Different type of chromitite and genetic model from Luobusa ophiolite, Tibet

	Different type of chromitite and genetic model from Luobusa ophiolite, Tibet
	Xiong FaHui 4; Yang JingSui ; Ba DengZhu ; Liu Zhao 1; Xu XiangZhen ; Feng GuangYing ; Niu XiaoLu ; Xu JiFeng 2
刊名	ACTA PETROLOGICA SINICA
	2014
卷号	30 期号:8 页码:2137-2163
关键词	Different type of chromitite PGE Re-Os isotope Mode Luobusa ophiolite
ISSN号	1000-0569
英文摘要	Podiform chromitite are the main source of chromium. Chromitite pods formed in the shallow mantle environment of the mid-ocean ridge or subduction zone setting. However, because of the founded diamond even more and more the deep mineral, people have begun to question the model of shallow podiform chromitite. In this paper, we identified two types of chromitite from Luobusa ophiolite, eastern of the Yarlung Zangbo suture zone, which one is massive chromitite as harzburgite envelope and another is disseminated chromitite as envelope of dunite shell. There is a big difference between the spinel chemical composition, PGE and Re-Os isotopic characteristics of the two types chromitite, which indicate the different evolutionary process. Geochemistry feature of mantle peridotite show the low Cr number of peridotite unrichment of LREE process to high Cr number of peridotite enrichment of LREE. A multi-stage model for explain the formation of the'podiform chromitite. Firstly, earlier slab dive to the mantle transition zone (410 similar to 660km) of continental crust and oceanic crust is dehydrated and dismembered, thermal and fluid transition produced and contributed to the molten mantle Cr release and aggregation. Then, plume/mantle convection driven transport chromite magma to move top of the condensation transition consolidation and add a strong reduction of fluid with carrying high-pressure minerals such as diamond and stishovite, and into the plasticity-semi-plakic mantle peridotite. As the material moves up the depth decreases, the early phase ultrahigh pressure (UHP) mineral phase transition into a predicament coesite, the high-pressure phase of chromite exsolution into coesite and clinopyroxene. Finally, in suprasubduction zones emplacement processes and environments, hydrous melt peridotite reacts with harzburgite formed a relatively small without UHP minerals disseminated chromite and dunite shell.
学科主题	火成岩岩石学
WOS关键词	PLATINUM-GROUP MINERALS ; HIGH-PRESSURE MINERALS ; PODIFORM CHROMITITES ; SOUTHERN TIBET ; MANTLE PLUMES ; DEEP MANTLE ; OMAN OPHIOLITE ; OCEANIC-CRUST ; METAMORPHIC ROCKS ; EARTHS MANTLE
WOS研究方向	Geology
语种	中文
出版者	SCIENCE PRESS
WOS记录号	WOS:000340023300003
内容类型	期刊论文
源URL	[http://119.78.100.197/handle/2HKVOGP0/40567]
专题	中国地质科学院地质研究所
作者单位	1.CAGS, CARMA, Inst Geol, State Key Lab Continental Tecton & Dynam, Beijing 100037, Peoples R China 2.China Univ Geosci, Sch Earth Sci & Mineral Resources, Beijing 100083, Peoples R China 3.Chinese Acad Sci, Guangzhou Inst Geochem, State Lab Isotope Geochem, Guangzhou 510640, Guangdong, Peoples R China 4.中国地质科学院地质研究所
推荐引用方式 GB/T 7714	Xiong FaHui,Yang JingSui,Ba DengZhu,et al. Different type of chromitite and genetic model from Luobusa ophiolite, Tibet[J]. ACTA PETROLOGICA SINICA,2014,30(8):2137-2163.
APA	Xiong FaHui.,Yang JingSui.,Ba DengZhu.,Liu Zhao.,Xu XiangZhen.,...&Xu JiFeng.(2014).Different type of chromitite and genetic model from Luobusa ophiolite, Tibet.ACTA PETROLOGICA SINICA,30(8),2137-2163.
MLA	Xiong FaHui,et al."Different type of chromitite and genetic model from Luobusa ophiolite, Tibet".ACTA PETROLOGICA SINICA 30.8(2014):2137-2163.