Petrology, mineralogy and geochemistry of the Emeishan continental flood;basalts, SW China: Evidence for activity of mantle plumes

	Petrology, mineralogy and geochemistry of the Emeishan continental flood;basalts, SW China: Evidence for activity of mantle plumes
	Zhang, ZC 3; Hao, YL ; Wang, FS ; Mahoney, JJ
刊名	ACTA GEOLOGICA SINICA-ENGLISH EDITION
	2004
卷号	78 期号:1;SI SI 页码:40-51
关键词	continental flood basalts picrite geochemistry Emeishan
ISSN号	1000-9515
英文摘要	Electronic microprobe analyses for olivine, clinopyroxene and Cr-spinel in picrites, which we have discovered recently in the Emeishan continental flood basalt province (ECFBP), show that the olivine is rich in Mg, and that Cr-spinel is rich in Cr. Based on the olivine-melt equilibrium, the primary parental melt compositions are calculated. The high-Mg olivine-hosted picrite can be regarded as parental melt. Thus, the melting temperature and pressure are estimated: T=1600degreesC and P=4.5 GPa. It suggests that the picrites are connected with the activity of mantle plumes. Their major element composition is comparable to many other CFBs by their high Fe-8, (CaO/Al2O3)(8) and low Na-8, indicating a high pressure. All rocks display a similar chondrite-normalized REE patterns, i.e., enrichment of LREE, relative depletion of HFSE and absence of negative Nb and Ta but depletion in P and K. Some incompatible element ratios, such as La/Ta, La/ Sm, (La/Nb)(PM), (Th/Ta)(PM), are in a limited range, show that they were derived from the mantle plume, and there was no or little crustal contamination during magma ascent en route to the surface. They were generated by 7% partial melting of garnet peridotite. The axis of the plume might be located beneath Lijiang Town, Yunnan province.
学科主题	火成岩岩石学
WOS关键词	PERMIAN-TRIASSIC BOUNDARY ; LARGE IGNEOUS PROVINCE ; LITHOSPHERE ; INTERACTION ; HAWAIIAN VOLCANISM ; HIGH-MG ; GENERATION ; MELT ; PETROGENESIS ; CONSTRAINTS ; PICRITES
WOS研究方向	Geology
语种	英语
出版者	GEOLOGICAL SOC CHINA
WOS记录号	WOS:000221717300007
内容类型	期刊论文
源URL	[http://119.78.100.197/handle/2HKVOGP0/37811]
专题	中国地质科学院地质研究所
作者单位	1.Chinese Acad Geol Sci, Inst Geol, Beijing 100037, Peoples R China. 2.Univ Hawaii, Sch Ocean & Earth Sci & Technol, Honolulu, HI 96822 USA. 3.中国地质科学院地质研究所
推荐引用方式 GB/T 7714	Zhang, ZC,Hao, YL,Wang, FS,et al. Petrology, mineralogy and geochemistry of the Emeishan continental flood;basalts, SW China: Evidence for activity of mantle plumes[J]. ACTA GEOLOGICA SINICA-ENGLISH EDITION,2004,78(1;SI SI):40-51.
APA	Zhang, ZC,Hao, YL,Wang, FS,&Mahoney, JJ.(2004).Petrology, mineralogy and geochemistry of the Emeishan continental flood;basalts, SW China: Evidence for activity of mantle plumes.ACTA GEOLOGICA SINICA-ENGLISH EDITION,78(1;SI SI),40-51.
MLA	Zhang, ZC,et al."Petrology, mineralogy and geochemistry of the Emeishan continental flood;basalts, SW China: Evidence for activity of mantle plumes".ACTA GEOLOGICA SINICA-ENGLISH EDITION 78.1;SI SI(2004):40-51.