science.gov (United States)

    Chicatelli, Amy K.; Rinehart, Aidan W.; Sowers, T. Shane; Simon, Donald L.

    2016-01-01

    The purpose of this effort is to develop, demonstrate, and evaluate three asymmetric thrust detection approaches to aid in the reduction of asymmetric thrust-induced aviation accidents. This paper presents the results from that effort and their evaluation in simulation studies, including those from a real-time flight simulation testbed. Asymmetric thrust is recognized as a contributing factor in several Propulsion System Malfunction plus Inappropriate Crew Response (PSM+ICR) aviation accidents. As an improvement over the state-of-the-art, providing annunciation of asymmetric thrust to alert the crew may hold safety benefits. For this, the reliable detection and confirmation of asymmetric thrust conditions is required. For this work, three asymmetric thrust detection methods are presented along with their results obtained through simulation studies. Representative asymmetric thrust conditions are modeled in simulation based on failure scenarios similar to those reported in aviation incident and accident descriptions. These simulated asymmetric thrust scenarios, combined with actual aircraft operational flight data, are then used to conduct a sensitivity study regarding the detection capabilities of the three methods. Additional evaluation results are presented based on pilot-in-the-loop simulation studies conducted in the NASA Glenn Research Center (GRC) flight simulation testbed. Data obtained from this flight simulation facility are used to further evaluate the effectiveness and accuracy of the asymmetric thrust detection approaches. Generally, the asymmetric thrust conditions are correctly detected and confirmed.

  12. Radiation Belts of Antiparticles in Planetary Magnetospheres

    Science.gov (United States)

    Pugacheva, G. I.; Gusev, A. A.; Jayanthi, U. B.; Martin, I. M.; Spjeldvik, W. N.

    2007-05-01

    The Earth's radiation belts could be populated, besides with electrons and protons, also by antiparticles, such as positrons (Basilova et al., 1982) and antiprotons (pbar). Positrons are born in the decay of pions that are directly produced in nuclear reactions of trapped relativistic inner zone protons with the residual atmosphere at altitudes in the range of about 500 to 3000 km over the Earth's surface. Antiprotons are born by high energy (E > 6 GeV) cosmic rays in p+p - p+p+p+ pbar and in p+p - p+p+n+nbar reactions. The trapping and storage of these charged anti-particles in the magnetosphere result in radiation belts similar to the classical Van Allen belts of protons and electrons. We describe the mathematical techniques used for numerical simulation of the trapped positron and antiproton belt fluxes. The pion and antiproton yields were simulated on the basis of the Russian nuclear reaction computer code MSDM, a Multy Stage Dynamical Model, Monte Carlo code, (i.e., Dementyev and Sobolevsky, 1999). For estimates of positron flux there we have accounted for ionisation, bremsstrahlung, and synchrotron energy losses. The resulting numerical estimates show that the positron flux with energy >100 MeV trapped into the radiation belt at L=1.2 is of the order ~1000 m-2 s-1 sr-1, and that it is very sensitive to the shape of the trapped proton spectrum. This confined positron flux is found to be greater than that albedo, not trapped, mixed electron/positron flux of about 50 m-2 s-1 sr-1 produced by CR in the same region at the top of the geomagnetic field line at L=1.2. As we show in report, this albedo flux also consists mostly of positrons. The trapped antiproton fluxes produced by CR in the Earth's upper rarified atmosphere were calculated in the energy range from 10 MeV to several GeV. In the simulations we included a mathematic consideration of the radial diffusion process, both an inner and an outer antiproton source, losses of particles due to ionization process

  13. Normative misperceptions of peer seat belt use among high school students and their relationship to personal seat belt use.

    Science.gov (United States)

    Litt, Dana M; Lewis, Melissa A; Linkenbach, Jeffrey W; Lande, Gary; Neighbors, Clayton

    2014-01-01

    This research examined gender-specific perceptions of peer seat belt use norms among high school students and their relationship with one's own seat belt use. We expected that students would underestimate the seat belt use of their peers and that these perceptions would be positively associated with their own seat belt use. High school students from 4 schools (N = 3348; 52% male) completed measures assessing perceived seat belt use and personal seat belt use. Findings demonstrated that students perceived that others engaged in less seat belt use than they do and that perceived norms were positively associated with one's own seat belt use. Peer influences are a strong predictor of behavior, especially among adolescents. Ironically, adolescents' behaviors are often influenced by inaccurate perceptions of their peers. This research establishes the presence of a misperception related to seat belt use and suggests that misperception is associated with own behaviors. This research provides a foundation for social norms-based interventions designed to increase seat belt use by correcting normative misperceptions among adolescents.

  14. Random Deterioration Process of Conveyor Belt Evaluated by Statistical Analysis of Core Failures Detected Along Belt Axis and Elapsed Time

    Science.gov (United States)

    Blazej, Ryszard; Jurdziak, Leszek; Kirjanów, Agata; Kozlowski, Tomasz

    2017-12-01

    Magnetic diagnostic methods are used for steel cord belt condition evaluation since the beginning of 1970s. Initially they generated an analogue signal for several tens of centimetres of conveyor belts scanned sequentially with one measuring head in several cycles or the whole width of the belt at one time thanks to the installation of many measuring heads across the entire cross section. This did not allow identification of single centimetre failures, but rather an aggregate assessment of the state of quite wide waist. Modern diagnostic devices, thanks to miniaturization, allow up to 200 heads per belt width to identify damage of individual cords. Instead of analogue signals, they generate a zero-one digital signal corresponding to a change in the magnetic field sign, which can illustrate damage on 2D images. This makes it easier to identify the location and size of the damage in the belt image. Statistical analysis of digital signals summed up for consecutive sections along the belt axis allows to present both the source signal and its aggregation for band of a given width to form aggregate measures of belt damage such as the damage density per 1 meter of belt. Observation of changes in these measurements at different times allows on evaluation of its rate of change over time, which can be used to forecast future belt condition and to select the proper moment of preventive belt replacement to another one to avoid emergency downtimes (egg in underground mines) or to recondition of belts (egg. in lignite surface mines). The paper presents the results of investigations of the damage condition of a core of a single belt segment working in one of the copper ore underground mines. Scanning of the belt condition was performed few times at intervals of several months. The paper presents the results of the analysis of the changes in core condition, showing the random character of the damage process along the axis and its change over time.

  15. Low Thrust Mission Trajectories to Near Earth Asteroids

    Science.gov (United States)

    Saripalli, Pratik; Cardiff, Eric

    2017-01-01

    The discovery of 2016 HO3 and its classification as a quasi-satellite has sparked a stronger interest towards Near Earth Asteroids (NEAs). This work presents low-thrust low-power mission designs to various NEAs using an EELV Secondary Payload Adapter (ESPA). A global trajectory optimizer (EMTG) was used to generate mission solutions to a select 13 NEAs using a 200 watt BHT-200 thruster as a proof of concept. The missions presented here demonstrate that a low-cost electric propulsion ESPA mission to NEAs is a feasible concept for many asteroids.

  16. Thrust vector control algorithm design for the Cassini spacecraft

    Science.gov (United States)

    Enright, Paul J.

    1993-01-01

    This paper describes a preliminary design of the thrust vector control algorithm for the interplanetary spacecraft, Cassini. Topics of discussion include flight software architecture, modeling of sensors, actuators, and vehicle dynamics, and controller design and analysis via classical methods. Special attention is paid to potential interactions with structural flexibilities and propellant dynamics. Controller performance is evaluated in a simulation environment built around a multi-body dynamics model, which contains nonlinear models of the relevant hardware and preliminary versions of supporting attitude determination and control functions.

  17. Syntectonic granites in thrust and strike slip regimes: the history of the Carmo and Cindacta plutons (southeastern Brazil)

    Science.gov (United States)

    Spanner, Bernd G.; Kruhl, Jörn H.

    2002-09-01

    The Carmo and Cindacta plutons (SE Brazil) represent syntectonic intrusions during the late-Proterozoic Brasiliano orogeny (700-500 Ma) in the southern Ribeira belt. A first magma pulse (the Carmo pluton) intruded as a thin lenticular body along a low-angle WSW-directed overthrust plane, which probably formed during the collision of the Congo and São Francisco cratons. The magma crystallized at a depth of ˜22 km. In a later stage of the Brasiliano orogeny, large-scale strike-slip shear zones developed. Along these zones, two successive compositionally different magma pulses (the Cindacta pluton) intruded. The first of these pulses probably intruded into a pull-apart structure, and the second was emplaced parallel to a strike-slip shear zone at a depth of ˜19 km. Both magmas cooled under the same deformation regime to the lower amphibolite facies. The two plutons exemplify the sheet-like intrusions of granitic magmas during thrust and strike-slip tectonics under conditions of continent collision.

  18. Megaboudins and lateral extension along the leading edge of a crystalline thrust sheet, Hudson Highlands, New York, U.S.A.

    Science.gov (United States)

    Gates, A. E.

    1996-10-01

    Megascopic lenses of crystalline rock along the leading edge of the Hudson Highland thrust sheet, New York, are boudins that formed as the result of lateral extension during Late Paleozoic compression. These 'megaboudins' range from 50 m on each side to 1.2 × 3.2 km and form a NE-trending chain along the northwest side of the Green Pond outlier and Hudson Highlands. The crystalline Hudson Highlands were first thrust northwestward onto shales and siltstones of the Martinsburg Formation during the Middle Ordovician Taconian Orogeny, and later eroded leaving a NE-trending elongate klippe along the leading edge. During subsequent compression, the klippe was laterally extended into a chain of fracture boudins with λ = 3.3. The cleavage and bedding in the surrounding shales and siltstones wraps around the boudins and into the boudin gaps. The cleavage and bedding wrap through 61-114 ° forming shallow to moderately NE-plunging fold axes on the northeast side of the gaps and shallow to moderately SE-plunging fold axes on the southeast side of the gaps. Strike-slip shear indicators at the boudin corners support the mass movement of shale and siltstone. In the wider boudin gaps, conjugate NW-striking normal faults form cross-strike grabens that juxtapose overlying Silurian strata into the gap areas. Fragments of brecciated gneiss from the boudins are also transported into the gap areas along these cross-strike normal faults. The boudins, dextral strike-slip stretching faults along the southeastern margin of the boudins, and asymmetric gap fill geometries are prime criteria for the recognition and characterization of lateral stretching in contractional fold and thrust belts.

  19. Inverse Analysis and Modeling for Tunneling Thrust on Shield Machine

    Directory of Open Access Journals (Sweden)

    Qian Zhang

    2013-01-01

    Full Text Available With the rapid development of sensor and detection technologies, measured data analysis plays an increasingly important role in the design and control of heavy engineering equipment. The paper proposed a method for inverse analysis and modeling based on mass on-site measured data, in which dimensional analysis and data mining techniques were combined. The method was applied to the modeling of the tunneling thrust on shield machines and an explicit expression for thrust prediction was established. Combined with on-site data from a tunneling project in China, the inverse identification of model coefficients was carried out using the multiple regression method. The model residual was analyzed by statistical methods. By comparing the on-site data and the model predicted results in the other two projects with different tunneling conditions, the feasibility of the model was discussed. The work may provide a scientific basis for the rational design and control of shield tunneling machines and also a new way for mass on-site data analysis of complex engineering systems with nonlinear, multivariable, time-varying characteristics.

  20. A review of definitions of the Himalayan Main Central Thrust

    Science.gov (United States)

    Martin, Aaron J.

    2017-09-01

    Most workers regard the Main Central Thrust (MCT) as one of the key high strain zones in the Himalaya because it accommodated at least 90 km of shortening, because that shortening exhumed and buried hanging wall and footwall rocks, and due to geometric and kinematic connections between the Main Central Thrust and the structurally overlying South Tibet Detachment. Geologists currently employ three unrelated definitions of the MCT: metamorphic-rheological, age of motion-structural, or protolith boundary-structural. These disparate definitions generate map and cross-section MCT positions that vary by up to 5 km of structural distance. The lack of consensus and consequent shifting locations impede advances in our understanding of the tectonic development of the orogen. Here, I review pros and cons of the three MCT definitions in current use. None of these definitions is flawless. The metamorphic-rheological and age of motion-structural definitions routinely fail throughout the orogen, whereas the protolith boundary-structural definition may fail only in rare cases, all limited to sectors of the eastern Himalaya. Accordingly, a definition based on high strain zone geometry and kinematics combined with identification of a protolith boundary is the best working definition of the MCT.

  1. Preloading of the thrust phase in cross-country skiing.

    Science.gov (United States)

    Komi, P V; Norman, R W

    1987-03-01

    Based on the assumption that the stretch-shortening cycle is a natural way of muscle function, the occurrence of such a cycle was investigated in a diagonal technique of cross-country skiing. Cinematographic, special force platform, and telemetered EMG techniques were employed. The four subjects studied were all elite international level cross-country skiers, and the measurements were taken either under world championship conditions (cinematography) or during special test situations outdoors (EMG, force platform, and cinematography). The skiing was performed on the fixed uphill course (competition) and on the variable uphill tracks (2.5 degrees-11 degrees). The latter condition allowed mounting of a special long force platform system under the track. The results indicated that the leg kick phase is preceded by a typical unweighting phase, which is followed by braking and propulsion phases. Angular velocity curves of the hip, knee, and ankle joints revealed indirectly the segmental occurrence of the stretch-shortening cycle. Similar phenomena could be identified for the elbow joint during the pole plant and thrust phases. On a steep uphill track, the muscle activation pattern and the ground reaction forces resembled in many instances those of slow level running. Based on the results, a model was suggested to describe how the preloading of the leg thrust phase takes place as a sequential flow from one joint to another.

  2. [Midterm results and revisions of the thrust plate prosthesis (TPP)].

    Science.gov (United States)

    Ishaque, B A; Wienbeck, S; Stürz, H

    2004-01-01

    Although already in use for 20 years, the concept of the metaphyseal anchored thrust plate prosthesis has not yet gained general acceptance. Clinical and radiological follow-up examinations were carried out 5 to 8 years after implantation of a TPP. We tried to answer the question if the metaphyseal anchorage of the cement-less TPP is equal to a diaphyseal anchorage of a cement-less stem prosthesis and to define the advantages of the TPP. We included 170 of the patients from our clinic with an implanted TPP in this study. Furthermore we reviewed the results of 30 revision hip arthroplasties of the TPP. The clinical examination were carried out using the Harris hip score while the radiological examinations were performed on the basis of predefined criteria. We found good clinical results. The preoperative Harris score of 48.7 increased to 93.7 at 24 months postoperatively. Radiolucencies were detected and were of varying relevance in dependence on their localization. The Kaplan-Meier survival analysis at 8 years was 90.5 %. The clinical results after changing the TPP were also good to excellent. The mean Harris hip score was 87.3. Our study suggests that in spite of a slightly higher aseptic loosening rate in comparison to the cement-less stem prosthesis, the thrust plate prosthesis proved to be worthwhile. On the basis of previous experience we assume that the TPP is a good alternative implant especially for young patients.

  3. Thrust producing mechanisms in ray-inspired underwater vehicle propulsion

    Directory of Open Access Journals (Sweden)

    Geng Liu

    2015-01-01

    Full Text Available This paper describes a computational study of the hydrodynamics of a ray-inspired underwater vehicle conducted concurrently with experimental measurements. High-resolution stereo-videos of the vehicle’s fin motions during steady swimming are obtained and used as a foundation for developing a high fidelity geometrical model of the oscillatory fin. A Cartesian grid based immersed boundary solver is used to examine the flow fields produced due to these complex artificial pectoral fin kinematics. Simulations are carried out at a smaller Reynolds number in order to examine the hydrodynamic performance and understand the resultant wake topology. Results show that the vehicle’s fins experience large spanwise inflexion of the distal part as well as moderate chordwise pitching during the oscillatory motion. Most thrust force is generated by the distal part of the fin, and it is highly correlated with the spanwise inflexion. Two sets of inter-connected vortex rings are observed in the wake right behind each fin. Those vortex rings induce strong backward flow jets which are mainly responsible for the fin thrust generation.

  4. Near Earth Asteroid Scout Thrust and Torque Model

    Science.gov (United States)

    Heaton, Andrew; Ahmad, Naeem; Miller, Kyle

    2017-01-01

    The Near Earth Asteroid (NEA) Scout is a solar sail mission whose objective is to scout at least one Near Earth Asteroid in preparation for manned missions to asteroids. NEA Scout will use a solar sail as the primary means of propulsion. Thus it is important for mission planning to accurately characterize the thrust of the sail. Additionally, the solar sail creates a relatively large solar disturbance torque that must be mitigated. For early mission design studies a flat plate model of the solar sail with a fixed center of pressure was adequate, but as mission concepts and the sail design matured, greater fidelity was required. Here we discuss the progress to a three-dimensional sail model that includes the effects of tension and thermal deformation that has been derived from a large structural Finite Element Model (FEM) developed by the Langley Research Center. We have found that the deformed sail membrane affects torque relatively much more than thrust. We have also found that other than uncertainty over the precise shape, the effect of small (approximately millimeter scale) wrinkles on the diffusivity of the sail is the leading remaining source of uncertainty. We demonstrate that millimeter-scale wrinkles can be modeled analytically as a change in the fraction of specular reflection. Finally we discuss the implications of these results for the NEA Scout mission.

  5. Tensile overpressure compartments on low-angle thrust faults

    Science.gov (United States)

    Sibson, Richard H.

    2017-08-01

    Hydrothermal extension veins form by hydraulic fracturing under triaxial stress (principal compressive stresses, σ 1 > σ 2 > σ 3) when the pore-fluid pressure, P f, exceeds the least compressive stress by the rock's tensile strength. Such veins form perpendicular to σ 3, their incremental precipitation from hydrothermal fluid often reflected in `crack-seal' textures, demonstrating that the tensile overpressure state, σ 3' = ( σ 3 - P f) time P f > σ 3. In compressional regimes ( σ v = σ 3), subhorizontal extension veins may develop over vertical intervals dilatant fault-fracture mesh structures may develop throughout a tabular rock volume. Evidence for the existence of fault-fracture meshes around low-angle thrusts comes from exhumed ancient structures and from active structures. In the case of megathrust ruptures along subduction interfaces, force balance analyses, lack of evidence for shear heating, and evidence of total shear stress release during earthquakes suggest the interfaces are extremely weak ( τ < 40 MPa), consistent with weakening by near-lithostatically overpressured fluids. Portions of the subduction interface, especially towards the down-dip termination of the seismogenic megathrust, are prone to episodes of slow-slip, non-volcanic tremor, low-frequency earthquakes, very-low-frequency earthquakes, etc., attributable to the activation of tabular fault-fracture meshes at low σ 3' around the thrust interface. Containment of near-lithostatic overpressures in such settings is precarious, fluid loss curtailing mesh activity.[Figure not available: see fulltext.

  6. Resin Transfer Moulding Of An Engine Thrust Frame Cone Cap

    Science.gov (United States)

    Brodsjo, Anders; Fatemi, Javad; de Vries, Henri

    2012-07-01

    For the Ariane 5 Midlife Evolution, a new Engine Thrust Frame for the upper stage is being developed. Part of this Engine Thrust Frame is the so-called Cone Cap, which closes the inverted cone shape of the structure. This part is highly loaded, as it transfers all the loads from the engines to the cone shape, and includes the hinge points for the mechanism that steer the engines. Besides strength to cope with the loads, stiffness is a very important design parameter. A composite design of this structure has been developed, which is approximately 15 kg’s lighter than the aluminium structure. To manufacture such a part in composites is challenging, because of the complexity of the shape and large laminate thickness. Due to these requirements, Resin Transfer Moulding has been selected as manufacturing method, which allows this highly integrated structure to be made in one step. As part of this project, a quarter segment of the full-scale design has been manufactured. From the design model, a detailed design for the dry fibre preform has been made using advanced composite laminate software tools. This preform was placed inside a heated, double sided tool and injected with the resin.

  7. Understanding Spacecraft Agility for Orbit Transfers on the Dawn Low-thrust Mission

    Science.gov (United States)

    Smith, Brett A.; Vanelli, C. Anthony; Lee, Allan Y.

    2012-01-01

    Conventional maneuver design processes were inadequate. Long thrusting durations with the small force of SEP. Increased coupling between ACS and NAV teams. Definition of quantifiable constraints proved impractical. Specifically for the Dawn mission, because of the attitude steering algorithm. A time-efficient simulation tool, qSTAT, was developed and allowed fast verification of candidate thrust profile designs. This approach allowed Dawn to overcome the complications of low-thrust orbit transfers.

  8. Modeling Resonant Structure in the Kuiper Belt

    Science.gov (United States)

    Holmes, E. K.; Dermott, S. F.; Grogan, K.

    1999-12-01

    There is a possible connection between structure in circumstellar disks and the presence of planets, our own zodiacal cloud being the prime example. Asymmetries in such a disk could be diagnostic of planets which would be otherwise undetectable. At least three different types of asymmetries can serve to indicate bodies orbiting a star in a disk: (1) a warp in the plane of symmetry of the disk, (2) an offset in the center of symmetry of the disk with respect to the central star, and (3) density anomalies in the plane of the disk due to resonant trapping of dust particles. In the asteroid belt, collisions between asteroids supply dust particles to the zodiacal cloud. By comparison, it has been postulated that collisions between KBOs could initiate a collisional cascade which would produce a Kuiper dust disk. In fact, the Kuiper Belt is the region of our solar system that is most analogous to the planetary debris disks we see around other stars such as Vega, β Pic, Fomalhaut, and ɛ Eridani (Backman and Paresce 1993). A Kuiper Disk would most likely have a resonant structure, with two concentrations in brightness along the ecliptic longitude. This large scale structure arises because many of the KBOs, the Plutinos, are in the 2:3 mean motion resonance with Neptune. By running numerical integrations of particles in Pluto-like orbits, the resonant structure of the Kuiper belt can be studied by determining the percentage of particles trapped in the resonance as a function of their initial velocity and beta, where β = Frad}/F{grav. The dynamical evolution of the particles is followed from source to sink with Poynting Robertson light drag, solar wind drag, radiation pressure, and the effects of planetary gravitational perturbations included. This research was funded in part by a NASA GSRP grant.

  9. Escape of asteroids from the main belt

    Science.gov (United States)

    Granvik, Mikael; Morbidelli, Alessandro; Vokrouhlický, David; Bottke, William F.; Nesvorný, David; Jedicke, Robert

    2017-02-01

    Aims: We locate escape routes from the main asteroid belt, particularly into the near-Earth-object (NEO) region, and estimate the relative fluxes for different escape routes as a function of object size under the influence of the Yarkovsky semimajor-axis drift. Methods: We integrated the orbits of 78 355 known and 14 094 cloned main-belt objects and Cybele and Hilda asteroids (hereafter collectively called MBOs) for 100 Myr and recorded the characteristics of the escaping objects. The selected sample of MBOs with perihelion distance q > 1.3 au and semimajor axis a random spin obliquities (either 0 deg or 180 deg) for each test asteroid. Results: We find more than ten obvious escape routes from the asteroid belt to the NEO region, and they typically coincide with low-order mean-motion resonances with Jupiter and secular resonances. The locations of the escape routes are independent of the semimajor-axis drift rate and thus are also independent of the asteroid diameter. The locations of the escape routes are likewise unaffected when we added a model for Yarkovsky-O'Keefe-Radzievskii-Paddack (YORP) cycles coupled with secular evolution of the rotation pole as a result of the solar gravitational torque. A Yarkovsky-only model predicts a flux of asteroids entering the NEO region that is too high compared to the observationally constrained flux, and the discrepancy grows larger for smaller asteroids. A combined Yarkovsky and YORP model predicts a flux of small NEOs that is approximately a factor of 5 too low compared to an observationally constrained estimate. This suggests that the characteristic timescale of the YORP cycle is longer than our canonical YORP model predicts.

  10. Permo-Triassic structural evolution of the Shiwandashan and Youjiang structural belts, South China

    Science.gov (United States)

    Li, Jianhua; Zhao, Guochun; Johnston, Stephen T.; Dong, Shuwen; Zhang, Yueqiao; Xin, Yujia; Wang, Wenbao; Sun, Hanshen; Yu, Yingqi

    2017-07-01

    We conducted field mapping coupled with radiometric dating across the Shiwandashan and Youjiang structural belts (SWSB and YJSB), to investigate how southwest South China evolved and to better understand its links to plate boundary dynamics during the Late Permian to Middle Triassic. Our results reveal an episodic tectono-magmatic evolutionary history of the SWSB and YJSB. The SWSB underwent significant NW-SE shortening punctuated by ∼250-240 Ma S-type pluton emplacement during the Late Permian to Middle Triassic; the shortening was expressed by thin-skinned NW-verging thrusts and folds, and conjugate sets of ∼N-trending sinistral and ∼E-trending dextral faults. The NW-SE shortening overlapped with, and was succeeded by Triassic NE-SW shortening in the YJSB. The NE-SW shortening was expressed by NE-verging thrusts and folds, which documented a northeastward propagation of foreland deformation. The NE-verging folds overprinted older NW-verging folds, forming superimposed folds at the juncture of the YJSB and SWSB in the Long'an area. Our results, combined with regional considerations, support a model of the NW-SE shortening as an Andean-type orogeny that developed in response to westward subduction of the Paleo-Pacific Plate, and the NE-SW shortening as a product of the Indochina-South China collision. The subduction of the Paleo-Pacific plate assisted in westward motion of the South China oceanic lithosphere, which may have facilitated the closure of the Paleo-Tethys ocean and subsequent collisions of South China with North China and Indochina.

  11. An Evaluation Study of a CALL Application: With BELT or without BELT

    Science.gov (United States)

    Genc, Humeyra

    2012-01-01

    The present study tried to evaluate the 6th grade students' attitudes towards the use of a CALL program which is called BELT Success used in English language learning course in a private school, the relationship to students' attitudes to their English language proficiency level, and finally teachers` experiences and opinions towards the use of…

  12. The Radiation Belt Storm Probes Mission: Advancing Our Understanding of the Earth's Radiation Belts

    Science.gov (United States)

    Sibeck, David; Kanekal, Shrikanth; Kessel, Ramona; Fox, Nicola; Mauk, Barry

    2012-01-01

    We describe NASA's Radiation Belt Storm Probe (RBSP) mission, whose primary science objective is to understand, ideally to the point of predictability, the dynamics of relativistic electrons and penetrating ions in the Earth's radiation belts resulting from variable solar activity. The overarching scientific questions addressed include: 1. the physical processes that produce radiation belt enhancement events, 2. the dominant mechanisms for relativistic electron loss, and 3. how the ring current and other geomagnetic processes affect radiation belt behavior. The RBSP mission comprises two spacecraft which will be launched during Fall 2012 into low inclination lapping equatorial orbits. The orbit periods are about 9 hours, with perigee altitudes and apogee radial distances of 600 km and 5.8 RE respectively. During the two-year primary mission, the spacecraft orbits precess once around the Earth and lap each other twice in each local time quadrant. The spacecraft are each equipped with identical comprehensive instrumentation packages to measure, electrons, ions and wave electric and magnetic fields. We provide an overview of the RBSP mission, onboard instrumentation and science prospects and invite scientific collaboration.

  13. Period Determination of Six Main Belt Asteroids

    Science.gov (United States)

    Ferrero, Andrea

    2014-07-01

    Observations of six main-belt asteroids (MBA) produced lightcurve parameters of: 487 Venetia, P = 13.34 ± 0.01 h, A = 0.20 mag; 684 Hildburg, P = 15.89 ± 0.01 h, A = 0.22 mag; 772 Tanete, P = 8.629 ± 0.001 h, A = 0.18 mag.; 1181 Lilith, P = 15.04 ± 0.01 h, A = 0.11 mag.; 1246 Chaka, P = 25.44 ± 0.01 h, A = 0.25 mag.; and 2834 Christy Carol, P = 12.79 ± 0.01 h, A = 0.39 mag.

  14. Finite-thrust optimization of interplanetary transfers of space vehicle with bimodal nuclear thermal propulsion

    Science.gov (United States)

    Kharytonov, Oleksii M.; Kiforenko, Boris M.

    2011-08-01

    The nuclear thermal rocket (NTR) propulsion is one of the leading promising technologies for primary space propulsion for manned exploration of the solar system due to its high specific impulse capability and sufficiently high thrust-to-weight ratio. Another benefit of NTR is its possible bimodal design, when nuclear reactor is used for generation of a jet thrust in a high-thrust mode and (with an appropriate power conversion system) as a source of electric power to supply the payload and the electric engines in a low-thrust mode. The model of the NTR thrust control was developed considering high-thrust NTR as a propulsion system of limited power and exhaust velocity. For the proposed model the control of the thrust value is accomplished by the regulation of reactor thermal power and propellant mass flow rate. The problem of joint optimization of the combination of high- and low-thrust arcs and the parameters of bimodal NTR (BNTR) propulsion system is considered for the interplanetary transfers. The interplanetary trajectory of the space vehicle is formed by the high-thrust NTR burns, which define planet-centric maneuvers and by the low-thrust heliocentric arcs where the nuclear electric propulsion (NEP) is used. The high-thrust arcs are analyzed using finite-thrust approach. The motion of the corresponding dynamical system is realized in three phase spaces concerning the departure planet-centric maneuver by means of high-thrust NTR propulsion, the low-thrust NEP heliocentric maneuver and the approach high-thrust NTR planet-centric maneuver. The phase coordinates are related at the time instants of the change of the phase spaces due to the relations between the space vehicle masses. The optimal control analysis is performed using Pontryagin's maximum principle. The numerical results are analyzed for Earth-Mars "sprint" transfer. The optimal values of the parameters that define the masses of NTR and NEP subsystems have been evaluated. It is shown that the low-thrust

  15. Control techniques of thrust vector for magnetic nozzle in laser fusion rocket

    Energy Technology Data Exchange (ETDEWEB)

    Kajimura, Yoshihiro [Department of Advanced Energy Engineering Science, Interdisciplinary Graduate School of Engineering Sciences, Kyushu University (Japan)]. E-mail: kajimura@aees.kyushu-u.ac.jp; Kawabuchi, Ryo [Department of Advanced Energy Engineering Science, Interdisciplinary Graduate School of Engineering Sciences, Kyushu University (Japan); Nakashima, Hideki [Department of Advanced Energy Engineering Science, Interdisciplinary Graduate School of Engineering Sciences, Kyushu University (Japan)

    2006-11-15

    An analysis of plasma behavior in a magnetic nozzle would be very useful for designing plasma propulsion systems using a laser fusion. We examine by using a three-dimensional (3D) hybrid code how a thrust vector varies with changing positions of the fusion explosion (off-axis explosion) for the one-coil system of a laser fusion rocket. Furthermore, we investigate plasma behaviors and the thrust efficiency, and optimize the thrust efficiency by changing the current and the position of a rear coil for two-coil system. We also discuss the possibility of control techniques of the thrust vector for a two-coil system.

  16. Pelvic belt effects on sacroiliac joint ligaments: a computational approach to understand therapeutic effects of pelvic belts.

    Science.gov (United States)

    Sichting, Freddy; Rossol, Jerome; Soisson, Odette; Klima, Stefan; Milani, Thomas; Hammer, Niels

    2014-01-01

    The sacroiliac joint is a widely described source of low back pain. Therapeutic approaches to relieve pain include the application of pelvic belts. However, the effects of pelvic belts on sacroiliac joint ligaments as potential pain generators are mostly unknown. The aim of our study was to analyze the influence of pelvic belts on ligament load by means of a computer model. Experimental computer study using a finite element method. A computer model of the human pelvis was created, comprising bones, ligaments, and cartilage. Detailed geometries, material properties of ligaments, and in-vivo pressure distribution patterns of a pelvic belt were implemented. The effects of pelvic belts on ligament strain were computed in the double-leg stance. Pelvic belts increase sacroiliac joint motion around the sagittal axis but decrease motion around the transverse axis. With pelvic belt application, most of the strained sacroiliac joint ligaments were relieved, especially the sacrospinous, sacrotuberous, and the interosseous sacroiliac ligaments. Sacroiliac joint motion and ligament strains were minute. These results agree with validation data from other studies. Assigning homogenous and linear material properties and excluding muscle forces are clear simplifications of the complex reality. Pelvic belts alter sacroiliac joint motion and provide partial relief of ligament strain that is subjectively marked, although minimal in absolute terms. These findings confirm theories that besides being mechanical stabilizers, the sacroiliac joint ligaments are likely involved in neuromuscular feedback mechanisms. The results from our computer model help with unraveling the therapeutic mechanisms of pelvic belts.

  17. Cenozoic deformation and exhumation of the Kampot Fold Belt and implications for south Indochina tectonics

    Science.gov (United States)

    Fyhn, Michael B. W.; Green, Paul F.; Bergman, Steven C.; Van Itterbeeck, Jimmy; Tri, Tran V.; Dien, Phan T.; Abatzis, Ioannis; Thomsen, Tonny B.; Chea, Socheat; Pedersen, Stig A. S.; Mai, Le C.; Tuan, Hoang A.; Nielsen, Lars H.

    2016-07-01

    Latest Mesozoic to earliest Cenozoic deformation affected SE Asia's Sundaland core. The deformation event bridges the Mesozoic SE Asian fusion with the Cenozoic era of rifting, translation, basin formation, and the creation of modern SE Asian oceans. Southern Cambodia and Vietnam are central to this shift, but geological investigations of the region are in their infancy. Based on apatite and zircon fission track analyses (AFTA and ZFTA), stratigraphic and structural observations, seismic data, thermal maturity, and igneous rock dating, the geological evolution of southern Cambodia and Vietnam is investigated. Diverse depositional styles, igneous activity, structural deformation and subsurface unconformities testify to a highly variable Phanerozoic tectonic setting. Major latest Cretaceous to Paleocene thrusting and uplift affected the Kampot Fold Belt and surrounding regions and the associated up to 11 km exhumation probably exceeds earlier denudation events since at least Permian time. The present relief of the Bokor Mountains rising high above the Kampot Fold Belt represents an artifact after differential erosion and only 2.5-4.5 km of erosion affected this area. The latest Cretaceous to Paleocene orogenesis affected much of greater Indochina probably owing to plate collision along eastern Sundaland or a combination of collisions along both east and west Sundaland. AFTA and ZFTA data document protracted cooling of Cretaceous granites and locally elevated thermal gradients persisting a few tens of million years after their emplacement. The thermal gradient had stabilized by early Miocene time, and Miocene cooling probably reflects a renewed denudation pulse driven by either regional tectonism or climate-enhanced erosion.

  18. Post-orogenic subsidence and uplift of the Carpathian belt: An integrated approach

    Science.gov (United States)

    Bertotti, G.; Matenco, L.; Drijkonigen, G.; Krijgsman, W.; Tarapoanca, M.; Panea, I.; Vasiliev, I.; Milea, M.; Cloetingh, S.

    2003-04-01

    Several hundred metres thick Pliocene to Quaternary sequences outcropping along the Carpathian front steeply dip away from the mountain belt towards the Carpathian foredeep. They overly the Carpathian fold-and-thrust belt and document that, following the main contractional stages, the orogenic wedge first subsided and was then uplifted. Uplift occurred coeval with substantial subsidence in the basin adjacent to the E, the Focsani Depression. To define the precise kinematics of such movements and thereby constrain these vertical movements taking place in the "wrong" place and in the "wrong" time, the Netherlands Research Center for Integrated Solid Earth Science has launched a large campaign of geological and geophysical investigation. The main components of the project are as follows: 1) acquisition of nearly 100km of seismic data designed to image the uppermost hundred metres of the Earth's crust and thereby making a precise connection between features visible in Industry lines and at the surface 2) paleomagnetic investigations in order to constrain the age of the poorly dated continental to lacustrine sediments 3) A seismic experiment designed to detect 3-D effects on 2-D acquisition 4) Structural work to determine the stress/strain conditions during subsidence and subsequent uplift At a larger scale, these activities are embedded in the effort made by ISES and connected groups to precisely constrain the kinematics of the Pannonian-Carpathian system. Seismic acquisition has been performed during the summer 2002 and has been technically very successful thanks also to the effort of the prospecting company Prospectiunii SA. Lines have been processed and are currently being interpreted. The most apparent feature is the lack of localized deformation demonstrating that subsidence and tilting affected areas of several tens of kilometers and are not related to single faults. Sampling for paleomagnetic studies has been carried out in 2002 along the same section where

  19. Fading of Jupiter's South Equatorial Belt

    Science.gov (United States)

    Sola, Michael A.; Orton, Glenn; Baines, Kevin; Yanamandra-Fisher, Padma

    2011-01-01

    One of Jupiter's most dominant features, the South Equatorial Belt, has historically gone through a "fading" cycle. The usual dark, brownish clouds turn white, and after a period of time, the region returns to its normal color. Understanding this phenomenon, the latest occurring in 2010, will increase our knowledge of planetary atmospheres. Using the near infrared camera, NSFCAM2, at NASA's Infrared Telescope Facility in Hawaii, images were taken of Jupiter accompanied by data describing the circumstances of each observation. These images are then processed and reduced through an IDL program. By scanning the central meridian of the planet, graphs were produced plotting the average values across the central meridian, which are used to find variations in the region of interest. Calculations using Albert4, a FORTRAN program that calculates the upwelling reflected sunlight from a designated cloud model, can be used to determine the effects of a model atmosphere due to various absorption, scattering, and emission processes. Spectra that were produced show ammonia bands in the South Equatorial Belt. So far, we can deduce from this information that an upwelling of ammonia particles caused a cloud layer to cover up the region. Further investigations using Albert4 and other models will help us to constrain better the chemical make up of the cloud and its location in the atmosphere.

  20. Seat belt utilisation and awareness in UAE.

    Science.gov (United States)

    Bendak, S; Al-Saleh, K

    2013-01-01

    Seat belts (SBs) are effective devices for reducing injury risk due to traffic accidents. Seat belt wearing was made compulsory in the United Arab Emirates (UAE) in January 1999 for drivers and front seat passengers (FSPs). No comprehensive study has ever assessed SB wearing rates across the country. Also, little is known on drivers' awareness of the importance of wearing seatbelts and how human factors affect wearing habits. This study aims to determine SB wearing rates for drivers and FSPs in UAE through an observational field study. It also aims to investigate perceptions and behaviour of drivers on this issue as well as human factors that affect wearing rate through a randomly distributed questionnaire. The results of the field study show that the overall SB wearing rate across the country was 61% for drivers and 43.4% for FSPs and that there were significant differences between the seven emirates that constitute the country. The questionnaire results show that age, education level, gender, marital status and nationality of drivers affect wearing habits and perceptions. Future implications in terms of improving traffic safety awareness are discussed.

  1. Geodynamics of the western part of the Mongolia Okhotsk collisional belt, Trans-Baikal region (Russia) and Mongolia

    Science.gov (United States)

    Zorin, Yu. A.

    1999-05-01

    After the western edge of the Mongolian microcontinent joined the Siberian continent in the region of Central Mongolia in the earliest Permian, these two continental blocks remained turned at an angle of about 120° with respect to each other and separated (on greater extent of their present-day boundary) by an enormous gulf of the Paleopacific called the Mongolia-Okhotsk ocean. Closure of this ocean at the Early/Middle Jurassic boundary led to the complete collision of Siberia and Mongolia, which by then had already become part of the Mongolia-North China continent. This main collisional episode, which lasted through the Middle and Late Jurassic, involved thrusting, folding and magmatism and produced the Mongolia-Okhotsk belt. The Onon island-arc, which was located in the Mongolia-Okhotsk ocean, was squeezed between the two major continents. Inasmuch as the third element (the island arc) was involved in the collision it is reasonable to distinguish two branches of the Mongolia-Okhotsk suture. These branches control the spatial distribution of gold mineralization in the Trans-Baikal region. On the southeastern periphery of Siberia the crust thickened considerably after the collision and a plateau-like uplift formed. In the Early Cretaceous, when compression ceased, the collisional uplift collapsed and the thrusts were transformed into low-angle normal faults, the motions on which were responsible for the formation of rift basins and exhumation of metamorphic core complexes.

  2. Miocene crustal extension following thrust tectonic in the Lower Sebtides units (internal Rif, Ceuta Peninsula, Spain): Implication for the geodynamic evolution of the Alboran domain

    Science.gov (United States)

    Homonnay, Emmanuelle; Corsini, Michel; Lardeaux, Jean-Marc; Romagny, Adrien; Münch, Philippe; Bosch, Delphine; Cenki-Tok, Bénédicte; Ouazzani-Touhami, Mohamed

    2018-01-01

    In Western Mediterranean, the Rif belt in Morocco is part of the Gibraltar Arc built during the Tertiary in the framework of Eurasia-Africa convergence. The structural and metamorphic evolution of the internal units of this belt as well as their timing, crucial to constrain the geodynamic evolution of the Alboran Sea, is still largely debated. Our study on the Ceuta Peninsula (Northern Rif) provides new structural, petrological and geochronological data (U-Th-Pb, Ar-Ar), which allow to precise the tectono-metamorphic evolution of the Lower Sebtides metamorphic units with: (1) a syn-metamorphic thrusting event developed under granulite facies conditions (7-10 kbar and 780-820 °C). A major thrust zone, the Ceuta Shear Zone, drove the emplacement of metapelites and peridotitic lenses from the Ceuta Upper Unit over the orthogneisses of the Monte Hacho Lower Unit. This compressional event ended during the Upper Oligocene. (2) an extensional event developed at the boundary between amphibolite and greenschist facies conditions (400-550 °C and 1-3 kbar). During this event, the Ceuta Shear Zone has been reactivated as a normal fault. Normal ductile shear zones contributed to the final exhumation of the metamorphic units during the Early Miocene. We propose that the compressional event is related to the formation of an orogenic wedge located in the upper plate, in a backward position, of the subduction zone driving the geodynamic evolution of the Alboran domain. In this context, the episode of lithospheric thinning could be related to the opening of the Alboran basin in a back-arc position. Furthermore, unlike the previous models proposed for the Rif belt, the tectonic coupling between mantle peridotites and crustal metamorphic rocks occurred in Ceuta Peninsula at a depth of 20-30 km under high temperature conditions, before the extensional event, and thus cannot be related to the back-arc extension. 1, BSE image of monazite. 2, CL image of monazite showing a thin rim

  3. The Social Construction of the Great Belt Fixed Link

    DEFF Research Database (Denmark)

    Munch, Birgitte

    1994-01-01

    Working paper in Technology Management. Actor Network theory (ANT) used upon the process of negotiating legislation and constructing the Great Belt fixed link.......Working paper in Technology Management. Actor Network theory (ANT) used upon the process of negotiating legislation and constructing the Great Belt fixed link....

  4. Respiratory Belt Transducer Constructed Using a Singing Greeting Card Beeper

    Science.gov (United States)

    Bhaskar, Anand; Subramani, Selvam; Ojha, Rajdeep

    2013-01-01

    An article by Belusic and Zupancic described the construction of a finger pulse sensor using a singing greeting card beeper. These authors felt that this beeper made of piezoelectric material could be easily modified to function as a respiratory belt transducer to monitor respiratory movements. Commercially available respiratory belt transducers,…

  5. Energy Saving for Belt Conveyors by Speed Control

    NARCIS (Netherlands)

    He, D.

    2017-01-01

    Belt conveyors are widely used in bulk solids handling and conveying systems. Considering the extensive use of belt conveyors, their operations involve a large amount of energy. Taking the relevant economic and social challenges into account, there is a strong demand for lowering the energy

  6. Estimates of effectiveness of safety belts under discussion.

    NARCIS (Netherlands)

    Wegman, F.C.M.

    1988-01-01

    The use of safety belts reduces the change to be injured or killed in an accident. It has been proven in laboratories by impact tests. To determine the effectivety of safety belts in real terms before- and- after comparisons are made with adjustments for other influences. It seems probable that

  7. Seat Belt Use During Pregnancy in a Nigerian Community ...

    African Journals Online (AJOL)

    This study was designed to determine compliance with car seat belt amongst antenatal patients and also identify the reasons for poor compliance with seat belt use. Ethical clearance was obtained from the Ethical Committee of the hospital prior to carrying out this study. This study was conducted between October and ...

  8. 46 CFR 169.825 - Wearing of safety belts.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Wearing of safety belts. 169.825 Section 169.825 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) NAUTICAL SCHOOLS SAILING SCHOOL VESSELS Operations § 169.825 Wearing of safety belts. The master of each vessel shall ensure that each person wears...

  9. Ambient Response Analysis of the Great Belt Bridge

    DEFF Research Database (Denmark)

    Brincker, Rune; Frandsen, J. B.; Andersen, P.

    2000-01-01

    In this paper an ambient response analysis of the Great Belt Bridge is presented. The Great Belt Bridge is one of the largest suspension bridges in the world, and the analysis was carried out in order to investigate the possibilities of estimating reliable damping values from the ambient response...

  10. Increasing of horizontal velocity of particles leaving a belt conveyor

    Science.gov (United States)

    Tavares, Abraão; Faria, Allbens

    2017-06-01

    We investigate the transport of granular materials by a conveyor belt via numerical simulations. We report an unusual increasing of particles horizontal velocity when they leave the belt and initiate free-fall. Using Discrete Elements Method, the mechanism underlying this phenomenon were investigated, and a study on how particle and system properties influences this effect were conducted.

  11. Design and Selection of a Belt Conveyor System for Increased ...

    African Journals Online (AJOL)

    The main aim of the modifications could not be realised as any increase in plant capacity beyond 850 t/h resulted in increased spillage on belt conveyor CB among a series of conveyors in the plant flow sheet. In this paper, the causes of the spillage on conveyor CB were investigated and a belt conveyor system capable of

  12. Increasing of horizontal velocity of particles leaving a belt conveyor

    Directory of Open Access Journals (Sweden)

    Tavares Abraão

    2017-01-01

    Full Text Available We investigate the transport of granular materials by a conveyor belt via numerical simulations. We report an unusual increasing of particles horizontal velocity when they leave the belt and initiate free-fall. Using Discrete Elements Method, the mechanism underlying this phenomenon were investigated, and a study on how particle and system properties influences this effect were conducted.

  13. Belt conveyor dynamics in transient operation for speed control

    NARCIS (Netherlands)

    He, D.; Pang, Y.; Lodewijks, G.

    2016-01-01

    Belt conveyors play an important role in continuous dry bulk material transport, especially at the mining industry. Speed control is expected to reduce the energy consumption of belt conveyors. Transient operation is the operation of increasing or decreasing conveyor speed for speed control.

  14. Performance approximation of pick-to-belt orderpicking systems

    NARCIS (Netherlands)

    M.B.M. de Koster (René)

    1994-01-01

    textabstractIn this paper, an approximation method is discussed for the analysis of pick-to-belt orderpicking systems. The aim of the approximation method is to provide an instrument for obtaining rapid insight in the performance of designs of pick-to-belt orderpicking systems. It can be used to

  15. Holocene slip rate and evidences of surface ruptures along the Main Frontal Thrust in Bhutan

    Science.gov (United States)

    Ritz, Jean-François; Berthet, Théo; Pelgay, Phuntsho; Ferry, Mathieu; Drukpa, Dowchu; Cattin, Rodolphe; Chophel, Jamyang; Thinley, Kinzang

    2013-04-01

    On the long term, the Himalayas absorb about 20 mm/yr of the convergence between the India and Eurasia plates. Morphotectonics studies East of Bhutan yielded an Holocene slip rate of 23 ± 6.2 mm/yr consistent with the 21 ± 1.5 mm/yr estimated in Nepal. In the past 1000 years, most of this crustal shortening is accommodated along the Main Frontal Thrust (MFT) by major M≥8 earthquakes. Recent paleoseismic investigations between the meizoseismal areas of the 1934 Bihar-Nepal and 1950 Assam earthquakes west and east of the Bhutan suggest that a great earthquake may have ruptured a 700 to 800 km long section of the MFT during a single event around AD 1100. However, between 89°E and 92°E where the MFT runs along the southern border of the Kingdom of Bhutan, no major earthquakes has been recorded so far. In December 2012, we carried out a morphotectonic and paleosismologic study within two sites along the MFT in central Bhutan. We identified several sequences of abandoned fluvial terraces that have been uplifted along the fault. From a kinematic GPS survey, we estimated that the oldest terrace sequence (T2) displays a cumulative offset of ~60 m. A younger sequence (T1) showed an offset of ~4 m on the lower terrace (T1a) and ~9 m on the upper one (T1b). We interpret this 4 m uplift as the vertical component of the last seismic event while the 9 m may be the cumulative offset of the two last earthquakes. These preliminary observations may suggest that the latest seismic event as well as the penultimate event correspond to two major M>8 events. Samples for 14C, OSL and 10Be dating (charcoals, fine sands and quartz rich cobbles, respectively) have been collected in excavations within the different uplifted alluvial surfaces in order to determine the ages of these two last seismic events as well as the Holocene uplift and shortening rates. Compiled with the morphotectonic and paleoseismological data published in the literature, these new results will allow discussing the

  16. Mesozoic Crustal Thickening of the Longmenshan Belt (NE Tibet, China) by Imbrication of Basement Slices: Insights From Structural Analysis, Petrofabric and Magnetic Fabric Studies, and Gravity Modeling

    Science.gov (United States)

    Xue, Zhenhua; Martelet, Guillaume; Lin, Wei; Faure, Michel; Chen, Yan; Wei, Wei; Li, Shuangjian; Wang, Qingchen

    2017-12-01

    This work first presents field structural analysis, anisotropy of magnetic susceptibility (AMS) measurements, and kinematic and microstructural studies on the Neoproterozoic Pengguan complex located in the middle segment of the Longmenshan thrust belt (LMTB), NE Tibet. These investigations indicate that the Pengguan complex is a heterogeneous unit with a ductilely deformed NW domain and an undeformed SE domain, rather than a single homogeneous body as previously thought. The NW part of the Pengguan complex is constrained by top-to-the-NW shearing along its NW boundary and top-to-the-SE shearing along its SE boundary, where it imbricates and overrides the SE domain. Two orogen-perpendicular gravity models not only support the imbricated shape of the Pengguan complex but also reveal an imbrication of high-density material hidden below the Paleozoic rocks on the west of the LMTB. Regionally, this suggests a basement-slice-imbricated structure that developed along the margin of the Yangtze Block, as shown by the regional gravity anomaly map, together with the published nearby seismic profile and the distribution of orogen-parallel Neoproterozoic complexes. Integrating the previously published ages of the NW normal faulting and of the SE directed thrusting, the locally fast exhumation rate, and the lithological characteristics of the sediments in the LMTB front, we interpret the basement-slice-imbricated structure as the result of southeastward thrusting of the basement slices during the Late Jurassic-Early Cretaceous. This architecture makes a significant contribution to the crustal thickening of the LMTB during the Mesozoic, and therefore, the Cenozoic thickening of the Longmenshan belt might be less important than often suggested.

  17. On the Design of Tilting-Pad Thrust Bearings

    DEFF Research Database (Denmark)

    Heinrichson, Niels

    2007-01-01

    Pockets are often machined in the surfaces of tilting-pad thrust bearings to allow for hydrostatic jacking in the start-up phase. Pockets and other recesses in the surfaces of bearing pads influence the pressure distribution and thereby the position of the pivot resulting in the most advantageous...... pad convergence ratio. In this thesis, a theoretical approach is applied in the attempt to quantify the influence of recesses in the pad surfaces. The recesses may be relatively deep and enclosed as is the case with pockets designed for hydrostatic jacking. Such recesses are characterized by low...... based on the Reynolds equation are used. They include the effects of variations of viscosity with temperature and the deformation of the bearing pads due to pressure and thermal gradients. The models are validated using measurements. Tilting-pad bearings of standard design are studied and the influences...

  18. Electric sail elliptic displaced orbits with advanced thrust model

    Science.gov (United States)

    Niccolai, Lorenzo; Quarta, Alessandro A.; Mengali, Giovanni

    2017-09-01

    This paper analyzes the performance of an Electric Solar Wind Sail for generating and maintaining an elliptic, heliocentric, displaced non-Keplerian orbit. In this sense, this paper extends and completes recent studies regarding the performances of an Electric Solar Wind Sail that covers a circular, heliocentric, displaced orbit of given characteristics. The paper presents the general equations that describe the elliptic orbit maintenance in terms of both spacecraft attitude and performance requirements, when a refined thrust model (recently proposed for the preliminary mission design) is taken into account. In particular, the paper also discusses some practical applications on particular mission scenarios in which an analytic solution of the governing equations has been found.

  19. Procedure for utilizing the lift and thrust forces of ornithopters

    Science.gov (United States)

    Bezard, C.

    1985-01-01

    This procedure is distinguished by two beating wings which together describe, in space, a succession of interlaced triangles. On these wings, whose incidence varies automatically, identical forces are exerted: simultaneous lift and thrust when they make their descent, which is inclined toward the front of the craft, and lift alone when they make their ascent, which is inclined toward the rear of the craft and follows a slide horizontal movement. A mechanical device makes these movements possible. It includes: two wings with hollow profiles, connected by a framework located above a rigid frame and attached to it by bars with joints. These bars are moved with control rods which gear down the drive force. A mechanism with elastic bands or springs automatically varies the incidence of the wings.

  20. Gravity as Archimedes? Thrust and a Bifurcation in that Theory

    Science.gov (United States)

    Arminjon, Mayeul

    2004-11-01

    Euler's interpretation of Newton's gravity (NG) as Archimedes' thrust in a fluid ether is presented in some detail. Then a semi-heuristic mechanism for gravity, close to Euler's, is recalled and compared with the latter. None of these two "gravitational ethers" can obey classical mechanics. This is logical since the ether defines the very reference frame, in which mechanics is defined. This concept is used to build a scalar theory of gravity: NG corresponds to an incompressible ether, a compressible ether leads to gravitational waves. In the Lorentz-Poincar\\'e version, special relativity is compatible with the ether, but, with the heterogeneous ether of gravity, it applies only locally. A correspondence between metrical effects of uniform motion and gravitation is assumed, yet in two possible versions (one is new). Dynamics is based on a (non-trivial) extension of Newton's second law. The observational status for the theory with the older version of the correspondence is summarized.

  1. Analysis of Tank PMD Rewetting Following Thrust Resettling

    Science.gov (United States)

    Weislogel, M. M.; Sala, M. A.; Collicott, S. H.; Rame, Enrique (Technical Monitor)

    2002-01-01

    Recent investigations have successfully demonstrated closed-form analytical solutions of spontaneous capillary flows in idealized cylindrical containers with interior corners. In this report, the theory is extended and applied to complex containers modeling spacecraft fuel tanks employing propellant management devices (PMDs). The specific problem investigated is one of spontaneous rewetting of a typical partially filled liquid fuel/cryogen tank with PMD after thrust resettling. The transients of this flow impact the logistics of orbital maneuvers and potentially tank thermal control. The general procedure to compute the initial condition (mean radius of curvature for the interface) for the closed-form transient flows is first outlined then solved for several 'complex' cylindrical tanks exhibiting symmetry. The utility and limitations of the technique as a design tool are discussed in a summary, which also highlights comparisons with NASA flight data of a model propellant tank with PMD.

  2. Data Archive and Portal Thrust Area Strategy Report

    Energy Technology Data Exchange (ETDEWEB)

    Sivaraman, Chitra [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Stephan, Eric G. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Macduff, Matt C. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Hagler, Clay D. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2014-09-01

    This report describes the Data Archive and Portal (DAP), a key capability of the U.S. Department of Energy's Atmosphere to Electron (A2e) initiative. The DAP Thrust Area Planning Group was organized to develop a plan for deploying this capability. Primarily, the report focuses on a distributed system--a DOE Wind Cloud--that functions as a repository for all A2e data. The Wind Cloud will be accessible via an open, easy-to-navigate user interface that facilitates community data access, interaction, and collaboration. DAP management will work with the community, industry, and international standards bodies to develop standards for wind data and to capture important characteristics of all data in the Wind Cloud.

  3. Vertical displacement during late-collisional escape tectonics (Brasiliano Orogeny) in the Ribeira Belt, São Paulo State, Brazil

    Science.gov (United States)

    Hackspacher, P. C.; Godoy, A. M.

    1999-07-01

    During the Brasiliano-Pan-African Orogeny, West Gondwana formed by collisional processes around the São Francisco-Congo Craton. The Ribeira belt, in southeastern Brazil, resulted from northwestward collision (650-600 Ma), followed by large-scale northeast-southwest dextral strike-slip shear movements related to late-collisional escape tectonics ( ca 600 Ma). In São Paulo State, three groups, also interpreted as terranes, are recognised in the Ribeira Belt, the Embu, Itapira and São Roque Groups. The Embu and Itapira Groups are formed of sillimanite-gneisses, schists and migmatites intruded by Neoproterozoic calc-alkaline granitoids, all thrusted northwestward. The São Roque Group is composed of metasediments and metavolcanics in greenschist-facies. Its deformation indicates a transpressional regime associated with tectonic escape. Sub-alkaline granites were emplaced in shallow levels during this regime. Microstructural studies along the Itu, Moreiras and Taxaquara Shear Zones demonstrate the coexistence of horizontal and vertical displacement components during the transpressional regime. The vertical component is regarded as responsible for the lateral juxtaposition of different crustal levels.

  4. Neptune's Eccentricity and the Nature of the Kuiper Belt

    Science.gov (United States)

    Ward, William R.; Hahn, Joseph M.

    1998-01-01

    The small eccentricity of Neptune may be a direct consequence of apsidal wave interaction with the trans-Neptune population of debris called the Kuiper belt. The Kuiper belt is subject to resonant perturbations from Neptune, so that the transport of angular momentum by density waves can result in orbital evolution of Neptune as well as changes in the structure of the Kuiper belt. In particular, for a belt eroded out to the vicinity of Neptune's 2:1 resonance at about 48 astronomical units, Neptune's eccentricity can damp to its current value over the age of the solar system if the belt contains slightly more than an earth mass of material out to about 75 astronomical units.

  5. Survey of current situation in radiation belt modeling

    Science.gov (United States)

    Fung, Shing F.

    2004-01-01

    The study of Earth's radiation belts is one of the oldest subjects in space physics. Despite the tremendous progress made in the last four decades, we still lack a complete understanding of the radiation belts in terms of their configurations, dynamics, and detailed physical accounts of their sources and sinks. The static nature of early empirical trapped radiation models, for examples, the NASA AP-8 and AE-8 models, renders those models inappropriate for predicting short-term radiation belt behaviors associated with geomagnetic storms and substorms. Due to incomplete data coverage, these models are also inaccurate at low altitudes (e.g., radiation data from modern space missions and advancement in physical modeling and data management techniques have now allowed the development of new empirical and physical radiation belt models. In this paper, we will review the status of modern radiation belt modeling. Published by Elsevier Ltd on behalf of COSPAR.

  6. Crustal structure and geodynamics of the Middle and Lower reaches of Yangtze metallogenic belt and neighboring areas: Insights from deep seismic reflection profiling

    Science.gov (United States)

    Lü, Qingtian; Shi, Danian; Liu, Zhendong; Zhang, Yongqian; Dong, Shuwen; Zhao, Jinhua

    2015-12-01

    A 300 km long seismic reflection profile was acquired across the Middle and Lower Reaches of the Yangtze River (MLY) metallogenic belt and its adjacent areas. The objective of the survey was to establish the deep architecture and geodynamic framework of the region. Results based on the interpretation of the deep seismic data include (1) Tan-Lu fault appears as a subvertical thrust fault or transpression fault with its deep portion dipping toward the southeast; (2) the Zhangbaling uplift is squeezed out along this fault; (3) complex upper crustal deformation structures beneath the Chuquan depression include both kink bands, thrusts, imbrication and fold structures reflecting contraction deformation, and detachment fault and normal-fault structures reflecting extensional deformation; (4) the "crocodile" reflection structure emerging beneath the Tan-Lu fault and Ningwu-Lishui volcanic basin, which represents the decoupled deformation process of the upper and lower crust associated with intra-continental subduction; (5) further to the southeast, the upper crust deformation shows a large-scale "wave-form" pattern, making crustal scale syncline and anticline; (6) the entire section of the reflection Moho is clearly discernible at depth of 30.0-34.5 km, and the Moho beneath the Middle and Lower Reaches of Yangtze River metallogenic belt is shallowest, while the Moho beneath the North China block is deeper than that beneath the Yangtze block. The Moho offsets could be seen beneath the Ningwu volcanic basin. The seismic reflection data suggest that lithosphere delamination and asthenosphere upwelling that may result from the Mesozoic intra-continental orogenesis is responsible for the formation of large scale magmatism and mineralization in the MLY metallogenic belt.

  7. Deep crustal structure of the UAE-Oman mountain belt from seismic and gravity data

    Science.gov (United States)

    Pilia, S.; Tanveer, M.; Ali, M.; Watts, A. B.; Searle, M. P.; Keats, B. S.

    2016-12-01

    The UAE-Oman mountains constitute a 700 km long, 50 km wide compressional orogenic belt that developed during the Cenozoic on an underlying extensional Tethyan rifted margin. It contains the world's largest and best-exposed thrust sheet of oceanic crust and upper mantle (Semail Ophiolite), which was obducted onto the Arabian rifted continental margin during the Late Cretaceous. Although the shallow structure of the UAE-Oman mountain belt is reasonably well known through the exploitation of a diverse range of techniques, information on deeper structure remains little. Moreover, the mechanisms by which dense oceanic crustal and mantle rocks are emplaced onto less dense and more buoyant continental crust are still controversial and remain poorly understood. The focus here is on an active-source seismic and gravity E-W transect extending from the UAE-mountain belt to the offshore. Seismic refraction data were acquired using the survey ship M/V Hawk Explorer, which was equipped with a large-volume airgun array (116 liters). About 400 air gun shots at 50-second time interval were recorded on land by eight broadband seismometers. In addition, reflection data were acquired at 20 seconds interval and recorded by a 5-km-long multichannel streamer. Results presented here include an approximately 85 km long (stretching about 35 km onshore and 50 km offshore) P-wave velocity crustal profile derived by a combination of forward modelling and inversion of both diving and reflected wave traveltimes using RAYINVR software. We employ a new robust algorithm based on a Monte Carlo approach (VMONTECARLO) to address the velocity model uncertainties. We find ophiolite seismic velocities of about 5.5 km/s, underlain by a thin layer of slower material (about 4.5 km/s). Furthermore, the velocity model reveals a Moho depth that rises from ca 30 km in the west to ca 20 km in the east. A poststack depth-migrated profile (about 50 km long) coincident with the offshore part of the refraction

  8. Pilot tests of a seat belt gearshift delay on the belt use of commercial fleet drivers : traffic tech.

    Science.gov (United States)

    2010-04-01

    Wearing a seat belt has been shown effective in avoiding : or reducing serious injury due to traffic crashes. While : belt use rates in the United States increased from under : 60% in 1994 to 83% in 2008, a substantial number of drivers : still drive...

  9. Wampum Belts with Initials and/or Dates as Design Elements: A Preliminary Review of One Subcategory of Political Belts

    Science.gov (United States)

    Becker, Marshall Joseph; Lainey, Jonathan

    2004-01-01

    Data on seventeen relatively well-documented examples as a preliminary review to an ongoing study of all that is known about belts that are a subcategory of the secular-political category is discussed. Evidence indicates that Wampum belts with initials and/or dates as design elements can clearly be demonstrated as but one subcategory of…

  10. Equilibria and Free Vibration of a Two-Pulley Belt-Driven System with Belt Bending Stiffness

    Directory of Open Access Journals (Sweden)

    Jieyu Ding

    2014-01-01

    Full Text Available Nonlinear equilibrium curvatures and free vibration characteristics of a two-pulley belt-driven system with belt bending stiffness and a one-way clutch are investigated. With nonlinear dynamical tension, the transverse vibrations of the translating belt spans and the rotation motions of the pulleys and the accessory shaft are coupled. Therefore, nonlinear piecewise discrete-continuous governing equations are established. Considering the bending stiffness of the translating belt spans, the belt spans are modeled as axially moving beams. The pattern of equilibria is a nontrivial solution. Furthermore, the nontrivial equilibriums of the dynamical system are numerically determined by using two different approaches. The governing equations of the vibration near the equilibrium solutions are derived by introducing a coordinate transform. The natural frequencies of the dynamical systems are studied by using the Galerkin method with various truncations and the differential and integral quadrature methods. Moreover, the convergence of the Galerkin truncation is investigated. Numerical results reveal that the study needs 16 terms after truncation in order to determine the free vibration characteristics of the pulley-belt system with the belt bending stiffness. Furthermore, the first five natural frequencies are very sensitive to the bending stiffness of the translating belt.

  11. Thermal ground water flow systems in the thrust zone in southeastern Idaho

    Energy Technology Data Exchange (ETDEWEB)

    Ralston, D.R.

    1983-05-01

    The results of a regional study of thermal and non-thermal ground water flow systems in the thrust zone of southern Idaho and western Wyoming are presented. The study involved hydrogeologic and hydrochemical data collection and interpretation. Particular emphasis was placed on analyzing the role that thrust zones play in controlling the movement of thermal and non-thermal fluids.

  12. Structural evidence for northeastward movement on the Chocolate Mountains Thrust, southeasternmost California

    Science.gov (United States)

    Dillon, J.T.; Haxel, G.B.; Tosdal, R.M.

    1990-01-01

    The Late Cretaceous Chocolate Mountains Thrust of southeastern California and southwestern Arizona places a block of Proterozoic and Mesozoic continental crust over the late Mesozoic continental margin oceanic sedimentary and volcanic rocks of the Orocopia Schist. The Chocolate Mountains Thrust is interpreted as a thrust (burial, subduction) fault rather than a low-angle normal fault. An important parameter required to understand the tectonic significance of the Chocolate Mountains and related thrusts is their sense of movement. The only sense of movement consistent with collective asymmetry of the thrust zone folds is top to the northeast. Asymmetric microstructures studied at several localities also indicate top to the northeast movement. Paleomagnetic data suggest that the original sense of thrusting, prior to Neogene vertical axis tectonic rotation related to the San Andreas fault system, was northward. Movement of the upper plate of the chocolate Mountains thrust evidently was continentward. Continentward thrusting suggests a tectonic scenario in which an insular or peninsular microcontinental fragment collided with mainland southern California. -from Authors

  13. Analogue modelling of different angle thrust-wrench fault interference in a brittle medium

    NARCIS (Netherlands)

    Rosas, F.M.; Duarte, João C.; Schellart, W. P.; Tomás, R.; Grigorova, V.; Terrinha, P.

    2015-01-01

    Analogue modelling experiments of thrust-wrench fault interference in a brittle medium are presented and discussed. Simultaneous reactivation of confining strike-slip and thrust faults bounding a (corner) zone of interference defined by the angle between the two fault systems is simulated, instead

  14. Experimental investigation of thrust augmentation by ejectors on a pulse detonation engine

    Directory of Open Access Journals (Sweden)

    Huang Xi-Qiao

    2015-01-01

    Full Text Available Utilizing gasoline as the fuel, air as oxidizer, a series of multi-cycle detonation experiments was conducted to study thrust augmentation by PDE-driven ejectors. The straight cylindrical ejectors with different inner diameter, length and inlet geometry were designed. The effects of the axial location of the ejectors relative to the end of the detonation tube, ejector length-to-diameter ratio on thrust augmentation were investigated, with the operating frequency of 25 Hz. A peak thrust augmentation level of 80.5% was achieved by adding an ejector to the exit of the detonation tube. Performance measurements of the PDE-ejector system showed that thrust augmentation is a strong function of the ejector axial position. The result indicated that there exists a maximum thrust augmentation with ejector upstream of the detonation tube exit at least. The exact location at which the maximum thrust augmentation was obtained varies with the ejector-to-PDE diameter ratio and the ejector inlet geometry. With the increase of the length-to-diameter ratio, thrust augmentation was noticeably enhanced and finally tended to a constant. There exists an optimum ejector length. In the present study, the optimum length-to-diameter ratio of ejector was 4.58. Furthermore, the effect of operating frequency on ejector thrust augmentation also investigated. The operating frequency was varied from 15 Hz to 35 Hz.

  15. A new method for optimization of low-thrust gravity-assist sequences

    Science.gov (United States)

    Maiwald, V.

    2017-09-01

    Recently missions like Hayabusa and Dawn have shown the relevance and benefits of low-thrust spacecraft concerning the exploration of our solar system. In general, the efficiency of low-thrust propulsion is one means of improving mission payload mass. At the same time, gravity-assist maneuvers can serve as mission enablers, as they have the capability to provide "free energy." A combination of both, gravity-assist and low-thrust propulsion, has the potential to generally improve mission performance, i.e. planning and optimization of gravity-assist sequences for low-thrust missions is a desirable asset. Currently no established methods exist to include the gravity-assist partners as optimization variable for low-thrust missions. The present paper explains how gravity-assists are planned and optimized, including the gravity-assist partners, for high-thrust missions and discusses the possibility to transfer the established method, based on the Tisserand Criterion, to low-thrust missions. It is shown how the Tisserand Criterion needs to be adapted using a correction term for the low-thrust situation. It is explained why this necessary correction term excludes an a priori evaluation of sequences and therefore their planning and an alternate approach is proposed. Preliminary results of this method, by application of a Differential Evolution optimization algorithm, are presented and discussed, showing that the method is valid but can be improved. Two constraints on the search space are briefly presented for that aim.

  16. Main-belt comets: sublimation-driven activity in the asteroid belt

    Science.gov (United States)

    Hsieh, Henry H.

    2016-01-01

    Our knowledge of main-belt comets (MBCs), which exhibit comet-like activity likely due to the sublimation of volatile ices, yet orbit in the main asteroid belt, has increased greatly since the discovery of the first known MBC, 133P/Elst-Pizarro, in 1996, and their recognition as a new class of solar system objects after the discovery of two more MBCs in 2005. I review work that has been done over the last 10 years to improve our understanding of these enigmatic objects, including the development of systematic discovery methods and diagnostics for distinguishing MBCs from disrupted asteroids (which exhibit comet-like activity due to physical disruptions such as impacts or rotational destabilization). I also discuss efforts to understand the dynamical and thermal properties of these objects.

  17. The JCMT Gould Belt Survey: Understanding the influence of outflows on Gould Belt clouds

    Science.gov (United States)

    Drabek-Maunder, E.; Hatchell, J.; Buckle, J. V.; Di Francesco, J.; Richer, J.

    2016-03-01

    Using James Clerk Maxwell Telescope (JCMT) Gould Belt Survey data from CO J = 3 → 2 isotopologues, we present a meta-analysis of the outflows and energetics of star-forming regions in several Gould Belt clouds. The majority of the regions are strongly gravitationally bound. There is evidence that molecular outflows transport large quantities of momentum and energy. Outflow energies are at least 20 per cent of the total turbulent kinetic energies in all of the regions studied and greater than the turbulent energy in half of the regions. However, we find no evidence that outflows increase levels of turbulence, and there is no correlation between the outflow and turbulent energies. Even though outflows in some regions contribute significantly to maintaining turbulence levels against dissipation, this relies on outflows efficiently coupling to bulk motions. Other mechanisms (e.g. supernovae) must be the main drivers of turbulence in most if not all of these regions.

  18. Design and Optimization of Low-thrust Orbit Transfers Using Q-law and Evolutionary Algorithms

    Science.gov (United States)

    Lee, Seungwon; vonAllmen, Paul; Fink, Wolfgang; Petropoulos, Anastassios; Terrile, Richard

    2005-01-01

    Future space missions will depend more on low-thrust propulsion (such as ion engines) thanks to its high specific impulse. Yet, the design of low-thrust trajectories is complex and challenging. Third-body perturbations often dominate the thrust, and a significant change to the orbit requires a long duration of thrust. In order to guide the early design phases, we have developed an efficient and efficacious method to obtain approximate propellant and flight-time requirements (i.e., the Pareto front) for orbit transfers. A search for the Pareto-optimal trajectories is done in two levels: optimal thrust angles and locations are determined by Q-law, while the Q-law is optimized with two evolutionary algorithms: a genetic algorithm and a simulated-annealing-related algorithm. The examples considered are several types of orbit transfers around the Earth and the asteroid Vesta.

  19. Very energetic protons in Saturn's radiation belt

    Science.gov (United States)

    Fillius, W.; Mcilwain, C.

    1980-01-01

    Very energetic protons are trapped in the inner Saturnian radiation belt. The University of California at San Diego instrument on Pioneer 11 has definitely identified protons of energy greater than 80 MeV on channel M3 and has tentatively detected protons of energy greater than 600 MeV on channel C3. The spatial distribution of the protons is distinct from that of the trapped electrons, the main difference being that the protons are strongly absorbed by the innermost moons and that the electrons are not. The source strength for injecting protons by the decay of cosmic ray albedo neutrons generated in the rings of Saturn has been estimated. The required proton lifetime is approximately 20 years.

  20. NASA's Radiation Belt Storm Probe Mission

    Science.gov (United States)

    Sibeck, David G.

    2011-01-01

    NASA's Radiation Belt Storm Probe (RBSP) mission, comprising two identically-instrumented spacecraft, is scheduled for launch in May 2012. In addition to identifying and quantifying the processes responsible for energizing, transporting, and removing energetic particles from the Earth's Van Allen radiation, the mission will determine the characteristics of the ring current and its effect upon the magnetosphere as a whole. The distances separating the two RBSP spacecraft will vary as they move along their 1000 km altitude x 5.8 RE geocentric orbits in order to enable the spacecraft to separate spatial from temporal effects, measure gradients that help identify particle sources, and determine the spatial extent of a wide array of phenomena. This talk explores the scientific objectives of the mission and the manner by which the mission has been tailored to achieve them.

  1. Measuring and modeling twilight's Belt of Venus.

    Science.gov (United States)

    Lee, Raymond L

    2015-02-01

    The Belt of Venus (or antitwilight arch) is a reddish band often seen above the antisolar horizon during clear civil twilights, and immediately beneath it is the bluish-gray earth's shadow (or dark segment) cast on the atmosphere. Although both skylight phenomena have prompted decades of scientific research, surprisingly few measurements exist of their spectral, colorimetric, and photometric structure. Hyperspectral imaging of several clear twilights supplies these missing radiometric details and reveals some common spectral features of the antisolar sky at twilight: (1) color differences between the dark segment and the sunlit sky above the antitwilight arch are small or nil; (2) antisolar color and luminance extremes usually occur at different elevation angles; and (3) the two twilight phenomena are most vivid for modest aerosol optical depths. A second-order scattering model that includes extinction by aerosols and ozone provides some preliminary radiative transfer explanations of these twilight features' color and brightness.

  2. Cretaceous to Eocene evolution of the southeastern Canadian Cordillera: Continuity of Rocky Mountain thrust systems with zones of "in-sequence" mid-crustal flow

    Science.gov (United States)

    Simony, Philip S.; Carr, Sharon D.

    2011-09-01

    culminations may have contributed to their doming. Crustal shortening ended at ca. 52 Ma due to a change in tectonic setting to that of a transtensional tectonic regime, coinciding with the end of thrusting in the External thrust belt and with crustal-scale extension in the Western Internal zone.

  3. Space Weather Effects in the Earth's Radiation Belts

    Science.gov (United States)

    Baker, D. N.; Erickson, P. J.; Fennell, J. F.; Foster, J. C.; Jaynes, A. N.; Verronen, P. T.

    2018-02-01

    The first major scientific discovery of the Space Age was that the Earth is enshrouded in toroids, or belts, of very high-energy magnetically trapped charged particles. Early observations of the radiation environment clearly indicated that the Van Allen belts could be delineated into an inner zone dominated by high-energy protons and an outer zone dominated by high-energy electrons. The energy distribution, spatial extent and particle species makeup of the Van Allen belts has been subsequently explored by several space missions. Recent observations by the NASA dual-spacecraft Van Allen Probes mission have revealed many novel properties of the radiation belts, especially for electrons at highly relativistic and ultra-relativistic kinetic energies. In this review we summarize the space weather impacts of the radiation belts. We demonstrate that many remarkable features of energetic particle changes are driven by strong solar and solar wind forcings. Recent comprehensive data show broadly and in many ways how high energy particles are accelerated, transported, and lost in the magnetosphere due to interplanetary shock wave interactions, coronal mass ejection impacts, and high-speed solar wind streams. We also discuss how radiation belt particles are intimately tied to other parts of the geospace system through atmosphere, ionosphere, and plasmasphere coupling. The new data have in many ways rewritten the textbooks about the radiation belts as a key space weather threat to human technological systems.

  4. Review of GEM Radiation Belt Dropout and Buildup Challenges

    Science.gov (United States)

    Tu, Weichao; Li, Wen; Morley, Steve; Albert, Jay

    2017-04-01

    In Summer 2015 the US NSF GEM (Geospace Environment Modeling) focus group named "Quantitative Assessment of Radiation Belt Modeling" started the "RB dropout" and "RB buildup" challenges, focused on quantitative modeling of the radiation belt buildups and dropouts. This is a community effort which includes selecting challenge events, gathering model inputs that are required to model the radiation belt dynamics during these events (e.g., various magnetospheric waves, plasmapause and density models, electron phase space density data), simulating the challenge events using different types of radiation belt models, and validating the model results by comparison to in situ observations of radiation belt electrons (from Van Allen Probes, THEMIS, GOES, LANL/GEO, etc). The goal is to quantitatively assess the relative importance of various acceleration, transport, and loss processes in the observed radiation belt dropouts and buildups. Since 2015, the community has selected four "challenge" events under four different categories: "storm-time enhancements", "non-storm enhancements", "storm-time dropouts", and "non-storm dropouts". Model inputs and data for each selected event have been coordinated and shared within the community to establish a common basis for simulations and testing. Modelers within and outside US with different types of radiation belt models (diffusion-type, diffusion-convection-type, test particle codes, etc.) have participated in our challenge and shared their simulation results and comparison with spacecraft measurements. Significant progress has been made in quantitative modeling of the radiation belt buildups and dropouts as well as accessing the modeling with new measures of model performance. In this presentation, I will review the activities from our "RB dropout" and "RB buildup" challenges and the progresses achieved in understanding radiation belt physics and improving model validation and verification.

  5. An Effective Belt Conveyor for Underground Ore Transportation Systems

    Science.gov (United States)

    Krol, Robert; Kawalec, Witold; Gladysiewicz, Lech

    2017-12-01

    Raw material transportation generates a substantial share of costs in the mining industry. Mining companies are therefore determined to improve the effectiveness of their transportation system, focusing on solutions that increase both its energy efficiency and reliability while keeping maintenance costs low. In the underground copper ore operations in Poland’s KGHM mines vast and complex belt conveyor systems have been used for horizontal haulage of the run-of-mine ore from mining departments to shafts. Basing upon a long-time experience in the field of analysing, testing, designing and computing of belt conveyor equipment with regard to specific operational conditions, the improvements to the standard design of an underground belt conveyor for ore transportation have been proposed. As the key elements of a belt conveyor, the energy-efficient conveyor belt and optimised carrying idlers have been developed for the new generation of underground conveyors. The proposed solutions were tested individually on the specially constructed test stands in the laboratory and in the experimental belt conveyor that was built up with the use of prototype parts and commissioned for the regular ore haulage in a mining department in the KGHM underground mine “Lubin”. Its work was monitored and the recorded operational parameters (loadings, stresses and strains, energy dissipation, belt tracking) were compared with those previously collected on a reference (standard) conveyor. These in-situ measurements have proved that the proposed solutions will return with significant energy savings and lower maintenance costs. Calculations made on the basis of measurement results in the specialized belt conveyor designing software allow to estimate the possible savings if the modernized conveyors supersede the standard ones in a large belt conveying system.

  6. Recent Mega-Thrust Tsunamigenic Earthquakes and PTHA

    Science.gov (United States)

    Lorito, S.

    2013-05-01

    The occurrence of several mega-thrust tsunamigenic earthquakes in the last decade, including but not limited to the 2004 Sumatra-Andaman, the 2010 Maule, and 2011 Tohoku earthquakes, has been a dramatic reminder of the limitations in our capability of assessing earthquake and tsunami hazard and risk. However, the increasingly high-quality geophysical observational networks allowed the retrieval of most accurate than ever models of the rupture process of mega-thrust earthquakes, thus paving the way for future improved hazard assessments. Probabilistic Tsunami Hazard Analysis (PTHA) methodology, in particular, is less mature than its seismic counterpart, PSHA. Worldwide recent research efforts of the tsunami science community allowed to start filling this gap, and to define some best practices that are being progressively employed in PTHA for different regions and coasts at threat. In the first part of my talk, I will briefly review some rupture models of recent mega-thrust earthquakes, and highlight some of their surprising features that likely result in bigger error bars associated to PTHA results. More specifically, recent events of unexpected size at a given location, and with unexpected rupture process features, posed first-order open questions which prevent the definition of an heterogeneous rupture probability along a subduction zone, despite of several recent promising results on the subduction zone seismic cycle. In the second part of the talk, I will dig a bit more into a specific ongoing effort for improving PTHA methods, in particular as regards epistemic and aleatory uncertainties determination, and the computational PTHA feasibility when considering the full assumed source variability. Only logic trees are usually explicated in PTHA studies, accounting for different possible assumptions on the source zone properties and behavior. The selection of the earthquakes to be actually modelled is then in general made on a qualitative basis or remains implicit

  7. Hydrodynamic optimization of trust ring pump and lubricating oil system for large hydroelectric units thrust bearing

    Science.gov (United States)

    Lai, X.; Lu, Z.; Zhang, X.; Yang, S.

    2014-03-01

    Thrust-ring-pump is a kind of extreme-low specific speed centrifugal pump with special structure as numerous restrictions form thrust bearing and operation conditions of hydro turbine generator unit. Because the oil circulating and cooling system with thrust-ring- pump has a lot of advantages in maintenance and compactness in structure, it has widely been used in large and medium-sized hydro-generator units. Since the diameter and the speed of the thrust ring is limited by the generator set, the matching relationship between the flow passage inside the thrust ring (equivalent to impeller) and oil bath (equivalent to volute) has great influence on hydrodynamic performance of thrust-ring-pump, additionally, the head and discharge are varying with the operation conditions of hydro-generator unit and characteristic of the oil circulating and cooling system. As so far, the empirical calculation method is employed during the actual engineering design, in order to guarantee the operating performance of the oil circulating and cooling system with thrust-ring-pump at different conditions, a collaborative hydrodynamic design and optimization of both the oil circulating and cooling system and thrust-ring-pump is purposed in this paper. Firstly, the head and discharge required at different conditions are decided by 1D flow numerical simulation of the oil circulating and cooling system. Secondly, the flow passages of thrust-ring-pump are empirically designed under the restrictions of diameter and the speed of the thrust ring according to the head and discharge from the simulation. Thirdly, the flow passage geometry matching optimization between holes inside the thrust ring and oil bath is implemented by means of 3D flow simulation and performance prediction. Then, the pumps and the oil circulating and cooling system are collaborative hydrodynamic optimized with predicted head- discharge curve and the efficiency-discharge curve of thrust-ring-pump. The presented methodology has

  8. Power Transmission Through Timing Belt In Two Wheeler Motors

    Directory of Open Access Journals (Sweden)

    Gurumurthy Veerapathiran

    2015-03-01

    Full Text Available This paper studies the effect of noise and friction on performance of the chain drive system for motor bikes. Experiment shows that chain transmission in chain drive system leads to poor overall performance, due to its noise and chain gets loose due to aging and sprockets wear due to chain friction etc., the proposed system consists of drive and driven pulley with timing belt transmission. Compared to conventional method, proposed method give improved tension in pulleys and belt by the additional arrangement called belt tensioner. This gives good overall performance of the system, and reduces noise, vibration and gives high transmission speed.

  9. Radiation Belt Storm Probes: Resolving Fundamental Physics with Practical Consequences

    Science.gov (United States)

    Ukhorskiy, Aleksandr Y.; Mauk, Barry H.; Fox, Nicola J.; Sibeck, David G.; Grebowsky, Joseph M.

    2011-01-01

    The fundamental processes that energize, transport, and cause the loss of charged particles operate throughout the universe at locations as diverse as magnetized planets, the solar wind, our Sun, and other stars. The same processes operate within our immediate environment, the Earth's radiation belts. The Radiation Belt Storm Probes (RBSP) mission will provide coordinated two-spacecraft observations to obtain understanding of these fundamental processes controlling the dynamic variability of the near-Earth radiation environment. In this paper we discuss some of the profound mysteries of the radiation belt physics that will be addressed by RBSP and briefly describe the mission and its goals.

  10. Formation and Decay of the Inner Electron Radiation Belt

    Science.gov (United States)

    2017-01-09

    Wave acceleration of electrons in the Van Allen radiation belts , Nature, 437, 227–230, doi:10.1038/nature03939. Kessel, R. L., N. J. Fox...prime mission of the Van Allen Probes Key Points: • Quantified upper limit of MeV electrons in the inner belt • Actual MeV electron intensity likely...have not happened yet since the launch of Van Allen Probes, significant enhancements of MeV electrons do not occur in the inner belt even

  11. Heavy Barbell Hip Thrusts Do Not Effect Sprint Performance: An 8-Week Randomized-Controlled Study.

    Science.gov (United States)

    Bishop, Chris; Cassone, Natasha; Jarvis, Paul; Turner, Anthony; Chavda, Shyam; Edwards, Mike

    2017-07-24

    The purpose of this study was to examine the effects of an 8-week barbell hip thrust strength training program on sprint performance. Twenty-one collegiate athletes (15 males and 6 females) were randomly assigned to either an intervention (n = 11, age 27.36 ± 3.17 years, height 169.55 ± 10.38 cm, weight 72.7± 18 kg) or control group (n = 10, age 27.2 ± 3.36 years, height 176.2 ± 7.94 cm, weight 76.39 ± 11.47 kg). 1RM hip thrust, 40m sprint time, and individual 10m split timings: 0-10, 10-20, 20-30, 30-40m, were the measured variables; these recorded at both the baseline and post testing time points. Following the 8-week hip thrust strength training intervention significantly greater 1RM hip thrust scores for the training group were observed (p 0.05, r = 0.05 - 0.37). No significant differences were seen for the control group for 1RM hip thrust (p = 0.106, d = 0.24 [mean difference 9.4 kg]) or sprint time (all sprint performance measures: p > 0.05, r = 0.13 - 0.47). These findings suggest that increasing maximum hip thrust strength through use of the barbell hip thrust does not appear to transfer into improvements in sprint performance in collegiate level athletes.

  12. Upstream blockage effect on the thrust force of a marine hydrokinetic device

    Science.gov (United States)

    Soliani, Giulio; Beninati, Maria Laura; Krane, Michael; Fontaine, Arnold

    2013-11-01

    The study evaluates the interaction of two model marine devices axially arranged one in front of the other, in a tandem configuration. Particular focus is given to the change that occurs in the thrust of the downstream marine hydrokinetic (MHK) device when the spatial arrangement of the two elements is varied. At critical spacing there is no thrust generation. The study is motivated by the need to predict the thrust behavior of MHK devices and determine the minimum separation distance to avoid the no thrust condition. The downstream element is a two-bladed, horizontal axis turbine, while the upstream blockage is a perforated disk with similar geometric properties intended to approximate the wake of the MHK device. Testing is conducted in the flume facility at Bucknell University. Experiments are performed for a fixed range of spacing between the perforated disk and the turbine. For each separation distance, the span-wise velocity profile upstream and downstream of the turbine is measured, as well as the device's rotational speed. The turbine's thrust coefficient is calculated. Plots of the thrust coefficient as a function of spacing depict the minimum separation distance to avoid the no thrust condition.

  13. Feasibility of electro-osmotic belt filter dewatering technology at pilot scale

    CSIR Research Space (South Africa)

    Snyman, HG

    2000-01-01

    Full Text Available -effective dewatering technologies, electro-osmotic belt filtering was developed by Smollen and Kafaar in 1995. The mechanical equipment resembles a belt filter press but the belts are stainless steel, woven belts, which act as the electrodes. In this study...

  14. MACRO MODEL OF SEAT BELT USE BY CAR DRIVERS AND PASSENGERS

    Directory of Open Access Journals (Sweden)

    Kazimierz JAMROZ

    2013-12-01

    Full Text Available The article presents some problems of seat belt use by car drivers and passengers. It looks in particular at seat belt use and effectiveness in selected countries. Next, factors of seat belt use are presented and methodology of model development. A macro model of seat belt use is presented based on data from around fifty countries from different continents.

  15. Practical and medical aspects of the use of car seat belts.

    NARCIS (Netherlands)

    Edelman, A. & Kampen, L.T.B. van

    1974-01-01

    An analysis is made of the influence of use and non-use of seat belts on type and severity of injuries to drivers and of the influence of seat belt type on type and severity of injuries to drivers. Users of lap belts and users of 3-point belts enjoy a comparable and considerable reduction of injury

  16. Non-Contact Thrust Stand Calibration Method for Repetitively-Pulsed Electric Thrusters

    Science.gov (United States)

    Wong, Andrea R.; Toftul, Alexandra; Polzin, Kurt A.; Pearson, J. Boise

    2011-01-01

    A thrust stand calibration technique for use in testing repetitively-pulsed electric thrusters for in-space propulsion has been developed and tested using a modified hanging pendulum thrust stand. In the implementation of this technique, current pulses are applied to a solenoidal coil to produce a pulsed magnetic field that acts against the magnetic field produced by a permanent magnet mounted to the thrust stand pendulum arm. The force on the magnet is applied in this non-contact manner, with the entire pulsed force transferred to the pendulum arm through a piezoelectric force transducer to provide a time-accurate force measurement. Modeling of the pendulum arm dynamics reveals that after an initial transient in thrust stand motion the quasisteady average deflection of the thrust stand arm away from the unforced or zero position can be related to the average applied force through a simple linear Hooke s law relationship. Modeling demonstrates that this technique is universally applicable except when the pulsing period is increased to the point where it approaches the period of natural thrust stand motion. Calibration data were obtained using a modified hanging pendulum thrust stand previously used for steady-state thrust measurements. Data were obtained for varying impulse bit at constant pulse frequency and for varying pulse frequency. The two data sets exhibit excellent quantitative agreement with each other as the constant relating average deflection and average thrust match within the errors on the linear regression curve fit of the data. Quantitatively, the error on the calibration coefficient is roughly 1% of the coefficient value.

  17. Finite element analysis of thrust angle contact ball slewing bearing

    Science.gov (United States)

    Deng, Biao; Guo, Yuan; Zhang, An; Tang, Shengjin

    2017-12-01

    In view of the large heavy slewing bearing no longer follows the rigid ring hupothesis under the load condition, the entity finite element model of thrust angular contact ball bearing was established by using finite element analysis software ANSYS. The boundary conditions of the model were set according to the actual condition of slewing bearing, the internal stress state of the slewing bearing was obtained by solving and calculation, and the calculated results were compared with the numerical results based on the rigid ring assumption. The results show that more balls are loaded in the result of finite element method, and the maximum contact stresses between the ball and raceway have some reductions. This is because the finite element method considers the ferrule as an elastic body. The ring will produce structure deformation in the radial plane when the heavy load slewing bearings are subjected to external loads. The results of the finite element method are more in line with the actual situation of the slewing bearing in the engineering.

  18. VPS Process for Copper Components in Thrust Chamber Assemblies

    Science.gov (United States)

    Elam, Sandra; Holmes, Richard; Hickman, Robert; McKechnie, Tim; Thom, George

    2005-01-01

    For several years, NASA's Marshall Space Flight Center (MSFC) has been working with Plasma Processes, Inc., (PPI) to fabricate thrust chamber liners with GRCop-84. Using the vacuum plasma spray (VPS) process, chamber liners of a variety of shapes and sizes have been created. Each has been formed as a functional gradient material (FGM) that creates a unique protective layer of NiCrAlY on the GRCop-84 liner s hot wall surface. Hot-fire testing was successfully conducted on a subscale unit to demonstrate the liner's durability and performance. Similar VPS technology has also been applied to create functional gradient coatings (FGC) on copper injector faceplates. Protective layers of NiCrAlY and zirconia were applied to both coaxial and impinging faceplate designs. Hot-fire testing is planned for these coated injectors in April 2005. The resulting material systems for both copper alloy components allows them to operate at higher temperatures with improved durability and operating margins.

  19. Centaur engine gimbal friction characteristics under simulated thrust load

    Science.gov (United States)

    Askew, J. W.

    1986-01-01

    An investigation was performed to determine the friction characteristics of the engine gimbal system of the Centaur upper stage rocket. Because the Centaur requires low-gain autopilots in order to meet all stability requirements for some configurations, control performance (response to transients and limit-cycle amplitudes) depends highly on these friction characteristics. Forces required to rotate the Centaur engine gimbal system were measured under a simulated thrust load of 66,723 N (15,000 lb) and in an altitude/thermal environment. A series of tests was performed at three test conditions; ambient temperature and pressure, ambient temperature and vacuum, and cryogenic temperature and vacuum. Gimbal rotation was controlled, and tests were performed in which rotation amplitude and frequency were varied by using triangular and sinusoidal waveforms. Test data revealed an elastic characteristic of the gimbal, independent of the input signal, which was evident prior to true gimbal sliding. The torque required to initiate gimbal sliding was found to decrease when both pressure and temperature decreased. Results from the low amplitude and low frequency data are currently being used in mathematically modeling the gimbal friction characteristics for Centaur autopilot performance studies.

  20. Belts Evaluated as Limb Tourniquets: BELT Study Comparing Trouser Supporters Used as Medical Devices in a Manikin Model of Wound Bleeding.

    Science.gov (United States)

    Bequette, Blake W; Kragh, John F; Aden, James K; Dubick, Michael A

    2017-06-01

    The purpose of the present study is to compare several models of commercially designed belts as used as a tourniquet. In the Belts Evaluated as Limb Tourniquets (BELT) study, an experiment was designed to test the effectiveness of pants belts as nonimprovised medical devices to control hemorrhage in a manikin. Models of belts included Tourni-belt, Tourniquet Belt, ParaBelt, and Battle Buddy. Data collected included effectiveness, time to stop bleeding, total time of application, pressure, blood loss, and composite results (score count of good results; composite outcome good if every component was good). Differences in effectiveness percentages among models were not statistically significant. The difference in mean between users was statistically significant for stop time, total time, pressure, blood loss, composite score, and composite outcome. Mean time to stop bleeding differed for only 1 pair of models after the Tukey-Kramer adjustment; ParaBelt was faster than Tourniquet Belt. Mean total time of application differed between ParaBelt-Tourniquet Belt and Tourni-belt-Tourniquet Belt; the former model in both pairs was faster. No significant difference in mean blood loss measured by model was found. For composite outcome score, no pairwise difference between models was significant. For composite outcome (good-bad), ParaBelt had good results in 75% of tests; the other 3 models had significantly worse results. In a preliminary laboratory analysis of belt tourniquet models using a manikin, performance differed by model. ParaBelt performed better than other models for the composite outcome. Published by Elsevier Inc.