新疆塔什库尔干县南青白口纪侵入体的发现——来自LA-ICP-MS锆石U-Pb同位素测年的证据

The Discovery of Qingbaikouan Plutonite in Taxorgan, Xinjiang, and Evidence from Zircon LA-ICP-MS U-Pb Dating of Intrusive Rock

笔者在新疆塔什库尔干县南进行1∶5万区域地质填图过程中,在前人划分的下古生界地层中解体出一套前寒武系,其中分布有片麻状英云闪长岩。岩石地球化学表明为钙碱性系列,具有火山弧花岗岩特征。两个英云闪长岩体中单颗粒锆石LA-ICP-MS年龄分别为855±14Ma、836±12Ma,是目前为止喀喇昆仑地区仅有的新元古代岩浆事件年龄。填补了喀喇昆仑地区前寒武纪岩浆事件研究的空白。

In the period of 1 ： 50000 field mapping, precambrian strata was distinguished from the Lower Paleozoic strata, intruding the Neoproterozoic tonalite pluton. In situ zircon U-Pb LA- ICP-MS dating on the tonalite pluton zircons yielded an age of the 855± 14Ma and 836±12Ma, representing the tonalite pluton intruding age and being the only Neoproterozoic age in Karakorum belt, which is important in studying of Karakorum Precambrian geological evolution.