黑龙江多宝山铜矿床中花岗闪长岩锆石SHRIMP U-Pb测年及其构造意义

摘要

在黑龙江多宝山斑岩铜矿床的花岗闪长岩中获得了锆石SHRIMP U-Pb同位素年龄453.2～486.9 Ma.结合野外地质接触关系,这个年龄是多宝山斑岩铜矿床的成岩成矿年龄.而以往测定的311～219 Ma成岩成矿年龄,应该是成矿期后岩浆活动所引起的热叠加事件年龄.岩石地球化学特征显示其形成于火山岛弧环境,与多宝山组火山岩形成环境一致.%The zircon SHRIMP U-Pb age of 453.2-486.9 Ma is obtained from the granodiorite in the Duobaoshan porphyry copper deposit, Heilongjiang Province. Considering the field geological contacts, this age should be the diagenetic and metallogenetic age of the deposit. The previously determined age of 311 -219 Ma might represent a superimposed heat event caused by the post-metallogenic magmatism. The lithogeochemistry shows that the deposit was formed in a volcanic arc environment, which is in accord with the forming environment of the Duobaoshan volcanic rock.