The South China Sea Basin is located at the junction of Tethys, Pacific margin, and paleo-Asia tectonic domains. The representative Wan'an Basin in the southwest of the South China Sea Basin has the well-developed Cenozoic strata, but the underappreciated expansion and evolution remains because of a limited understanding of tectonic subsidence and extension mechanism of the basins. Based on the regional geological data, including structural style and stratigraphic sequence, the tectonic evolution history of Wan'an Basin is simulated by utilizing the backstripping method, and the extension factor and extension velocity of Wan'an Basin are obtained after fitting the structural subsidence history through an iterative adjustment of the tensile factor in the McKenzie pure shear tensile model. Furthermore, the heat transfer equation of the lithosphere is used to determine the heat flow of the substrate. The results are given as follows. 1) It is the combined action of the South China Sea expansion, the ridge jump, and the southwest sub-basin expansion that control the sedimentation, extension, and thermal anomalies in Wan'an Basin. 2) Wan'an Basin has unique characteristics of space-time evolution that the left and right rotations of the fracture zone affect the sedimentation which presents a V-shaped transition and that “early east and west, then north and south” is the mainly feature of the extension. 3) Due to the tectonic activity, the extension and thermal anomalies in the basin gradually decline in the directions from the fault to the both sides at different rates.
[1] 任纪舜,王作勋,陈炳蔚,等. 新一代中国大地构造图[J]. 中国区域地质,1997,16(3):2-7.
[2] Kusumastuti A,Rensbergen P V,Warren J K. Seismic sequence analysis and reservoir potential of drowned miocene carbonate platforms in the Madura Strait,East Java,Indonesia[J]. Aapg Bulletin,2002,86(2):213-232.
[3] 姚伯初. 南海西南海盆的海底扩张及其构造意义[J]. 南海地质研究,1997(9):20-36.
[4] Briais A,Patriat P,Tapponnier P. Updated interpretation of magnetic anomalies and seafloor spreading stages in the South China Sea:implications for the Tertiary tectonics of Southeast Asia[J]. Journal of Geophysical Research:Solid Earth,1993,98(B4):6299-6328.
[5] 姚永坚,吕彩丽,王利杰,等. 南沙海区万安盆地构造演化与成因机制[J]. 海洋学报,2018,40(5):62-74.
[6] 施秋华,夏斌,万志峰,等. 万安盆地构造沉降与沉积速率及其油气资源前景[J]. 沉积与特提斯地质,2014,34(2):43-46.
[7] 刘振湖. 南海万安盆地沉降作用与油气前景[J]. 中国海上油气地质,1998,12(4):19-25.
[8] 杨楚鹏,姚永坚,李学杰,等. 万安盆地新生代层序地层格架与岩性地层圈闭[J]. 地球科学——中国地质大学学报,2011,36(5):845-852.
[9] 杨木壮,王明君,梁金强,等. 南海万安盆地构造沉降及其油气成藏控制作用[J]. 海洋地质与第四纪地质,2003,23(2):85-88.
[10] 寻博靖. 万安盆地重磁场特征研究与构造分析[D]. 西安:西安石油大学,2017.
[11] 杨胜雄,邱燕,朱本铎. 南海地质地球物理图系[M]. 天津:中国航海图书出版社,2015.
[12] 张厚和,赫栓柱,刘鹏,等. 万安盆地油气地质特征及其资源潜力新认识[J]. 石油实验地质,2017,39(5):625-632.
[13] 安慧婷,李三忠,索艳慧,等. 南海西部新生代控盆断裂及盆地群成因[J]. 海洋地质与第四纪地质,2012,32(6):95-111.
[14] Liu H,Yan P,Zhang B,et al. Role of the Wan-Na fault system in the western Nansha Islands (southern South China Sea)[J]. Journal of Asian Earth Sciences,2004,23(2):221-233.
[15] Morley C K. A tectonic model for the Tertiary evolution of strike-slip faults and rift basins in SE Asia[J]. Tectonophysics,2002,347(4):189-215.
[16] 刘海龄,姚永坚,沈宝云,等. 南海西缘结合带的贯通性[J]. 地球科学——中国地质大学学报,2015,40(4):615-632.
[17] Taylor B,Hayes D E. The tectonic evolution of the South China Basin[J]. Tectonic & Geologic Evolution of Southeast Asian Seas & Islands,1980,23:89-104.
[18] Watts A B,Ryan W B F. Flexure of the lithosphere and continental margin basins[J]. Tectonophysics,1976,36(1):25-44.
[19] Bond G C,Kominz M A. Construction of tectonic subsidence curves for the early Paleozoic miogeocline, southern Canadian Rocky Mountains:implications for subsidence mechanisms, age of breakup, and crustal thinning[J]. Geological Society of America Bulletin,1984,95(2):155-173.
[20] Mcintyre A. Basin analysis:principles and applications[J]. Economic Geology,2006,113(2):409-442.
[21] 张云帆,廖杰,孙珍,等. 南沙海域构造沉降特征[J]. 地球科学——中国地质大学学报,2011,36(5):949-955.
[22] 赵中贤,孙珍,陈广浩,等. 南沙海域新生代构造特征和沉降演化[J]. 地球科学——中国地质大学学报,2011,36(5):815-822.
[23] Haq B U,Hardenbol J,Vail P R. Chronology of fluctuating sea levels since the Triassic[J]. Science,1987,235(4793):1156-1167.
[24] Athy L F. Density, porosity, and compaction of sedimentary rocks[J]. Aapg Bulletin,1930,14(1):1-24.
[25] King H M,Rubey W W. Role of fluid pressure in mechanics of overthrust faulting:I. Mechanics of fluid-filled porous solids and its application to overthrust faulting[J]. Geological Society of America Bulletin,1959,70(5):115-116.
[26] Clift P,Lin J. Preferential mantle lithospheric extension under the South China margin[J]. Marine & Petroleum Geology,2001,18(8):929-945.
[27] Sclater J G,Christie P A F. Continental stretching:explanation of post-mid-cretaceous subsidence of Central North Sea Basin:Abstract[J]. Aapg Bulletin,1980,85(B7):3711-3739.
[28] Salisbury M H,Shinobara M,Richter C,et al. Proceedings of the ocean drilling program, initial reports[R].Texas,College Station:Ocean Drilling Program,2000:184-185.
[29] 刘振湖. 北康盆地古地热场与油气远景[J]. 海洋地质与第四纪地质,2004,24(2):79-84.
[30] McKenzie D. Some remarks on the development of sedimentary basins[J]. Earth and Planetary Science Letters,1978,40(1):25-32.
[31] White N,Bellingham P. A two-dimensional inverse model for extensional sedimentary basins 1.Theory[J]. Journal of Geophysical Research:Atmospheres,2002,107(B10). doi:10.1029/2001JB000173.:2259-2279.
[32] 李思田,解习农,王华,等. 沉积盆地分析基础与应用[M]. 北京:高等教育出版社,2004:275-288.
[33] 汪集旸,等. 地热学及其应用[M]. 北京:科学出版社,2015.
[34] 李家彪,丁巍伟,高金耀,等. 南海新生代海底扩张的构造演化模式:来自高分辨率地球物理数据的新认识[J]. 地球物理学报,2011,54(12):3004-3015.
[35] Patriat P,Achache J. India|-Eurasia collision chronology has implications for crustal shortening and driving mechanism of plates[J]. Nature,1984,311(5987):615-621.
[36] Aitchison J C,Ali J R,Davis A M. When and where did India and Asia collide?[J]. Journal of Geophysical Research Solid Earth,2007,112(B5):51-70.
[37] Charusiri P,Imsamut S,Zhuang Z,et al. Paleomagnetism of the earliest Cretaceous to early late Cretaceous sandstones, Khorat Group, Northeast Thailand:implications for tectonic plate movement of the Indochina block[J]. Gondwana Research,2006,9(3):310-325.
[38] Takemoto K,Halim N,Otofuji Y I,et al. New paleomagnetic constraints on the extrusion of Indochina:late Cretaceous results from the Song Da terrane, northern Vietnam[J]. Earth & Planetary Science Letters,2005,229(3/4):273-285.
[39] 吴峧岐,高红芳,孙桂华. 南沙海域万安盆地地质构造与沉积体系特征[J]. 海洋地质与第四纪地质,2012,32(5):1-11.
