论吉林夹皮沟金矿成矿时代

Discussion on minerogenetic epoch of the gold deposit in Jiapigou of Jilin Province

吉林夹皮沟金矿是我国产于变质地体中典型的造山型金矿,其成矿时代一直存在很大争议。通过标志性地质体与矿脉、特别是脉岩与矿脉的关系研究,成矿时限界定在显生宙中酸性脉岩形成之后且基性脉岩形成之前。同位素测年表明,成矿时代为170～160 Ma。金成矿作用与区域动力学过程存在明显的耦合关系,即侏罗纪太平洋板块俯冲欧亚大陆导致区域敦—密断裂大规模左旋平移的构造背景下,区内发生强烈的构造—岩浆活动伴随金的成矿作用。

Jiapigou gold deposit is one of the typical orogenetic gold deposits associated with metamorphic terrains. However,its minerogenetic epoch has been debated. According to the study of relationships between marked geologic bodies and veins,especially between dykes and veins,the minerogenetic time was considered as later than the acid dykes forming and earlier than the basic dykes forming in Phanerozoic. The isotopic dafing of the minerogenetic time is about 170～160 Ma. The gold minerogenesis coupled with regional dynamics evolution during Jurassic,correspondingly the subduction of Pacific Plate resulted in the large scale sinistral strike slip movement of Dunhua-Mishan fracture zone. With this background,the tectono-magmatic activities and gold mineralization occurred in Jiapigou area.