青海省沱沱河地区乌石峰蛇绿混杂岩形成环境探讨  

RESEARCH ON FORMATION ENVIRONMENT OF THE WUSHIFENG OPHIOLITE MELANGE BELT IN TUOTUOHE AREA,QINGHAI PROVINCE

作　　者：杨立朋[1] 

机构地区：[1]中化地质矿山总局地质研究院,河北涿州072754

出　　处：《化工矿产地质》2013年第3期129-135,142,共8页Geology of Chemical Minerals

摘　　要：青海沱沱河晚古生代乌石峰蛇绿混杂岩(CPW)是古特提斯缝合系中可可西里增生楔的一部分,具典型的碰撞混杂岩带特征。基于Dilek等对蛇绿岩新定义和分类方案,并运用其推荐的SiO2-MgO图解、MORB标准化微量元素比值蛛网图、Ti/V图解和Nb/Yb-Th/Yb图解对乌石峰蛇绿混杂岩的形成环境进行了判别和探讨,发现青海沱沱河乌石峰蛇绿岩应形成于弧后-弧前环境,为与俯冲作用相关的上盘俯冲带型的次级类型弧后-弧前型蛇绿岩。The Wushifeng ophiolite melange belt of the late Paleozoic in Tuotuohe area,Qinghai is a part of Hoh Xil accretionary wedge of paleoTethys suture zone, with a typical collision melange belt feature. Based on the new definition and classification scheme of Dilek et al.,the formation environment of the Wushifeng ophiolite melange belt was identified and discussed by using the recommended SiO2-MgO diagram, MORB normalized spider diagram of trace element ratio, Ti/V diagram and Nb/Yb-Th/Yb diagram, Wushifeng ophiolite melange in Tuo-tuo River area ahs been found, Qinghai Province should be formed in the backarc to forearc environments, subtype ophiolites（backarc to forearc type ophiolites） of the subduction-related suprasubduction-zone ophiolites.

关 键 词：蛇绿混杂岩 形成环境 沱沱河 青海省 

分 类 号：P588.145[天文地球—岩石学]