The Study Of Minerogenic Magmatite Characteristic And It's Ore-bearing Potential Of Gaerqiong Copper-Gold Deposit, GeJi County, Tibet

Gaerqiong Copper-gold deposit belongs to the western suture zone of Gangdese-nianqintanggula plate and the composite plate of southern Qiangtang-Sanjiang rivers,located at the junction of the two structure unit that Shiquanhe-LateYanshan period junction zone and Gangdese-nianqintanggula plate.What the deposite diggings are carbonatite and pyroclasticrock which belongs to Duoai Formation of Zelong Group, Cretaceous system.The main emergence intrusiverock are quartz diorite, granite porphyry and diorite porphyrite of Late Yanshan period.The main ore body lied in the 3-0-16 line, over 900m in strike with NWW and over 400m in dip with NNE in length.The ore originated in the aureole belt of carbonatite and quartz diorite,outputing as bedded vein and lensing, and the form of which was controlled by the exomorphiczone structure of rock mass.The available element is mainly copper and gold, with major ore minera such as chalcopyrite,bornite and nature gold, and gangue mineral such as skarnmineral.The ore structure is priority to crystallization,solid solution isolated structure,and the texture is priority to sparsity disseminationstructure.According to study the form,it is presented that metallogenic epoch can be setted of magmatic stage,skarn stage and thermal metallogenic stage as twice intrusion of quartz dioriten and granite porphyry. According to study the space distribution,shape and attitude of the ore body,the characteristic of petrology,petrochemistry and lithogeochemistry,it is learned that the host rock of the skarn ore was quartz diorite and proposed that granite porphyry had certain mineralizing potential.Quartz diorite and granite porphyry pertained to the series of cal-alkaline and high-K calc-alkaline, transitional granite between peraluminous and metaluminous series, characterized by minor negative Eu anomalies and LREE enrichment in rare earth and the enrichment of large ion lithophile elements(LILE) such as Rb,K and Sr and depletion of high field strength element(sHPSE)such as Th,Nb,Ta and Ti of trace elements.Based on discussing the ore-bearing potential evaluated train of thought and evaluated methods of different type ore,raised ore-bearing potential interpretational criteria of skarnal host rock, established three layers as mainly evaluated series which were regional geo-chemistry block,rock and mineral in deposit from micro to macro level with the metallogenic information of each level as evaluation contents.It was discussed that the intrusive rock had a good mineralizing potential by the means of indication of petrology,mineralogy and geochemistry and the deposit shows a good potential of porphyry deposit.