Zircon U-Pb Dating of Diorite from the Keyinbulake Cu-Zn Deposit in Altay, Xinjiang and Its Geological Implications

The Keyinbulake copper-zinc deposit is located at Chonghuer volcanic-sedimentary basin in Southern Altay. Granite pluton was exposed widely in this deposit,where the ore body occurred in the exocontact zones between granite and Upper Silurian-Lower Devonian Kangbutiebao Formation. In the underground mining process, there are geological phenomena of the diorite vein interspersed with copper and zinc ore bodies and granite. Zircon LA-MC-ICP-MS U-Pb dating of diorite has yielded a weighted average age of 262.0±2.1 Ma (MSDW=4.6), showing that the magmatic activitytook place in Middle-Late Permian. Combine with geological characteristic and the age of monzonitic granite, it's confined taht the Keyinbulake copper-zinc deposit was formed in the Early-Middle Permian, with an age of appreciably 278~262 Ma.