Zircon U-Pb geochronology, Hf isotopes, and geochemistry constraints on the age and tectonic affinity of the basement granitoids from the Qiongdongnan Basin, northern South China Sea
-
Abstract: Studies in the northern South China Sea (SCS) basement remain important for understanding the evolution of the Southeast Asian continental margin. Due to a thick cover of sediments and scarce borehole penetration, little is known about the age and tectonic affinity of this basement. In this study, an integrated study of zircon U-Pb geochronology, Hf isotopes, and whole-rock major and trace elements on seven basement granitoids from seven boreholes of Qiongdongnan Basin has been carried out. New zircon U-Pb results for these granitoids present middle-late Permian ((270.0±1.2) Ma; (253±3.4) Ma), middle to late Triassic ((246.2±3.4) Ma; (239.3±0.96) Ma; (237.9±0.99) Ma; (228.9±1.0) Ma) and Late Cretaceous ages ((120.6±0.6) Ma). New data from this study, in combination with the previous dataset, indicates that granitoid ages in northern SCS basement vary from 270 Ma to 70.5 Ma, with three age groups of 270–196 Ma, 162–142 Ma, and 137–71 Ma, respectively. Except for the late Paleozoic-Mesozoic rocks in the basement of the northern SCS, a few old zircon grains with the age of (2708.1±17) Ma to (2166.6±19) Ma provide clues to the existence of the pre-Proterozoic components. The geochemical signatures indicate that the middle Permian-early Cretaceous granitoids from the Qiongdongnan Basin are I-type granites formed in a volcanic arc environment, which were probably related to the subduction of the Paleo-Pacific Plate.
-
Key words:
- Qiongdongnan Basin /
- basement granitoids /
- geochemistry /
- U-Pb and Hf isotopes /
- Paleo-Pacific Plate subduction
-
Figure 2. Cathodoluminescence (CL) images of representative detrital zircons were analyzed for the U-Pb ages. The red and yellow circles denote the analytical spots for the LA-ICP-MS U-Pb dating and Lu-Hf isotopes, respectively. Numbers near the circles indicate are spot number (U-Pb ages), 207Pb/206Pb ages are selected for zircons older than 1000 Ma, and 206Pb/238U ages for zircons less than 1000 Ma.
Figure 3. The Th/U ratio of zircon grains with U-Pb ages. Most of them have high Th/U ratios ranging from 0.11 to 1.58, together with the euhedral-subhedral in shape and fine-scale oscillatory growth zoning in CL images (Fig. 2), suggesting igneous origin (Belousova et al., 2002; Koschek, 1993).
Figure 5. εHf (t) values versus U-Pb ages, illustrating the comparison of εHf (t) of zircon from the basement granitoids in the Qiongdongnan Basin. DM: depleted mantle; CHUR: Bulk earth (chondritic uniform reservoir). Hf-isotope evolution line for depleted mantle is after Griffin et al. (2000). The dotted lines in a represent average crust 176Lu/177Hf=0.015 (Griffin et al., 2002).
Figure 6. Geochemical features of the basement granitoids from the Qiongdongnan Basin. a. SiO2 versus K2O+Na2O (Middlemost, 1994), b. A/CNK versus A/NK diagram (Maniar and Piccoli, 1989), c. SiO2 versus K2O scheme, where the subdivisions from low-K tholeiite, calc-alkaline, high-K calc-alkaline to shoshonite are from Rickwood (1989), d. SiO2 versus P2O5, e. Rb versus Y, and f. Rb versus Th plot for identification of I-type from S-type granite (Chappell, 1999).
Figure 7. Chondrite-normalized REE patterns (a), and primitive mantle normalized trace element patterns (b), of basement granitoids from the Qiongdongnan Basin. Chondrite and primitive mantle values are from Sun and McDonough (1989).
Figure 8. Distribution of and age summary of granitoids in northern South China Sea Basin. Crosses denote samples analyzed in this study, while circles present ages reported in previous studies (blue ones, K-Ar ages from Li et al. (1999a) and Qiu et al. (1996); red ones, U-Pb ages from Cui et al. (2021), Shi et al. (2011) and Xu et al. (2016, 2017). Black curves denote basin boundary.
Figure 9. Ga×10 000/Al versus Ce plot for identification of A-type granite from I- and S-type granites (Whalen et al., 1987) (a), Y+Nb versus Rb plot for discriminating syn-collisional granite, volcanic-arc granite, within-plate granite, and ocean-ridge granite (Pearce et al., 1984) (b), Y versus Sr/Y plot (Defant et al., 2002) (c), and (Yb)N versus (La/Yb)N plot (Martin, 1993) (d). TTG: tonalite-trondhjemite-granodiorite; ADR: andesite-dacite-rhyolite.
Figure 10. Probability density plots of precambrian U-Pb ages for zircons in this study (a) and xenocrystic/inherited zircon ages in the cathaysia block (b). Data source for references (Wang et al., 2020a, b; Jiang et al., 2020) .
-
Barbarin B. 1999. A review of the relationships between granitoid types, their origins and their geodynamic environments. Lithos, 46(3): 605–626. doi: 10.1016/S0024-4937(98)00085-1 Barckhausen U, Engels M, Franke D, et al. 2014. Evolution of the South China Sea: Revised ages for breakup and seafloor spreading. Marine and Petroleum Geology, 58: 599–611. doi: 10.1016/j.marpetgeo.2014.02.022 Belousova E, Griffin W, O’Reilly S Y, et al. 2002. Igneous zircon: trace element composition as an indicator of source rock type. Contributions to Mineralogy and Petrology, 143(5): 602–622. doi: 10.1007/s00410-002-0364-7 Blichert-Toft J. 2008. The Hf isotopic composition of zircon reference material 91500. Chemical Geology, 253(3–4): 252–257 Blichert-Toft J, Albarède F. 1997. The Lu-Hf isotope geochemistry of chondrites and the evolution of the mantle-crust system. Earth and Planetary Science Letters, 148(1–2): 243–258 Blichert-Toft J, Chauvel C, Albarède F. 1997. Separation of Hf and Lu for high-precision isotope analysis of rock samples by magnetic sector-multiple collector ICP-MS. Contributions to Mineralogy and Petrology, 127(3): 248–260. doi: 10.1007/s004100050278 Braitenberg C, Wienecke S, Wang Y. 2006. Basement structures from satellite-derived gravity field: South China Sea ridge. Journal of Geophysical Research: Solid Earth, 111(B5): B05407 Cao L C, Jiang T, Wang Z F, et al. 2015. Provenance of Upper Miocene sediments in the Yinggehai and Qiongdongnan basins, northwestern South China Sea: Evidence from REE, heavy minerals and zircon U-Pb ages. Marine Geology, 361: 136–146. doi: 10.1016/j.margeo.2015.01.007 Chappell B W. 1999. Aluminium saturation in I- and S-type granites and the characterization of fractionated haplogranites. Lithos, 46(3): 535–551. doi: 10.1016/S0024-4937(98)00086-3 Chen Chenghong, Lee Chi-Yu, Shinjo R. 2008. Was there Jurassic paleo-Pacific subduction in South China?: Constraints from 40Ar/39Ar dating, elemental and Sr-Nd-Pb isotopic geochemistry of the Mesozoic basalts. Lithos, 106(1–2): 83–92 Cheong C S, Kim N, Kim J, et al. 2014. Petrogenesis of Late Permian sodic metagranitoids in southeastern Korea: SHRIMP zircon geochronology and elemental and Nd-Hf isotope geochemistry. Journal of Asian Earth Sciences, 95: 228–242. doi: 10.1016/j.jseaes.2014.06.005 Cui Yuchi, Shao Lei, Li Zhengxiang, et al. 2021. A Mesozoic Andean-type active continental margin along coastal South China: New geological records from the basement of the northern South China Sea. Gondwana Research, 99: 36–52. doi: 10.1016/j.gr.2021.06.021 Cullen A, Reemst P, Henstra G, et al. 2010. Rifting of the South China Sea: new perspectives. Petroleum Geoscience, 16(3): 273–282. doi: 10.1144/1354-079309-908 Defant M J, Xu Jifeng, Kepezhinskas P, et al. 2002. Adakites: some variations on a theme. Acta Petrologica Sinica, 18(2): 129–142 Fisher C M, Vervoort J D, Hanchar J M. 2014. Guidelines for reporting zircon Hf isotopic data by LA-MC-ICPMS and potential pitfalls in the interpretation of these data. Chemical Geology, 363: 125–133. doi: 10.1016/j.chemgeo.2013.10.019 Griffin W L, Pearson N J, Belousova E, et al. 2000. The Hf isotope composition of cratonic mantle: LAM-MC-ICPMS analysis of zircon megacrysts in kimberlites. Geochimica et Cosmochimica Acta, 64(1): 133–147. doi: 10.1016/S0016-7037(99)00343-9 Griffin W L, Wang X, Jackson S E, et al. 2002. Zircon chemistry and magma mixing, SE China: In-situ analysis of Hf isotopes, Tonglu and Pingtan igneous complexes. Lithos, 61(3–4): 237–269 Hayes D E, Nissen S S. 2005. The South China sea margins: Implications for rifting contrasts. Earth and Planetary Science Letters, 237(3–4): 601–616 He Zhenyu, Xu Xisheng. 2012. Petrogenesis of the Late Yanshanian mantle-derived intrusions in southeastern China: Response to the geodynamics of paleo-Pacific plate subduction. Chemical Geology, 328: 208–221. doi: 10.1016/j.chemgeo.2011.09.014 Horie K, Yamashita M, Hayasaka Y, et al. 2010. Eoarchean-Paleoproterozoic zircon inheritance in Japanese Permo-Triassic granites (Unazuki area, Hida Metamorphic complex): unearthing more old crust and identifying source terrranes. Precambrian Research, 183(1): 145–157. doi: 10.1016/j.precamres.2010.06.014 Huang Baojia, Tian Hui, Li Xushen, et al. 2016. Geochemistry, origin and accumulation of natural gases in the deepwater area of the Qiongdongnan Basin, South China Sea. Marine and Petroleum Geology, 72: 254–267. doi: 10.1016/j.marpetgeo.2016.02.007 Jackson S E, Pearson N J, Griffin W L, et al. 2004. The application of laser ablation-inductively coupled plasma-mass spectrometry to in situ U−Pb zircon geochronology. Chemical Geology, 211(1–2): 47–69 Jiang Changhong, Wang Xiaolei, Wang Shuo, et al. 2020. Paleoproterozoic basement beneath the Eastern Cathaysia Block revealed by zircon xenocrysts from late Mesozoic volcanics. Precambrian Research, 350: 105922. doi: 10.1016/j.precamres.2020.105922 Koschek G. 1993. Origin and significance of the SEM cathodoluminescence from zircon. Journal of Microscopy, 171(3): 223–232. doi: 10.1111/j.1365-2818.1993.tb03379.x Lei Chao, Ren Jiaye. 2016. Hyper-extended rift systems in the Xisha Trough, northwestern South China Sea: Implications for extreme crustal thinning ahead of a propagating ocean. Marine and Petroleum Geology, 77: 846–864. doi: 10.1016/j.marpetgeo.2016.07.022 Li Zhengxiang. 1998. Tectonic history of the major east asian lithospheric blocks since the mid-proterozoic—a synthesis. In: Flower M F J, Chung Sun-Lin, Lo Ching-Hua, et al. Mantle Dynamics and Plate Interactions in East Asia. Washington, DC, USA: American Geophysical Union Li Jianhua, Dong Shuwen, Cawood P A, et al. 2018. An Andean-type retro-arc foreland system beneath northwest South China revealed by SINOPROBE profiling. Earth and Planetary Science Letters, 490: 170–179. doi: 10.1016/j.jpgl.2018.03.008 Li Zhengxiang, Li Xianhau. 2007. Formation of the 1300-km-wide intracontinental orogen and postorogenic magmatic province in Mesozoic South China: a flat-slab subduction model. Geology, 35(2): 179–182. doi: 10.1130/G23193A.1 Li Wuxian, Li Xianhua, Li Zhengxiang. 2005a. Neoproterozoic bimodal magmatism in the Cathaysia Block of South China and its tectonic significance. Precambrian Research, 136(1): 51–66. doi: 10.1016/j.precamres.2004.09.008 Li Xianhua, Li Zhengxiang, Li Wuxian, et al. 2006. Initiation of the Indosinian orogeny in South China: evidence for a Permian magmatic arc on Hainan Island. Journal of Geology, 114(3): 341–353. doi: 10.1086/501222 Li Puping, Liang Huixian, Dai Yiding, et al. 1999a. Origin and tectonic setting of the Yanshanian igneous rocks in the Pearl River Mouth basin. Guangdong Geology (in Chinese), 14(1): 1–8 Li Zhengxiang, Li Xianhua, Kinny P D, et al. 1999b. The breakup of Rodinia: did it start with a mantle plume beneath South China?. Earth and Planetary Science Letters, 173(3): 171–181 Li Sunxiong, Yun Ping, Fan Yuan, et al. 2005b. Zircon U-Pb age and its geological significance for Qiongzhong pluton in Qiongzhong area, Hainan Island. Geotectonica et Metallogenia (in Chinese), 29(2): 227–233, 241 Liu Hailing, Yan Pin, Zhang Boyou, et al. 2004a. Pre-cenozoic basements of the South China Sea and Eastern Tethyan realm. Marine Geology and Quaternary Geology (in Chinese), 24(1): 15–28 Liu Hailing, Yang Tian, Zhu Shufen, et al. 2004b. Tectonic evolution of Cenozoic sedimentary basements in the northwestern South China Sea. Acta Oceanologica Sinica (in Chinese), 26(3): 54–67 Liu Qian, Yu Jinhai, Wang Qin, et al. 2012. Ages and geochemistry of granites in the Pingtan–Dongshan Metamorphic Belt, Coastal South China: New constraints on Late Mesozoic magmatic evolution. Lithos, 150: 268–286. doi: 10.1016/j.lithos.2012.06.031 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 Liu Hailing, Zheng Hongbo, Wang Yanlin, et al. 2011. Basement of the South China Sea area: tracing the Tethyan realm. Acta Geologica Sinica-English Edition, 83(3): 637–655 Lu Baoliang, Su Xiaomeng, Zhang Gongcheng, et al. 2011. Seismic-potential field response characteristics and identification of basement lithology of the northern South China Sea basin. Chinese Journal of Geophysics (in Chinese), 54(2): 563–572 Lu Baoliang, Wang Pujun, Zhang Gongcheng, et al. 2015. Characteristic of regional fractures in South China Sea and its basement tectonic framework. Progress in Geophysics (in Chinese), 30(4): 1544–1553 Maniar P D, Piccoli P M. 1989. Tectonic discrimination of granitoid. GSA Bulletin, 101(5): 635–643. doi: 10.1130/0016-7606(1989)101<0635:TDOG>2.3.CO;2 Martin H. 1993. The mechanisms of petrogenesis of the Archaean continental crust-comparison with modern processes. Lithos, 30(3): 373–388 Meng Miaomiao, Liang Jinqiang, Lu Jing’an, et al. 2021. Quaternary deep-water sedimentary characteristics and their relationship with the gas hydrate accumulations in the Qiongdongnan Basin, Northwest South China Sea. Deep-Sea Research Part I: Oceanographic Research Papers, 177: 103628. doi: 10.1016/j.dsr.2021.103628 Middlemost E A K. 1994. Naming materials in the magma/igneous rock system. Earth-Science Reviews, 37(3–4): 215–224 Morley C K. 2002. A tectonic model for the Tertiary evolution of strike-slip faults and rift basins in SE Asia. Tectonophysics, 347(4): 189–215. doi: 10.1016/S0040-1951(02)00061-6 Pearce J A, Harris N B W, Tindle A G. 1984. Trace element discrimination diagrams for the tectonic interpretation of granitic rocks. Journal of Petrology, 25(4): 956–983. doi: 10.1093/petrology/25.4.956 Qin Guoqian. 1987. A preliminary study on foraminiferal assemblages of well 1 Xiyong. Xisha Islands and their coral reef formation. Tropic Oceanology (in Chinese), 6(3): 10–20 Qiu Y X, Li P L. 1996. Late Cretaceous-Cenozoic tectonic evolution and nature of continental margin in the northern South China Sea and Taiwan Strait. Guangdong Geology (in Chinese), 11(3): 10–16 Ren Jishun. 1964. A preliminary study on pre-Devonian geotectonic problems of southeastern China. Acta Geologica Sinica (in Chinese), 44(4): 418–431 Rickwood P C. 1989. Boundary lines within petrologic diagrams which use oxides of major and minor elements. Lithos, 22(4): 247–263. doi: 10.1016/0024-4937(89)90028-5 Sajona F G, Maury R C, Bellon H, et al. 1993. Initiation of subduction and the generation of slab melts in western and eastern Mindanao, Philippines. Geology, 21(11): 1007–1010. doi: 10.1130/0091-7613(1993)021<1007:IOSATG>2.3.CO;2 Shen Linwei, Yu Jihai, O’Reilly S Y, et al. 2018. Subduction-related middle Permian to early Triassic magmatism in central Hainan Island, South China. Lithos, 318–319: 158 –175 Shi Hesheng, Xu Changhai, Zhou Zuyi, et al. 2011. Zircon U-Pb dating on granitoids from the Northern South China Sea and its geotectonic relevance. Acta Geologica Sinica-English Edition, 85(6): 1359–1372. doi: 10.1111/j.1755-6724.2011.00592.x Sláma J, Košler J, Condon D J, et al. 2008. Plešovice zircon—A new natural reference material for U–Pb and Hf isotopic microanalysis. Chemical Geology, 249(1–2): 1–35 Söderlund U, Patchett P J, Vervoort J D, et al. 2004. The 176Lu decay constant determined by Lu-Hf and U-Pb isotope systematics of Precambrian mafic intrusions. Earth and Planetary Science Letters, 219(3–4): 311–324 Su Ao, Chen Honghan, Chen Xu, et al. 2018. New insight into origin, accumulation and escape of natural gas in the Songdong and Baodao regions in the eastern Qiongdongnan basin, South China Sea. Journal of Natural Gas Science and Engineering, 52: 467–483. doi: 10.1016/j.jngse.2018.01.026 Su Nairong, Zeng Lin, Li Pinglu. 1995. Geological features of mesozoic sags in the eastern part of Pearl River Mouth Basin. China Offshore Oil and Gas (Geology) (in Chinese), 9(4): 228–236 Sun Shensu, McDonough W F. 1989. Chemical and isotopic systematics of oceanic basalts: Implications for mantle composition and processes. Geological Society, London, Special Publications, 42(1): 313–345 Sun Xiaomeng, Zhang Xuqing, Zhang Gongcheng, et al. 2014. Texture and tectonic attribute of Cenozoic basin basement in the northern South China Sea. Science China Earth Sciences, 57(6): 1199–1211. doi: 10.1007/s11430-014-4835-2 Tapponnier P, Peltzer G, Armijo R. 1986. On the Mechanics of the Collision Between India and Asia. In: Coward M, Ries A, eds. Collosion Tectonics. London, UK: Geological Society of London Special Publication, 115–157 Taylor B, Hayes D E. 1980. The tectonic evolution of the South China Basin. In: Hayes D E, ed. The Tectonic and Geologic Evolution of Southeast Asian Seas and Islands. Washington, DC, USA:American Geophysical Union, 89–104 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. Geophysics Monographs Series, Washington, DC, USA: American Geophysical Union, 23–56 Wang Kai, Dong Shuwen, Yao Weihua, et al. 2020a. Xenocrystic/inherited Precambrian zircons entrained within igneous rocks from eastern South China: Tracking unexposed ancient crust and implications for late Paleoproterozoic orogenesis. Gondwana Research, 84: 194–210. doi: 10.1016/j.gr.2020.02.015 Wang Yuejun, Fan Weiming, Zhang Guowei, et al. 2013. Phanerozoic tectonics of the South China Block: Key observations and controversies. Gondwana Research, 23(4): 1273–1305. doi: 10.1016/j.gr.2012.02.019 Wang Jialin, Zhang Xinbing, Wu Jiansheng, et al. 2002. Integrated geophysical researches on base texture of Zhujiang River Mouth basin. Journal of Tropical Oceanography (in Chinese), 21(2): 13–22 Wang Tingting, Zheng Jianping, Zhao Huan. 2020b. Unexposed Archean components and complex evolution beneath the Cathaysia Block: Evidence from zircon xenocrysts in the Cenozoic basalts in Leizhou Peninsula, South China. Journal of Asian Earth Sciences, 192: 104268. doi: 10.1016/j.jseaes.2020.104268 Whalen J B, Currie K L, Chappell B W. 1987. A-type granites: Geochemical characteristics, discrimination and petrogenesis. Contributions to Mineralogy and Petrology, 95(4): 407–419. doi: 10.1007/BF00402202 Wiedenbeck M, Corfu P A F, Griffin W L, et al. 1995. Three natural zircon standards for U-Th-Pb, Lu-Hf, trace element and REE analyses. Geostandards Newsletter, 19(1): 1–23. doi: 10.1111/j.1751-908X.1995.tb00147.x Xie Caifu, Zhu Jinchu, Ding Shijiang, et al. 2006. Identification of Hercynian shoshonitic intrusive rocks in central Hainan Island and its geotectonic implications. Chinese Science Bulletin, 51(20): 2507–2519. doi: 10.1007/s11434-006-2122-0 Xu Changhai, Que Xiaoming, Shi Hesheng, et al. 2013. The southward extension of cathaysia block: evidence from zircon U-Pb dates of borehole volcanics in the northern South China Sea. Acta Geologica Sinica-English Edition, 87(5): 1370–1386. doi: 10.1111/1755-6724.12135 Xu Changhai, Shi Hesheng, 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. doi: 10.1080/00206814.2015.1056256 Xu Changhai, Zhang Lu, Shi Hesheng, et al. 2017. Tracing an Early Jurassic magmatic arc from South to East China seas. Tectonics, 36(3): 466–492. doi: 10.1002/2016TC004446 Yan Lili, He Zhenyu, Jahn B M, et al. 2016. Formation of the Yandangshan volcanic–plutonic complex (SE China) by melt extraction and crystal accumulation. Lithos, 266–267: 287–308 Yan Quanshu, Metcalfe I, Shi Xuefa. 2017. U-Pb isotope geochronology and geochemistry of granites from Hainan Island (northern South China Sea margin): Constraints on late Paleozoic-Mesozoic tectonic evolution. Gondwana Research, 49: 333–349. doi: 10.1016/j.gr.2017.06.007 Yan Quanshu, Shi Xuefa, Castillo P R. 2014. The late Mesozoic-Cenozoic tectonic evolution of the South China Sea: A petrologic perspective. Journal of Asian Earth Sciences, 85: 178–201. doi: 10.1016/j.jseaes.2014.02.005 Yan Yi, Xia Bin, Lin Ge, et al. 2007. Geochemical and Nd isotope composition of detrital sediments on the north margin of the South China Sea: provenance and tectonic implications. Sedimentology, 54(1): 1–17. doi: 10.1111/j.1365-3091.2006.00816.x Yi K, Cheong C S, Kim J, et al. 2012. Late Paleozoic to early Mesozoic arc-related magmatism in southeastern Korea: SHRIMP zircon geochronology and geochemistry. Lithos, 153: 129–141. doi: 10.1016/j.lithos.2012.02.007 Zhao Guochun, Cawood P A. 1999. Tectonothermal evolution of the Mayuan Assemblage in the Cathaysia Block; implications for Neoproterozoic collision-related assembly of the South China Craton. American Journal of Science, 299(4): 309–339. doi: 10.2475/ajs.299.4.309 Zhao Xilin, Mao Jianren, Ye Haimin, et al. 2013. New SHRIMP U-Pb zircon ages of granitic rocks in the Hida Belt, Japan: implications for tectonic correlation with Jiamushi massif. Island Arc, 22(4): 508–521. doi: 10.1111/iar.12045 Zhou Di, Chen Hanzong, Wu Shimin, et al. 2002. Opening of the South China Sea by dextral splitting of the East Asian continental margin. Acta Geologica Sinica (in Chinese), 76(2): 180–190 Zhou X M, Li Wuxian. 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 Zhou Xinmin, Sun Tao, Shen Weizhou, et al. 2006. Petrogenesis of Mesozoic granitoids and volcanic rocks in South China: a response to tectonic evolution. Episodes, 29(1): 26–33. doi: 10.18814/epiiugs/2006/v29i1/004 Zhu Weilin, Huang Baojia, Mi Lijun, et al. 2009. Geochemistry, origin, and deep-water exploration potential of natural gases in the Pearl River Mouth and Qiongdongnan basins, South China Sea. AAPG Bulletin, 93(6): 741–761. doi: 10.1306/02170908099 Zhu Weilin, Xie Xinong, Wang Zhenfeng, 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. doi: 10.1007/s11430-017-9089-9 -
Table S3.docx Table S1.xlsx Table S2.docx