东昆仑巴音郭勒地区锆石裂变径迹年代学：构造活动新证据

东昆仑西段祁漫塔格地区总体研究程度较低，前人年代学资料报道亦少，且主要属于印支期之前。本文在巴音郭勒地区花岗岩类样品中获得了系列锆石裂变径迹年龄数据，不仅为本地区地质研究提供了裂变径迹年代学资料，而且揭示了所经历的多期构造活动。锆石裂变径迹年龄变化在201～109 Ma之间，具有201、185、164～163和139～109 Ma年龄组。这些年龄很好地体现了地区内所经历的两次挤压和两次伸展构造活动，其中年龄201和139～109 Ma是羌塘地体和冈底斯地体，先后于中-晚三叠世和晚侏罗世-早白垩世时期分别向北俯冲并与其北侧地块相互碰撞-汇聚-拼合的体现；而年龄185 Ma和164～163 Ma则分别与早侏罗世和中侏罗世区内造山后伸展事件有关。

Zircon Fission Track Thermochronology: New Evidence on Tectonic Activity in Bayinguole Area,Eastern Kunlun Mountains

By now fewer research works have been done in Qimantage area, western section of Eastern Kunlun Mountains. A little published dating data fell into Indosinian period. A series of zircon fission track ages from granitoid samples were achieved and multiphase tectonic-magmatic activities were revealed in this paper. The zircon fission track age range from 201 Ma to 109 Ma might be divided into four groups, i.e. 201 Ma, 185 Ma, 164-163 Ma and 139-109 Ma. These ages indicate two compressional and two stretching tectonic activities. The 201 Ma and 139-109 Ma ages present northward subductions of Qiangtang Terrane and Gangdise Terrane in Middle-Later Triassic and Late Jurassic respectively, resulting in collision-convergences with north-side terranes. The ages of 185 Ma and 164-163 Ma reflect post-orogenic stretching events in Early Jurassic and Late Jurassic, respectively.