A discussion on the age of volcanic rocks in Xiaorequanzi Formation, Queletag, Xinjiang
新疆觉罗塔格小热泉子组火山岩的时代探讨

Xiaorequanzi Formation is a unit of volcanic rock among Carboniferous-Permian volcano-sedimentary rocks which are widely exposed in Queletag, East Tianshan, Xinjiang. It has been divided into Early Carboniferous by referring the neigboring Digar Formation which is defined to Middle Carboniferous by fossil age. Different ages have been given on Xiaorequanzi copper mine in the southern part of Queletag. In the northern part, isotopic chronology data is absent where we dated it using SHRIMP. Isotopic chronology evidence shows that the volcanic rocks and dyke at Digar and Ganggou are of 271~275Ma. These ages are consistent with the recent results in adjacent region by other geologists. According to present evidence, Xiaorequanzi Formation ought to be Early Permian and other strata units and their relative age may be renewed.