萨尔托海铬铁矿中的矿物包体研究  

Study on the Mineral Inclusions in Sartohay Chromitites

作　　者：田亚洲[1,2] 杨经绥[2] 

机构地区：[1]贵州大学资源与环境工程学院,贵阳550025 [2]大陆构造与动力学重点实验室地幔研究中心中国地质科学院地质研究所,北京100037

出　　处：《地质学报》2016年第11期3114-3128,共15页Acta Geologica Sinica

基　　金：中国地质调查局地调项目(编号12120115027201);国家自然科学基金创新研究群体项目(编号41221061)联合资助成果

摘　　要：铬铁矿中矿物包体的研究对于探索铬铁矿的成因具有重要的指示意义。通过薄片扫描电镜背散射结合电子探针分析,在萨尔托海高铝铬铁矿中发现了大量矿物包体,包括:单斜辉石、斜方辉石、橄榄石、钠-金云母、钠-铬韭闪石、出溶的单斜辉石等,这些矿物呈单相或多相产出,在铬尖晶石结晶时被包裹。含水矿物钠-金云母,钠-铬韭闪石的大量出现指示含水环境,表明铬铁矿形成于含水的母岩浆中,可能形成于受俯冲流体/熔体影响的弧后扩张背景。结合之前在萨尔托海铬铁矿中发现的超高压矿物金刚石,认为萨尔托海铬铁矿的形成可能经历了深部地幔和浅部含水大洋岩石圈两个阶段。Study of mineral inclusions in chromitites is of great significance in recognizing the origin of chromitites. In this paper, a large number of mineral inclusions including CPXs, OPXs, olivines, aspidolites, Na-Cr pargasites, CPX exsolution lamellaes were discovered in Sartohay high-Al chromitites, which were trapped in Cr-spinels as single phase and multiple phase when the Cr-spinels crystallized. Hydrous minerals, aspidolites and Na-Cr pargasites, imply hydrous condition, which probably indicates that parental magmas of chromitites were hydrous in back arc spreading ridge influenced by subducted fluid/melt. Taking account into the UHP diamonds discovered in chromitites, the formation of Sartohay chromitites probably experienced the deep mantle and shallow oceanic lithosphere setting.

关 键 词：矿物包体 铬铁矿 萨尔托海 西准噶尔 新疆 

分 类 号：P618.3[天文地球—矿床学]