Structure characteristics and genetic mechanism of extensional faults in Cheduba accretionary wedge-slope basin，Myanmar
YANG Songling1, XIE Jielai2
1. Research Institute of Exploration & Development Technology, CNOOC International Ltd, Beijing 100028, China; 2. SPG Secretariat of CPS, BGP, CNPC, Zhuozhou, Hebei 072751, China
Abstract：In recent years,as a kind of rare oil/gas-bearing basin,accretionary wedge-slope basins have been paid more and more attention to.At present,exploration and research on this kind of basin is relatively less,so its complex structural features,especially the genesis of the complex fault system,have been debating.There are a lot of seismic and geological data about the Cheduba accretionary wedge-slope basin,which provide a basis for study-ing the tectonic characteristics and fault genesis of the basin.Based on the regional geology and under the guidance of the idea of “vertical (tectonic) layers and lateral (segments) blocks”,firstly the fault type is defined in different stages; then the genetic mechanism of the extensional faults that are nearly parallel to the orientation of the accretionary wedge structural belt is discussed.This solves the contradiction between geological understanding and stress.On this basis,a new induced extension model of normal fault development is proposed,and three group of faults with different properties are identified in the Cheduba accretionary wedge- slope basin: S-N compressional faults,NE-SW extensional-transregional faults and NW-SE extensional faults.Controlled by oblique subduction of the ocea-nic crust of the Indian plate to the West Myanmar microplate,the compressive stress field perpendicular to the trench formed S-N compressional faults,and resulted in large-scale thrust activities,the shear stress parallel to the trench formed regulatory NE-SW extensional or transregional faults under the regional right-lateral strike-slip effect and the extensional stress field induced by different horizontal motion components during the activities of the accretionary wedge compression thrust fault zone in the front and back edge of the slope basin resulted in NW-SE extensional faults.The findings of this study are references to other accretionary wedge-slope basins.
周祖翼,李春峰.大陆边缘构造与地球动力学[M].北京:科学出版社,2008.ZHOU Zuyi,LI Chunfeng.Continental Margin Tectonics and Geodynamics[M].Science Press,Beijing,2008.
[2]
任建业.海洋底构造导论[M].北京:中国地质大学出版社,2008.REN Jianye.Introduction of Suboceanic Structure[M].China University of Geosciences Press,Beijing,2008.
[3]
Moore G F,Karig D E.Development of sedimentary basins on the lower trench slope[J].Geology,1976,4(11):693-697.
[4]
Mascle A,Biju-Duval B,Clarens P D,et al.Growth of accretionary prisms:tectonic processes from caribbean examples[J].Developments in Geotectonics,1986,21:375-400.
[5]
Moore G F,Curray J R.Structure of the Sunda Trench lower slope off sumatra from multichannel seismic reflection data[J].Marine Geophysical Researches,1980,4(3):319-340.
Amaral J,Crepieux N,Levache D,et al.Petroleum system characterization,Sinu area(offshore,Colombia)[C].8th Simposio Bolivariano-Exploracion Petrolera en las Cuencas Subandinas,2003.
[8]
Lindberg F A,Ellis J M,Dekker L L.Regional frontier exploration in the Sinu Basin,Northwest Colombia[C].SEG Technical Program Expanded Abstracts,1989,8:1375.
[9]
张波,袁炳强,宋立军,等.哥伦比亚西努-圣哈辛托盆地油气地质特征[J].断块油气田,2014,21(2):152-156.ZHANG Bo,YUAN Bingqiang,SONG Lijun,et al.Petroleum geological features of Sinu-San Jacinto Basin in Colombia[J].Fault-Block Oil and Gas Field,2014,21(2):152-156.
[10]
蔡文杰,朱光辉,姜烨,等.缅甸俯冲增生带的构造特征及勘探前景[J].天然气地球科学,2011,22(4):670-673.CAI Wenjie,ZHU Guanghui,JIANG Ye,et al.Structure features and exploration prospect of subduction-accretionary belt in Myanmar[J].Natural Gas Geoscience,2011,22(4):670-673.
[11]
赖江德,张进铎,蔡东地,等.缅甸M区块地震构造样式分析与研究[J].物探与化探,2009,33(1):24-26.LAI Jiangde,ZHANG Jinduo,CAI Dongdi,et al.An analysis of the seismic structural style of the M block in Myanmar[J].Geophysical & Geochemical Exploration,2009,33(1):24-26.
[12]
蔡文杰,朱光辉,姜烨,等.增生楔盆地物源及沉积相分析——以缅甸某区块为例[J].复杂油气藏,2012,5(4):9-13.CAI Wenjie,ZHU Guanghui,JIANG Ye,et al.A study of provenance and sedimentary facies of accretionary wedge basin:taking a block in Myanmar as an example[J].Complex Hydrocarbon Reservoirs,2012,5(4):9-13.
[13]
邱春光,朱光辉,谢晓军,等.主动大陆边缘海沟-斜坡盆地沉积体系分析——以缅甸若开海岸盆地某工区为例[J].沉积与特提斯地质,2011,31(3):13-19.QIU Chunguang,ZHU Guanghui.XIE Xiaojun,et al.Sedimentary systems in the trench-slope basins along the active continental margins:an example from one block in the Arakan Sea Basin,Myanmar[J].Sedimentary Geology and Tethyan Geology,2011,31(3):13-19.
[14]
张舜尧,马立祥,杨志斌,等.主动大陆边缘增生楔构造发育及沉积特征分析——以缅甸增生楔为例[J].地质科技情报,2015,34(1):89-94.ZHANG Shunyao,MA Lixiang,YANG Zhibin,et al.Accretionary wedge tectonic and sedimentation research of active continental margin:an example of accretionary wedge in Myanmar[J].Geological Science and Technology Information,2015,34(1):89-94.
[15]
Contardo X,Cembrano J,Jensen A,et al.Tectono-sedimentary evolution of marine slope basins in the Chilean Forearc (33°30'-36°50'S):Insights into their link with the subduction process[J].Tectonophysics,2008,459(1-4):0-218.DOI:10.1016/j.tecto.2007.12.014.
[16]
Martin K M,Gulick S P S,Bangs N L B,et al.Possible strain partitioning structure between the Kumano Fore-Arc Basin and the slope of the Nankai Trough Accretionary Prism[J].Geochemistry Geophysics Geosystems,2010,11(5):1-15.
[17]
Wu S G,Takahashi N,Sakamoto I.Seismic sequences and structures in the Eastern Nankai Trough,North Philippine Sea[J].Journal of Geosciences of China,2002,4(2):7-18.
[18]
李春峰,苏新,姜涛,等.日本南海海槽俯冲增生楔前缘的构造变形特征[J].地球科学进展,2010,25(2):203-211.LI Chunfeng,SU Xing,JIANG Tao,et al.Deformation at the front of the accretionary prism of the Nankai Trough,Japan:evidence from core samples[J].Advances in Earth Science,2010,25(2):203-211.
[19]
Flinch J F,Amaral J,Doulcet A,et al.Onshore-offshore structure of the Northern Colombia Accretio-nary Complex[C].AAPG International Conference,Barcelona,Spain,2003.
[20]
Flinch J,Amaral J,A.Doulcet A,et al.Structure of the offshore Sinu accretionary wedge,Northern Colombia[C].8th Simposio Bolivariano-Exploracion Petrolera en las Cuencas Subandinas,2003.
[21]
Wandrey C J.Eocene to Miocene Composite Total Petroleum System,Irrawaddy-Andaman and North Burma Geologic Provinces,Myanmar[R].US Geological Survey,Reston,Virginia,2006.
[22]
许志琴,杨经绥,李海兵,等.印度-亚洲碰撞大地构造[J].地质学报,2011,85(1):1-33.XU Zhiqin,YANG Jingsui,LI Haibing,et al.On the tectonics of the India-Asia collision[J].Acta Geologica Sinica,2011,85(1):1-33.
[23]
Nielsen C,Chamot-Rooke N,Rangin C.From partial to full strain partitioning along the Indo-Burmese Hyper-Oblique Subduction[J].Marine Geology,2004,209(1-4):303-327.
[24]
Socquet A,Vigny C,Chamot-Rooke N,et al.India and Sunda Plates motion and deformation along their boundary in Myanmar determined by GPS[J].Journal of Geophysical Research:Solid Earth,2006,111:B05406.DOI:10.1029/2005JB003877.
[25]
俞红玉,陶开,蔡晨,等.东日本大地震地震序列的震源机制解特征及其动力学意义[J].地球物理学报,2013,56(8):2655-2669.YU Hongyu,TAO Kai,CAI Chen,et al.Focal mechanism solutions of the Tohoku-Oki Earthquake sequence and their geodynamical implications[J].Chinese Journal of Geophysics,2013,56(8):2655-2669.
[26]
Alam M,Alam M M,Curray J R,et al.An overview of the sedimentary geology of the Bengal Basin in relation to the regional tectonic framework and basin-fill history[J].Sedimentary Geology,2003,155(3):179-208.
[27]
Radha Krishna M,Sanu T D.Seismotectonics and rates of active crustal deformation in the Burmese Arc and adjacent regions[J].Journal of Geodynamics,2000,30(4):401-421.
[28]
Pivnik D A,Nahm J,Tucker R S,et al.Polyphase de-formation in a fore-arc back-arc basin,Salin Subbasin,Myanmar[J].AAPG Bulletin,1998,82(10):1837-1856.
[29]
杨松岭,孙云艳,张欲晓,等.缅中盆地Pyay油田勘探挖潜效果[J].石油地球物理勘探,2006,31(增刊1):47-51.YANG Songling,SUN Yunyan.ZHANG Yuxiao,et al.Effect of digging potential in Pyay Oilfield of Mid Burma Basin[J].Oil Geophysical Prospecting,2006,31(S1):47-51.
[30]
Goldfinger C,Kulm L V D,Yeats R S,et al.Oblique strike-slip faulting of the Central Cascadia Submarine Forearc[J].Journal of Geophysical Research,1997,102(B4):8217-8243.DOI:10.1029/96jb02655.
[31]
Osozawa S.Normal faults in an accretionary complex formed at trench-trench-ridge triple junction,as an indicator of angle between the trench and subducted ridge[J].Island Arc,2006,2(3):142-151.
[32]
陈景达.板块构造大陆边缘与含油气盆地[M].北京:石油大学出版社,1989.CHEN Jingda.Plate Tectonic Continental Margin and Petroliferous Basin[M].China University of Petro-leum Press,Beijing,1989.
[33]
李三忠,郭晓玉,侯方辉,等.活动大陆边缘的板片窗构造[J].海洋地质前沿,2004,20(11):6-18.LI Sanzhong,GUO Xiaoyu,HOU Fanghui,et al.Slab window in the active continental margin[J].Marine Geology Letters,2004,20(11):6-18.
[34]
Dragert H,Hyndman R D,Rogers G C,et al.Current deformation and the width of the seismogenic zone of the Northern Cascadia Subduction Thrust[J].Journal of Geophysical Research,1994,99(B1):653-668.
[35]
Moore G F,Bangs N L,Taira A,et al.Three-dimensional splay fault geometry and implications for Tsunami generation[J].Science,2007,318(5853):1128-1131.
[36]
迈尔A D著;孙枢等译.沉积盆地分析原理[M].北京:石油工业出版社,1991.Miall A D.Principles of Sedimentary Basin Analysis[M].Petroleum Industry Press,Beijing,1991.
