Petrogenesis of high-alumina basalts: Implications for magmatic processes associated with the opening of the South China Sea

doi:10.1016/j.chemgeo.2023.121641

CORC > 深海科学与工程研究所 > 中国科学院深海科学与工程研究所 > 深海科学研究部 > 深海地质与地球化学研究室

	Petrogenesis of high-alumina basalts: Implications for magmatic processes associated with the opening of the South China Sea
	Wang, Wei 1,5; Tian, Liyan 4; Castillo, Paterno R.3; Wu, Tao 2; Dong, Yunpeng 1; Liu, Hongling 4; Chen, Lingxuan 4
刊名	CHEMICAL GEOLOGY
	2023-10-05
卷号	636 页码:15
关键词	High Al content Plagioclase accumulation Subduction of proto-SCS South China Sea extension IODP Sites U1500 and U1503
ISSN号	0009-2541
DOI	10.1016/j.chemgeo.2023.121641
通讯作者	Tian, Liyan(lytian@idsse.ac.cn)
英文摘要	Results of International Ocean Discovery Program (IODP) Expeditions on the northern continental margin of the South China Sea (SCS) have nullified the early notion that the SCS is a magma-poor margin. However, there are continuing debates on how the rapid transition from continent to ocean is supported by geochemical and petrologic data, and whether such a process was related to plate subduction or mantle plume activities. Here we present the results of bulk-rock and plagioclase phenocryst geochemistry of the basalts generated during the early spreading stage (initial and steady ocean stages) of SCS basin extension, which were drilled at IODP Sites U1500 and U1503, respectively. We combined these findings with published data from the late spreading stage of the SCS basin, which provides an excellent opportunity to examine the magmatic processes associated with the evolution of the SCS basin. Our results revealed that the SCS basalts generally exhibit higher Al contents than global Mid-Ocean Ridge Basalts, particularly at lower MgO contents, which is similar to the characteristics of modern arc basalts. Nevertheless, their origins are site-specific and complex. For instance, some of the Site U1503 basalts originated through fractional crystallization of water-rich parental magmas with the lowest degree of melting, while the basalts from the other sites, including Site U1500, were primarily generated by the accumulation of plagioclase. More specifically, the water-rich magmas from Site U1503 displayed strong subduction signals in terms of trace elements, and their correlations with Al2O3 content suggest that they are the product of partial melting of the mantle wedge, closely related to the northward subduction of proto-SCS. This subduction had a significant effect on triggering the opening of the SCS, rather than a mantle plume. Moreover, the Site U1500 basalts exhibit a significant increase in plagioclase An values with the increase of host magma Al contents, indicating that the plagioclase floatation mechanism cannot account for the origin of their plagioclase accumulation. Therefore, we propose that the high abundance of plagioclase in Site U1500 basalts requires rapid ascent of magma, supporting a rapid rifting and strong magmatism during the initial opening of the SCS.
资助项目	IODP China ; Key Research and Development Pro-gram (International Science and Technology Cooperation Development Program) of Hainan Province[GHYF2022009] ; National Natural Science Foundation of China[42025601] ; National Natural Science Foundation of China[41876044]
WOS关键词	PLAGIOCLASE ULTRAPHYRIC BASALTS ; MIDOCEAN RIDGE BASALTS ; P-WAVE TOMOGRAPHY ; PHASE-RELATIONS ; CALC-ALKALINE ; MAGNETIC-ANOMALIES ; CONTINENTAL-MARGIN ; SUBDUCTION ZONES ; MELT INCLUSIONS ; MANTLE BENEATH
WOS研究方向	Geochemistry & Geophysics
语种	英语
出版者	ELSEVIER
WOS记录号	WOS:001048786900001
资助机构	IODP China ; Key Research and Development Pro-gram (International Science and Technology Cooperation Development Program) of Hainan Province ; National Natural Science Foundation of China
内容类型	期刊论文
源URL	[http://ir.idsse.ac.cn/handle/183446/10436]
专题	深海科学研究部_深海地质与地球化学研究室
通讯作者	Tian, Liyan
作者单位	1.Northwest Univ, Dept Geol, State Key Lab Continental Dynam, Xian 710069, Peoples R China 2.Zhejiang Univ, Ocean Coll, 1 Zheda Rd, Zhoushan 316021, Peoples R China 3.Univ Calif San Diego, Scripps Inst Oceanog, 9500 Gilman Dr, La Jolla, CA 92093 USA 4.Chinese Acad Sci, Inst Deep Sea Sci & Engn, Sanya 572000, Peoples R China 5.Chinese Acad Geol Sci, SinoProbe Lab, Beijing 100094, Peoples R China
推荐引用方式 GB/T 7714	Wang, Wei,Tian, Liyan,Castillo, Paterno R.,et al. Petrogenesis of high-alumina basalts: Implications for magmatic processes associated with the opening of the South China Sea[J]. CHEMICAL GEOLOGY,2023,636:15.
APA	Wang, Wei.,Tian, Liyan.,Castillo, Paterno R..,Wu, Tao.,Dong, Yunpeng.,...&Chen, Lingxuan.(2023).Petrogenesis of high-alumina basalts: Implications for magmatic processes associated with the opening of the South China Sea.CHEMICAL GEOLOGY,636,15.
MLA	Wang, Wei,et al."Petrogenesis of high-alumina basalts: Implications for magmatic processes associated with the opening of the South China Sea".CHEMICAL GEOLOGY 636(2023):15.