Continental drift process revealed by high precision seismic survey in the central basin of the South China Sea

doi:10.13745/j.esf.sf.2022.6.10

Abstract

Abstract:

The formation and evolution of the South China Sea have been widely studied. More than five genetic models have been proposed. The current popular model is seafloor spreading, but the model could not reasonably explain the mid-ocean ridge jumping in the South China Sea and the continental fragments found in the central basin of the South China Sea. In this study, based on two high precision seismic exploration sections in the central basin of the South China Sea, a new tectonic geological interpretation of the two seismic exploration sections was given on the basis of an in-depth analysis of the layered structure of the oceanic crust. Then, through examination of the formation process of extensional tectonics, a model of continental drift driven by mantle upwelling and continental crust gravity slip was developed. Finally, the formation mechanism and evolutionary process of the South China Sea was studied in detail. The formation of the South China Sea can be described by a “tectonic extrusion+active drift” model, where “tectonic extrusion” refers to large-scale passive extrusion of the microcontinents in the southeastern margin of the Eurasia plate caused by the India-Eurasia collision, while “active drift” refers to active drift of the microcontinents after extrusion. The residual seismic reflection in the central basin of the South China Sea is a phenomenon of seafloor spreading caused by active drift of microcontinents. Furthermore, the geotectonic evolution of the microcontinents surrounding the South China Sea was restored. The proposed new model can reasonably explain the phenomenon of mid-ocean ridge jumping in the South China Sea and the genetic mechanism of continental debris. The proposed new continent drift model provides a new dynamic model for plate movement.

Key words: central basin of South China Sea, genesis of the South China Sea, high precision seismic exploration, dynamic mechanism, continental drift

CLC Number:

LIANG Guanghe. Continental drift process revealed by high precision seismic survey in the central basin of the South China Sea[J]. Earth Science Frontiers, 2022, 29(4): 293-306.

Figures/Tables 12

Fig.1 Tectonic background of the South China Sea and its surrounding areas. Adapted after [2].

Fig.2 Two seismic profiles in South China Sea. Modified after [7]. a is the profile position map; b is the N4-3 seismic exploration profile; and c is the N3-2 seismic exploration profile.

Fig.3 Physical characteristics of ocean crust stratification. Modified after [37].

Fig.4 Geological interpretation of the N4-3 seismic exploration profile in the South China Sea. a is a simple geological interpretation of the N4-3 seismic exploration profile, adapted from [7]; b is the latest geological interpretation of N4-3.

Fig.5 Geological interpretation of the N3-2 seismic exploration profile in the South China Sea. a is the seismic exploration profile of N3-2; b is the latest geological interpretation of N3-2.

Fig.6 Schematic diagram of extensional structure and gravity slip formed by mantle upwelling. a-Mantle upwelling causes extensional structure; b-Mantle upwelling causes gravity slip; c-After the continental block gravity slip, the depressurization behind it caused mantle melting upwelling and gravity slip again.

Fig.7 Schematic diagram of the new continent drift model, demonstrating the process is driven by mantle upwelling and gravitational slip

Fig.8 The “extrusion+drift” model of South China Sea

Fig.9 The Spreading process of the Continental margin of the South China Sea. Modified after [1].

Fig.10 One-direction continents drift model of south China Sea. a-The state of south China Continental margin and paleo South China Sea during 65 Ma; b-The state of 35 Ma; c-The current state of the South China Sea.

Fig.11 Schematic diagram of continental drift through N4-3 profile. a-Geological interpretation map of N4-3;b-The initial state of continental drift in this profile; c-Intermediate state of continental drift in this profile.

Fig.12 Schematic diagram of tectonic evolution in the South China Sea

References 50

[1]	栾锡武, 张亮. 南海构造演化模式: 综合作用下的被动扩张[J]. 海洋地质与第四纪地质, 2009, 29(6): 59-74.
[2]	余梦明. 南海的形成与消亡: 南海及其周缘新生代火成岩之地球化学限定[D]. 广州: 中国科学院广州地球化学研究所, 2018.
[3]	SUN L H, SUN Z, ZhANG Y Y, et al. Multi-stage carbonate veins at IODP Site U1504 document Early Cretaceous to early Cenozoic extensional events on the South China Sea margin[J]. Marine Geology, 2021, 422: 106656.
[4]	TAPPONNIER P, PELTZER G, LEDAY, et al. Propagating extrusion tectonics in Asia New Insights from simple experiments with plasticine[J]. Geology, 1982, 10: 611-616.
[5]	谢建华, 夏斌, 张宴华, 等. 印度-欧亚板块碰撞对南海形成的影响研究: 一种数值模拟方法[J]. 海洋通报, 2005, 24(5): 47-53.
[6]	KARIG D E. Origin and development of marginal basins in the western Pacific[J]. Journal of Geophysical Research, 1971, 76(11): 2542-2561.
[7]	DING W W, SUN Z, KELSIE D, et al. Structures within the oceanic crust of the central South China Sea basin and their implications for oceanic accretionary processes[J]. Earth and Planetary Science Letters, 2018, 488: 115-125.
[8]	HOLLOWAY N H. North Palawan block, Philippines: its relation to Asian mainland and role in evolution of South China Sea[J]. AAPG Bulletin, 1982, 66(9): 1355-1383.
[9]	RANGIN C, SPAKMAN W, PUBELLIER M, et al. Tomographic and geological constraints on subduction along the eastern Sundaland continental margin (South-East Asia)[J]. Bulletin de la Société Géologique de France, 1999, 170(6): 775-788.
[10]	ZHOU H, XIAO L, DONG V, et al. Geochemical and geochronological study of the Sanshui basin bimodal volcanic rock suite, China: implications for basin dynamics in southeastern China[J]. Journal of Asian Earth Sciences, 2009, 34(2): 178-189.
[11]	ZHANG G L, LUO Q, ZHAO J, et al. Geochemical nature of sub-ridge mantle and opening dynamics of the South China Sea[J]. Earth and Planetary Science Letters, 2018, 489: 145-155.
[12]	郭令智, 施央申, 马瑞士. 西太平洋中、新生代活动大陆边缘和岛弧构造的形成和演化[J]. 地质学报, 1983, 57(1): 13-23.
[13]	刘昭蜀, 杨树康, 何善谋, 等. 南海陆缘地堑系及边缘海的演化旋回[J]. 热带海洋, 1983, 2(4): 3-11.
[14]	陈国达. 东亚陆缘扩张带: 一条离散式大陆边缘成因的探讨[J]. 大地构造与成矿学, 1997, 21(4): 285-293.
[15]	邵磊, 李献华, 汪品先, 等. 南海渐新世以来构造演化的沉积记录: ODP1148站深海沉积物中的证据[J]. 地球科学进展, 2004, 19(4): 539-544. DOI
[16]	LI C F, XU X, LIN J, et al. Ages and magnetic structures of the South China Sea constrained by deep tow magnetic surveys and IODP Expedition 349[J]. Geochemistry, Geophysics, Geosystems, 2014, 15(12): 4958-4983.
[17]	邱燕, 陈国能, 刘方兰, 等. 南海西南海盆花岗岩的发现及其构造意义[J]. 地质通报, 2008, 27(12): 2104-2107.
[18]	任纪舜, 徐芹芹, 赵磊, 等. 寻找消失的大陆[J]. 地质论评, 2015, 61(5): 969-989.
[19]	TAPPONNIER P, PELTZER G, ARMIJO R. On the mechanics of the collision between India and Asia[J]. London: Geological Society, London, Special Publication, 1986, 19: 115-157.
[20]	汪品先, 翦知湣. 探索南海深部的回顾与展望[J]. 中国科学: 地球科学, 2019, 49(10): 1590-1606.
[21]	HAYES D E, NISSEN S S. The South China sea margins: Implications for rifting contrasts[J]. Earth and Planetary Science Letters, 2005, 237(3/4): 601-616.
[22]	TAYLOR B, HAYES D E. Origin and history of the South China Basin[C]//HAYES D E. The tectonics and geologic evolution of Southeast Asian Seas and islands:Part 2. Geophysical Monograph Series. Washington. DC: American Geophysical Union, 1983, 27: 23-56.
[23]	张功成, 贾庆军, 王万银, 等. 南海构造格局及其演化[J]. 地球物理学报, 2018, 61(10): 4194-4215,
[24]	姚伯初, 万玲. 中国南海海域岩石圈三维结构及演化[M]. 北京: 地质出版社, 2006: 180-221.
[25]	OKAL E A, BERGEAL J M. Mapping the Miocene Farallon Ridge jump on the Pacific plate, a seismic line of weakness[J]. Earth and Planetary Science Letters, 1983, 63(1): 113-122.
[26]	DESCHAMPS A, FUJIWARA T. Asymmetric accretion along the slow spreading Mariana Ridge[J]. Geochemistry, Geophysics, Geosystems, 2013, 4(10), 237.
[27]	MISRA A A, SINHA N, MUKHERJEE S. Repeat ridge jumps and microcontinent separation: insights from NE Arabian Sea[J]. Marine and Petroleum Geology, 2015, 59(59): 406-428.
[28]	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.
[29]	汪品先. 追踪边缘海的生命史: “南海深部计划”的科学目标[J]. 科学通报, 2012, 57(20): 1807-1826.
[30]	吕炳全. 海洋地质学概论[M]. 上海: 同济大学出版社, 2008: 1-299.
[31]	CIAZELA J, KOEPKE J, DICK H J B, et al. Mantle rock exposures at oceanic core complexes along mid-ocean ridges[J]. Geologos, 2015, 21(4): 207-231.
[32]	VITHANA M V P, XU M, ZHAO X, et al. Geological and geophysical signatures of the East Pacific Rise 8°-10°N[J]. Solid Earth Sciences, 2019, 4(2): 66-83.
[33]	XU M, ZHAO X, CANALES J P. Structural variability within the Kane oceanic core complex from full waveform inversion and reverse time migration of streamer data[J]. Geophysical Research Letters, 2020, 47(7): 1-9.
[34]	DICK H J B. Evidence for multi-stage MeltTransport in the lower ocean crust: the Atlantis bank gabbroic massif (IODPHole U1473A, SW Indian ridge)[J]. Journal of Petrology, 2020, 61(9): egaa082.
[35]	余星, 初凤友, 董彦辉, 等. 拆离断层与大洋核杂岩: 一种新的海底扩张模式[J]. 地球科学: 中国地质大学学报, 2013, 38(5): 995-1004.
[36]	DIETZ R S. Continent and ocean basin evolution by spreading of the sea floor[J]. Nature, 1961, 190: 854-857.
[37]	吴福元, 刘传周, 张亮亮, 等. 雅鲁藏布蛇绿岩: 事实与臆想[J]. 岩石学报, 2014, 30: 293-325.
[38]	YU J H, YAN P, QIU Y, et al. Oceanic crustal structures and temporal variations of magmatic budget during seafloor spreading in the East Sub-basin of the South China Sea[J]. Marine Geology, 2021, 436: 106475.
[39]	梁光河, 杨巍然. 从南大西洋裂解过程解密大陆漂移的驱动力[J]. 地学前缘, 2022, 29(1): 1-14.
[40]	王二七. 关于印度与欧亚大陆初始碰撞时间的讨论[J]. 中国科学: 地球科学, 2017, 47: 284-292.
[41]	FLOWER M, TAMAKI K, HOANG N. Mantle extrusion: a model for dispersed volcanism and Dupal‐like asthenosphere in East Asia and the Western Pacific[C]. Washington, DC: American Geophysical Union, 1998: 67-88.
[42]	LIU M, CUI X, LIU F. Cenozoic rifting and volcanism in eastern China: a mantle dynamic link to the Indo-Asian collision?[J]. Tectonophysics, 2004, 393(1/2/3/4): 29-42.
[43]	SUN L H, SUN Z, ZHANG Y Y, et al. Multi-stage carbonate veins at IODP Site U1504 document early Cretaceous to early Cenozoic extensional events on the South China Sea margin[J]. Marine Geology, 2021, 422: 106656.
[44]	MUTTER J C, KARSON J A. Structural processes at slow spreading ridges[J]. Science, 1992, 257: 627-634.
[45]	张训华. 单向拉张与南海海盆的形成[J]. 海洋地质动态, 1997, 5: 1-3.
[46]	张训华, 王忠蕾, 侯方辉, 等. 印支运动以来中国海陆地势演化及阶梯地貌特征[J]. 地球物理学报, 2014, 57(12): 3968-3980.
[47]	黎雨晗, 黄海波, 贺恩远, 等. 中国海—西太平洋典型剖面(南幅)揭示的微陆块窄洋盆构造格局[J]. 地球物理学报, 2020, 63(5): 1938-1958.
[48]	徐义刚, 黄小龙, 颜文, 等. 南海北缘新生代构造演化的深部制约(I): 幔源包体[J]. 地球化学, 2002, 3: 230-242.
[49]	孙金龙, 曹敬贺, 徐辉龙. 南海东部现时地壳运动、震源机制及晚中新世以来的板块相互作用[J]. 地球物理学报, 2014, 57(12): 4074-4084.
[50]	梁光河. 从东海和南海北部盆地群演化探讨日本大陆板块的形成过程[J]. 地学前缘, 2020, 27(1): 244-259. DOI