Paleoclimatic and Paleoenvironmental Changes Recorded by Elemental Geochemistry in the Northwestern South China Sea since the Past~55 ka
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摘要: 南海西北部的西沙碳酸盐台地北坡受到陆源和海洋自生物质的供应,蕴含丰富的气候变化信息.为探究该区域的古气候环境演变历史,选取长828 cm的SS7岩心,利用AMS14C测年以及有孔虫氧同位素建立该区域的年代学框架,并进行元素地球化学分析.该岩心底部年龄为~55 ka BP,沉积物的元素主要受到陆源碎屑输入、海洋自生作用、氧化还原条件、海洋化学沉积作用等因素的控制.碎屑组分元素比值K/Rb和K/Ti能用于反映源区地表化学风化程度,进而反映源区过去55 ka的东亚夏季风的演化.区域东亚夏季风在约40 ka BP明显减弱,且对Heinrich、新仙女木等北半球快速变冷的事件有明显地响应.过去55 ka的东亚夏季风,不仅受到北半球低纬度夏季日照辐射量的控制,还受到赤道太平洋大气动力(如太平洋沃克环流)的影响.Abstract: The north slope of Xisha carbonate platform in the northwestern South China Sea is supplied by land and marine biogenic materials, so the sediments contain abundant information on climate change. In order to explore the evolution history of paleoclimate and environment in this area, the 828 cm-long core SS7 was selected for elemental geochemical analysis in combination with the chronological framework established by the AMS14C and oxygen isotope of forams. The results show that the core age at bottom is~55 ka BP, and the elements within sediments are mainly controlled by the terrigenous clastic input, marine authigenesis, redox conditions, and marine chemical deposition. The K/Rb and K/Ti can be used to reflect the surface chemical weathering in the source area and the evolution of the East Asian summer monsoon (EASM) over the past 55 ka. The regional EASM apparently decreased at about 40 ka BP, and the decreases of K/Rb and K/Ti values responded to the rapidly cooling events in the northern hemisphere, including the Heinrich events and the Younger Drays. The EASM over the past 55 ka is not only controlled by the summer insolation in the low-latitude of the northern hemisphere, but also affected by the atmospheric dynamics in the equatorial Pacific (such as the Walker circulation in the Pacific).
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Key words:
- South China Sea /
- East Asian summer monsoon /
- elements /
- Xisha Islands /
- last glacial period /
- geochemistry
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图 1 SS7岩心位置及周边地形
底图来源于自然资源部数据服务栏目,审图号:GS(2016)2891号
Fig. 1. Location of the studied core SS7 and surrounding topography
图 6 SS7岩心的元素比值与区域和全球气候变化的对比
a. SS7岩心的沉积速率;b. 全球相对海平面,据Rohling et al. (2009);c. K/Rb;d. K/Ti;e. 湖光岩玛珥湖的热带季雨林孢粉含量,据Mingram et al. (2004);f. 湖光岩玛珥湖木本/草本木质素比值,据Fuhrmann et al. (2003);g. 亚洲季风区平均有效湿度,据Herzschuh (2006);h. 黄土高原蓝田剖面磁化率,据Liu et al. (2005);i. 印度尼西亚Towuti湖的叶蜡正构烷烃碳同位素,据Russell et al. (2014);j. 热带太平洋东、西部的表层海水温度差,据Dyez and Ravelo (2014);k. 北纬30°夏季日照辐射量,据Berger and Loutre (1991);l. 华南石笋氧同位素,据Dykoski et al. (2005)、Wang et al. (2001);m. 格陵兰岛冰心GISP2的氧同位素,据Dansgaard et al. (1993)
Fig. 6. Comparison of elemental ratios with regional and global climate change
表 1 SS7岩心元素和氧化物的主成分分析结果
Table 1. Principal component analysis of elements and oxides of core SS7
元素/氧化物 成分1 成分2 成分3 元素/氧化物 成分1 成分2 成分3 CaO -0.984 -0.061 -0.097 Ta 0.841 0.097 0.073 SiO2 0.981 -0.057 -0.049 MgO 0.795 -0.556 0.143 TiO2 0.977 -0.137 -0.026 Co 0.712 -0.125 0.608 Sr -0.976 -0.048 0.037 Pb 0.588 0.361 0.397 LOI -0.970 0.201 -0.011 Ba -0.577 0.432 0.318 Al2O3 0.964 0.110 0.155 P2O5 0.023 -0.888 0.122 Ga 0.963 -0.065 0.192 TOC -0.390 0.849 -0.161 Rb 0.962 -0.061 0.228 Li 0.191 0.829 0.231 Sc 0.942 -0.165 0.221 Na2O -0.020 0.791 0.043 Nb 0.941 0.164 0.058 W 0.224 0.785 0.074 Cs 0.936 -0.230 0.218 Cu 0.025 0.780 0.275 Fe2O3 0.931 -0.210 0.260 MnO 0.278 -0.777 0.231 V 0.910 -0.001 0.259 U -0.290 0.716 0.083 K2O 0.897 -0.374 0.072 Zn 0.254 -0.125 0.868 Zr 0.891 -0.158 -0.263 Ni 0.007 0.414 0.815 Th 0.848 0.222 0.317 方差(%) 58.62 19.77 6.94 Cr 0.844 -0.258 0.118 累积方差(%) 58.62 78.39 85.33 -
An, Z. S., Porter, S. C., 1997. Millennial-Scale Climatic Oscillations during the Last Interglaciation in Central China. Geology, 25(7): 603-606. https://doi.org/10.1130/0091-7613(1997)0250603:mscodt>2.3.co;2 doi: 10.1130/0091-7613(1997)0250603:mscodt>2.3.co;2 Berger, A., Loutre, M. F., 1991. Insolation Values for the Climate of the Last 10 Million Years. Quaternary Science Reviews, 10(4): 297-317. https://doi.org/10.1016/0277-3791(91)90033-Q Cai, G. Q., Qiu, Y., Peng, X. C., et al., 2010. The Geochemical Characteristics of Trace Elements and Rees in Surficial Sediments of the Southwestern South China Sea and Their Implications. Marine Geology & Quaternary Geology, 30(5): 53-62 (in Chinese with English abstract). http://www.cqvip.com/QK/71135X/201107/35889894.html Chen, H. J., Xu, Z. K., Cai, M. J., et al., 2019. Provenance of Clay-Sized Detrital Sediments and Its Paleoenvironmental Implications at Site U1456 in the Eastern Arabian Sea since 30 ka. Earth Science, 44(8): 2803-2817 (in Chinese with English abstract). http://en.cnki.com.cn/Article_en/CJFDTotal-DQKX201908024.htm Dansgaard, W., Johnsen, S. J., Clausen, H. B., et al., 1993. Evidence for General Instability of Past Climate from a 250-kyr Ice-Core Record. Nature, 364(6434): 218-220. https://doi.org/10.1038/364218a0 Dyez, K. A., Ravelo, A. C., 2014. Dynamical Changes in the Tropical Pacific Warm Pool and Zonal SST Gradient during the Pleistocene. Geophysical Research Letters, 41(21): 7626-7633. https://doi.org/10.1002/2014GL061639 Dykoski, C. A., Edwards, R. L., Cheng, H., et al., 2005. A High-Resolution, Absolute-Dated Holocene and Deglacial Asian Monsoon Record from Dongge Cave, China. Earth and Planetary Science Letters, 233(1-2): 71-86. https://doi.org/10.1016/j.epsl.2005.01.036 Fairbanks, R. G., Mortlock, R. A., Chiu, T. C., et al., 2005. Radiocarbon Calibration Curve Spanning 0 to 50 000 Years BP Based on Paired 230Th/234U/238U and 14C Dates on Pristine Corals. Quaternary Science Reviews, 24(16-17): 1781-1796. https://doi.org/10.1016/j.quascirev.2005.04.007 Fuhrmann, A., Mingram, J., Lücke, A., et al., 2003. Variations in Organic Matter Composition in Sediments from Lake Huguang Maar (Huguangyan), South China during the last 68 ka: Implications for Environmental and Climatic Change. Organic Geochemistry, 34(11): 1497-1515. https://doi.org/10.1016/S0146-6380(03)00158-X Herzschuh, U., 2006. Palaeo-Moisture Evolution in Monsoonal Central Asia during the Last 50, 000 Years. Quaternary Science Reviews, 25(1-2): 163-178. https://doi.org/10.1016/j.quascirev.2005.02.006 Hu, D. K., Böning, P., Köhler, C. M., et al., 2012. Deep Sea Records of the Continental Weathering and Erosion Response to East Asian Monsoon Intensification since 14 ka in the South China Sea. Chemical Geology, 326-327: 1-18. https://doi.org/10.1016/j.chemgeo.2012.07.024 Hu, D. K., Clift, P. D., Wan, S. M., et al., 2015. Testing Chemical Weathering Proxies in Miocene-Recent Fluvial-Derived Sediments in the South China Sea. Geological Society, London, Special Publications, 429(1): 45-72. https://doi.org/10.1144/sp429.5 Huang, J., Wan, S. M., Xiong, Z. F., et al., 2016. Geochemical Records of Taiwan-Sourced Sediments in the South China Sea Linked to Holocene Climate Changes. Palaeogeography, Palaeoclimatology, Palaeoecology, 441: 871-881. https://doi.org/10.1016/j.palaeo.2015.10.036 Jin, H. Y., Jian, Z. M., Xie, X., et al., 2011. Late Quaternary East Asian Monsoonal Evolution Recorded by High Resolution Elemental Ratios in the Northern South China Sea. Quaternary Sciences, 31(2): 207-215 (in Chinese with English abstract). http://en.cnki.com.cn/Article_en/CJFDTOTAL-DSJJ201102001.htm Li, C. Z., 1987. Geochemistry of Elements in Surface Sediments of the South China Sea Basin. Donghai Marine Science, 5(1-2): 77-91 (in Chinese). http://en.cnki.com.cn/Article_en/CJFDTOTAL-DHHY1987Z1010.htm Li, M. K., Ouyang, T. P., Tian, C. J., et al., 2019. Sedimentary Responses to the East Asian Monsoon and Sea Level Variations Recorded in the Northern South China Sea over the Past 36 kyr. Journal of Asian Earth Sciences, 171: 213-224. https://doi.org/10.1016/j.jseaes.2018.01.001 Lin, Z. J., Chen, D. F., Liu, Q., 2008. Geochemical Indices for Redox Conditions of Marine Sediments. Bulletin of Mineralogy, Petrology and Geochemistry, 27(1): 72-80 (in Chinese with English abstract). http://en.cnki.com.cn/Article_en/CJFDTOTAL-KYDH200801012.htm Liu, W. G., Huang, Y. S., An, Z. S., et al., 2005. Summer Monsoon Intensity Controls C4/C3 Plant Abundance during the Last 35 ka in the Chinese Loess Plateau: Carbon Isotope Evidence from Bulk Organic Matter and Individual Leaf Waxes. Palaeogeography, Palaeoclimatology, Palaeoecology, 220(3-4): 243-254. https://doi.org/10.1016/j.palaeo.2005.01.001 Mingram, J., Schettler, G., Nowaczyk, N., et al., 2004. The Huguang Maar Lake-AHigh-Resolution Record of Palaeoenvironmental and Palaeoclimatic Changes over the Last 78, 000 Years from South China. Quaternary International, 122(1): 85-107. https://doi.org/10.1016/j.quaint.2004.02.001 Nesbitt, H. W., Markovics, G., Price, R. C., 1980. Chemical Processes Affecting Alkalis and Alkaline Earths during Continental Weathering. Geochimica et Cosmochimica Acta, 44(11): 1659-1666. https://doi.org/10.1016/0016-7037(80)90218-5 Nesbitt, H. W., Young, G. M., 1982. Early Proterozoic Climates and Plate Motions Inferred from Major Element Chemistry of Lutites. Nature, 299(5885): 715-717. https://doi.org/10.1038/299715a0 Qiu, Y., Peng, X. C., Wang, Y. M., et al., 2017. Erosive Process and Sedimentary Characteristics of the Quaternary Sediments in the Northern South China Sea. Geological Publishing House, Beijing (in Chinese). Reimer, P. J., Baillie, M. L., Bard, E., et al., 2009. IntCal09 and Marine09 Radiocarbon Age Calibration Curves, 0‒50, 000 Years cal BP. Radiocarbon, 51(4): 1111-1150. https://doi.org/10.1017/s0033822200034202 Rohling, E. J., Grant, K., Bolshaw, M., et al., 2009. Antarctic Temperature and Global Sea Level Closely Coupled over the Past Five Glacial Cycles. Nature Geoscience, 2(7): 500-504. https://doi.org/10.1038/ngeo557 Russell, J. M., Hendrik, V., Konecky, B. L., et al., 2014. Glacial Forcing of Central Indonesian Hydroclimate since 60, 000 y B.P. Proceedings of the National Academy of Sciences of the United States of America, 111: 5100-5105. https://doi.org/10.1073/pnas.1402373111 Wan, S. M., Toucanne, S., Clift, P. D., et al., 2015. Human Impact Overwhelms Long-Term Climate Control of Weathering and Erosion in Southwest China. Geology, 43(5): 439-442. https://doi.org/10.1130/g36570.1 Wang, P. X., 2014. China's Participation in the Ocean Drilling Program: Decade Retrospect and Future Prospect. Advances in Earth Science, 29(3): 322-326 (in Chinese with English abstract). http://en.cnki.com.cn/Article_en/CJFDTOTAL-DXJZ201403003.htm Wang, P. X., Sun, X. J., 1994. Last Glacial Maximum in China: Comparison between Land and Sea. Catena, 23(3-4): 341-353. https://doi.org/10.1016/0341-8162(94)90077-9 Wang, Y. J., 2001. A High-Resolution Absolute-Dated Late Pleistocene Monsoon Record from Hulu Cave, China. Science, 294(5550): 2345-2348. https://doi.org/10.1126/science.1064618 Wei, G. J., Liu, Y., Li, X. H., et al., 2004. Major and Trace Element Variations of the Sediments at ODP Site 1144, South China Sea, during the Last 230 ka and Their Paleoclimate Implications. Palaeogeography, Palaeoclimatology, Palaeoecology, 212(3-4): 331-342. https://doi.org/10.1016/j.palaeo.2004.06.011 Wei, G., Liu, Y., Li, X., et al., 2003. Climatic Impact on Al, K, Sc and Ti in Marine Sediments: Evidence from ODP Site 1144, South China Sea. Geochemical Journal, 37(5): 593-602. https://doi.org/10.2343/geochemj.37.593 Wu, M., Li, S. R., Chu, F. Y., et al., 2011. Paleoclimate Environmental Significance of Clay Mineral Analysis of Core B106 at Offshore Hainan Island. Journal of Huaihai Institute of Technology (Natural Sciences Edition), 20(1): 85-91 (in Chinese with English abstract). http://www.cqvip.com/QK/90998X/201101/37035532.html Yan, H., Sun, L., Oppo, D. W., et al., 2011. South China Sea Hydrological Changes and Pacific Walker Circulation Variations over the Last Millennium. Nature Communications, 2: 293. https://doi.org/10.1038/ncomms1297 Yang, G. F., Chen, Z. H., Zhang, H. J., et al., 2018. Paleoclimatic Variations in Ningjinpo Area since Late Pleistocene as Indicated by N-Alkanes. Earth Science, 43(11): 4001-4007 (in Chinese with English abstract). http://www.researchgate.net/publication/330192417_Paleoclimatic_Variations_in_Ningjinpo_Area_since_Late_Pleistocene_as_Indicated_by_n-Alkanes Yu, Z. J., Wan, S. M., Colin, C., et al., 2016. Co-Evolution of Monsoonal Precipitation in East Asia and the Tropical Pacific ENSO System since 2.36 Ma: New Insights from High-Resolution Clay Mineral Records in the West Philippine Sea. Earth and Planetary Science Letters, 446: 45-55. https://doi.org/10.1016/j.epsl.2016.04.022 Zhang, H., Griffiths, M. L., Chiang, J. C. H., et al., 2018. East Asian Hydroclimate Modulated by the Position of the Westerlies during Termination I. Science, 362(6414): 580-583. https://doi.org/10.1126/science.aat9393 Zhao, Q. H., Jian, Z. M., Wang, J. L., et al., 2001. Neogene Oxygen Isotopic Stratigraphy, ODP Site 1148, Northern South China Sea. Science China Earth Sciences, 44(10): 934-942. https://doi.org/10.1007/BF02907086 Zhao, Y., Yu, Z. C., Chen, F. H., et al., 2009. Vegetation Response to Holocene Climate Change in Monsoon-Influenced Region of China. Earth-Science Reviews, 97(1-4): 242-256. https://doi.org/10.1016/j.earscirev.2009.10.007 Zhou, H., Liu, L. J., Xu, Y. Q., et al., 2018. Sediment Characteristics and Paleoenvironmental Significance of Core DLW3101 from Northern Slope of the South China Sea. Acta Oceanologica Sinica, 40(7): 103-115 (in Chinese with English abstract). http://en.cnki.com.cn/Article_en/CJFDTOTAL-SEAC201807009.htm Zhou, X., Sun, L. G., Chu, Y. X., et al., 2016. Catastrophic Drought in East Asian Monsoon Region during Heinrich Event 1. Quaternary Science Reviews, 141: 1-8. https://doi.org/10.1016/j.quascirev.2016.03.029 蔡观强, 邱燕, 彭学超, 等, 2010. 南海西南海域表层沉积物微量和稀土元素地球化学特征及其意义. 海洋地质与第四纪地质, 30(5): 53-62. https://www.cnki.com.cn/Article/CJFDTOTAL-HYDZ201005010.htm 陈红瑾, 徐兆凯, 蔡明江, 等, 2019. 30 ka以来东阿拉伯海U1456站位粘土粒级碎屑沉积物来源及其古环境意义. 地球科学, 44(8): 2803-2817. doi: 10.3799/dqkx.2018.185 金海燕, 翦知湣, 谢昕, 等, 2011. 南海北部晚第四纪高分辨率元素比值反映的东亚季风演变. 第四纪研究, 31(2): 207-215. doi: 10.3969/j.issn.1001-7410.2011.02.02 李粹中, 1987. 南海中部沉积物的元素地球化学特征. 东海海洋, 5(1-2): 77-91. https://www.cnki.com.cn/Article/CJFDTOTAL-DHHY1987Z1010.htm 林治家, 陈多福, 刘芊, 2008. 海相沉积氧化还原环境的地球化学识别指标. 矿物岩石地球化学通报, 27(1): 72-80. doi: 10.3969/j.issn.1007-2802.2008.01.012 邱燕, 彭学超, 王英民, 等, 2017. 南海北部海域第四系侵蚀过程与沉积响应. 北京: 地质出版社. 汪品先, 2014. 我国参加大洋钻探的近十年回顾与展望. 地球科学进展, 29(3): 322-326. https://www.cnki.com.cn/Article/CJFDTOTAL-DXJZ201403003.htm 吴敏, 李胜荣, 初凤友, 等, 2011. 海南岛近海B106柱粘土矿物学指标的古气候环境意义. 淮海工学院学报, 20(1): 85-91. doi: 10.3969/j.issn.1672-6685.2011.01.022 杨桂芳, 陈正洪, 张慧娟, 等, 2018. 宁晋泊晚更新世以来气候变化的正构烷烃分子记录. 地球科学, 43(11): 4001-4007. doi: 10.3799/dqkx.2018.575 周航, 刘乐军, 徐元芹, 等, 2018. 南海北部陆坡区DLW3101孔沉积物特征及古环境意义. 海洋学报, 40(7): 103-115. doi: 10.3969/j.issn.0253-4193.2018.07.009