东昆仑清水泉蛇纹岩中含石墨变基性岩的成因

大陆碰撞造山带中的地幔楔橄榄岩/蛇纹岩中常含有不同类型的变基性岩透镜体，它们可记录来自俯冲板片的熔/流与地幔楔橄榄岩之间的反应，是理解俯冲带不同深度壳-幔物质循环过程的一个窗口。本项目选择东昆仑造山带清水泉麻粒岩地体中蛇纹岩中的含石墨的变基性岩透镜体作为研究对象，根据岩石成因就是矿物成因的指导思想，对变基性岩中的主要矿物、次要矿物和副矿物等进行成因矿物学研究，分析各矿物的结构构造、生长世代、矿物包裹体、主微量元素及同位素组成等，并结合岩石地球化学和同位素年代学资料，查明变基性岩的形成时代和形成温压条件以及物质来源，探讨变基性岩的形成过程，为深入认识大陆俯冲带下地壳深度陆壳物质循环和造山过程提供重要的岩石矿物学证据。

The different types of meta-mafic rocks as lens occurred in the mantle wedge peridotite( serpentinite) in continental collision orogenic belt. They can record reaction between the melt/fluid from subduction slab and the mantle wedge peridotite, which is a window to understand the crust-mantle material cycle at different depths in subduction zone.This research will focus on the graphite-bearing meta-mafic rocks in the serpentinite from Qingshuiuquan area,East Kunlun, NW China. Based on the idea that minerals record petrogenesis information, the graphite-bearing meta-mafic rocks will be studied on their genesis of major, minor and accessory minerals, involving structure, growing generation, inclusions, major, trace elements and isotopic compositions of minerals. Combined with geochemistry and geochronology of these rocks, we will determine timing of peak and retrograde metamorphism, P-T condition and possible protolith or source of metasomatic melt/fluid, reveal the formations of the graphite-bearing meta-mafic rocks. It provides important petrological and mineralogical evidences to understand process of the continental materials recycling into shallow mantle wedge in subduction zone and orogenesis.