Geochemistry of the Yumen picrites-basalts from the Emeishan large igneous province: Implications for their mantle source, PGE behaviors, and petrogenesis

doi:10.1016/j.lithos.2021.106364

IOCAS-IR > 海洋地质与环境重点实验室

	Geochemistry of the Yumen picrites-basalts from the Emeishan large igneous province: Implications for their mantle source, PGE behaviors, and petrogenesis
	Yao, Jun-Hua 1,2,3,4,7; Zhu, Wei-Guang 1; Wang, Yan-Jun 6; Zhong, Hong ; Bai, Zhong-Jie 1,5; Bai, Zhong-Jie 1
	2021-11-01
发表期刊	LITHOS
ISSN	0024-4937
卷号	400 页码:15
通讯作者	Zhu, Wei-Guang([email protected])
摘要	Olivine compositions are often used to infer the source lithology of basaltic rocks, but the effect of source melting conditions on olivine chemistry remains poorly studied. Here we present mineral chemistry, whole-rock major and trace elements, Sr-Nd isotopes, and platinum-group element (PGE) concentrations for high-Ti picritic-basaltic rocks from Yumen area. These data provide new constraints on the source lithology and petrogenesis of these high-Ti rocks in the Emeishan large igneous province (ELIP). The picrites have primitive compositional features (e.g., high Mg # values, depleted Sr-Nd isotopic compositions, no PGE depletions and/or fractionations). Some basaltic rocks have negative Nb-Ta anomalies, enriched Sr-Nd isotopic compositions, and depleted and/or fractionated PGE contents, indicative of fractional crystallisation, variable degrees of crustal contamination, and magmatic sulfide segregation. Combined with published data for the ELIP, the compositions of the primitive magmas and 10000Zn/Fe and FC3MS (FeO/CaO - 3 x MgO/SiO2, all in wt%) values of the ELIP high-Ti picrites are similar to those of garnet peridotite-derived experimental melts. Based on the primitive magma compositions, the ELIP high-Ti melts could have been produced by mantle melting at 4.0-5.4 GPa and 1620-1660 degrees C, and started to crystallise olivine at 1410-1550 degrees C, based on the Al-in-olivine thermometer, which are higher temperatures than for mid-ocean ridge basalts and ELIP low-Ti magmas. The high-Ni and low-Mn olivine phenocrysts in the ELIP high-Ti samples crystallised from peridotite-derived, MgO-rich melts at high temperatures. Variations in the physicochemical source melting conditions was enough to explain the differences in olivine Ni and Mn contents in the ELIP high- and low-Ti picrites-basalts. Additionally, the almost constant Pd, Pt, and Rh contents with decreasing Mg # values indicate intermediate partition behaviors in the ELIP magmas. No correlations exist between whole-rock 10,000 x Pd/Yb and Mg # , (Th/Nb)(N), and epsilon(Nd)(t) values, implying that selective assimilation of crustal sulfur resulted in magmatic sulfide saturation. We propose that the ELIP high-Ti magmas were derived from a deep-sourced garnet peridotite, and experienced various igneous processes during ascent through the continental lithosphere to form different types of ELIP high-Ti basaltic rocks.
关键词	Emeishan large igneous province Yumen picrites-basalts PGE Olivine composition Mantle peridotite
DOI	10.1016/j.lithos.2021.106364
收录类别	SCI
语种	英语
资助项目	Strategic Priority Research Program of the Chinese Academy of Sciences[XDB18030204]; National Science Foundation of China[41425011]; National Science Foundation of China[41572074]; National Science Foundation of China[41273049]; Natural Science Foundation of Shandong Province[ZR2020MD070]
WOS研究方向	Geochemistry & Geophysics ; Mineralogy
WOS类目	Geochemistry & Geophysics ; Mineralogy
WOS记录号	WOS:000702535400002
出版者	ELSEVIER
引用统计	被引频次：6[WOS] [WOS记录] [WOS相关记录]
文献类型	期刊论文
条目标识符	http://ir.qdio.ac.cn/handle/337002/176483
专题	海洋地质与环境重点实验室
通讯作者	Zhu, Wei-Guang
作者单位	1.Chinese Acad Sci, Inst Geochem, State Key Lab Ore Deposit Geochem, Guiyang 550081, Peoples R China 2.Chinese Acad Sci, Ctr Deep Sea Res, Qingdao 266071, Peoples R China 3.Chinese Acad Sci, Key Lab Marine Geol & Environm, Inst Oceanol, Qingdao 266071, Peoples R China 4.Chinese Acad Sci, Ctr Ocean Mega Sci, Qingdao 266071, Peoples R China 5.Univ Chinese Acad Sci, Beijing 100049, Peoples R China 6.East China Univ Technol, State Key Lab Nucl Resources & Environm, Nanchang 330013, Jiangxi, Peoples R China 7.Guangdong Prov Key Lab Marine Resources & Coastal, Guangzhou, Guangdong, Peoples R China
第一作者单位	中国科学院海洋研究所
推荐引用方式 GB/T 7714	Yao, Jun-Hua,Zhu, Wei-Guang,Wang, Yan-Jun,et al. Geochemistry of the Yumen picrites-basalts from the Emeishan large igneous province: Implications for their mantle source, PGE behaviors, and petrogenesis[J]. LITHOS,2021,400:15.
APA	Yao, Jun-Hua,Zhu, Wei-Guang,Wang, Yan-Jun,Zhong, Hong,Bai, Zhong-Jie,&Bai, Zhong-Jie.(2021).Geochemistry of the Yumen picrites-basalts from the Emeishan large igneous province: Implications for their mantle source, PGE behaviors, and petrogenesis.LITHOS,400,15.
MLA	Yao, Jun-Hua,et al."Geochemistry of the Yumen picrites-basalts from the Emeishan large igneous province: Implications for their mantle source, PGE behaviors, and petrogenesis".LITHOS 400(2021):15.

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