甘肃小顶山火山岩特征及与金矿化的关系

Character of the Xiaodingshan volcanic rocks and its relationship with the gold mineralization, Gansu

小顶山火山岩体主体是中川杂岩体最末(喜马拉雅期)的一次喷出熔岩,其周围岩浆岩脉(次火山岩)的侵入时代广泛。岩体与脉岩均位于马泉金矿床之内。岩浆岩脉与金矿体赋存于断裂之内,与断裂产状基本一致。花岗岩脉形成于金成矿期(成矿与成脉同期);中性岩脉大部分形成于金成矿之后;岩浆岩脉对金矿体主要起破坏作用;煌斑岩脉不是本区的金源层。二十号矿带确是四号矿带东延部分。

The host body of the Xiaodingshan volcanic rocks is derived from the last (Himalayan) blowout lava of the Zhongchuan complex, with wideranging intrusive period of magmatic veins(subvolcanic rocks) surrounding. The rock bodies and veins are all located in the Maquan gold deposit. The magmatic veins and gold bodies occurred in the faults, which have the same occurrences with fault. This paper discuses the relationship between the magmatic veins and gold bodies, its found that the granites were formed at the gold mineralization stage (mineralization is synchorounous with veining), the neutral veins were mostly formed after the gold mineralization stage, the magmatic veins were destructive to the gold bodies and the lamprophric veins were not one of the gold resources. It points out that the No20 ore belt is exactly the eastextended part of the No4.