雅鲁藏布江蛇绿岩再研究:从地质调查到矿物记录

蛇绿岩带出现于全球大多数碰撞构造带上，通常是板块缝合带的标志，西藏雅鲁藏布江缝合带蛇绿岩带对于此种概念模型是毫无争议的。根据近年来现代洋壳和蛇绿岩研究成果以及分析技术，在20世纪80年代中法合作项目研究成果基础上，笔者再次对西起日喀则拉孜、东至泽当金鲁，长约500km的雅鲁藏布江缝合带蛇绿岩进行了研究。在野外调查基础上，对雅鲁藏布江蛇绿岩中500多个尖晶石样品的地球化学特征进行了分析研究，以探讨蛇绿岩的成因及其动力学背景，提出雅鲁藏布江蛇绿岩带属于超俯冲作用(suprasubduction)的产物，与近年来其他研究成果的认识一致。

Yarlung-Zangbo Ophiolites Revisited:from Geological Survey to Mineral Records

Ophiolites belt occur in most of collisional chains around the world and generally mark the suture zone between plates of geological distinctive origins. The Yarlung-Zangbo ophiolites suture zone and related ophiolites are no exception to this concept. Previous extensive survey was conducted during the 1980 Sino-French Cooperative Investigation of the Himalayas. Progress in the ophiolite research field and new developments in the study of modern oceanic crust guided us in the recent field investigation. Our investigated segment spans from Lhazhi, Xigaze to Jinlu, Zedong that makes a stripe some 500 km long. Based on the field survey, we analyzed geochemical characteristics of more than 500 spinel samples from the Yarlung-Zangbu ophiolites, in order to present and discuss geneses and geodynamics of the Yarlung-Zangbu ophiolites. Mineral chemistry has revealed that the Yarlung-Zangbu ophiolites are the product of suprasubduction. This conclusion is similar to that of other related researched in recent years.