The Balakot Formation foreland basin sediments, located in the Hazara\|Kashmir syntaxis, Pakistan, consist of a >8km thick succession of clastic red beds and calcrete, interpreted as deposited in a tidal environmen...The Balakot Formation foreland basin sediments, located in the Hazara\|Kashmir syntaxis, Pakistan, consist of a >8km thick succession of clastic red beds and calcrete, interpreted as deposited in a tidal environment. Within this sequence are intercalated four distinct grey fossiliferous marl and silt units, 20～60m thick, dated at Late Palaeocene to Mid Eocene (Bossart & Ottiger 1989). Thus the Balakot Formation has been interpreted as the oldest continental foreland basin deposits and has been used to determine the timing of India\|Eurasia collision (Rowley 1996) which has implications for the degree of diachroneity of collision (Burbank et al. 1996; Uddin and Lundberg 1998) and rapidity of metamorphism (Treloar 1997), to interpret the palaeotectonics and palaeogeography of the mountain belt (Critelli and Garzanti 1994; Pivnik and Wells 1996), understand the relationship between mountain belt evolution and exhumation processes (Treloar et al. 1991) and construct models of foreland basin evolution and geometry (DeCelles et al. 1998; Burbank et al 1996).展开更多
A stratigraphic and depositional filling modal of Triassic—Jurassic North Tarim foreland basin system is erected, through synthetic analysis of geological setting, depositional provenance, sequence stratigraphy, and ...A stratigraphic and depositional filling modal of Triassic—Jurassic North Tarim foreland basin system is erected, through synthetic analysis of geological setting, depositional provenance, sequence stratigraphy, and quantitative tectonic stratigraphy. The result suggests that the major factors controlling formation and evolution of the system are oblique collision and convergence of different plates, and favorite hydrocarbon plays is predicted.The geological setting analysis emphasizes the historical succession of the foreland basin system formation and evolution. The tectonic setting analysis sketchy outlines formation of the system and tectonic setting of its successive evolution. The sedimentary geology analysis reveals the uplift and subsidence of the basin basement a seesaw style movement.展开更多
The Himalayan peripheral foreland basin developed when India and Asia collided.Previous studies in the Himalayan foreland were mostly concentrated on Neogene continental clastic sedimentation in sub-Himalaya or Paleog...The Himalayan peripheral foreland basin developed when India and Asia collided.Previous studies in the Himalayan foreland were mostly concentrated on Neogene continental clastic sedimentation in sub-Himalaya or Paleogene shallow marine sedimentation along Pakistan,India,and Nepal in Lesser Himalaya. The lack of early stage of underfilled。展开更多
In the foreland belts of Pamir\|West Kunlun (PWK) and Southern Tienshan (ST), the thin\|skinned thrusting systems (tsts) from mountains thrusting to the Southwest Tarim Basin (STB) and the back\|thrusting systems (bts...In the foreland belts of Pamir\|West Kunlun (PWK) and Southern Tienshan (ST), the thin\|skinned thrusting systems (tsts) from mountains thrusting to the Southwest Tarim Basin (STB) and the back\|thrusting systems (bts) from basin thrusting to the adjacent mountains were developed. The different active structural systems can be segmented: Kazike\|Arte deformed bts and tsts, Yigeziya tsts, Qimugen arcurate bts, Qipan thrusting and faulted\|folded system, Kekeya tsts, Keliyang—Yuliqun bts, Sangzhu\|Duwa tsts and Cele arcurate thr usting system along the PWK foreland belts, and Kalajun—Kalpin tsts, Atushi\|Bapanshuimo bts along the foreland belts of ST.Through the study of aerial magnetic anomalies and many seismic profiles, we found that all bts and their triangle zones were formed over the NE—SW basement depressions of STB (thickness of sedimentary covers >10km). We also found that all tsts were formed over the basement uplift belts of STB (thickness of sedimentary covers <10km, 6～10km in general).In the basement depression of the basin, the bts and their triangle zones could be transformed to tsts due to continuous compression. The largest displacement of the tsts or bts is located in the convex part but the shortest displacement is located in the conjunction area of two segments. The arcurate tsts and bts display different displacements along foreland belts.展开更多
The Chuxiong Basin in central Yunnan,locates in the west edge of Yangtze platform to the southeast of Tibet and is a Mesozoic oil\|bearing peripheral foreland basin, which developed mainly during the Late Triassic, an...The Chuxiong Basin in central Yunnan,locates in the west edge of Yangtze platform to the southeast of Tibet and is a Mesozoic oil\|bearing peripheral foreland basin, which developed mainly during the Late Triassic, and passed gradually into an intracontinental downwarped basin during Jurassic time. The integration of geological and geophysical data shows that the basin is separated by the Yupaojiang\|Shaqiao fault into two parts. According to the classic models, the Triassic sediments in the western thrust zone are generally interpreted as the foredeep sediments, while the eastern part is believed to be a foreland bulge and an intracontinental depression. However the authors in the present paper argued, on the basis of structure and texture, distribution, stacking pattern and sediment provenance in combination with the geochemical and geophysical data, that the Triassic sediments in the western thrust zone should be assigned to the wedge\|top sediments, whereas the foreland area in the eastern part recorded progressive deposition in the foreland basin system. The earlier foredeep sediments might have been consumed under the nappe zone in the west rather than cropped out on the surface. (1) Viewed from the horizontal distribution of sedimentary facies, although the strata in the western thrust zone have undergone multiple phases of tectonic deformation, the earlier Triassic sediments are still well preserved. On the other hand, relatively weak tectonic deformation of the strata in the foreland area in the east once occurred, and the early strata were apparently consumed under the thrust zone in the west. (2) The stacking patterns of the sediments indicate that the Middle and Lower Triassic strata in the basin should be ascribed to the typical passive continental marginal sediments, which are overlain unconformably by the Carnian or Norian (Upper Triassic) strata with a depositional break during the Ladinian—Carnian, implying that the Chuxiong foreland basin might originate during the early Carnian. Before this period, the whole basin was once in the passive continental marginal area, where stable carbonate deposits prevailed. (3) The Upper Triassic strata may be divided into four second\|order sequences altogether: four for the wedge\|top sediments in the west; three for the eastern part, and one or two for the margins of the basin. The isochronous surfaces in individual sequences can be regionally correlated. (4) The evidences from structure and texture, composition, palaeocurrent direction and geochemical signature have revealed that the Upper Triassic sediments from the wedge\|top sediments in the western nappe zone are characterized by low compositional and textural maturity, and progressively thinned sediment thickness toward the western orogenic zone as the source area. The present\|day foreland area in the east only accepted the post\|Norian deposits with high compositional and textural maturity. The principal source of detritus lay to the Xikang\|Yunnan oldland in the east. During the late Late Triassic, the thrust zone overthrusted upon the thick rigid lithospheric crust, giving rise to weak warping and slow subsidence of the basin. For this reason, no typical foredeep sediments are observed.展开更多
Mesozoic Qiangtang foreland Basin is located between Jinshajiang suture belt and Bangong—Nujiang suture belt and an important petroliferous basin in the north of Qinghai—Xizang plateau. This foreland basin is E—W e...Mesozoic Qiangtang foreland Basin is located between Jinshajiang suture belt and Bangong—Nujiang suture belt and an important petroliferous basin in the north of Qinghai—Xizang plateau. This foreland basin is E—W elongated basin with 800km in length and 200km to 300km in width. Both margins of the basin are large suture belt and linked to thrusting of large suture belt, so Mesozoic Qiangtang foreland basin belongs to composite foreland basins according to Jordan’s classification of the foreland basin(1988). The foreland basin is filled with 5000～8000m thick late Triassic to Cretaceous marine sediments. The spacial changes of the stratigraphy indicates that the basin texture looks like a symmetric body, and it can be subdivided into three tectonic geomorphic units from north to south ,such as northern basin, center uplift, and southern basin. The depth in the north varies from 5000 to 8000m,the depth in center uplift varies from zero to 1000m, the depth in the south varies from 5000 to 7000m, Which show that the occurrence of the Mesozoic filling stratigraphy are thicker in the north and the south of the basin, but thinner in the center uplift of the basin. There are two center of subsidence of the basin, both of them are located in south and north foredeep belt, lying in the front of suture belt. The basin is one of common foreland basins between suture belt and belongs to typical symmetric foreland basin.This kind of basin geometry allows large thickness of synsedimentary molasse sediments to be preserved and related to basement uplifts and thrusts in the cratonic edge of the mountain belt.From late Triassic to Cretaceous the foreland basin is filled by four tectonic sequences, including late Triassic tectonic sequence(TS\-1),early Jurassic tectonic sequence(TS\-2), middle Jurassic to early Cretaceous tectonic sequence(TS\-3) and middle to late Cretaceous tectonic sequence (TS\-4).A tectonic Sequence is a body of genetically related strata isolated by unconformity ,deposited in a basining stage responding to a thrusting episode. Late Triassic tectonic sequence(TS\-1) is bounded by Ta and Tb and composed of the Xiaochaka formation which is more than 2500m in depth, it is a coarsing\|upward tectonic sequence,the lower is fan delta sediments with debris conglomerate,the middle is carbonate ramp sediments,the upper is delta sediments; early Jurassic tectonic sequence(TS\-2) is bounded by Tb and Tc and composed of the Nadigangri formation which is more than 1000m in depth, it is a thinning\|upward tectonic sequence,the lower is fan delta sediments with debris conglomerate,the upper is subaquatic detrital sediments; middle Jurassic to early Cretaceous tectonic sequence(TS\-3) is bounded by Tc and Td and composed of the Quemocuo formation,Buqu formation, Xiali formation, Suowa formation and Xueshan formation, which is more than 3000m in depth; middle to late Cretaceous tectonic sequence (TS\-4) is bounded by Td and Tf and composed of the Abushan formation, it is a thinning—upward alluvial fan sediments with more than 1000m in depth.展开更多
文摘The Balakot Formation foreland basin sediments, located in the Hazara\|Kashmir syntaxis, Pakistan, consist of a >8km thick succession of clastic red beds and calcrete, interpreted as deposited in a tidal environment. Within this sequence are intercalated four distinct grey fossiliferous marl and silt units, 20～60m thick, dated at Late Palaeocene to Mid Eocene (Bossart & Ottiger 1989). Thus the Balakot Formation has been interpreted as the oldest continental foreland basin deposits and has been used to determine the timing of India\|Eurasia collision (Rowley 1996) which has implications for the degree of diachroneity of collision (Burbank et al. 1996; Uddin and Lundberg 1998) and rapidity of metamorphism (Treloar 1997), to interpret the palaeotectonics and palaeogeography of the mountain belt (Critelli and Garzanti 1994; Pivnik and Wells 1996), understand the relationship between mountain belt evolution and exhumation processes (Treloar et al. 1991) and construct models of foreland basin evolution and geometry (DeCelles et al. 1998; Burbank et al 1996).
文摘A stratigraphic and depositional filling modal of Triassic—Jurassic North Tarim foreland basin system is erected, through synthetic analysis of geological setting, depositional provenance, sequence stratigraphy, and quantitative tectonic stratigraphy. The result suggests that the major factors controlling formation and evolution of the system are oblique collision and convergence of different plates, and favorite hydrocarbon plays is predicted.The geological setting analysis emphasizes the historical succession of the foreland basin system formation and evolution. The tectonic setting analysis sketchy outlines formation of the system and tectonic setting of its successive evolution. The sedimentary geology analysis reveals the uplift and subsidence of the basin basement a seesaw style movement.
文摘The Himalayan peripheral foreland basin developed when India and Asia collided.Previous studies in the Himalayan foreland were mostly concentrated on Neogene continental clastic sedimentation in sub-Himalaya or Paleogene shallow marine sedimentation along Pakistan,India,and Nepal in Lesser Himalaya. The lack of early stage of underfilled。
文摘In the foreland belts of Pamir\|West Kunlun (PWK) and Southern Tienshan (ST), the thin\|skinned thrusting systems (tsts) from mountains thrusting to the Southwest Tarim Basin (STB) and the back\|thrusting systems (bts) from basin thrusting to the adjacent mountains were developed. The different active structural systems can be segmented: Kazike\|Arte deformed bts and tsts, Yigeziya tsts, Qimugen arcurate bts, Qipan thrusting and faulted\|folded system, Kekeya tsts, Keliyang—Yuliqun bts, Sangzhu\|Duwa tsts and Cele arcurate thr usting system along the PWK foreland belts, and Kalajun—Kalpin tsts, Atushi\|Bapanshuimo bts along the foreland belts of ST.Through the study of aerial magnetic anomalies and many seismic profiles, we found that all bts and their triangle zones were formed over the NE—SW basement depressions of STB (thickness of sedimentary covers >10km). We also found that all tsts were formed over the basement uplift belts of STB (thickness of sedimentary covers <10km, 6～10km in general).In the basement depression of the basin, the bts and their triangle zones could be transformed to tsts due to continuous compression. The largest displacement of the tsts or bts is located in the convex part but the shortest displacement is located in the conjunction area of two segments. The arcurate tsts and bts display different displacements along foreland belts.
文摘The Chuxiong Basin in central Yunnan,locates in the west edge of Yangtze platform to the southeast of Tibet and is a Mesozoic oil\|bearing peripheral foreland basin, which developed mainly during the Late Triassic, and passed gradually into an intracontinental downwarped basin during Jurassic time. The integration of geological and geophysical data shows that the basin is separated by the Yupaojiang\|Shaqiao fault into two parts. According to the classic models, the Triassic sediments in the western thrust zone are generally interpreted as the foredeep sediments, while the eastern part is believed to be a foreland bulge and an intracontinental depression. However the authors in the present paper argued, on the basis of structure and texture, distribution, stacking pattern and sediment provenance in combination with the geochemical and geophysical data, that the Triassic sediments in the western thrust zone should be assigned to the wedge\|top sediments, whereas the foreland area in the eastern part recorded progressive deposition in the foreland basin system. The earlier foredeep sediments might have been consumed under the nappe zone in the west rather than cropped out on the surface. (1) Viewed from the horizontal distribution of sedimentary facies, although the strata in the western thrust zone have undergone multiple phases of tectonic deformation, the earlier Triassic sediments are still well preserved. On the other hand, relatively weak tectonic deformation of the strata in the foreland area in the east once occurred, and the early strata were apparently consumed under the thrust zone in the west. (2) The stacking patterns of the sediments indicate that the Middle and Lower Triassic strata in the basin should be ascribed to the typical passive continental marginal sediments, which are overlain unconformably by the Carnian or Norian (Upper Triassic) strata with a depositional break during the Ladinian—Carnian, implying that the Chuxiong foreland basin might originate during the early Carnian. Before this period, the whole basin was once in the passive continental marginal area, where stable carbonate deposits prevailed. (3) The Upper Triassic strata may be divided into four second\|order sequences altogether: four for the wedge\|top sediments in the west; three for the eastern part, and one or two for the margins of the basin. The isochronous surfaces in individual sequences can be regionally correlated. (4) The evidences from structure and texture, composition, palaeocurrent direction and geochemical signature have revealed that the Upper Triassic sediments from the wedge\|top sediments in the western nappe zone are characterized by low compositional and textural maturity, and progressively thinned sediment thickness toward the western orogenic zone as the source area. The present\|day foreland area in the east only accepted the post\|Norian deposits with high compositional and textural maturity. The principal source of detritus lay to the Xikang\|Yunnan oldland in the east. During the late Late Triassic, the thrust zone overthrusted upon the thick rigid lithospheric crust, giving rise to weak warping and slow subsidence of the basin. For this reason, no typical foredeep sediments are observed.
文摘Mesozoic Qiangtang foreland Basin is located between Jinshajiang suture belt and Bangong—Nujiang suture belt and an important petroliferous basin in the north of Qinghai—Xizang plateau. This foreland basin is E—W elongated basin with 800km in length and 200km to 300km in width. Both margins of the basin are large suture belt and linked to thrusting of large suture belt, so Mesozoic Qiangtang foreland basin belongs to composite foreland basins according to Jordan’s classification of the foreland basin(1988). The foreland basin is filled with 5000～8000m thick late Triassic to Cretaceous marine sediments. The spacial changes of the stratigraphy indicates that the basin texture looks like a symmetric body, and it can be subdivided into three tectonic geomorphic units from north to south ,such as northern basin, center uplift, and southern basin. The depth in the north varies from 5000 to 8000m,the depth in center uplift varies from zero to 1000m, the depth in the south varies from 5000 to 7000m, Which show that the occurrence of the Mesozoic filling stratigraphy are thicker in the north and the south of the basin, but thinner in the center uplift of the basin. There are two center of subsidence of the basin, both of them are located in south and north foredeep belt, lying in the front of suture belt. The basin is one of common foreland basins between suture belt and belongs to typical symmetric foreland basin.This kind of basin geometry allows large thickness of synsedimentary molasse sediments to be preserved and related to basement uplifts and thrusts in the cratonic edge of the mountain belt.From late Triassic to Cretaceous the foreland basin is filled by four tectonic sequences, including late Triassic tectonic sequence(TS\-1),early Jurassic tectonic sequence(TS\-2), middle Jurassic to early Cretaceous tectonic sequence(TS\-3) and middle to late Cretaceous tectonic sequence (TS\-4).A tectonic Sequence is a body of genetically related strata isolated by unconformity ,deposited in a basining stage responding to a thrusting episode. Late Triassic tectonic sequence(TS\-1) is bounded by Ta and Tb and composed of the Xiaochaka formation which is more than 2500m in depth, it is a coarsing\|upward tectonic sequence,the lower is fan delta sediments with debris conglomerate,the middle is carbonate ramp sediments,the upper is delta sediments; early Jurassic tectonic sequence(TS\-2) is bounded by Tb and Tc and composed of the Nadigangri formation which is more than 1000m in depth, it is a thinning\|upward tectonic sequence,the lower is fan delta sediments with debris conglomerate,the upper is subaquatic detrital sediments; middle Jurassic to early Cretaceous tectonic sequence(TS\-3) is bounded by Tc and Td and composed of the Quemocuo formation,Buqu formation, Xiali formation, Suowa formation and Xueshan formation, which is more than 3000m in depth; middle to late Cretaceous tectonic sequence (TS\-4) is bounded by Td and Tf and composed of the Abushan formation, it is a thinning—upward alluvial fan sediments with more than 1000m in depth.
