新疆东准噶尔早泥盆世早期花岗岩的确定及其地质意义

Determination of the Early Devonian granite in East Junggar, Xinjiang, China and its geological implications

摘要: 根据锆石SHRIMP U-Pb定年获得的（413±8）Ma（MSWD=0.73）206Pb/238U表面年龄和锆石的矿物学特征, 确定东准噶尔中部被泥盆系覆盖的白云母花岗岩的形成时代为早泥盆世早期。通过对已有的区域地质资料与该岩体岩石学特征的综合分析，推测东准噶尔中部和南部地区在早泥盆世早期处于伸展构造背景。

Abstract: Based on zircon apparent 206Pb/238U age of (413±8)Ma（MSWD=0.73）obtained by SHRIMP U-Pb dating and CL image observation of the zircons, intrusive age of the muscovite granite (alaskite) unconformablly covered by the Devonian sedimentary sequences in the central East Junggar orogenic belt is determined as the earliest Devonian. Combining the petrological characteristics of the granite with available regional geological data, the earliest Devonian tectonic setting of the East Junggar area is supposed as being extensional.