粤北大宝山矿区徐屋岩体SHRIMP锆石U-Pb年龄及其地质意义

SHRIMP zircon U-Pb ages of Xuwu subdacitic porphyry in the Dabaoshan ore district of northern Guangdong Province and its geological implications

徐屋岩体位于粤北大宝山矿区南部,是区内花岗岩体的重要组成部分。首次采用SHRIMP锆石U-Pb定年方法对徐屋岩体进行了年代学研究,获得其成岩年龄为441.2±4.2Ma(MSWD=1.02),表明其为加里东期岩浆活动的产物。结合前人年龄数据表明,大宝山矿区存在有加里东期和燕山期2次成岩作用和1次成矿作用,且成矿作用与燕山期花岗岩关系密切。

The Xuwu subdacitic porphyry is located in the south of the Dabaoshan ore district. This paper reports for the first time the SHRIMP zircon U-Pb age of Xuwu dacitic porphyry （441.2±4.2Ma）, suggesting Caledonian. Combined with the previous dat-ing results, the authors conclude that there are two rock-forming stages （Caledonian and Yanshanian） and one ore-forming stage （Yanshanian） in the Dabaoshan ore district, with the mineralization mainly related to the Yanshanian intrusions.