Four detachment systems have been found in the Tarim Basin. They are made up of the Proterozoic,Palaeozoic, Mesozoic-Eogene and Neogene-Quaternary, respectively. The shallow-level detachments are char-acterized by the...Four detachment systems have been found in the Tarim Basin. They are made up of the Proterozoic,Palaeozoic, Mesozoic-Eogene and Neogene-Quaternary, respectively. The shallow-level detachments are char-acterized by the occurrence of fold-thrust belts in the Meso-Cenozoic. The mid-level detachments are markedby nappes, decollement folds and drag anticlines in the Palaeozoic. The deep-level detachments are representedby ductile shear belts in the basement. Mid-and deep-level detachments mainly occur in the Northern, Centraland Southern Uplifts which are major hydrocarbon accumulation belts of large-scale oil fields. Shallow-leveldetachments mainly exist in the Kuqa, Southwestern and Southeastern Depressions, which are favourable beltsfor finding medium- and small-sized oil-gas fields.展开更多
Refering to geological evidences and recent Lincheng-Julu deep seismic reflection profile in the west-central part of North China Basin, it is concluded preliminarily that a low angle detachment structure may exist in...Refering to geological evidences and recent Lincheng-Julu deep seismic reflection profile in the west-central part of North China Basin, it is concluded preliminarily that a low angle detachment structure may exist in the central part of North China depression. Numerical method is used to simulate the influence of hot mantle intrusive bodies to Cenozoic basin tectonic movements. Numerical simulations show that,① The intrusion of hot mantle material has led to an extensional stress state in the upper crust in central North China depression. As time increasing, the extensional stress state changed slightly in the upper crust and was in keeping with the normal faulting tectonics in the upper crust in depression area. ② In Cenozoic era, under the effects of magmatic intrusion and the resistance of Taihang Mountain, the weak zone produced by the Mesozoic thrust faulting would become a detachment structure.③ With the elapse of time, the horizontal compressive stress gradually concentrated in the median crust, and the concentration of stress may generate strike-slip earthquakes in the median crust above the intrusive body.展开更多
文摘Four detachment systems have been found in the Tarim Basin. They are made up of the Proterozoic,Palaeozoic, Mesozoic-Eogene and Neogene-Quaternary, respectively. The shallow-level detachments are char-acterized by the occurrence of fold-thrust belts in the Meso-Cenozoic. The mid-level detachments are markedby nappes, decollement folds and drag anticlines in the Palaeozoic. The deep-level detachments are representedby ductile shear belts in the basement. Mid-and deep-level detachments mainly occur in the Northern, Centraland Southern Uplifts which are major hydrocarbon accumulation belts of large-scale oil fields. Shallow-leveldetachments mainly exist in the Kuqa, Southwestern and Southeastern Depressions, which are favourable beltsfor finding medium- and small-sized oil-gas fields.
文摘Refering to geological evidences and recent Lincheng-Julu deep seismic reflection profile in the west-central part of North China Basin, it is concluded preliminarily that a low angle detachment structure may exist in the central part of North China depression. Numerical method is used to simulate the influence of hot mantle intrusive bodies to Cenozoic basin tectonic movements. Numerical simulations show that,① The intrusion of hot mantle material has led to an extensional stress state in the upper crust in central North China depression. As time increasing, the extensional stress state changed slightly in the upper crust and was in keeping with the normal faulting tectonics in the upper crust in depression area. ② In Cenozoic era, under the effects of magmatic intrusion and the resistance of Taihang Mountain, the weak zone produced by the Mesozoic thrust faulting would become a detachment structure.③ With the elapse of time, the horizontal compressive stress gradually concentrated in the median crust, and the concentration of stress may generate strike-slip earthquakes in the median crust above the intrusive body.
