新疆东昆仑阿牙克岩体地球化学与^(40)Ar/^(39)Ar年代学研究及其大地构造意义

Geochemical characteristics and 40Ar/39 Ar age of the Ayak adamellite and its tectonic significance in the east Kunlun, Xinjiang.

阿牙克岩体出露在新疆东昆仑阿牙克库木湖北侧的祁漫塔格山西段,侵入在早古生代低绿片岩相蛇绿混杂岩即“祁漫塔格群”之中。岩体地球化学特征显示其可能形成在伸展构造环境,角闪石的^(40)Ar/^(39)Ar坪年龄为420±4Ma;等时年龄为416±21Ma,证实早古生代末期东昆仑地区已从挤压构造体制转化为伸展构造体制,表明昆仑山具有多期造山作用叠合的大地构造特征。

The Kunlun mountain is the northern boundary of the Tibet plateau. The Ayak adaniellite is a batholite which was intruded into the Qimantage ophiolitic melange of early Palaeozoic era in the East Kunlun of Xinjiang province. It is suggested that the pluton was generated in an extensional tectonic environment by studying on its major and trace element. The plateau age and isotope age of the amphibole are 420 4Ma and 416 21 Ma. They indicate that the extensional tectonic regime had been changed in Late Silurian period from the pressed tectonic regime in early Palaeozoic era.