Geochemical Characteristic Of Jiama Polymetallic Copper Deposit, MoZhugongka County, Tibet

The Jiama polymetallic copper deposit locates in mid-south of Gangdese-Nyainqentanglha plate ,Tethys-Himalayan tectonic megaprovince, Tibet. Main(Skarn ore body) ore body is hosted in stratiform structural zone between limestone,marble of the upper Jurassic and sandy slate,chert of the low Cretaceous, and is controlled by sub-fold produced regional thrust nappe structure and ore field gliding nappe structure. The length is over 3000m in strike with NWW and over 2000m in dip with NNE. The morphology of ore body is stratiform,thick plated,beded,lenticular ,and the whole form is"chair".Main ore body located in line 47-0-56 is hard core of skarn ore body in Jiama ore field. Metallogenic epoch can be setted off magmatic,skarn,thermal metallogenic epoch which also can be setted off Cu-Mo sulphide phase,Cu sulphide-sulphate phase,Cu-Pb-Zn sulphide phase and Au metallogenic phase,supergene metallogenic epoch, through studying texture and structure of ores,paragenesis of minerals and mineral components, and forms a typical thermal metallogenic combination.The Jiama polymetallic copper deposit was regarded as high grading and big scale. Genetic problem of the deposit was being a controversy focus which focus on sedimentary exhalative metallogenic theory and magmatic contact metasomatic metallogenic theory. The article puts forward that Jiama polymetallic copper deposit is not a Sedex deposit,but a porphyry-skarn deposit, through the study of rock geochemical characteristic,trace element geochemical characteristic,stable isotope geochemical characteristic,??d inclusion geochemical characteristic,metallogenic chronology and so on, and that the deposit formed The crust extension and rifting occurring in the late post_collisional stage since Miocen (<18Ma) ,holding the same dynamical background to earth with mian porphyry Cu-Mo deposits in Gangdese metallogenic zone. Their cognitions point out the way of finding similar deposits in region.