The growth strata was investigated in the Early Cretaceous deposits including Fahliyan, Gadvan and Dariyan formations in the Well 3 that is located between Qatar-Fars height and Hormuz Strait in Persian Gulf. This stu...The growth strata was investigated in the Early Cretaceous deposits including Fahliyan, Gadvan and Dariyan formations in the Well 3 that is located between Qatar-Fars height and Hormuz Strait in Persian Gulf. This study is based on the lithostratigraphic analysis and microfossils distribution. Lithostratigraphically, the Well 3 is divided into three rock units including Fahliyan, Gadvan and Dariyan. Based on the microfossils content, the age of studied successions is Berriasian to Aptian. The comparison of seismic studies, lithostratigraphic analysis and microfossils distribution show that growth and generation of anticlines construct in the Early Cretaceous. As a result, the Fahliyan, Gadvan and Dariyan rock units have potential reservoir and oil trap.展开更多
The northwestward subduction of the Izanagi Plate beneath the eastern Eurasian Plate during the Late Mesozoic caused a series of compressional deformation events in the Yanshan fold and thrust belt(YFTB), but the tect...The northwestward subduction of the Izanagi Plate beneath the eastern Eurasian Plate during the Late Mesozoic caused a series of compressional deformation events in the Yanshan fold and thrust belt(YFTB), but the tectonic deformation timing, tectonic properties and relationship between tectonic uplift and sediment accumulation in the intermontane basins continue to be debated. For this reason, the sedimentology, sediment provenance, and basin structure of the Qianjiadian Basin(QJB) in the northern Beijing region during the Late Jurassic and Early Cretaceous were studied in detail. The results suggest that a fault-propagation fold-type(FPFT) growth structure and growth strata developed on the western edge of the QJB and that the top part of Member 2 and Member 3 of the Tuchengzi Formation are growth strata controlled by the limb rotation mechanism. In two small thrust faults in the QJB, the Mesoproterozoic Xiamaling Formation is thrust over the Tuchengzi Formation, and these faults may have controlled the development of the fault-bend fold-type growth strata. An analysis of the "source-to-sink" process suggests that the hanging wall succession of the Shangyi-Pingquan fault(SPF) was the main source area of the Late Jurassic to early Early Cretaceous strata in the QJB. A zircon206 Pb/238 U age of 140.8±2.4 Ma for the volcanic rocks at the bottom of the FPFT growth strata represents the timing of the initiation of FPFT growth structure development. The discovery of the FPFT growth structure and growth strata in the QJB indicate that the QJB was an intermontane flexural basin controlled by fold and thrust structures during the early Early Cretaceous. Near the E-W-trending SPF, the NE-SW-trending Qianjiadian thrust fault(QJTF) and two small intrabasinal thrust faults may constitute a unified right-lateral strike-slip system that formed in response to the northwestward flat subduction of the Izanagi Plate beneath the East Asian continent during the Jurassic-Early Cretaceous.展开更多
As a consequence of the collision of India with Asia, the Qilian Shan, rising 4000～5000m above the Gobi, marks the northeastern boundary of the Tibet—Qinghai Plateau. The Qilian Shan developed as a WNW—ESE fold\|an...As a consequence of the collision of India with Asia, the Qilian Shan, rising 4000～5000m above the Gobi, marks the northeastern boundary of the Tibet—Qinghai Plateau. The Qilian Shan developed as a WNW—ESE fold\|and\|thrust belt with most of the movement directed towards the NEN—NE. Its foreland margin, the Jiuxi Basin, accommodates thick sequences of Late Cenozoic alluvial sediments derived from the Qilian Shan. Thin\|skinned fold\|and\|thrust deformation in the Jiuxi basin flanking the Qilian Shan, feature Mesozoic and Cenozoic sedimentary rocks that have been detached from the underlying basal decollement and folded into a series of NW—WNW trending anticlines and synclines. Towards the south deformation in the Jiuxi basin is accommodated by a west\|north\|west fold train (Qingcaowan, Laojunmiao, and Shiyougou folds) developed during the Quaternary. These form a distinct topographic feature separating the Qilian Shan from the central Jiuxi Basin. The doubly plunging Laojunmiao anticline is 10km long and 5km wide. It is asymmetric in shape, having a steep to overturned northern limb, and a backlimb dips to the south at 20～30°. The Laojunmiao anticline is composed of two distinct stratigraphic sequences which are defined by a syntectonic unconformity.展开更多
The Tianshan range,a Paleozoic orogenic belt in Central Asia,has undergone multiple phases of tectonic activities characterized by the N-S compression after the early Mesozoic,including the far-field effects of the Ce...The Tianshan range,a Paleozoic orogenic belt in Central Asia,has undergone multiple phases of tectonic activities characterized by the N-S compression after the early Mesozoic,including the far-field effects of the Cenozoic Indian-Asian collision.However,there are limited reports on the tectonic deformation and initiation of Triassic intracontinental deformation in the Tianshan range.Understanding this structural context is crucial for interpreting the early intracontinental deformation history of the Eurasian continent during the early Mesozoic.Growth strata and syn-tectonic sediments provide a rich source of information on tectonic activities and have been extensively used in the studies of orogenic belts.Based on detail fieldwork conducted in this study,the middle-late Triassic Kelamayi Formation of the northern Kuqa Depression in the southern Tianshan fold-thrust belt has been identified as the typical syn-tectonic growth strata.The youngest detrital zircon component in two lithic sandstone samples from the bottom and top of the Kelamayi growth strata yielded U-Pb ages of 223.4±3.1 and 215.5±2.9 Ma,respectively,indicating that the maximum depositional age of the bottom and top of the Kelamayi growth strata is 226-220 and 218-212 Ma.The geochronological distribution of detrital samples from the Early-Middle Triassic and Late Triassic revealed abrupt changes,suggesting a new source supply resulting from tectonic activation in the Tianshan range.The coupling relationship between the syn-tectonic sedimentation of the Kelamayi Formation and the South Tianshan fold-thrust system provides robust evidence that the Triassic intracontinental deformation of the South Tianshan range began at approximately 226-220 Ma(during the Late Triassic)and ended at approximately 218-212 Ma.These findings provide crucial constraints for understanding the intraplate deformation in the Tianshan range during the Triassic.展开更多
文摘The growth strata was investigated in the Early Cretaceous deposits including Fahliyan, Gadvan and Dariyan formations in the Well 3 that is located between Qatar-Fars height and Hormuz Strait in Persian Gulf. This study is based on the lithostratigraphic analysis and microfossils distribution. Lithostratigraphically, the Well 3 is divided into three rock units including Fahliyan, Gadvan and Dariyan. Based on the microfossils content, the age of studied successions is Berriasian to Aptian. The comparison of seismic studies, lithostratigraphic analysis and microfossils distribution show that growth and generation of anticlines construct in the Early Cretaceous. As a result, the Fahliyan, Gadvan and Dariyan rock units have potential reservoir and oil trap.
基金supported by the National Key Research and Development Project (Grant No. 2017YFC0601405)the National Natural Science Foundation of China (Grant Nos. 41572189 & 41820104004)the Strategic Priority Research Program of the Chinese Academy of Sciences (Grant No. XDB18030604)
文摘The northwestward subduction of the Izanagi Plate beneath the eastern Eurasian Plate during the Late Mesozoic caused a series of compressional deformation events in the Yanshan fold and thrust belt(YFTB), but the tectonic deformation timing, tectonic properties and relationship between tectonic uplift and sediment accumulation in the intermontane basins continue to be debated. For this reason, the sedimentology, sediment provenance, and basin structure of the Qianjiadian Basin(QJB) in the northern Beijing region during the Late Jurassic and Early Cretaceous were studied in detail. The results suggest that a fault-propagation fold-type(FPFT) growth structure and growth strata developed on the western edge of the QJB and that the top part of Member 2 and Member 3 of the Tuchengzi Formation are growth strata controlled by the limb rotation mechanism. In two small thrust faults in the QJB, the Mesoproterozoic Xiamaling Formation is thrust over the Tuchengzi Formation, and these faults may have controlled the development of the fault-bend fold-type growth strata. An analysis of the "source-to-sink" process suggests that the hanging wall succession of the Shangyi-Pingquan fault(SPF) was the main source area of the Late Jurassic to early Early Cretaceous strata in the QJB. A zircon206 Pb/238 U age of 140.8±2.4 Ma for the volcanic rocks at the bottom of the FPFT growth strata represents the timing of the initiation of FPFT growth structure development. The discovery of the FPFT growth structure and growth strata in the QJB indicate that the QJB was an intermontane flexural basin controlled by fold and thrust structures during the early Early Cretaceous. Near the E-W-trending SPF, the NE-SW-trending Qianjiadian thrust fault(QJTF) and two small intrabasinal thrust faults may constitute a unified right-lateral strike-slip system that formed in response to the northwestward flat subduction of the Izanagi Plate beneath the East Asian continent during the Jurassic-Early Cretaceous.
文摘As a consequence of the collision of India with Asia, the Qilian Shan, rising 4000～5000m above the Gobi, marks the northeastern boundary of the Tibet—Qinghai Plateau. The Qilian Shan developed as a WNW—ESE fold\|and\|thrust belt with most of the movement directed towards the NEN—NE. Its foreland margin, the Jiuxi Basin, accommodates thick sequences of Late Cenozoic alluvial sediments derived from the Qilian Shan. Thin\|skinned fold\|and\|thrust deformation in the Jiuxi basin flanking the Qilian Shan, feature Mesozoic and Cenozoic sedimentary rocks that have been detached from the underlying basal decollement and folded into a series of NW—WNW trending anticlines and synclines. Towards the south deformation in the Jiuxi basin is accommodated by a west\|north\|west fold train (Qingcaowan, Laojunmiao, and Shiyougou folds) developed during the Quaternary. These form a distinct topographic feature separating the Qilian Shan from the central Jiuxi Basin. The doubly plunging Laojunmiao anticline is 10km long and 5km wide. It is asymmetric in shape, having a steep to overturned northern limb, and a backlimb dips to the south at 20～30°. The Laojunmiao anticline is composed of two distinct stratigraphic sequences which are defined by a syntectonic unconformity.
基金supported by the National Key Research and Development Project(Grant No.2018YFC0603700)research grants from the China Geological Survey(Grant Nos.DD20230408,DD20190011,DD20191011 and DD20221824)+1 种基金the Fundamental Research Funds from the Chinese Academy of Geological Sciences(Grant No.JKY202011)the Key Laboratory of Airborne Geophysics and Remote Sensing Geology Ministry of Natural Resources(Grant No.2023YFL23)。
文摘The Tianshan range,a Paleozoic orogenic belt in Central Asia,has undergone multiple phases of tectonic activities characterized by the N-S compression after the early Mesozoic,including the far-field effects of the Cenozoic Indian-Asian collision.However,there are limited reports on the tectonic deformation and initiation of Triassic intracontinental deformation in the Tianshan range.Understanding this structural context is crucial for interpreting the early intracontinental deformation history of the Eurasian continent during the early Mesozoic.Growth strata and syn-tectonic sediments provide a rich source of information on tectonic activities and have been extensively used in the studies of orogenic belts.Based on detail fieldwork conducted in this study,the middle-late Triassic Kelamayi Formation of the northern Kuqa Depression in the southern Tianshan fold-thrust belt has been identified as the typical syn-tectonic growth strata.The youngest detrital zircon component in two lithic sandstone samples from the bottom and top of the Kelamayi growth strata yielded U-Pb ages of 223.4±3.1 and 215.5±2.9 Ma,respectively,indicating that the maximum depositional age of the bottom and top of the Kelamayi growth strata is 226-220 and 218-212 Ma.The geochronological distribution of detrital samples from the Early-Middle Triassic and Late Triassic revealed abrupt changes,suggesting a new source supply resulting from tectonic activation in the Tianshan range.The coupling relationship between the syn-tectonic sedimentation of the Kelamayi Formation and the South Tianshan fold-thrust system provides robust evidence that the Triassic intracontinental deformation of the South Tianshan range began at approximately 226-220 Ma(during the Late Triassic)and ended at approximately 218-212 Ma.These findings provide crucial constraints for understanding the intraplate deformation in the Tianshan range during the Triassic.
