西昆仑库地蛇绿岩中基性火山岩的Sm-Nd等时线年龄

Sm-Nd isotopic ages of basic rocks in Kudi ophiolite of west Kunlun

本文总结了前人有关库地蛇绿岩系各组成单元以及与其有成因联系的岩浆岩的年代学资料,同时利用Sm-Nd法测定了一些克沟基性火山岩的形成时代,获得了 2个晚元古代全岩等时线年龄:1023±51 Ma和834±29 Ma。在此基础上,对库地蛇绿岩系的形成和演化时代进行了讨论,认为库地蛇绿岩中基性火山岩的Sm-Nd等时线年龄可能代表了库地洋开始消减俯冲的年代。

The Kudi ophiolite is the north most suture zone in the Tibetan Plateau, and it was considered to be the remnant of the Paleo-Tethys. Isotopic and radiolarian ages on different components of Kudi ophiolite and its associated rocks by former researchers are summarized and analyzed. By using Sm/Nd isotopic chronological dating, two Late Protozoic ages of the basic rocks of Kudi ophiolite, 1023±51 and 834±29 Ma,respectively,were obtained. On the basis of further discussion on the formation of Kudi ophiolite, we considered that these ages might represent the time period of the subduction of Kudi ocean.