• 责任者：Wang Huiqing (Earth Science Faculty ; China University of Geosciences ; Wuhan 430074 ; China) ; Zhu Yunhai
• 刊名：Acta Petrologica et Mineralogica
• 出版年：2009
• 卷期：28(4)
• 关键词：蛇绿岩 ; ophiolite ; 构造环境 ; tectonic setting ; 秦岭 ; Qinling Mountains
• 页码：p.316-328
• 图表：11 illus., 5 tables, 19 refs.
• 分类号：0801
• issnNo：ISSN1000-6524
• isbnNo：CN11-1966/P

///Located in Tongren of Qinghai Province, the Longwuxia Gorge ophiolite lies at the juncture between West Qinling and Middle Qilian orogenic belts and is composed of mantle peridotite (dunite, serpentinized dunite), ultramafic cumulate units (clinopyroxene-peridotites, olivine-pyroxenites), mafic cumulate units (olivine-bearing gabbro, gabbro etc.) and diabases. EPMA analyses of the minerals show that olivines belong to the chrysolite family, and clinopyroxenes mostly have the composition similar to that of augite and diopside. Discrimination diagrams based on clinopyroxene geochemical data indicate that ophiolite originated in a compression tectonic background related closely to volcanic-arc. REE concentrations of most samples assume the chondrite-normalized distribution pattern with weak LREE enrichment, which is very different from the pattern of MORB. The enrichment of large ion lithophile trace elements (e. g., Ba, Rb and Sr) and the depletion of Nb, P are similar to these of the subduction zone components. High field strength elements discrimination diagrams also prove the above conclusion.