High-Cr and high-Al chromitite found in western Yarlung-Zangbo suture;zone in Tibet

	High-Cr and high-Al chromitite found in western Yarlung-Zangbo suture;zone in Tibet
	Xiong FaHui 1; Yang JingSui ; Liu Zhao 2; Guo GuoLin 1; Chen SongYong ; Xu XiangZhen ; Li Yuan ; Liu Fei
刊名	ACTA PETROLOGICA SINICA
	2013
卷号	29 期号:6 页码:1878-1908
关键词	High-Cr chromitite High-Al chromitite Peridotite Partial melting Western Yarlung Zangbo suture zone
ISSN号	1000-0569
英文摘要	Based on their mineral chemistry podiform chromitites are divided into high-alumina (Cr-# = 20 similar to 60) (Cr-# = 100 x Cr/(Cr + Al)) and high-chromium (Cr-# = 60 similar to 80) varieties (Thayer, 1970). Only one type occurs in a given peridotite massif, although some ophiolites contain several massifs which can have different chromitite compositions. We report here the first known occurrence of both high chrome and high alumina chromitite in a single massif, the Purang mafic-ultramafic body in the western Yarlung-Zangbo suture zone of Tibet. This massif consists chiefly of mantle peridotite, with lesser amounts of pyroxenite and gabbro. The mantle peridotites are mostly harzburgite and minor lherzolite; a few dike-like bodies of dunite are also present. Seven small, lenticular bodies of chromitite ore have been found in the harzburgite, with ore textures ranging from massive to disseminated to sparsely disseminated; no nodular ore has been observed. Individual ore bodies are 2 similar to 6m long, 0.5 similar to 2m wide and strick NW, parallel to the main structure of the peridotite. Ore bodies 1 and 6 consist of high-Al chromitite (Cr-# = 52 similar to 55), whereas orebodies 2, 3, 4 and 5 are high-Cr varieties (Cr-# = 63 similar to 89). In addition to magnesiochromite, all of the orebodies contain minor olivine, amphibole and serpentine. Mineral structures show that the peridotites experienced plastic deformation and partial melting. The mineralogy and geochemistry of the Purang peridotites suggest that they formed originally at a mid-ocean ridge (MOR) and were later modified by suprasubduction zone (SSZ) melts. Base on the chemical composition of spinel-olivine/clinopyroxene can identify Purang peridotite have three stage different partial melting, including the early partial melting (degree about 10%), later partial melting (degree about 20% similar to 30%), and partial decompression partial melting (degree about 15%). Compare to other typical high Al and high Cr podiform chromitite and peridotite in mineral assemblages, mineral chemistry and geochemistry show that there are many similar character, even existence a good prospecting space.
学科主题	矿床地质
WOS关键词	MELT-ROCK REACTION ; BELT EASTERN CUBA ; UPPER-MANTLE ; PODIFORM ; CHROMITITES ; LUOBUSA OPHIOLITE ; YUNGBWA OPHIOLITE ; SUBDUCTION ZONE ; SOUTHERN TIBET ; HIGH-PRESSURES ; PLATINUM-GROUP
WOS研究方向	Geology
语种	中文
出版者	SCIENCE PRESS
WOS记录号	WOS:000322427000004
内容类型	期刊论文
源URL	[http://119.78.100.197/handle/2HKVOGP0/40178]
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, State Key Lab Continental Tecton & Dynam, CARMA, Beijing 100037, Peoples R China. 2.E China Inst Technol, State Key Lab Breeding Base Nucl Resources & Envi, Nanchang 330013, Peoples R China. 3.China Univ Geosci, Sch Earth Sci & Mineral Resources, Beijing 100083, Peoples R China.
推荐引用方式 GB/T 7714	Xiong FaHui,Yang JingSui,Liu Zhao,et al. High-Cr and high-Al chromitite found in western Yarlung-Zangbo suture;zone in Tibet[J]. ACTA PETROLOGICA SINICA,2013,29(6):1878-1908.
APA	Xiong FaHui.,Yang JingSui.,Liu Zhao.,Guo GuoLin.,Chen SongYong.,...&Liu Fei.(2013).High-Cr and high-Al chromitite found in western Yarlung-Zangbo suture;zone in Tibet.ACTA PETROLOGICA SINICA,29(6),1878-1908.
MLA	Xiong FaHui,et al."High-Cr and high-Al chromitite found in western Yarlung-Zangbo suture;zone in Tibet".ACTA PETROLOGICA SINICA 29.6(2013):1878-1908.