珠江口盆地开平凹陷边界断层三维几何学与运动学
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摘要
神开断层位于开平凹陷北部,是发育在南海被动大陆边缘洋陆过渡带的大型伸展拆离边界断层.本文以高精度2/3D地震资料和测井资料为基础,首次对神开断层的三维几何学和运动学特征进行剖析.根据断距变化,结合走向、倾向、倾角特征,将神开断层分为西南、中、东北三段;空间上认为神开断层断面是由多个等倾角区组成的复杂曲面,重建其几何学形态模型,通过5个垂向轴面和3个横向轴面将神开断层断面分为20个区.以正断层相关褶皱理论为指导,对神开断层运动学特征进行深入研究;根据平衡剖面对比,认为断层西南段、东北段在始新世早期开始发育,中段在始新世中晚期发育并与西南段和东北段连锁形成一条断层;断层旋转程度自西南向东北变弱;断层西南段反转强度最大,中段次之,东北段无反转.神开断层西南段为"反犁式"形态;中段为"座椅式"形态,与大洋核杂岩伴生;东北段为"犁式"形态.断层下盘的波瓦状构造为古老的拆离断层面,与神开断层一起构成拆离断层系.
Located in the north of the Kaiping Depression,the Shenkai fault is a large-scale extensional detachment boundary fault developed at the passive continental margin of the South China sea.In this study,the 3 Dgeometrical and kinematic characteristics of the Shenkai fault was firstly analyzed based on high-resolution 2/3 Dseismic data and logging data.According to the variations in displacement of the fault as well as the strike,dip and dip-angle characteristics,this fault was divided into three segments,i.e.southwest,central and northeast.The fault plane,which could be subdivided into 20 subzones by 5 vertical axial planes and 3 transversalaxial planes,is a curved surface consisting of several dip domains.The kinematic characteristic of the fault was analyzed on the basis of the theory of normal fault-bend folds.Based on the balanced geologic cross-sections,we established that the southwest and northeast segments of this fault developed in the early Eocene;the central segment formed in the middle and late Eocene,then the southwest and northeast segments were linked into one fault.The rotation degree of the fault weakens from southwest to northeast.The largest reverse degree appears on the southwest segment,followed by the central segment and the northeast segment,without reversal.The anti-listric form developed in the southwest segment and seat-type normal faults are in the central segment and listric in the northeast segment,respectively.The detachment fault system is made up of the Shenkai fault and the old imbricate detachment structure on its footwall.
Located in the north of the Kaiping Depression,the Shenkai fault is a large-scale extensional detachment boundary fault developed at the passive continental margin of the South China sea.In this study,the 3 Dgeometrical and kinematic characteristics of the Shenkai fault was firstly analyzed based on high-resolution 2/3 Dseismic data and logging data.According to the variations in displacement of the fault as well as the strike,dip and dip-angle characteristics,this fault was divided into three segments,i.e.southwest,central and northeast.The fault plane,which could be subdivided into 20 subzones by 5 vertical axial planes and 3 transversalaxial planes,is a curved surface consisting of several dip domains.The kinematic characteristic of the fault was analyzed on the basis of the theory of normal fault-bend folds.Based on the balanced geologic cross-sections,we established that the southwest and northeast segments of this fault developed in the early Eocene;the central segment formed in the middle and late Eocene,then the southwest and northeast segments were linked into one fault.The rotation degree of the fault weakens from southwest to northeast.The largest reverse degree appears on the southwest segment,followed by the central segment and the northeast segment,without reversal.The anti-listric form developed in the southwest segment and seat-type normal faults are in the central segment and listric in the northeast segment,respectively.The detachment fault system is made up of the Shenkai fault and the old imbricate detachment structure on its footwall.
引文
Chen H Z,Wu X J,Zhou D,et al.2005.Meso-Cenozoic Faults in Zhujiangkou River Mouth Basin and Their Geodynamic Background.Journal of Tropical Oceanography,24(2):52-61.
Cheng Z H,Ding W W,Fang Y X,et al.2013.Research progress in continental margin dynamics of South China Sea:From continental rifting to sea-floor spreading.Marine Geology Frontiers(in Chinese),29(1):1-10.
Dai Y D,Pang X,Li P L.1998.Study on hydrocarbon accumulation in Kaiping Sag of Pearl River Mouth Basin.China Offshore Oil and Gas:Geology(in Chinese),12(1):12-18.
Davis G A,Zheng D Y.2002.Metamorphic core complexes:Definition,types and tectonic setting.Geological Bulletin of China(in Chinese),21(4-5):185-192.
De Matos R M D.1993.Geometry of the hanging wall above a system of listric normal faults:A numerical solution.AAPGBulletin,77(11):1839-1859.
Dong D D.2008.Structural evolution and resource effect of the deepwater area,the northern margin of the south China sea[Ph.D.thesis].Beijing:Institute of Oceanology,Chinese Academy of Sciences.
Gao LM,He D F,Gui B L,et al.2014.3D geometrical and kinematic characteristics of boundary faults in Minfeng subsag,Dongying sag,Bohai bay basin.Petroleum Exploration and Development(in Chinese),41(5):546-553.
Gui B L,He D F,Yan F W,et al.2012.3Dgeometry and kinematics of Daxing fault:its constraints on the origin of Langgu depression,Bohaiwan gulf basin,China.Earth Science Frontiers(in Chinese),19(5):86-99.
Lei C,Ren J Y,Tong D J.2013.Geodynamics of the oceancontinent transition zone,northern margin of the South China Sea:Implications for the opening of the South China Sea.Chinses J.Geophys.(in Chinese),56(4):1287-1299,doi:10.6038/cjg20130423.
Medwedeff D A.1989.Growth fault-bend folding at southeast Lost Hills,San Joaquin Valley,California.AAPG Bulletin,73(1):54-67.
Pang X,Chen J,Dai Y D,et al.1995.Study on hydrocarbon accumulation and exploration targets in west baiyun-kaiping sag of pearl river mouth basin.China Offshore Oil and Gas:Geology,9(4):237-245.
Ren J Y,Pang X,Lei C,et al.2015.Ocean and continent transition in passive continental margins and analysis of lithospheric extension and breakup process:Implication for research of the deepwater basins in the continental margins of South China Sea.Earth Science Frontiers(in Chinese),22(1):102-114.
Shaw J H,Hook S C,Sitohang E P.1997.Extensional fault-bend folding and synrift deposition:An example from the Central Sumatra Basin,Indonesia.AAPG Bulletin,81(3):367-379.
Sun Z,Liu S Q,Pang X,et al.2016.Recent research progress of the rifting-breakup process in passive continental margins.Journal of Tropical Oceanography(in Chinese),35(1):1-16.
Wernicke B,Burchfiel B C.1982.Modes of extensional tectonics.Journal of Structural Geology,4(2):105-115.
Xiao H B,Suppe J.1922.Origin of rollover.American Association of Petroleum Geologists Bulletin,76(4):509-529.
Yu Z T,Li J B,Ding W W,et al.2014.Progress in researches on oceanic core complexes and detachment faults.Advances in Marine Science(in Chinese),32(3):415-426.
陈汉宗,吴湘杰,周蒂等.2005.珠江口盆地中新生代主要断裂特征和动力背景分析.热带海洋学报,24(2):52-61.
程子华,丁巍伟,方银霞等.2013.南海大陆边缘动力学研究进展:从陆缘裂解到海底扩张.海洋地质前沿,29(1):1-10.
戴一丁,庞雄,李平鲁.1998.珠江口盆地开平凹陷油气聚集条件分析.中国海上油气:地质,12(1):12-18.
Davis G A,郑亚东.2002.变质核杂岩的定义、类型及构造背景.地质通报,21(4-5):185-192.
董冬冬.2008.南海北部陆缘深水区构造演化及其资源效应[博士论文].北京:中国科学院研究生院.
高丽明,何登发,桂宝玲等.2014.东营凹陷民丰洼陷边界断层三维几何学及运动学特征.石油勘探与开发,41(5):546-553.
桂宝玲,何登发,闫福旺等.2012.大兴断层的三维几何学与运动学及其对廊固凹陷成因机制的约束.地学前缘,19(5):86-99.
雷超,任建业,佟殿军.2013.南海北部洋陆转换带盆地发育动力学机制.地球物理学报,56(4):1287-1299,doi:10.6038/cjg20130423.
庞雄,陈隽,戴一丁等.1995.珠江口盆地白云西一开平凹陷油气聚集及勘探目标研究.中国海上油气:地质,9(4):237-245.
任建业,庞雄,雷超等.2015.被动陆缘洋陆转换带和岩石圈伸展破裂过程分析及其对南海陆缘深水盆地研究的启示.地学前缘,22(1):102-114.
孙珍,刘思青,庞雄等.2016.被动大陆边缘伸展-破裂过程研究进展.热带海洋学报,35(1):1-16.
于志腾,李家彪,丁巍伟等.2014.大洋核杂岩与拆离断层研究进展.海洋科学进展,32(3):415-426.
Cheng Z H,Ding W W,Fang Y X,et al.2013.Research progress in continental margin dynamics of South China Sea:From continental rifting to sea-floor spreading.Marine Geology Frontiers(in Chinese),29(1):1-10.
Dai Y D,Pang X,Li P L.1998.Study on hydrocarbon accumulation in Kaiping Sag of Pearl River Mouth Basin.China Offshore Oil and Gas:Geology(in Chinese),12(1):12-18.
Davis G A,Zheng D Y.2002.Metamorphic core complexes:Definition,types and tectonic setting.Geological Bulletin of China(in Chinese),21(4-5):185-192.
De Matos R M D.1993.Geometry of the hanging wall above a system of listric normal faults:A numerical solution.AAPGBulletin,77(11):1839-1859.
Dong D D.2008.Structural evolution and resource effect of the deepwater area,the northern margin of the south China sea[Ph.D.thesis].Beijing:Institute of Oceanology,Chinese Academy of Sciences.
Gao LM,He D F,Gui B L,et al.2014.3D geometrical and kinematic characteristics of boundary faults in Minfeng subsag,Dongying sag,Bohai bay basin.Petroleum Exploration and Development(in Chinese),41(5):546-553.
Gui B L,He D F,Yan F W,et al.2012.3Dgeometry and kinematics of Daxing fault:its constraints on the origin of Langgu depression,Bohaiwan gulf basin,China.Earth Science Frontiers(in Chinese),19(5):86-99.
Lei C,Ren J Y,Tong D J.2013.Geodynamics of the oceancontinent transition zone,northern margin of the South China Sea:Implications for the opening of the South China Sea.Chinses J.Geophys.(in Chinese),56(4):1287-1299,doi:10.6038/cjg20130423.
Medwedeff D A.1989.Growth fault-bend folding at southeast Lost Hills,San Joaquin Valley,California.AAPG Bulletin,73(1):54-67.
Pang X,Chen J,Dai Y D,et al.1995.Study on hydrocarbon accumulation and exploration targets in west baiyun-kaiping sag of pearl river mouth basin.China Offshore Oil and Gas:Geology,9(4):237-245.
Ren J Y,Pang X,Lei C,et al.2015.Ocean and continent transition in passive continental margins and analysis of lithospheric extension and breakup process:Implication for research of the deepwater basins in the continental margins of South China Sea.Earth Science Frontiers(in Chinese),22(1):102-114.
Shaw J H,Hook S C,Sitohang E P.1997.Extensional fault-bend folding and synrift deposition:An example from the Central Sumatra Basin,Indonesia.AAPG Bulletin,81(3):367-379.
Sun Z,Liu S Q,Pang X,et al.2016.Recent research progress of the rifting-breakup process in passive continental margins.Journal of Tropical Oceanography(in Chinese),35(1):1-16.
Wernicke B,Burchfiel B C.1982.Modes of extensional tectonics.Journal of Structural Geology,4(2):105-115.
Xiao H B,Suppe J.1922.Origin of rollover.American Association of Petroleum Geologists Bulletin,76(4):509-529.
Yu Z T,Li J B,Ding W W,et al.2014.Progress in researches on oceanic core complexes and detachment faults.Advances in Marine Science(in Chinese),32(3):415-426.
陈汉宗,吴湘杰,周蒂等.2005.珠江口盆地中新生代主要断裂特征和动力背景分析.热带海洋学报,24(2):52-61.
程子华,丁巍伟,方银霞等.2013.南海大陆边缘动力学研究进展:从陆缘裂解到海底扩张.海洋地质前沿,29(1):1-10.
戴一丁,庞雄,李平鲁.1998.珠江口盆地开平凹陷油气聚集条件分析.中国海上油气:地质,12(1):12-18.
Davis G A,郑亚东.2002.变质核杂岩的定义、类型及构造背景.地质通报,21(4-5):185-192.
董冬冬.2008.南海北部陆缘深水区构造演化及其资源效应[博士论文].北京:中国科学院研究生院.
高丽明,何登发,桂宝玲等.2014.东营凹陷民丰洼陷边界断层三维几何学及运动学特征.石油勘探与开发,41(5):546-553.
桂宝玲,何登发,闫福旺等.2012.大兴断层的三维几何学与运动学及其对廊固凹陷成因机制的约束.地学前缘,19(5):86-99.
雷超,任建业,佟殿军.2013.南海北部洋陆转换带盆地发育动力学机制.地球物理学报,56(4):1287-1299,doi:10.6038/cjg20130423.
庞雄,陈隽,戴一丁等.1995.珠江口盆地白云西一开平凹陷油气聚集及勘探目标研究.中国海上油气:地质,9(4):237-245.
任建业,庞雄,雷超等.2015.被动陆缘洋陆转换带和岩石圈伸展破裂过程分析及其对南海陆缘深水盆地研究的启示.地学前缘,22(1):102-114.
孙珍,刘思青,庞雄等.2016.被动大陆边缘伸展-破裂过程研究进展.热带海洋学报,35(1):1-16.
于志腾,李家彪,丁巍伟等.2014.大洋核杂岩与拆离断层研究进展.海洋科学进展,32(3):415-426.