摘要
应用SHRIMPⅡ锆石U-Pb法,对西藏休古嘎布蛇绿岩中的辉绿岩墙进行了测年,获得辉绿岩形成年龄为122.3±2.4Ma。该年龄代表了休古嘎布-达巴特提斯洋盆的形成时代,与雅鲁藏布江缝合带中段洋盆形成时代(126±1.5Ma)相当,此结果对于确定研究区特提斯洋盆的古构造格局及其发育演化过程等提供了重要的年代学制约。
SHRIMPⅡ technique is applied to U - Pb dating of the diabase dike of Xiugugabu ophiolite in Tibet. The result shows that the age of the diabase is 122.3 ± 2.4 Ma. This age stands for the formation time of the ocean basin of Xiugugabu - Daba Tethys, and is very close to that of the middle part of the Yarlung - Zangbo suture zone （126 ± 1.5 Ma）. This outcome provides a well chronologic condition for discussing the palaeotectonic framework and the evolution of the Tethys basin in the study area. In addition, the formation time of the ophiolite in the study area and the Yungbwa ophiolite may be different from each other, or the difference is possibly resulted from various methods of dating. It is still uncertain but is worthy of further discussion.
出处
《大地构造与成矿学》
EI
CAS
CSCD
北大核心
2006年第1期93-97,共5页
Geotectonica et Metallogenia
基金
中国科学院知识创新工程项目(KZCX2-SW-117)资助.
