Geological Characteristic of Jiama Skarn-type Cu-polymetallic Ore Body in Tibet

Jiama deposit is a typical porphyry-hornfels-Skarn type Cu-polymetallic deposit in the middle east of Gangdise metallogenic belt in Tibet,China,the formation of jiama deposit related with the acid dykes and granite porphyry of Himalayan.The orebody is mainly concerned with copper-molybdenum-Lead-Zinc(gold-silver) of skarn-type,copper-molybdenum of hornfels-type,copper-molybdenum(gold-silver) of porphyry-type.The main orebody of Jiama copper-polymetallic ore deposit distributes in the expansion space between layers of Late Jurassic Duodigou Formation and Early Cretaceous Linbuzong Formation,which is a typical skarn orebody,but has association character of typical elements of Cu-Mo-Au-Ag-Pb-Zn.The ore minerals are mainly about chalcopyrite,bornite,molybdenite,tetrahedrite and chalcocite with sparse disseminated and veinlet-disseminated granular-like structure and self-shaped-subhedral granular structure.The metallogenic element zoning includes Pb+Zn(Au+Ag)→Pb+Zn(Cu+Au+Ag)→Cu(Mo+Au+Ag)→Cu+Mo+(Au+Ag)→Mo as a complete metallogenic element zoning and the ore mineral zoning related to magmatism.It was suggested that under the guide of metallogenic series theory,the following exploration should establish the exploration model of porphyry-hornfels-skarns,the emphasis of exploration should be on searching deep and peripheral hidden porphyry Cu-polymetallic deposit,and the ore-prospecting potential in Gulang district is tremendous.