胶东乳山金矿蚀变岩中绢云母(40)Ar/(39)Ar年龄及其对金成矿事件的制约

The Rushan gold deposit,which is located in the Jiaodong Peninsula,is Currently the largest lode type gold deposit in china in terms of gold resources in single lode.It is characterized with multi-stage mineralization.In order to study the time of early alteration/mineralization,the (40)Ar/(39)Ar dating method is employed to analyze sericite from quartz-sericite-pyrite alteration zone beside the auriferous quartz lodes of the Rushan gold deposit.The result shows that the quartz-sericite-pyrite alteration occurred at ca.129 Ma,10 Ma earlier than that of the main gold mineralization. This means that the Rushan gold deposit was formed through multi-stage hydrothermal events.As the age of quartz-sericite-pyrite alteration(129 Ma) is within the age range(120±10 Ma) of a large hydrothermal metallogenic event,it is suggested that the hydrothermal alteration and mineralization of the Rushan gold deposit are still related to that single large metallogenic event.It is proved that the Rushan deposit and other gold deposits in the Jiaodong Peninsula were formed in Mesozoic under the condition of tectonic regime transaction,strong thinning of lithosphere,and large-scale metallogeny.This new data helped us to understand much moor of the gold metallogeny and geodynamic settings in the Jiaodong Peninsula.