Subduction initiation for the formation of high-Cr chromitites in the Kop ophiolite, NE Turkey

doi:10.1016/j.lithos.2016.05.025

CORC > 地质与地球物理研究所 > 中国科学院地质与地球物理研究所 > 岩石圈演化国家重点实验室

	Subduction initiation for the formation of high-Cr chromitites in the Kop ophiolite, NE Turkey
	Zhang, Peng-Fei 1; Uysal, Ibrahim 2; Zhou, Mei-Fu 1; Su, Ben-Xun 3; Avci, Erdi 2
刊名	LITHOS
	2016-09-01
卷号	260 页码:345-355
关键词	Kop ophiolite High-Cr chromitite Proto-forearc Depleted mantle Asthenosphere upwelling Metasomatism
DOI	10.1016/j.lithos.2016.05.025
文献子类	Article
英文摘要	The Kop ophiolite in NE Turkey is a forearc fragment of Neo-Tethys ocean, consisting mainly of a paleo-Moho transition zone (MTZ) and a harzburgitic upper mantle unit. Locally, the Kop MTZ contains cumulate dunites and high-Cr chromitites (Cr# up to ca. 79), which are cut by pyroxenites. Dunites and chromitites in the MTZ have REE concentrations that are 1-2 orders of magnitude lower than those of chondrite; they are either depleted in LREE or have concave REE shapes. The LREE depleted patterns are interpreted to reflect production of cumulate rocks by magmas derived from a depleted mantle, the concave patterns the modification of these rocks by LREE-enriched fluids. Clinopyroxenes from pyroxenites are diopsidic and characterized by high Mg#s (ca. 92-96) and high CaO contents (ca. 24-25 wt.%); their Al2O3 contents (1.0-3.0 wt.%) fall between those of clinopyroxenes in N-MORB and komatiite/boninite, suggesting that the parental melts originated from more refractory mantle than abyssal lherzolites. However, these clinopyroxenes display LREE depleted patterns consistent with those of clinopyroxenes in abyssal lherzolites, indicating their genetic connection with decompression melting of asthenosphere. The cross-cutting relationship between pyroxenite veins and chromitiferous rocks suggests that depleted mantle remained beneath the proto-forearc after chromitite formation; it had not been significantly modified by slab-derived components and continued interacting with the upwelling asthenosphere until pyroxenite crystallization. This study provides a temporal constraint on the formation of high-Cr chromitites; they possibly began to be produced during the transition between early and late proto-forearc spreading, during which subduction dehydration had not well developed. (C) 2016 Elsevier B.V. All rights reserved.
WOS关键词	MELT-ROCK INTERACTION ; MARIANA FORE-ARC ; RARE-EARTH-ELEMENTS ; TRACE-ELEMENT ; PODIFORM CHROMITITES ; UPPER-MANTLE ; ABYSSAL PERIDOTITES ; OMAN OPHIOLITE ; GEOCHEMICAL CHARACTERISTICS ; HYDROTHERMAL CIRCULATION
WOS研究方向	Geochemistry & Geophysics ; Mineralogy
语种	英语
WOS记录号	WOS:000381529800025
资助机构	National Science Foundation of China(41473038) ; National Science Foundation of China(41473038) ; "Strategic Priority Research Program (B)" of the Chinese Academy of Sciences(XDB03010203 ; "Strategic Priority Research Program (B)" of the Chinese Academy of Sciences(XDB03010203 ; XDB03010800) ; XDB03010800) ; National Science Foundation of China(41473038) ; National Science Foundation of China(41473038) ; "Strategic Priority Research Program (B)" of the Chinese Academy of Sciences(XDB03010203 ; "Strategic Priority Research Program (B)" of the Chinese Academy of Sciences(XDB03010203 ; XDB03010800) ; XDB03010800)
内容类型	期刊论文
源URL	[http://ir.iggcas.ac.cn/handle/132A11/53325]
专题	地质与地球物理研究所_岩石圈演化国家重点实验室
作者单位	1.Univ Hong Kong, Dept Earth Sci, Hong Kong, Hong Kong, Peoples R China 2.Karadeniz Tech Univ, Dept Geol Engn, TR-61080 Trabzon, Turkey 3.Chinese Acad Sci, Inst Geol & Geophys, State Key Lab Lithospher Evolut, Beijing 100029, Peoples R China
推荐引用方式 GB/T 7714	Zhang, Peng-Fei,Uysal, Ibrahim,Zhou, Mei-Fu,et al. Subduction initiation for the formation of high-Cr chromitites in the Kop ophiolite, NE Turkey[J]. LITHOS,2016,260:345-355.
APA	Zhang, Peng-Fei,Uysal, Ibrahim,Zhou, Mei-Fu,Su, Ben-Xun,&Avci, Erdi.(2016).Subduction initiation for the formation of high-Cr chromitites in the Kop ophiolite, NE Turkey.LITHOS,260,345-355.
MLA	Zhang, Peng-Fei,et al."Subduction initiation for the formation of high-Cr chromitites in the Kop ophiolite, NE Turkey".LITHOS 260(2016):345-355.