西藏羌塘改则地区高压麻粒岩的研究及其构造意义

The high-pressure granulite from Gerze area , south Tibet, located in Longmu Co-Shuanghu suture zone, was first discovered as the unique high-grade metamorphic rocks with the features of high-pressure in central Qiangtang currently. In this project, we take the high-pressure granulite as a research object. Based on detailed field observation and systematic study on petrology、geochemistry and geochronology , we will find out its characteristics of outcrop and petrology、metamorphic conditions、ages of its protolith and metamorphism, as well as the metamorphic PTt path, and finally investigate its petrogenesis and exhumation mechanism .Through the research of this project, some important constraints must be provided for the further studies on the tectonic evolution and metamorphism of Qiangtang terrane.

藏北羌塘中部的高压麻粒岩出露于龙木错-双湖-澜沧江板块缝合带中，是青藏高原内部新发现的唯一具高压特征的高级变质岩石。本项目以高压麻粒岩为研究主体,以高压麻粒岩形成的构造事件为研究目标,开展高压麻粒岩及其原岩的精细调查。具体研究高压麻粒岩（岩石类型组合）的空间分布、规模以及岩石学和变质作用特征；以先进的实验测试技术为依托获得高压麻粒岩的岩石化学、地球化学、同位素年代学等准确数据，确定高压麻粒岩的原岩性质、变质条件、原岩年龄、变质年龄，建立其变质作用演化的PTt轨迹，最终探讨高压麻粒岩的成因与折返机制。该项研究必将丰富和深化青藏高原特别是羌塘地块的变质作用及构造演化研究，具有重要的科学意义。