Lying on the west edge of Dongting Lake,the Taiyangshan area in Hunan Province is part of a hilly region which has uplifted since the Late Cenozoic.According to field investigation of the six existing faults in the Ta...Lying on the west edge of Dongting Lake,the Taiyangshan area in Hunan Province is part of a hilly region which has uplifted since the Late Cenozoic.According to field investigation of the six existing faults in the Taiyangshan area,we found that four of them are not active in the Quaternary,and that the Gangshi-Hefu fault is likely to have been active in the early Mid-Pleistocene.The geological evidence derived suggests that the Xiaowupu fault was active from the late Mid-Pleistocene to the early late-Pleistocene.It cut the stratum with a TL age of 123±10ka BP and has the property of thrusting.The research results are of great significance for understanding the seismogenic structure of the Changde earthquake with M6 3/4 in 1631.展开更多
The Bohai Bay Basin(BBB)is the most petroliferous Cenozoic basin in the east of China.It consists of seven depressions.Each depression has been subjected to different stress states and then has experienced varying fau...The Bohai Bay Basin(BBB)is the most petroliferous Cenozoic basin in the east of China.It consists of seven depressions.Each depression has been subjected to different stress states and then has experienced varying faulting processes since the Neogene,especially during the Neotectonism(from the Pliocene to the present).On the basis of the investigation of fault patterns,fault densities and fault activity rates(FARs)for each depression,this paper demonstrates the discrepancy of faulting development and evolution across the BBB.The dynamic mechanism for the differences in faulting is also discussed by the analysis of the regional stress state.The Bozhong Depression is just situated in the transtensional zone induced by the two active strike-slip faults,namely Yingkou-Weifang and Beijing-Penglai.In this depression,the major faults which cut through the Paleogene or the Cenozoic have had higher than 10 m/Ma FARs since the Neogene,and the highest FARs have reached or exceeded 25 m/Ma during the Neotectonism.As a result,most of the petroleum has migrated along these major faults and accumulated within the Neogene.In contrast,in the other depressions of the BBB away from the Bozhong Depression,the FARs of the major faults were decreased to lower than 10 m/Ma since the Neogene,and tended to be zero during the Neotectonism.Therefore,the major faults could not serve as vertical conduits for petroleum migration,and the petroleum was entrapped in the Paleogene.Consequently,the faulting since the Neogene,especially during the Neotectonism,controlled the petroleum richness in vertical strata.展开更多
基金funded by the National Science and Technology Support Project entitled "Study on Key Technologies for Strong Earthquake Zoning (2006BAC13B01)"
文摘Lying on the west edge of Dongting Lake,the Taiyangshan area in Hunan Province is part of a hilly region which has uplifted since the Late Cenozoic.According to field investigation of the six existing faults in the Taiyangshan area,we found that four of them are not active in the Quaternary,and that the Gangshi-Hefu fault is likely to have been active in the early Mid-Pleistocene.The geological evidence derived suggests that the Xiaowupu fault was active from the late Mid-Pleistocene to the early late-Pleistocene.It cut the stratum with a TL age of 123±10ka BP and has the property of thrusting.The research results are of great significance for understanding the seismogenic structure of the Changde earthquake with M6 3/4 in 1631.
基金supported by National Natural Science Foundation of China (Grant Nos. 90914006, 41271265)National Science & Technology Specific Project (Grant No. 2011ZX05023-006-07)
文摘The Bohai Bay Basin(BBB)is the most petroliferous Cenozoic basin in the east of China.It consists of seven depressions.Each depression has been subjected to different stress states and then has experienced varying faulting processes since the Neogene,especially during the Neotectonism(from the Pliocene to the present).On the basis of the investigation of fault patterns,fault densities and fault activity rates(FARs)for each depression,this paper demonstrates the discrepancy of faulting development and evolution across the BBB.The dynamic mechanism for the differences in faulting is also discussed by the analysis of the regional stress state.The Bozhong Depression is just situated in the transtensional zone induced by the two active strike-slip faults,namely Yingkou-Weifang and Beijing-Penglai.In this depression,the major faults which cut through the Paleogene or the Cenozoic have had higher than 10 m/Ma FARs since the Neogene,and the highest FARs have reached or exceeded 25 m/Ma during the Neotectonism.As a result,most of the petroleum has migrated along these major faults and accumulated within the Neogene.In contrast,in the other depressions of the BBB away from the Bozhong Depression,the FARs of the major faults were decreased to lower than 10 m/Ma since the Neogene,and tended to be zero during the Neotectonism.Therefore,the major faults could not serve as vertical conduits for petroleum migration,and the petroleum was entrapped in the Paleogene.Consequently,the faulting since the Neogene,especially during the Neotectonism,controlled the petroleum richness in vertical strata.
