Geological Characteristics And Ore Genesis Of The Heishishan Cu-Pb-Zn Deposit In Wulonggou Area,East Kunlun

Heishishan Cu-Pb-Zn deposit is located in the middle part of the East Kunlun structural belt.It is a skarn type polymetallic deposit dominated by Cu.The ore bodies are mainly developed in the contact zone between the ore-forming granite and the marble of Jinshuikou group.The marble is lenticular or intercalated in the gneiss of Jinshuikou group.Both the ore-forming granite and diorite are emplaced along the NW trending fault structure.The ore bodies are produced in the form of imbricate monoclinic in space.The ore bodies are lenticular,vein like and stratoid in shape.The occurrence of the ore bodies is close to that of the strata;Skarn minerals are mainly andradite,diopside,hedenbergite,actinolite,ferroactinolite and epidote;metal minerals are magnetite,molybdenite,arsenopyrite,pyrite,chalcopyrite,bornite,pyrrhotite,sphalerite and galena.The temperature measurement results of fluid inclusions show that the fluid inclusions in Heishishan Cu Pb Zn deposit are mainly gas-liquid two-phase inclusions,and the number of daughter mineral inclusions is very small.It is only observed in pyrite bearing quartz veins in early sulfide stage,and the temperature and salinity gradually decrease in each stage.H-O isotope study shows that the ore-forming fluid in dry skarn stage mainly comes from granite magmatic hydrothermal system C-O isotope shows that?¹³C_V-PDB of sulfide bearing calcite vein in the deposit has typical characteristics of magmatic carbon,and the altered marble near the deposit is affected by fluid,which is lower than that of normal marine sedimentary limestone.Sulfur isotope analysis results show obvious magmatic sulfur characteristics;lead isotope characteristics of sulfides are similar to those of granite,indicating that the ore-forming materials are derived from magma and have the characteristics of crust mantle mixed subduction zone.The Heishishan copper deposit was formed during the subduction collision transition period of the Paleo Tethys ocean in the East Kunlun area in the early Middle Triassic.The magmatic activity was very strong.The ore-forming granite magma rose,emplaced and evolved continuously.The fluid exsolution contacted and metasomatized with the marble of the Jinshuikou group,abundant skarn minerals are formed.With the formation of skarn minerals,the system changed from an oxidizing environment to reduce the environment,at the same time,the temperature and other conditions of the system change constantly,and a large number of metal sulfides precipitate.To sum up,it can be found that the characteristics of Heishishan deposit are consistent with the typical skarn deposit.This paper considers that Heishishan deposit is a skarn Cu-Pb-Zn deposit.