Geochemical characteristics of Sr isotopes in the LS33 drill core from the Qiongdongnan Basin, South China Sea, and their response to the uplift of the Tibetan Plateau
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Abstract: Making full use of modern analytical and testing techniques to explore and establish new indexes or methods for extracting paleoseawater geochemical information from sediments will help to reconstruct the sedimentary paleoenvironment in different research areas. The connection between the subsidence of the South China Sea basin and the uplift of the Tibetan Plateau has been a scientific concern in recent decades. To explore the information on the sedimentary paleoenvironment, provenance changes and uplift of Tibetan Plateau contained in core sediments (debris), we selected core samples from Well LS33 in the Qiongdongnan Basin, South China Sea, and analyzed the contents of typical elements (Al, Th, and rare earth elements) that can indicate changes in provenance and the Sr isotopic compositions, which can reveal the geochemical characteristics of the paleoseawater depending on the type of material (authigenic carbonate and terrigenous detritus). The results show the following: (1) during the late Miocene, the Red River transported a large amount of detrital sediments from the ancient continental block (South China) to the Qiongdongnan Basin. (2) The authigenic carbonates accurately record changes in the 87Sr/86Sr ratios in the South China Sea since the Oligocene. These ratios reflect the semi-closed marginal sea environment of the South China Sea (relative to the ocean) and the sedimentary paleoenvironment evolution process of the deep-water area of the Qiongdongnan Basin from continental to transitional and then to bathyal. (3) Since the Neogene, the variations in the 87Sr/86Sr ratio in the authigenic carbonates have been consistent with the variations in the uplift rate of the Tibetan Plateau and the sediment accumulation rate in the Qiongdongnan Basin. These consistent changes indicate the complex geological process of the change in the rock weathering intensity and terrigenous Sr flux caused by changes in the uplift rate of the Tibetan Plateau, which influence the Sr isotope composition of seawater.
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Figure 1. Topographic map of the Qiongdongnan Basin (modified from Liu et al. (2015)).
Figure 2. Lithological profile of Well LS33 (modified from Liu et al. (2018)).
Figure 4. Comparison curves of the 87Sr/86Sr ratios of ocean water (black), reef carbonate of Well Xike-1 (blue) and authigenic carbonate components of Well LS33 core samples (red dot). 87Sr/86Sr ratios of reef carbonates in Well Xike-1 are from Bi et al. (2019); 87Sr/86Sr ratios of ocean water are from Prokoph et al. (2008).
Figure 5. Changes in the Red River Basin in the late Miocene (a) and modern times (b) (modified from van Hoang et al. (2009)). Orange indicates late Paleozoic sedimentary rocks, blue indicates Triassic sedimentary rocks, and purple indicates early Paleozoic sedimentary rocks. YGHB: Yinggehai Basin; QDNB: Qiongdongnan Basin.
Figure 6. Schematic diagram of Red River sediment entering the Qiongdongnan Basin in the late Miocene (modified from Wang et al. (2011b)).
Figure 8. 87Sr/86Sr ratio (dots represent average values and line segments represent the range of variation) of authigenic carbonates (red), reef carbonates in Well Xike-1, seawater of the South China Sea (blue; Bi et al., 2019) and the ocean (black; Prokoph et al., 2008).
Figure 9. 87Sr/86Sr ratio of authigenic carbonates, heavy mineral composition (Liu et al., 2015), clay content (Li, 2013), and benthic foraminifer assemblage (Liu et al., 2018) in the LS33 drill core.
Figure 10. Comparison curves of 87Sr/86Sr ratio growth rate of authigenic carbonate in Well LS33 (a), uplift rate of the Tibetan Plateau (b), sediment accumulation rate in Qiongdongnan Basin (c), and the 87Sr/86Sr ratio of the reef carbonates in Well Xike-1 (d) (the data in b are from Jiang and Li (2014); the data in c are from Huang and Wang (2006); the data in d are from Bi et al. (2019)).
Table 1. 87Sr/86Sr ratios of the authigenic carbonate and terrigenous detritus, the Al2O3 and Th contents, and LREE/HREE ratios of the terrigenous detritus in the LS33 drill core samples
Chronostratigraphy Depth/m 87Sr/86Sr ratio
(Authigenic carbonate)Al2O3 content/% Th content/10–6 LREE/HREE
ratio87Sr/86Sr ratio
(Terrigenous detritus)Measured
valueMean
valueMeasured
valueMean
valueMeasured
valueMean
valueMeasured
valueMean
valueMeasured
valueMean
valueQuaternary 2210 0.7094040 0.7092843 15.72 17.43 14.48 14.71 8.83 9.12 0.7162635 0.7167942 Pliocene 2265 0.7093042 17.40 14.44 9.27 0.7168650 2395 0.7093653 17.28 15.18 9.20 0.7163923 2450 0.7094133 17.35 14.73 9.33 0.7173571 2525 0.7091499 18.04 14.72 9.11 0.7166764 2635 0.7090691 18.78 14.68 8.97 0.7172111 Late Miocene 2730 0.7090530 0.7090314 19.27 19.47 14.68 15.80 9.84 9.50 0.7203499 0.7179774 2775 0.7090548 19.07 15.53 9.58 0.7194971 2905 0.7090457 19.17 16.27 9.24 0.7161784 3015 0.7090111 19.52 15.73 9.44 0.7167459 3120 0.7089924 20.30 16.79 9.39 0.7171156 Middle Miocene 3160 0.7089885 0.7089444 17.94 16.41 14.37 15.11 8.92 8.43 0.7143662 0.7136054 3255 0.7089648 18.18 14.23 7.77 0.7137450 3305 0.7089330 17.44 14.47 7.43 0.7137476 3340 0.7088912 17.28 16.25 8.03 0.7145771 Early Miocene 3451 0.7087743 0.7087501 17.14 15.94 7.96 0.7139058 3523 0.7087647 17.00 17.61 8.78 0.7135312 3598 0.7087113 17.65 17.67 9.64 0.7144416 Late Oligocene 3673 0.7085298 0.7085095 16.02 13.00 8.11 0.7128788 3694 0.7085239 16.06 15.11 8.41 0.7127631 3766 0.7084581 15.74 15.47 8.05 0.7130270 3847 0.7085480 12.90 13.29 8.39 0.7130234 3931 0.7084875 13.53 13.96 9.72 0.7132584 Early Oligocene 4015 0.7084890 0.7090238 − − − − − − − − 4102 0.7088337 − − − − 4189 0.7089190 − − − − 4267 0.7092434 − − − − 4339 0.7096338 − − − − Note: − represents no data. Table 2. Sr and Mn contents and Mn/Sr ratios of authigenic carbonate in LS33 drill core samples
Chronostratigraphy Depth/m Sr content/10−6 Mean value Mn content/% Mean value Mn/Sr ratio Quaternary 2210 710.66 710.66 0.37 0.37 5.19 Pliocene 2265 849.50 1 070.63 0.30 0.28 3.53 2395 909.12 0.33 3.62 2450 886.74 0.29 3.24 2 525 1400.33 0.26 1.89 2 635 1 307.45 0.22 1.69 Late Miocene 2 730 1321.12 1497.18 0.27 0.24 2.01 2775 1372.93 0.20 1.48 2905 1383.49 0.23 1.63 3015 1678.38 0.22 1.29 3120 1729.99 0.27 1.56 Middle Miocene 3160 1342.02 1587.38 0.31 0.32 2.33 3255 1652.94 0.35 2.10 3305 1593.73 0.31 1.92 3340 1760.85 0.30 1.72 Early Miocene 3 451 1 500.05 1 908.61 0.15 0.20 0.97 3523 2095.57 0.24 1.16 3598 2130.22 0.22 1.01 Late Oligocene 3 673 1 536.91 1 335.33 0.13 0.16 0.86 3694 1489.59 0.11 0.73 3766 1486.84 0.15 0.98 3847 1070.38 0.20 1.90 3931 1092.91 0.19 1.75 Early Oligocene 4 015 877.33 1 065.87 0.35 0.40 3.96 4102 928.04 0.23 2.44 4189 2914.12 0.52 1.78 4267 335.57 0.43 12.92 4339 274.30 0.49 18.03 -
Bagherpour B, Bucher H, Schneebeli-Hermann E, et al. 2018. Early Late Permian coupled carbon and strontium isotope chemostratigraphy from South China: Extended Emeishan volcanism?. Gondwana Research, 58: 58–70. doi: 10.1016/j.gr.2018.01.011 Bi Dongjie, Zhang Daojun, Zhai Shikui, et al. 2017. The coupling relationships among the Qinghai-Tibet Plateau uplifting, the Qiongdongnan Basin subsiding and the Xisha Islands’ Reefs developing. Haiyang Xuebao (in Chinese), 39(1): 52–63 Bi Dongjie, Zhang Daojun, Zhai Shikui, et al. 2019. Seawater 87Sr/86Sr values recorded by reef carbonates from the Xisha Islands (South China Sea) since the Neogene and its response to the uplift of Qinghai-Tibetan Plateau. Geological Journal, 54(6): 3878–3890. doi: 10.1002/gj.3386 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. doi: 10.1029/92JB02280 Cai Guofu, Shao Lei, Qiao Peijun, et al. 2013. Marine transgression and evolution of depositional environment in the Paleogene strata of Qiongdongnan Basin, South China Sea. Acta Petrolei Sinica (in Chinese), 34(S2): 91–101 Cao Licheng, Jiang Tao, Wang Zhenfeng, et al. 2013. Characteristics of heavy minerals and their implications for Neogene provenances evolution in Qiongdongnan Basin. Journal of Central South University (Science and Technology) (in Chinese), 44(5): 1971–1981 Chen Kui. 2012. Sediment source analysis of oil and gas objective strata in the Qiongdongnan Basin (in Chinese) [dissertation]. Qingdao: Ocean University of China Chen Hongyan, Sun Zhipeng, Zhai Shikui, et al. 2015. Analysis of well-seismic stratigraphic correlation and establishment of regional stratigraphic framework in the Qiongdongnan Basin of northern South China Sea. Haiyang Xuebao (in Chinese), 37(5): 1–14 DePaolo D J. 1986. Detailed record of the Neogene Sr isotopic evolution of seawater from DSDP Site 590B. Geology, 14(2): 103–106. doi: 10.1130/0091-7613(1986)14<103:DROTNS>2.0.CO;2 Derry L A, Keto L S, Jacobsen S B, et al. 1989. Sr isotopic variations in Upper Proterozoic carbonates from Svalbard and East Greenland. Geochimica et Cosmochimica Acta, 53(9): 2331–2339. doi: 10.1016/0016-7037(89)90355-4 Du Tongjun. 2013. Sequence stratigraphic and deep water sedimentary characteristic in the Qiongdongnan Basin (in Chinese) [dissertation]. Qingdao: Ocean University of China Edwards C T, Saltzman M R, Leslie S A, et al. 2015. Strontium isotope (87Sr/86Sr) stratigraphy of Ordovician bulk carbonate: Implications for preservation of primary seawater values. Geological Society of America Bulletin, 127(9–10): 1275–1289 Gong Chenglin, Wang Yingmin, Zhu Weilin, et al. 2011. The Central Submarine Canyon in the Qiongdongnan Basin, northwestern South China Sea: Architecture, sequence stratigraphy, and depositional processes. Marine and Petroleum Geology, 28(9): 1690–1702. doi: 10.1016/j.marpetgeo.2011.06.005 Harris N. 1995. Significance of weathering Himalayan metasedimentary rocks and leucogranites for the Sr isotope evolution of seawater during the early Miocene. Geology, 23(9): 795–798. doi: 10.1130/0091-7613(1995)023<0795:SOWHMR>2.3.CO;2 Holloway N H. 1982. North Palawan block, Philippines-its relation to Asian mainland and role in evolution of South China Sea. American Association of Petroleum Geologists Bulletin, 66(9): 1355–1383 Huang Wei, Wang Pinxian. 2006. Sediment mass and distribution in the South China Sea since the Oligocene. Science in China Series D: Earth Sciences, 49(11): 1147–1155. doi: 10.1007/s11430-006-2019-4 Hutchison C. 1989. Geological Evolution of Southeast Asia. Oxford: Clarendon Press Jiang Xiaodian, Li Zhengxiang. 2014. Seismic reflection data support episodic and simultaneous growth of the Tibetan Plateau since 25 Myr. Nature Communications, 5: 5453, Kaufman A J, Knoll A H. 1995. Neoproterozoic variations in the C-isotopic composition of seawater: Stratigraphic and biogeochemical implications. Precambrian Research, 73(1–4): 27–49 Kroeger K F, Reuter M, Forst M H, et al. 2007. Eustasy and sea water Sr composition: application to high-resolution Sr-isotope stratigraphy of Miocene shallow-water carbonates. Sedimentology, 54(3): 565–585. doi: 10.1111/j.1365-3091.2006.00849.x Le Guerroué E, Allen P A, Cozzi A. 2006. Chemostratigraphic and sedimentological framework of the largest negative carbon isotopic excursion in Earth history: The Neoproterozoic Shuram formation (Nafun Group, Oman). Precambrian Research, 146(1–2): 68–92 Lei Chao, Ren Jianye, Pei Jianxiang, et al. 2011. Tectonic framework and multiple episode tectonic evolution in deepwater area of Qiongdongnan Basin, northern continental margin of South China Sea. Earth Science-Journal of China University of Geosciences (in Chinese), 36(1): 151–162 Lei Chao, Ren Jianye, Zhang Jing. 2015. Tectonic province divisions in the South China Sea: implications for basin geodynamics. Earth Science-Journal of China University of Geosciences (in Chinese), 40(4): 744–762. doi: 10.3799/dqkx.2015.062 Li Tingdong. 1995. The uplifting process and mechanism of the Qinhai-Tibet Plateau. Acta Geoscientia Sinica (in Chinese), 16(1): 1–9 Li Na. 2013. The sedimentary paleoenvironment and provenance analysis in deepwater area of Qiongdongnan Basin since Oligocene (in Chinese) [dissertation]. Qingdao: Ocean University of China Liu Xiaofeng. 2015. The evolution of sedimentary paleoenvironment and provenance in the deepwater area of the Qiongdongnan Basin (in Chinese) [Dissertation]. Qingdao: Ocean University of China Liu Xiaofeng, Sun Zhipeng, Liu Xinyu, et al. 2018. Chronostratigraphic framework based on micro-paleontological data from drilling LS33a in deep water area of northern South China Sea. Acta Sedimentologica Sinica (in Chinese), 36(5): 890–902 Liu Xinyu, Xie Jinyou, Zhang Huolan, et al. 2009. Chronostratigraphy of planktonic foraminifera in the Yinggehai-Qiongdongnan Basin. Acta Micropalaeontologica Sinica (in Chinese), 26(2): 181–192 Liu Xiaofeng, Zhang Daojun, Zhai Shikui, et al. 2015. A heavy mineral viewpoint on sediment provenance and environment in the Qiongdongnan Basin. Acta Oceanologica Sinica, 34(4): 41–55. doi: 10.1007/s13131-015-0648-1 Luo Zhaohua, Mo Xuanxue, Hou Zengqian, et al. 2006. An integrated model for the Cenozoic evolution of the Tibetan Plateau: constraints from igneous rocks. Earth Science Frontiers (in Chinese), 13(4): 196–211 McArthur J M, Burnett J, Hancock J M. 1992. Strontium isotopes at K/T boundary. Nature, 355(6355): 28. doi: 10.1038/355028a0 Mi Lijun, Yuan Yusong, Zhang Gongcheng, et al. 2009. Characteristics and genesis of geothermal field in deep-water area of the northern South China Sea. Acta Petrolei Sinica (in Chinese), 30(1): 27–32 Milliman J D, Syvitski J P M. 1992. Geomorphic/tectonic control of sediment discharge to the ocean: The importance of small mountainous rivers. The Journal of Geology, 100(5): 525–544. doi: 10.1086/629606 Palmer M R, Edmond J M. 1989. The strontium isotope budget of the modern ocean. Earth & Planetary Science Letters, 92(1): 11–26 Palmer M R, Elderfield H. 1985. Sr isotope composition of sea water over the past 75 Myr. Nature, 314(6011): 526–528. doi: 10.1038/314526a0 Prokoph A, Shields G A, Veizer J. 2008. Compilation and time-series analysis of a marine carbonate δ18O, δ13C, 87Sr/86Sr and δ34S database through Earth history. Earth-Science Reviews, 87(3–4): 113–133 Rollinson H R. 1993. Using Geochemical Data: Evaluation, Presentation, Interpretation. New York: Longman Scientific Technical, 48–51 Ruppel S C, James E W, Barrick J E, et al. 1996. High-resolution 87Sr/86Sr chemostratigraphy of the Silurian: Implications for event correlation and strontium flux. Geology, 24(9): 831–834. doi: 10.1130/0091-7613(1996)024<0831:HRSSCO>2.3.CO;2 Shao Lei, Cui Yuchi, Qiao Peijun, et al. 2019. Implications on the Early Cenozoic palaeogeographical reconstruction of SE Eurasian margin based on northern South China Sea palaeo-drainage system evolution. Journal of Palaeogeography (in Chinese), 21(2): 216–231 Su Ming, Xie Xinong, Xie Yuhong, et al. 2014. The segmentations and the significances of the Central Canyon System in the Qiongdongnan Basin, northern South China Sea. Journal of Asian Earth Sciences, 79: 552–563. doi: 10.1016/j.jseaes.2012.12.038 Sun Zhiguo, Han Changfu, Ju Lianjun, et al. 1997. Comparison between the uplift of the Tibetan Plateau and the sedimentation of coral reefs in Xisha Islands. Marine Sciences (in Chinese), 24(4): 64–67 Sun Zhuan, Liu Hao, Wu Zhe. 2011. The analysis of Cenozoic tectonic sequence of Qiongdongnan Basin in the South China Sea. Offshore Oil (in Chinese), 31(1): 8–15 Tian Shanshan. 2010. Tectonic subsidence analysis and paleotopography restoration of postrifting strata in the Qiongdongnan Basin (in Chinese) [dissertation]. Wuhan: China University of Geosciences van der Beek P, Van Melle J, Guillot S, et al. 2009. Eocene Tibetan plateau remnants preserved in the northwest Himalaya. Nature Geoscience, 2(5): 364–368. doi: 10.1038/ngeo503 van Hoang L, Wu Fuyuan, Clift P D, et al. 2009. Evaluating the evolution of the Red River system based on in situ U-Pb dating and Hf isotope analysis of zircons. Geochemistry, Geophysics, Geosystems, 10(11): Q11008 Wang Pinxian. 1995. ODP and Qinghai/Xizang (Tibetan) Palteau. Advance in Earth Sciences (in Chinese), 10(3): 254–257 Wang Guocan, Cao Kai, Zhang Kexin, et al. 2011a. Spatio-temporal framework of tectonic uplift stages of the Tibetan Plateau in Cenozoic. Science China Earth Sciences, 54(1): 29–44. doi: 10.1007/s11430-010-4110-0 Wang Xun, Liu Sheng’ao, Wang Zhengrong, et al. 2018. Zinc and strontium isotope evidence for climate cooling and constraints on the Frasnian-Famennian (~372 Ma) mass extinction. Palaeogeography, Palaeoclimatology, Palaeoecology, 498: 68–82 Wang Yingmin, Xu Qiang, Li Dong, et al. 2011b. Late Miocene Red River submarine fan, northwestern South China Sea. Chinese Science Bulletin, 56(14): 1488–1494. doi: 10.1007/s11434-011-4441-z Wei Kuisheng, Cui Hanyun, Ye Shufen, et al. 2001. High-precision sequence stratigraphy in Qiongdongnan Basin. Earth Science-Journal of China University of Geosciences (in Chinese), 26(1): 59–66 Xie Xinong, Müller R D, Li Sitian, et al. 2006. Origin of anomalous subsidence along the northern South China Sea margin and its relationship to dynamic topography. Marine and Petroleum Geology, 23(7): 745–765. doi: 10.1016/j.marpetgeo.2006.03.004 Xiu Chun, Zhai Shikui, Huo Suxia, et al. 2018. Provenance of sediments of the Yacheng Formation in the Lingnan Low Uplift, Qiongdongnan Basin: Evidences from U-Pb dating of detrital zircons and geochemistry of the sediments. Bulletin of Mineralogy, Petrology and Geochemistry (in Chinese), 37(6): 1102–1113 Xu Qiang, Li Dong, Zhu Weilin, et al. 2020. Shrimp U-Pb ages of detrital zircons: Discussions on provenance control and the Red River capture event. Sedimentary Geology and Tethyan Geology (in Chinese), 40(3): 20–30 Xu Zhiqin, Yang Jingsui, Li Haibing, et al. 2011. On the tectonics of the India-Asia collision. Acta Geologica Sinica (in Chinese), 85(1): 1–33. doi: 10.1111/j.1755-6724.2011.00375.x Yuan Shengqiang, Wu Shiguo, Yao Genshun. 2010. The controlling factors analysis of Qiongdongnan slope deepwater channels and its significance to the hydrocarbon exploration. Marine Geology and Quaternary Geology (in Chinese), 30(2): 61–66. doi: 10.3724/SP.J.1140.2010.02061 Zakharov Y D, Dril S I, Shigeta Y, et al. 2018. New aragonite 87Sr/86Sr records of Mesozoic ammonoids and approach to the problem of N, O, C and Sr isotope cycles in the evolution of the Earth. Sedimentary Geology, 364: 1–13. doi: 10.1016/j.sedgeo.2017.11.011 Zhong Dalai, Ding Lin. 1996. A discussion of the process and mechanism of Tibetan Plateau uplifting. Science in China Series D: Earth Sciences (in Chinese), 26(4): 289–295