LA-ICP-MS zircon U-Pb dating from granite-porphyry rcoks in Xikuangbei, East Junggar, Xinjiang, China. Geological Bulletin of China

The weighted average 206Pb/238U age from LA-ICP-MS U-Pb zircon dating of the Xikuangbei granite-porphyry in East Junggar is (281±10)Ma，MSWD=9.3，the lower intersection point of 206Pb/238U-207Pb/235U concordia curve is (278±11)Ma，MSWD=7.5，within the tolerate error range, these two results belong to Early Permian. It is indicated that formation of the Xikuangbei granite-porphyry is during post-collision hypogene magmatic activity (around 330～265Ma)，which is later than Wulunguhe and Kalamaili alkali granite (around 300Ma). Late Paleozoic intrusion represented by granite-porphyry continued to late Early Permian