Compositions of upper mantle fluids beneath eastern China: Implications for mantle evolution

	Compositions of upper mantle fluids beneath eastern China: Implications for mantle evolution
	Zhang, MJ ; Wang, XB ; Liu, G ; Zhang, TW ; Bo, WR
	2004
关键词	chemical composition mantle fluids lherzolite xenoliths eastern China
卷号	78
期号	1
页码	125-130
英文摘要	The composition of gases trapped in olivine, orthopyroxene and clinopyroxene in lherzolite xenoliths collected from different locations in eastern China has been measured by the vacuum stepped-heating mass spectrometry. These xenoliths are hosted in alkali basalts and considered as residues of partial melting of the upper mantle, and may contain evidence of mantle evolution. The results show that various kinds of fluid inclusions in lherzolite xenoliths have been released at distinct times, which could be related to different stages of mantle evolution. In general, primitive fluids of the upper mantle (PFUM) beneath eastern China are dominated by H-2, CO2 and CO, and are characterized by high contents of H-2 and reduced gases. The compositions of PFUM are highly variable and related to tectonic settings. CO, CO2 and H-2 are the main components of the PFUM beneath cratons; the PFUM in the mantle enriched in potassic metasomatism in the northern part of northeastern China has a high content of H-2,while CO2 and SO2 are the dominant components of the PFUM in the Su-Lu-Wan (Jiangsu-Shandong-Anhui) region, where recycled crustal fluids were mixed with deeper mantle components. There are several fluids with distinct-compositions beneath eastern China, such as primitive fluids of upper mantle(CO, CO2 and H-2), partial melting fluids (CO2 and CO) and metasomatic fluids mixed with recycled crustal fluids (CO2, N-2,SO2 and CH4) etc. Fluids of the upper mantle beneath the North China craton are different from that of the South China craton in total gases and chemical compositions: the contents of the reduced gases of the PFUM in the NCC are higher than those in the SCC.
会议录	ACTA GEOLOGICA SINICA-ENGLISH EDITION
会议录出版者	GEOLOGICAL SOC CHINA
会议录出版地	26 BAIWANZHUANG, FUWAI, BEIJING 100037, PEOPLES R CHINA
语种	英语
WOS研究方向	Geology
WOS记录号	WOS:000221717300017
内容类型	会议论文
源URL	[http://ir.fio.com.cn/handle/2SI8HI0U/5306]
专题	自然资源部第一海洋研究所
作者单位	1.Lanzhou Univ, Inst Geol Sci, Lanzhou 730000, Gansu, Peoples R China; 2.CAS, Lanzhou Inst Geol, Key Lab Gas Geochem, Lanzhou 730000, Peoples R China; 3.State Ocean Adm, Inst Oceanog 1, Qingdao 266061, Shandong, Peoples R China
推荐引用方式 GB/T 7714	Zhang, MJ,Wang, XB,Liu, G,et al. Compositions of upper mantle fluids beneath eastern China: Implications for mantle evolution[C]. 见:.