The Experts below are selected from a list of 261 Experts worldwide ranked by ideXlab platform
Esmaeil Shabanian - One of the best experts on this subject based on the ideXlab platform.
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The Transfer of Strike-Slip Partitioned Motion of Oblique Convergence Across the Zagros Fold-and-Thrust Belt
Journal of Seismology and Earthquake Engineering, 2020Co-Authors: Christine Authemayou, Olivier Bellier, Dominique Chardon, Zaman Malekzade, M. Abassi, Esmaeil ShabanianAbstract:Oblique Plate Convergence in collision zones may lead to complex regional strain partitioning because inherited crustal faults have various orientations with respect to the orogenic belt and the Convergence vector. Combined field structural and geomorphic investigations and SPOT image analysis document the kinematic framework enhancing transfer of strike-slip partitioned right-lateral motion from along the backstop to the interior of the Zagros foldand-thrust belt in a context of active, high-angle right-oblique Plate Convergence. Transfer occurs by slip on the N-trending right-lateral Kazerun fault system that connects to the termination of the Main Recent Fault, a major NW-trending dextral fault partitioning oblique Convergence at the rear of the belt. The Kazerun Fault system consists in three N-trending fault zones ended by bent, orogen-parallel splay thrust faults allowing slip from along the Main Recent Fault to become distributed by transfer to longitudinal thrust faults and folds.
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late cenozoic partitioning of oblique Plate Convergence in the zagros fold and thrust belt iran
Tectonics, 2006Co-Authors: Christine Authemayou, Olivier Bellier, Dominique Chardon, Esmaeil Shabanian, Zaman Malekzadeh, M R AbbassiAbstract:The NW trending Zagros fold-and-thrust belt is affected by two major dextral faults: (1) the NW trending Main Recent Fault that accommodates partitioning of oblique Convergence at the rear of the western Zagros and (2) the north trending Kazerun Fault located in the central Zagros. Combined structural and fault kinematics studies and SPOT images analysis have shown a Pliocene kinematic change accompanied by a fault pattern reorganization, which has led to a modification in the accommodation of oblique Convergence. Since the late Pliocene, the distributed transpressional deformation operating at the rear of the belt has become partitioned along the newly formed Main Recent Fault. This fault cuts through early Pliocene nappes and transpressional structures by right-laterally reactivating high-angle thrusts. The southeastern termination of the Main Recent Fault connects to the northern termination of Kazerun Fault that consists of three fault zones that end in bent, orogen-parallel splay thrust faults. The Kazerun Fault, together with a series of north to NNW trending inherited basement strike-slip faults, define an orogen-scale fan-shaped fault pattern pointing toward the Main Recent Fault-Kazerun Fault junction. This structural pattern allows slip from along the Main Recent Fault to become distributed by transfer to the longitudinal thrust faults and folds of the Zagros belt, with the fan-shaped fault pattern acting as a horse-tail termination of the Main Recent Fault.
Dominique Chardon - One of the best experts on this subject based on the ideXlab platform.
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The Transfer of Strike-Slip Partitioned Motion of Oblique Convergence Across the Zagros Fold-and-Thrust Belt
Journal of Seismology and Earthquake Engineering, 2020Co-Authors: Christine Authemayou, Olivier Bellier, Dominique Chardon, Zaman Malekzade, M. Abassi, Esmaeil ShabanianAbstract:Oblique Plate Convergence in collision zones may lead to complex regional strain partitioning because inherited crustal faults have various orientations with respect to the orogenic belt and the Convergence vector. Combined field structural and geomorphic investigations and SPOT image analysis document the kinematic framework enhancing transfer of strike-slip partitioned right-lateral motion from along the backstop to the interior of the Zagros foldand-thrust belt in a context of active, high-angle right-oblique Plate Convergence. Transfer occurs by slip on the N-trending right-lateral Kazerun fault system that connects to the termination of the Main Recent Fault, a major NW-trending dextral fault partitioning oblique Convergence at the rear of the belt. The Kazerun Fault system consists in three N-trending fault zones ended by bent, orogen-parallel splay thrust faults allowing slip from along the Main Recent Fault to become distributed by transfer to longitudinal thrust faults and folds.
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late cenozoic partitioning of oblique Plate Convergence in the zagros fold and thrust belt iran
Tectonics, 2006Co-Authors: Christine Authemayou, Olivier Bellier, Dominique Chardon, Esmaeil Shabanian, Zaman Malekzadeh, M R AbbassiAbstract:The NW trending Zagros fold-and-thrust belt is affected by two major dextral faults: (1) the NW trending Main Recent Fault that accommodates partitioning of oblique Convergence at the rear of the western Zagros and (2) the north trending Kazerun Fault located in the central Zagros. Combined structural and fault kinematics studies and SPOT images analysis have shown a Pliocene kinematic change accompanied by a fault pattern reorganization, which has led to a modification in the accommodation of oblique Convergence. Since the late Pliocene, the distributed transpressional deformation operating at the rear of the belt has become partitioned along the newly formed Main Recent Fault. This fault cuts through early Pliocene nappes and transpressional structures by right-laterally reactivating high-angle thrusts. The southeastern termination of the Main Recent Fault connects to the northern termination of Kazerun Fault that consists of three fault zones that end in bent, orogen-parallel splay thrust faults. The Kazerun Fault, together with a series of north to NNW trending inherited basement strike-slip faults, define an orogen-scale fan-shaped fault pattern pointing toward the Main Recent Fault-Kazerun Fault junction. This structural pattern allows slip from along the Main Recent Fault to become distributed by transfer to the longitudinal thrust faults and folds of the Zagros belt, with the fan-shaped fault pattern acting as a horse-tail termination of the Main Recent Fault.
Xiaodong Yang - One of the best experts on this subject based on the ideXlab platform.
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comparison of fold thrust belts driven by Plate Convergence and gravitational failure
Earth-Science Reviews, 2020Co-Authors: Xiaodong Yang, Frank Peel, Lisa C Mcneill, David J SandersonAbstract:Abstract Deepwater fold-thrust belts (FTBs) are predominantly formed by the deformation of sedimentary sequences as a result of subduction of oceanic Plates at active margins, gravitational failure at passive margins, or a combination of these two driving mechanisms at both types of margin. A key question is: Is the FTB driven by gravitational failure basically the same as the FTB driven by Plate Convergence or are there fundamental differences? To address this, we reviewed FTB examples from different tectonic settings (end members and hybrid systems) in terms of geometry, structure, deformation, shortening rate, and tectonic process. The energy source in gravity-driven systems lies within the sedimentary material itself that is being deformed by updip extension and downdip contraction, whereas in the Plate Convergence-driven systems, it lies outside the local sediment pile and within the broader undeformed crust and lithosphere. The energy in gravity-driven systems is resupplied by sediment input from large river deltas and therefore deformation tends to be episodic, linked to episodes of major sediment input; whereas in a system driven by Plate motions, the energy is resupplied by movement of a boundary upon which force is acting, and tends to be stable and less episodic. Therefore the sedimentation plays an important role in the gravity-driven deformation, but a less important role in the Plate Convergence-driven deformation. In gravity-driven systems, it promotes upward propagation of normal faulting at upslope by increasing maximum principal stress but hinders upward propagation of thrusting (i.e. mostly buried structures) by increasing minimum principal stress at downslope; while in Plate Convergence systems, thrusts and folds tend to deform seafloor as a result of large compression, with less effect from sedimentation. Despite the varying basal strength, the observed thrust faults in both systems are mostly basinward-verging, in slight contrast to the theoretical model predication (with homogeneous material), implicating the control of likely variability of stratigraphic strength on thrust vergence. The shortening rate across Plate Convergence-driven systems is high (several tens mm/yr), and continuous on a long timescale; whereas across the gravity-driven fold-thrust belts, it is generally slow (several mm/yr) and more variable or even catastrophic through time. Despite overall seaward younging of thrusting, fault activity differs slightly among different systems. Focused activity at the frontal structures of FTBs is more common at the Plate Convergence system while activity focused in the rear to middle of FTBs is more common in the gravity-driven system. Plate Convergence-driven system is primarily limited by rate of Plate motion, i.e. the rate at which the Plate is fed into the FTB, whereas in gravity-driven system, the movement is limited (resisted) by the strength of sediments and detachment.
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Tectonics of Fold-Thrust Belts Driven by Plate Convergence and Gravitational Instability
2018Co-Authors: Xiaodong YangAbstract:Fold-thrust belts (FTBs) related to Plate Convergence are found in active margins and in the foreland of orogenic belts, while those related to gravitational failure are typically found on passive margins. Seismic imaging of the subsurface structure, combined with decades of study and analysis, have resulted in a good first-pass understanding of their tectonics and mechanics, but there are still many significant unresolved issues. Numerical models were used to investigate aspects of thrust belt growth: the interplay between the overall wedge taper, width and height, deformation front, internal movement, and fault position, activity, displacement and dip. After a new thrust initiates at the wedge front, the entire wedge shortens and thickens to re- attain critical taper, with significant frontal thrust activity and minor activity on older thrusts. Models show that thrust belts grow cyclically, with periods of accretion (rapid thrust-front advance, high displacement and strain rate), and periods of adjustment (slow wedge deformation, low displacement and strain rate). Detailed observation of the zone in front of the thrust front indicates that deformation in that region is a critical component of system advance. New area balancing methods, involving evaluation of the role of the regional slope, have been developed to improve the accuracy of structural restoration and shortening quantification. Application to analogue models and natural fold-thrust belts highlights the importance of regional slope in area balancing restoration: a higher regional dip results in reduced shortening while a lower regional dip leads to increased shortening. Accuracy of the shortening estimate requires independent constraint of parameters, particularly the initial regional slope. The tectonics of the Northwest Borneo Fold-Thrust Belt (NBFB), offshore Brunei, are investigated using 3D seismic data. The NBFB contains three fold types: fault-propagation folds (dominant); detachment folds (minor); and fault-bend folds (rare). For each fold, structural style varies along strike, in response to changes in the magnitude of folding, basal decollement strength, and inherited structure and basement topography. Fault spacing responds to basement topography and topography also blocks forward propagation of the fold-thrust belt. Fault dip increases as the fault and fold matures. The low taper angle (mostly 0.7 of lithostatic pressure). Evidence of two distinct stages of fault (fold) activity, wide distribution of active contractional deformation across the entire belt (rather than just at the toe), and present-day extensional inactivity, suggest that the NBFB results from a combination of primary gravitational tectonics and secondary Plate Convergence. Fold-thrust belts caused by Plate Convergence are compared with gravity-driven systems. The energy source in gravity-driven systems is the release of gravitational potential energy within the sediment pile, producing upslope extension and downslope contraction. This is resupplied by sedimentation. Episodic sediment input leads to fluctuations in deformation rate. In contrast, the energy source of Convergence driven systems is movement of a stressed lithosphere-scale boundary. Plate movement is continuous, so thrust belt deformation is less episodic. Back-thrusts and fault back rotation are more common in Convergence-driven systems and landward-vergent thrusts can be present. The rate of shortening across Convergence-driven systems is high and generally continuous on a long time scale. Whereas rates are lower across the contractional domain of a gravity-driven system and more variable through time. A Plate-driven system is limited by Plate motion rate, i.e. the rate at which the Plate is fed into the FTB, whereas a gravity driven system is resisted by the strength of the sediments and detachment.
Christine Authemayou - One of the best experts on this subject based on the ideXlab platform.
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The Transfer of Strike-Slip Partitioned Motion of Oblique Convergence Across the Zagros Fold-and-Thrust Belt
Journal of Seismology and Earthquake Engineering, 2020Co-Authors: Christine Authemayou, Olivier Bellier, Dominique Chardon, Zaman Malekzade, M. Abassi, Esmaeil ShabanianAbstract:Oblique Plate Convergence in collision zones may lead to complex regional strain partitioning because inherited crustal faults have various orientations with respect to the orogenic belt and the Convergence vector. Combined field structural and geomorphic investigations and SPOT image analysis document the kinematic framework enhancing transfer of strike-slip partitioned right-lateral motion from along the backstop to the interior of the Zagros foldand-thrust belt in a context of active, high-angle right-oblique Plate Convergence. Transfer occurs by slip on the N-trending right-lateral Kazerun fault system that connects to the termination of the Main Recent Fault, a major NW-trending dextral fault partitioning oblique Convergence at the rear of the belt. The Kazerun Fault system consists in three N-trending fault zones ended by bent, orogen-parallel splay thrust faults allowing slip from along the Main Recent Fault to become distributed by transfer to longitudinal thrust faults and folds.
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late cenozoic partitioning of oblique Plate Convergence in the zagros fold and thrust belt iran
Tectonics, 2006Co-Authors: Christine Authemayou, Olivier Bellier, Dominique Chardon, Esmaeil Shabanian, Zaman Malekzadeh, M R AbbassiAbstract:The NW trending Zagros fold-and-thrust belt is affected by two major dextral faults: (1) the NW trending Main Recent Fault that accommodates partitioning of oblique Convergence at the rear of the western Zagros and (2) the north trending Kazerun Fault located in the central Zagros. Combined structural and fault kinematics studies and SPOT images analysis have shown a Pliocene kinematic change accompanied by a fault pattern reorganization, which has led to a modification in the accommodation of oblique Convergence. Since the late Pliocene, the distributed transpressional deformation operating at the rear of the belt has become partitioned along the newly formed Main Recent Fault. This fault cuts through early Pliocene nappes and transpressional structures by right-laterally reactivating high-angle thrusts. The southeastern termination of the Main Recent Fault connects to the northern termination of Kazerun Fault that consists of three fault zones that end in bent, orogen-parallel splay thrust faults. The Kazerun Fault, together with a series of north to NNW trending inherited basement strike-slip faults, define an orogen-scale fan-shaped fault pattern pointing toward the Main Recent Fault-Kazerun Fault junction. This structural pattern allows slip from along the Main Recent Fault to become distributed by transfer to the longitudinal thrust faults and folds of the Zagros belt, with the fan-shaped fault pattern acting as a horse-tail termination of the Main Recent Fault.
David J Sanderson - One of the best experts on this subject based on the ideXlab platform.
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comparison of fold thrust belts driven by Plate Convergence and gravitational failure
Earth-Science Reviews, 2020Co-Authors: Xiaodong Yang, Frank Peel, Lisa C Mcneill, David J SandersonAbstract:Abstract Deepwater fold-thrust belts (FTBs) are predominantly formed by the deformation of sedimentary sequences as a result of subduction of oceanic Plates at active margins, gravitational failure at passive margins, or a combination of these two driving mechanisms at both types of margin. A key question is: Is the FTB driven by gravitational failure basically the same as the FTB driven by Plate Convergence or are there fundamental differences? To address this, we reviewed FTB examples from different tectonic settings (end members and hybrid systems) in terms of geometry, structure, deformation, shortening rate, and tectonic process. The energy source in gravity-driven systems lies within the sedimentary material itself that is being deformed by updip extension and downdip contraction, whereas in the Plate Convergence-driven systems, it lies outside the local sediment pile and within the broader undeformed crust and lithosphere. The energy in gravity-driven systems is resupplied by sediment input from large river deltas and therefore deformation tends to be episodic, linked to episodes of major sediment input; whereas in a system driven by Plate motions, the energy is resupplied by movement of a boundary upon which force is acting, and tends to be stable and less episodic. Therefore the sedimentation plays an important role in the gravity-driven deformation, but a less important role in the Plate Convergence-driven deformation. In gravity-driven systems, it promotes upward propagation of normal faulting at upslope by increasing maximum principal stress but hinders upward propagation of thrusting (i.e. mostly buried structures) by increasing minimum principal stress at downslope; while in Plate Convergence systems, thrusts and folds tend to deform seafloor as a result of large compression, with less effect from sedimentation. Despite the varying basal strength, the observed thrust faults in both systems are mostly basinward-verging, in slight contrast to the theoretical model predication (with homogeneous material), implicating the control of likely variability of stratigraphic strength on thrust vergence. The shortening rate across Plate Convergence-driven systems is high (several tens mm/yr), and continuous on a long timescale; whereas across the gravity-driven fold-thrust belts, it is generally slow (several mm/yr) and more variable or even catastrophic through time. Despite overall seaward younging of thrusting, fault activity differs slightly among different systems. Focused activity at the frontal structures of FTBs is more common at the Plate Convergence system while activity focused in the rear to middle of FTBs is more common in the gravity-driven system. Plate Convergence-driven system is primarily limited by rate of Plate motion, i.e. the rate at which the Plate is fed into the FTB, whereas in gravity-driven system, the movement is limited (resisted) by the strength of sediments and detachment.
