北大别山薄刀岭银矿区薄刀岭岩体锆石U-Pb年龄及其地质意义

Zircon U-Pb Age and Geological Significance of Bodaoling Rock in Bodaoling Silver Deposit,North Dabieshan

薄刀岭银矿为大别地区发现的重要中型银矿床之一,与矿区内薄刀岭岩体密切相关。地球化学数据显示薄刀岭二长花岗岩为过铝质高钾钙碱性I型花岗岩,具富碱明显、相对富钾的特征。岩体LA-ICP-MS锆石U-Pb测年为(144.0±1.1)Ma,属早白垩世,为该时期大别地区整体挤压局部伸展环境的产物。

Bodaoling Silver Mine is one of the important medium-sized silver deposits found in Dabie area,which is closely related to the Bodaoling rock mass.Geochemical data prove that the monzonitic is peraluminous high-potassium calcium-alkali type I granite,which is obviously alkali rich and potassium-rich.The LA-ICP-MS zircon U-Pb age of the granite is(144.0±1.1)Ma,which was formed in the Early Cretaceous due to overall compression and local extensional environment in Dabie area.