• 责任者：Chen Jiping (Shaanxi Center of Geological Survey ; Xi’an 710016 ; China) ; Liao Qun’an
• 刊名：Earth Science
• 出版年：2013
• 卷期：38(6)
• 关键词：镁铁质岩 ; mafic rocks ; 超镁铁质岩 ; ultramafics ; 天山 ; Tianshan Mountains
• 页码：p.1183-1196
• 图表：9 illus., 2 tables, 51 refs.
• 分类号：0801
• issnNo：ISSN1000-2383
• isbnNo：CN42-1233/P

     Controlled by the NEE-trending Huangshan-Jingerquan ductile sheer zone, the Huangshandong and Xiangshan maficuhramafic complex belongs to the Huangshan-Jingerquan mafic-uhramafic rock belt located in the north of East-Tianshan. Huangshandong is characterized by being of calc-alkalic and tholeiitic series and being composed of pyroxene peridotite and gabbro, whereas Xiangshan mafic-uhramafie rocks are made up of pyroxene peridotite, olivine pyroxenite, hornblende gabbro and diabase, belonging to the tholeiitic series. Both rocks are enriched in large ion lithophile elements （such as K, Sr, Ba） and high field strength elements （such as Pb, U）, depleted in high field strength elements （such as Nb, P） and slightly depleted in high field strength elements （such as Zr, Hf）. However, they are different in the REE pattern, with Huangshandong showing the enrichment of LREE, similar to OIB features, while the Xiangshan rocks presenting the flat pattern of REE. They are the result of partial melting from the spinel source region and magma experienced olivine, pyroxene, plagioclase and amphibole. But they are subject to crust assimilation contamination to a different extent. Using the LA-ICP-MS method, we obtain the age of Huangshandong and Xiangshan at 277± 1.1 Ma and 285 ±1. 1 Ma respectively, which demonstrates they generated from the same tectonic setting, resulted from the lithospheric delamination at the root and the upwelling of asthenosphere in the partial melting of lithospheric mantle, corresponding to post-collision intermittent extension setting.