VIEW ON HYPABYSSAL AND UNTRAHYABSSAL VEIN GOLD DEPOSIT CHARACTERISTIC AND CLASSIFICATION
Yang Yongqiang; Zhang Yuan(EditorioL BOard of Journal)( Department of Earth Sciences)
Hypabyssal and untrahypabyssal vein gold deposit are formed in the place0～1.5 km beneath the ground.Its host rocks are various types such as volcanic rocks,subvolcanic rocks,sedimentary rocks, metamorphic rocks,et al.The authors wotildrather use the concept of hypabyssal vein gold deposit than volcanic type gold deposit,because the former is direct and practical for exploration of hypabyssal deposit.Meanwhile, it is the deepth of ore deposit formation control the ore body shapeocctlrrence, scale, composition,structure,texture. Therefore it is important to studythis type of gold deposit. This paper introduces some characteristics and schemes ofhypabyssal vein gold deposit.The gold deposit can be divided into three types,accordingto the ratio of Au :Ag,i.e. Au-Te type,Au-type,Au-Ag type. According togangue mineral compositions,linseite-sericite type and quartz-alunite type can be setup.To the gold deposit beared in volcanic hostrocks, three types,the calc-alkalic rocktype,the alkalic rock type and sub-alkalic rock type can be divided.