GEOLOGICAL CHARACTERISTICS AND GENESIS OF THE SONGJIAGOU GOLD DEPOSIT IN MOUPING COUNTY,SHANDONG PROVINCE

The Songjiagou gold deposit was newly discovered in the Jiaolai Basin in recent years.It occurs in conglomerate of the Early Cretaceous Laiyang Group on the margin of the Jiaolai Basin, and was formed in detached faults before a volcanic period with involvement of meteoric water.The host rocks have been extensively subjected to pyritization,silicification,sericitization and carbonatization.Individual ore－ body has the maximum length of 400 m,oblique extension of 600～ 700 m and gold grade of (1～ 15)× 10－ 6.Comparative studies show that the Songjiagou type gold deposit,an altered conglomerate type gold deposit,is different from traditional conglomerate type gold deposits,Jiaojia type gold deposits and Linglong type gold deposits in the Jiaodong Block,but bears a resemblance to the Witwatersland gold deposit in South Africa to some extent.It is a new type of gold deposit in the Jiaodong Block,and is expected to be superlarge one.