阿尔泰南缘杰尔库都克酸性岩脉LA-ICP-MS锆石U-Pb测年

摘要

野外地质调查发现在阿尔泰造山带南缘杰尔库都克地区，额尔齐斯断裂以南发育一套酸性岩脉。岩脉主要侵位于石炭系火山-沉积地层中，岩石主要为流纹斑岩。LA-ICP-MS锆石U-Pb测年结果显示，酸性岩脉形成于（279±3）Ma的早二叠世。岩脉是岩石圈(地壳)伸展的重要标志，该年龄的获得为阿尔泰造山带南缘早二叠世岩石圈伸展提供了重要证据。%Field investigation revealed a series of acidic dyke swarm distributed in the Jieerkuduke area to the south of Ertix fault belt in the Southern Altay Range. The acidic dykes intruded in the Carboniferous volcanic-sedimentary rock sequence and the rocks of the dyke are rhyolite-porphyries. LA-ICP-MS zircon U-Pb dating indicates that the acidic dykes were formed at (279±3) Ma. Since dyke is the significant symbol of lithospheric (or crustal) extension, this dating provides important evidence for the Early Permian lithospheric extension in the Southern Altay Range.