Characteristics of the main ore minerals in the Jiama Cu-polymetallic ore deposit,Tibet

Abstract: The characteristics of the major minerals in the Jiama Cu-polymetallic deposit are analyzed through the use of microscope and electron probe.It is identified with the microscope that the ores are mainly of crystal,replacement or solid-solution separation structure,mostly veinlet-disseminated and secondarily moderately,densely and massively disseminated.Based on different host rock,the ores are classified as skarn-type and hornfels-type;Based on different mineral combination,six ore types are classified,which are galena sphalerite ore,chalcopyrite molybdenite ore,molybdenite ore,chalcopyrite ore,chalcopyrite bornite ore and chalcopyrite bornite tetrahedrite ore.These ores are distributed vertically from top to bottom in the ore body respectively.The analysis of the electroprobe data of minerals reveals that the main useful components are Cu,Mo,Pb,Zn and Ag,Au and other concomitants are abundant.And,further,the metallogenetic period is subdivided and the deposit is identified as a skarn-hornfels type.