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

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.