Tectonics and Sedimentation of the Zhongsha Trough Basin: Implications to the Basin Evolution in Distal Rifting Margin
-
摘要:
深水远端裂陷盆地演化是大陆边缘构造研究的热点.中沙海槽盆地位于西北次海盆和西南次海盆之间,是一个临近洋盆的裂陷盆地.根据最新的地球物理资料,揭示了该盆地的沉积层序和构造演化.中沙海槽盆地裂开后期地层厚度约为200~1 500 m,可划分为6个地震层序.古近系分布局限,仅限于中沙海槽盆地和中沙南盆地的深凹部位;新近系一般厚为200~1 100 m;第四系厚度薄且变化小.中沙海槽盆地主要特征如下:(1)岩浆活动强烈,岩体数量较多,遍布整个盆地,地震剖面上的反射特征表明有侵入型和喷出型两类岩石.重磁异常综合解释表明火成岩成分为中‒酸性和中‒基性两类;(2)裂陷盆地位于拆离的磁性基底隆起之上,磁性基底北深南浅,埋深在6.0~10.4 km之间;(3)莫霍面埋深在15~24 km之间,地壳由陆向海逐渐减薄、由盆地到岛礁逐渐变厚.中沙海槽盆地通常以犁式正断层为边界断层,其构造变形以伸展构造为主,断层走向主要有NE-SW向和NW-SE向,其中NE-SW向控制了新生代沉积坳陷的发育.
Abstract:The basin evolution in distal rifting margin has been hotspot in the continental margin scientific planning. Zhongsha trough basin located between the Northwest Sub-Basin and Southwest Sub-Basin is a typical distal rifting basin nearby the ocean basin. In this study, the seismic sequence and tectonic have been unraveled based on the newly collected geophysical data. The basin has been filled with sediments of 200-1 500 m in thickness and 6 identified seismic sequences. Eogene sequence is limited at trough center; while Neogene sequence covered in the whole basin with thickness of 200-1 100 m. Quaternary sedimentary layer is thin hemipelagic deposits. The distal basin has three characters as follows. (1) Intensive magma activity occurred in the whole basin. It was characterized by a large amount of igneous intrusion and eruption on the seismic sections. (2) the rifting basin located over acoustic basement. It has magmatic feature and varied at 6.0-10.4 km buried depth. (3) Buried depth of Moho varies between 15 and 24 km. It is thinner seaward and thick to coral reefal islands. The tectonic deformation is characterized by rifting structures which included NE-SW and NW-SE trending faults, of which the NE-SW striking faults controlled the Cenozoic depression development.
-
Key words:
- seismic sequence /
- acoustic basement /
- distal rifting basin /
- tectonic evolution /
- Xisha uplift /
- South China Sea /
- marine geology
-
图 5 穿过中沙海槽盆地的地震剖面
该剖面揭示了主要构造单元和地震层序;地震剖面位置见图 1
Fig. 5. Seismic section across the Zhongsha trough basin
-
[1] Briais, A., Patriat, P., Tapponnier, P., 1993. Updated Interpretation of Magnetic Anomalies and Seafloor Spreading Stages in the South China Sea: Implications for the Tertiary Tectonics of Southeast Asia. Journal of Geophysical Research: Solid Earth, 98(B4): 6299-6328. https://doi.org/10.1029/92jb02280 [2] Chen, H., Xie, X. N., Mao, K. N., et al., 2020. Depositional Characteristics and Formation Mechanisms of Deep-Water Canyon Systems along the Northern South China Sea Margin. Journal of Earth Science, 31(4): 808-819. https://doi.org/10.1007/s12583-020-1284-z [3] Ding, W. W., 2021. Continental Margin Dynamics of South China Sea: From Continental Break-Up to Seafloor Spreading. Earth Science, 46(3): 790-800 (in Chinese with English abstract). [4] Ding, W. W., Li, J. B., 2016. Propagated Rifting in the Southwest Sub-Basin, South China Sea: Insights from Analogue Modelling. Journal of Geodynamics, 100: 71-86. https://doi.org/10.1016/j.jog.2016.02.004 [5] Ding, W. W., Schnabel, M., Franke, D., et al., 2012. Crustal Structure across the Northwestern Margin of South China Sea: Evidence for Magma-Poor Rifting from a Wide-Angle Seismic Profile. Acta Geologica Sinica (English Edition), 86(4): 854-866. https://doi.org/10.1111/j.1755-6724.2012.00711.x [6] Dong, M., Zhang, J., Brune, S., et al., 2020. Quantifying Postrift Lower Crustal Flow in the Northern Margin of the South China Sea. Journal of Geophysical Research: Solid Earth, 125(2): e2019JB018910. https://doi.org/10.1029/2019jb018910 [7] Franke, D., Barckhausen, U., Baristeas, N., et al., 2011. The Continent-Ocean Transition at the Southeastern Margin of the South China Sea. Marine and Petroleum Geology, 28(6): 1187-1204. https://doi.org/10.1016/j.marpetgeo.2011.01.004 [8] Gong, Z. S., Li, S. T., Xia, K. Y., 1997. Basin Analysis and Petroleum Accumulation in the Northern South China Sea. Science Press, Beijing (in Chinese). [9] Hao, T. Y. Xu, Y., Sun, F. L., et al., 2011. Integrated Geophysical Research on the Tectonic Attribute of Conjugate Continental Margin of South China Sea. Chinese Journal of Geophysics, 54(12): 3098-3116 (in Chinese with English abstract). [10] Haq, B. U., Hardenbol, J., Vail, P. R., 1987. Chronology of Fluctuating Sea Levels since the Triassic. Science, 235(4793): 1156-1167. https://doi.org/10.1126/science.235.4793.1156 [11] Huang, H. B., He, E. Y., Qiu, X. L., et al., 2020. Insights about the Structure and Development of Zhongsha Bank in the South China Sea from Integrated Geophysical Modelling. International Geology Review, 62(7-8): 1070-1080. https://doi.org/10.1080/00206814.2019.1653798 [12] Huang, H. B., Qiu, X. L., Xu, H. L., et al., 2011. Preliminary Results of the Earthquake Observation and the Onshore-Offshore Seismic Experiments on Xisha Block. Chinese Journal of Geophysics, 54(12): 3161-3170 (in Chinese with English abstract). [13] Jin, Q. H., 1989. Geology and Hydrocarbon Resources in the South China Sea. Geological Publishing House, Beijing (in Chinese). [14] Li, C. F., Shi, X. B., Zhou, Z. Y., et al., 2010. Depths to the Magnetic Layer Bottom in the South China Sea Area and Their Tectonic Implications. Geophysical Journal International, 182(3): 1229-1247. https://doi.org/10.1111/j.1365-246X.2010.04702.x [15] Li, J. B., 2005. Formation and Evolution of China's Marginal Seas and Resource Effects. China Ocean Press, Beijing (in Chinese). [16] Li, J. B., Ding, W. W., Gao, J. Y., et al., 2011. Cenozoic Evolution Model of the Sea-Floor Spreading in South China Sea: New Constraints from High Resolution Geophysical Data. Chinese Journal of Geophysics, 54(12): 3004-3015 (in Chinese with English abstract). [17] Liu, Z. S., Zhao, H. T., Fan, S. Q., 2002. Geology of South China Sea. Science Press, Beijing (in Chinese). [18] Luan, X. W., Wang, J., Liu, H., et al., 2021. A Discussion on Tethys in Northern Margin of South China Sea. Earth Science, 46(3): 866-884 (in Chinese with English abstract). [19] Miller, K., Mountain, G., Wright, J., et al., 2011. A 180-Million-Year Record of Sea Level and Ice Volume Variations from Continental Margin and Deep-Sea Isotopic Records. Oceanography, 24(2): 40-53. https://doi.org/10.5670/oceanog.2011.26 [20] Nissen, S. S., Hayes, D. E., Yao, B. C., et al., 1995. Gravity, Heat Flow, and Seismic Constraints on the Processes of Crustal Extension: Northern Margin of the South China Sea. Journal of Geophysical Research: Solid Earth, 100(B11): 22447-22483. https://doi.org/10.1029/95jb01868 [21] Qiu, Y., Huang, W. K., Du, W. B., et al., 2021. Analysis on the Formation of the Thin Continental Crust in the South China Sea. Earth Science, 46(3): 899-915 (in Chinese with English abstract). [22] Qiu, Y., Peng, X. C., Li, W. C., et al., 2004. Characteristics of Geology and Geophysics of the Slop in Qiongdongnan Basin, the South China Sea. Gresearch of Eological South China Sea, (1): 55-65 (in Chinese with English abstract). [23] Shao, L., Pang, X., Zhang, G. C., et al., 2009. Late Oligocene Tectonic Event in the Northern South China Sea and Its Implications. Earth Science, 34(5): 717-724 (in Chinese with English abstract). [24] Taylor, B., Hayes, D. E., 1983. Origin and History of the South China Sea Basin. In: Hayes, D. E., ed., The Tectonic and Geologic Evolution of Southeast Asian Seas and Islands: Part 2. American Geophysical Union, Washington, D. C. . https://doi.org/10.1029/gm027p0023 [25] Wang, Z. F., Cui, Y. C., Shao, L., et al., 2015. Carbonate Platform Development and Sea-Level Variations of Xisha Islands: Based on BIT Index of Well Xike-1. Earth Science, 40(5): 900-908 (in Chinese with English abstract). [26] Weimer, P., Slatt, R. M., Bouroullec, R., et al., 2006. Introduction to the Petroleum Geology of Deepwater Setting. American Association of Petroleum Geologists, Tulsa. https://doi.org/10.1306/st571314 [27] Wu, S. G., Gao, J. W., Zhao, S. J., et al., 2014. Post-Rift Uplift and Focused Fluid Flow in the Passive Margin of Northern South China Sea. Tectonophysics, 615-616: 27-39. https://doi.org/10.1016/j.tecto.2013.12.013 [28] Wu, S. G., Wang, D. W., Yao, G. S., 2015. Geophysical Recognition of Deep Water Deposits and Reservoirs in the South China Sea. Science Press, Beijing (in Chinese). [29] Yao, B. C., Wan, L., Liu, Z. H., 2004. Tectonic Dynamics of Cenozoic Sedimentary Basins and Hydrocarbon Resources in the South China Sea. Earth Science, 29(5): 543-549 (in Chinese with English abstract). [30] Yao, B. C., Wan, L., Wu, N. Y., 2005. Cenozoic Tectonic Evolution and the 3D Structure of the Lithosphere of the South China Sea. Regional Geology of China, 24(1): 1-8 (in Chinese with English abstract). [31] Yao, B. C., Zeng, W. J., Hayes, D. E., 1994. The Geological Memoir of South China Sea Surveyed Jointly by China and USA. China University of Geosciences Phess, Wuhan (in Chinese). [32] Yuan, Y., Zhao, M. H., He, E. Y., et al., 2021. The Crustal Structures and Rift-Breakup Models of Typical Rifted Margins. Earth Science, 46(3): 801-816 (in Chinese with English abstract). [33] Zhang, G. C., Mi, L. J., Wu, S. G., et al., 2007. Deepwater Area—The New Prospecting Targets of Northern Continental Margin of South China Sea. Acta Petrolei Sinica, 28(2): 15-21 (in Chinese with English abstract). [34] Zhang, H., Shao, L., Zhang, G. C., et al., 2015. Distribution and Petroleum Geologic Significance of Eocene Marine Strata in the South China Sea. Earth Science, 40(4): 660-670 (in Chinese with English abstract). [35] Zhang, Y., Yu, K. F., Qian, H. D., et al., 2020. The Basement and Volcanic Activities of the Xisha Islands: Evidence from the Kilometre-Scale Drilling in the Northwestern South China Sea. Geological Journal, 55(1): 571-583. https://doi.org/10.1002/gj.3416 [36] Zhu, W. L., Xie, X. N., Wang, Z. F., et al., 2017. New Insights on the Origin of the Basement of the Xisha Uplift, South China Sea. Science in China (Series D), 47(12): 1460-1468 (in Chinese). [37] Zhu, W. L., Zhang, G. C., Yang, S. K., et al., 2007. Natural Gas Geology of Continental Margin Basin in Northern South China Sea. Petroleum Industry Press, Beijing (in Chinese). [38] 丁巍伟, 2021. 南海大陆边缘动力学: 从陆缘破裂到海底扩张. 地球科学, 46(3): 790-800. doi: 10.3799/dqkx.2020.303 [39] 龚再升, 李思田, 夏堪原, 1997. 南海北部大陆边缘盆地分析与油气聚集. 北京: 科学出版社. [40] 郝天珧, 徐亚, 孙福利, 等, 2011. 南海共轭大陆边缘构造属性的综合地球物理研究. 地球物理学报, 54(12): 3098-3116. doi: 10.3969/j.issn.0001-5733.2011.12.011 [41] 黄海波, 丘学林, 徐辉龙, 等, 2011. 南海西沙地块岛屿地震观测和海陆联测初步结果. 地球物理学报, 54(12): 3161-3170. doi: 10.3969/j.issn.0001-5733.2011.12.016 [42] 金庆焕, 1989. 南海地质与油气资源. 北京: 地质出版社. [43] 李家彪, 2005. 中国边缘海形成演化与资源效应. 北京: 海洋出版社. [44] 李家彪, 丁巍伟, 高金耀, 等, 2011. 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. 地球物理学报, 54(12): 3004-3015. doi: 10.3969/j.issn.0001-5733.2011.12.003 [45] 刘昭蜀, 赵焕庭, 范时清, 2002. 南海地质. 北京: 科学出版社. [46] 栾锡武, 王嘉, 刘鸿, 等, 2021. 关于南海北部特提斯的讨论. 地球科学, 46(3): 866-884. doi: 10.3799/dqkx.2020.332 [47] 邱燕, 黄文凯, 杜文波, 等, 2021. 南海边缘海减薄陆壳成因剖析. 地球科学, 46(3): 899-915. doi: 10.3799/dqkx.2020.393 [48] 邱燕, 彭学超, 李文成, 等, 2004. 琼东南盆地陆坡区地质‒地球物理特征分析. 南海地质研究, (1): 55-65. https://www.cnki.com.cn/Article/CJFDTOTAL-NHDZ200400007.htm [49] 邵磊, 庞雄, 张功成, 等, 2009. 南海北部渐新世末的构造事件. 地球科学, 34(5): 717-724. doi: 10.3321/j.issn:1000-2383.2009.05.001 [50] 王振峰, 崔宇驰, 邵磊, 等, 2015. 西沙地区碳酸盐台地发育过程与海平面变化: 基于西科1井BIT指标分析数据. 地球科学, 40(5): 900-908. doi: 10.3799/dqkx.2015.074 [51] 吴时国, 王大伟, 姚根顺, 2015. 南海深水沉积与储层的地球物理识别. 北京: 科学出版社. [52] 姚伯初, 万玲, 刘振湖, 2004. 南海海域新生代沉积盆地构造演化的动力学特征及其油气资源. 地球科学, 29(5): 543-549. doi: 10.3321/j.issn:1000-2383.2004.05.007 [53] 姚伯初, 万玲, 吴能友, 2005. 南海新生代构造演化及岩石圈三维结构特征. 地质通报, 24(1): 1-8. doi: 10.3969/j.issn.1671-2552.2005.01.001 [54] 姚伯初, 曾维军, Hayes, D. E., 1994. 中美合作调研南海地质专报. 武汉: 中国地质大学出版社. [55] 袁野, 赵明辉, 贺恩远, 等, 2021. 张裂陆缘地壳结构特征与张裂模式. 地球科学, 46(3): 801-816. doi: 10.3799/dqkx.2020.361 [56] 张功成, 米立军, 吴时国, 等, 2007. 深水区: 南海北部大陆边缘盆地油气勘探新领域. 石油学报, 28(2): 15-21. https://www.cnki.com.cn/Article/CJFDTOTAL-SYXB200702002.htm [57] 张浩, 邵磊, 张功成, 等, 2015. 南海始新世海相地层分布及油气地质意义. 地球科学, 40(4): 660-670. doi: 10.3799/dqkx.2015.053 [58] 朱伟林, 解习农, 王振峰, 等, 2017. 南海西沙隆起基底成因新认识. 中国科学(D辑), 47(12): 1460-1468. https://www.cnki.com.cn/Article/CJFDTOTAL-JDXK201712008.htm [59] 朱伟林, 张功成, 杨少坤, 等, 2007. 南海北部大陆边缘盆地天然气地质. 北京: 石油工业出版社.