Late Mesozoic Magmatic Arc: Constraints from Well KP1-1-1 Detrital Zircon U-Pb Data, South China Sea
-
摘要: 晚中生代是古太平洋板块俯冲和南海北部岩浆弧发育时期,开展珠江口盆地KP1-1-1井钻遇的浅变质砂岩的近源沉积研究有助于揭示岩浆弧源区的构造特点.根据LA-ICPMS碎屑锆石分析,KP1-1-1浅变质砂岩中存在129~155 Ma、155~172 Ma和172~196 Ma三个年龄组分,这一特点与区域上构造岩浆事件一致.碎屑岩浆锆石流体活动性元素富集(如U和Th),高场强元素亏损(如Nb、Hf和Ti);元素组成U/Yb(0.34~3.92)、Sc/Yb(0.48~2.28)、Hf/Th(14.4~186.6)和Th/Nb(24.3~462.7)具有大陆岩浆弧特点;计算的锆石Ti温度为551~786℃,表明属于低温弧岩浆作用.碎屑岩中172~196 Ma锆石组分记录了东沙-大仑-雁荡岩浆弧向西南的进一步延伸,与侏罗纪早期古太平洋斜向俯冲到华南陆块之下有关.155~172 Ma岩浆锆石与古板块强烈俯冲有关,对应于华南165~150 Ma大规模花岗质岩浆活动.129~155 Ma时期板块俯冲减弱或俯冲带后撤,可与浙闽同时期板内强烈火山活动对比.碎屑岩中测得最年轻年龄为128.8 Ma,表明KP1-1-1钻遇浅变质砂岩形成时代晚于128 Ma,应属于白垩系,不是传统上认为的下古生界岩系.Abstract: The Late Mesozoic is an important tectonic episode for Paleo-Pacific slab subduction and magmatic arc evolution in the South China Sea. The low-metamorphosed sandstone drilled by KP1-1-1 belongs to a proximal deposition which helps to reveal tectonic characteristics of the magmatic arc provenance. Based on LA-ICPMS detrital zircon analysis, age components of 129-155 Ma, 155-172 Ma, and 172-196 Ma are identified from KP1-1-1 sandstone in the western Pearl River Mouth Basin, in accordance with regional tectono-magmatic events. These magmatic zircons which derive from arc-related magmatic source are characterized by low-temperature (551-786℃), enrichment of fluid-mobile elements (U, Th) and depletion of high field-strength elements (Nb, Hf and Ti). They are characterized by high element ratios of U/Yb (0.34-3.92), Sc/Yb (0.48-2.28), Hf/Th (14.4-186.6), and Th/Nb (24.3-462.7), indicating the related magmatism in a continental arc environment. The age component of 172-196 Ma from the sandstone registers the Early Jurassic Dongsha-Talun-Yandang magmatic arc further stretching southwest in East to South China Seas, as a result of oblique initial subduction of the Paleo-Pacific slab. The major component of 155-172 Ma reveals an intensified slab subduction and arc-related magmatism in South China Sea, comparable to voluminous granitic magmatism (165-150 Ma) in South China. The minor component of 129-155 Ma found, however, implies a reduced arc-related magmatism due to slow subduction or slab rollback, sharply in contrast to intensified rhyolite volcanism (120-160 Ma) developed in Zhejiang to Fujian coastal areas. The minimum U-Pb age 128.8 Ma of detrital zircon defines the stratigraphic age of KP1-1-1 sandstone as Cretaceous, not the latest Late Proterozoic to Early Paleozoic as traditionally treated.
-
Key words:
- South China Sea /
- detrital zircon /
- magmatic arc /
- Late Mesozoic /
- stratigraphic age /
- geochronology
-
图 1 南海北部主要盆地、KP1-1-1井位和砂岩岩性照片
据中海石油(中国)有限公司湛江分公司,2021.《南海西部海域油气勘探年报(2020年度)》
Fig. 1. Main Cenozoic basins of the northern South China Sea with KP1-1-1 sandstone locality and lithology
图 3 珠江口盆地KP1-1-1井碎屑锆石相关图解
a. Th/U比值;b~d. 构造环境判别,图b和图c底图据Grimes et al.(2015),图d底图据Yang et al.(2012);e. 锆石类型,底图据Grimes et al.(2007);f. 锆石Ti温度
Fig. 3. Relative diagrams of zircons for Well KP1-1-1 from the Pearl River Mouth Basin
-
Breitfeld, H. T., Davies, L., Hall, R., et al., 2020. Mesozoic Paleo-Pacific Subduction beneath SW Borneo: U-Pb Geochronology of the Schwaner Granitoids and the Pinoh Metamorphic Group. Frontiers in Earth Science, 8: 568715. https://doi.org/10.3389/feart.2020.568715 Chappell, B. W., White, A. J. R., Williams, I. S., et al., 2004. Low-and High-Temperature Granites. Earth and Environmental Science Transactions of the Royal Society of Edinburgh, 95(1-2): 125-140. https://doi.org/10.1017/S0263593300000973 Grimes, C. B., John, B. E., Kelemen, P. B., et al., 2007. Trace Element Chemistry of Zircons from Oceanic Crust: A Method for Distinguishing Detrital Zircon Provenance. Geology, 35(7): 643-646. https://doi.org/10.1130/g23603a.1 Grimes, C. B., Wooden, J. L., Cheadle, M. J., et al., 2015. "Fingerprinting" Tectono-Magmatic Provenance Using Trace Elements in Igneous Zircon. Contributions to Mineralogy and Petrology, 170(5-6): 1-26. https://doi.org/10.1007/s00410-015-1199-3 Hoskin, P. W. O., Schaltegger, U., 2003. The Composition of Zircon and Igneous and Metamorphic Petrogenesis. Reviews in Mineralogy and Geochemistry, 53(1): 27-62. https://doi.org/10.2113/0530027 Isozaki, Y., Aoki, K., Nakama, T., et al., 2010. New Insight into a Subduction-Related Orogen: A Reappraisal of the Geotectonic Framework and Evolution of the Japanese Islands. Gondwana Research, 18(1): 82-105. https://doi.org/10.1016/j.gr.2010.02.015 Jin, F. M., Huang, J., Pu, X. G., et al., 2020. Characteristics of the Cretaceous Magmatism in Huanghua Depression and Their Relationships with Hydrocarbon Enrichment. Journal of Earth Science, 31(6): 1273-1292. https://doi.org/10.1007/s12583-020-1308-8 Li, X. H., Li, W. X., Li, Z. X., 2007. On the Genetic Classification and Tectonic Implications of the Early Yanshanian Granitoids in the Nanling Range, South China. Chinese Science Bulletin, 52(14): 1873-1885. https://doi.org/10.1007/S11434-007-0259-0 Li, Z. X., Li, X. H., 2007. Formation of the 1 300-km-Wide Intracontinental Orogen and Postorogenic Magmatic Province in Mesozoic South China: A Flat-Slab Subduction Model. Geology, 35(2): 179-182. https://doi.org/10.1130/g23193a.1 Li, Z. X., Li, X. H., Chung, S. L., et al., 2012. Magmatic Switch-on and Switch-off along the South China Continental Margin since the Permian: Transition from an Andean-Type to a Western Pacific-Type Plate Boundary. Tectonophysics, 532-535: 271-290. https://doi.org/10.1016/j.tecto.2012.02.011 Liu, L., Xu, X. S., Xia, Y., 2016. Asynchronizing Paleo-Pacific Slab Rollback beneath SE China: Insights from the Episodic Late Mesozoic Volcanism. Gondwana Research, 37: 397-407. https://doi.org/10.1016/j.gr.2015.09.009 Liu, L., Xu, X. S., Zou, H. B., 2012. Episodic Eruptions of the Late Mesozoic Volcanic Sequences in Southeastern Zhejiang, SE China: Petrogenesis and Implications for the Geodynamics of Paleo-Pacific Subduction. Lithos, 154: 166-180. https://doi.org/10.1016/j.lithos.2012.07.002 Liu, Y. S., Hu, Z. C., Gao, S., et al., 2008. In Situ Analysis of Major and Trace Elements of Anhydrous Minerals by LA-ICP-MS without Applying an Internal Standard. Chemical Geology, 257(1-2): 34-43. https://doi.org/10.1016/j.chemgeo.2008.08.004 Liu, Y. S., Hu, Z. C., Zong, K. Q., et al., 2010. Reappraisement and Refinement of Zircon U-Pb Isotope and Trace Element Analyses by LA-ICP-MS. Chinese Science Bulletin, 55(15): 1535-1546. https://doi.org/10.1007/S11434-010-3052-4 Lu, B.L., Sun, X.M., Zhang, G.C., et al., 2011. Seismic-Potential Field Response Characteristics and Identification of Basement Lithology of the Northern South China Sea Basin. Chinese Journal of Geophysics, 54(2): 563-572 (in Chinese with English abstract). 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). Ludwig, K.R., 2003. ISOPLOT 3.00: A Geochronological Toolkit for Microsoft Excel. Berkeley Geochronology Center, Berkeley. Maruyama, S., Isozaki, Y., Kimura, G., et al., 1997. Paleogeographic Maps of the Japanese Islands: Plate Tectonic Synthesis from 750 Ma to the Present. Island Arc, 6(1): 121-142. https://doi.org/10.1111/j.1440-1738.1997.tb00043.x Miller, C. F., McDowell, S. M., Mapes, R. W., 2003. Hot and Cold Granites Implications of Zircon Saturation Temperatures and Preservation of Inheritance. Geology, 31(6): 529-532. https://doi.org/10.1130/0091-7613(2003)0310529:hacgio>2.0.co;2 doi: 10.1130/0091-7613(2003)0310529:hacgio>2.0.co;2 Pang, X., Chen, C.M., Peng, D.J., et al., 2007. The Pearl River Deep-Water Fan System & Petroleum in South China Sea. Science Press, Beijing, 38-42 (in Chinese). Ren, J.Y., 2018. Genetic Dynamics of China Offshore Cenozoic Basins. Earth Science, 43(10): 3337-3361 (in Chinese with English abstract). Shu, L.S., Yu, J.H., Jia, D., et al., 2008. Early Paleozoic Orogenic Belt in the Eastern Segment of South China. Geological Bulletin of China, 27(10): 1581-1593 (in Chinese with English abstract). Sun, X. M., Zhang, X. Q., Zhang, G. C., et al., 2014. Texture and Tectonic Attribute of Cenozoic Basin Basement in the Northern South China Sea. Scientia Sinica Terrae, 44(6): 1312-1323 (in Chinese). doi: 10.1360/zd-2014-44-6-1312 Tian, L.X., Shi, H.S., Liu, J., et al., 2020. Great Discovery and Significance of New Frontier Exploration in Huizhou Sag, Pearl River Mouth Basin. China Petroleum Exploration, 25(4): 22-30 (in Chinese with English abstract). Wakita, K., Metcalfe, I., 2005. Ocean Plate Stratigraphy in East and Southeast Asia. Journal of Asian Earth Sciences, 24(6): 679-702. https://doi.org/10.1016/j.jseaes.2004.04.004 Watson, E. B., Wark, D. A., Thomas, J. B., 2006. Crystallization Thermometers for Zircon and Rutile. Contributions to Mineralogy and Petrology, 151(4): 413-433. https://doi.org/10.1007/S00410-006-0068-5 Xie, Y.H., Gao, Y.D., 2020. Recent Domestic Exploration Progress and Direction of CNOOC. China Petroleum Exploration, 25(1): 20-30 (in Chinese with English abstract). Xing, G. F., Li, J. Q., Duan, Z., et al., 2021. Mesozoic-Cenozoic Volcanic Cycle and Volcanic Reservoirs in East China. Journal of Earth Science, 32(4): 742-765. https://doi.org/10.1007/s12583-021-1476-1 Xiu, C., Zhang, D.J., Zhai, S.K., et al., 2016. Zricon U-Pb Age of Granitic Rocks from the Basement beneath the Shi Island, Xisha Islands and Its Geological Significance. Marine Geology & Quaternary Geology, 36(3): 115-126 (in Chinese with English abstract). Xu, C. H., Shi, H. S., Barnes, C. G., et al., 2016. Tracing a Late Mesozoic Magmatic Arc along the Southeast Asian Margin from the Granitoids Drilled from the Northern South China Sea. International Geology Review, 58(1): 71-94. https://doi.org/10.1080/00206814.2015.1056256 Xu, C. H., Zhang, L., Shi, H. S., et al., 2017. Tracing an Early Jurassic Magmatic Arc from South to East China Seas. Tectonics, 36(3): 466-492. https://doi.org/10.1002/2016tc004446 Xu, X.S., 2008. Several Problems Worthy to Be Noticed in the Rewearch of Granites and Volcanic Rocks in SE China. Geological Journal of China Universities, 14(3): 283-294 (in Chinese with English abstract). Yan, Q. S., Shi, X. F., Liu, J. H., et al., 2010. Petrology and Geochemistry of Mesozoic Granitic Rocks from the Nansha Micro-Block, the South China Sea: Constraints on the Basement Nature. Journal of Asian Earth Sciences, 37(2): 130-139. https://doi.org/10.1016/j.jseaes.2009.08.001 Yang, J. H., Cawood, P. A., Du, Y. S., et al., 2012. Detrital Record of Indosinian Mountain Building in SW China: Provenance of the Middle Triassic Turbidites in the Youjiang Basin. Tectonophysics, 574-575: 105-117. https://doi.org/10.1016/j.tecto.2012.08.027 Zhang, G.C., Jia, Q.J., Wang, W.Y., et al., 2018. On Tectonic Framework and Evolution of the South China Sea. Chinese Journal of Geophysics, 61(10): 4194-4215 (in Chinese with English abstract). Zhou, X.M., Chen, P.R., Xu, X.S., et al., 2007. Petrogenesis of Late Mesozoic Granite and Dynamic Evolution of Lithosphere in Nanling Region. Science Press, Beijing (in Chinese). Zhou, X. M., Li, W. X., 2000. Origin of Late Mesozoic Igneous Rocks in Southeastern China: Implications for Lithosphere Subduction and Underplating of Mafic Magmas. Tectonophysics, 326(3-4): 269-287. https://doi.org/10.1016/S0040-1951(00)00120-7 Zhou, X. M., Sun, T., Shen, W. Z., et al., 2006. Petrogenesis of Mesozoic Granitoids and Volcanic Rocks in South China: A Response to Tectonic Evolution. Episodes, 29(1): 26-33. https://doi.org/10.18814/epiiugs/2006/v29i1/004 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 China Earth Sciences, 60(12): 2214-2222. https://doi.org/10.1007/S11430-017-9089-9 鲁宝亮, 孙晓猛, 张功成, 等, 2011. 南海北部盆地基底岩性地震-重磁响应特征与识别. 地球物理学报, 54(2): 563-572. doi: 10.3969/j.issn.0001-5733.2011.02.036 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 庞雄, 陈长民, 彭大钧, 等, 2007. 南海珠江深水扇系统及油气. 北京: 科学出版社, 38-42. 任建业, 2018. 中国近海海域新生代成盆动力机制分析. 地球科学, 43(10): 3337-3361. doi: 10.3799/dqkx.2018.330 舒良树, 于津海, 贾东, 等, 2008. 华南东段早古生代造山带研究. 地质通报, 27(10): 1581-1593. doi: 10.3969/j.issn.1671-2552.2008.10.001 孙晓猛, 张旭庆, 张功成, 等, 2014. 南海北部新生代盆地基底结构及构造属性. 中国科学: 地球科学, 44(6): 1312-1323. https://www.cnki.com.cn/Article/CJFDTOTAL-JDXK201406022.htm 田立新, 施和生, 刘杰, 等, 2020. 珠江口盆地惠州凹陷新领域勘探重大发现及意义. 中国石油勘探, 25(4): 22-30. https://www.cnki.com.cn/Article/CJFDTOTAL-KTSY202004003.htm 谢玉洪, 高阳东, 2020. 中国海油近期国内勘探进展与勘探方向. 中国石油勘探, 25(1): 20-30. https://www.cnki.com.cn/Article/CJFDTOTAL-KTSY202001003.htm 修淳, 张道军, 翟世奎, 等, 2016. 西沙岛礁基底花岗质岩石的锆石U-Pb年龄及其地质意义. 海洋地质与第四纪地质, 36(3): 115-126. https://www.cnki.com.cn/Article/CJFDTOTAL-HYDZ201603014.htm 徐夕生, 2008. 华南花岗岩-火山岩成因研究的几个问题. 高校地质学报, 14(3): 283-294. https://www.cnki.com.cn/Article/CJFDTOTAL-GXDX200803004.htm 张功成, 贾庆军, 王万银, 等, 2018. 南海构造格局及其演化. 地球物理学报, 61(10): 4194-4215. https://www.cnki.com.cn/Article/CJFDTOTAL-DQWX201810024.htm 周新民, 陈培荣, 徐夕生, 等, 2007. 南岭地区晚中生代花岗岩成因与岩石圈动力学演化. 北京: 科学出版社. -