Basic features and ore prospect evaluation of the Gangdise island arc,Ti bet,and its copper polymetallic ore belt

The Gangdise island-arc belt is parallel to the Yarlung Zangbo suture zone.Middle to Tertiary intermediate-acid volcanic rocks,I-type intermediate-acid,island-arc and continental-margin,calc-alka-line intrusions related genetically to the suture and S-type granite formed by intracontinental convergence-orogeny are extensively developed in the Gangdise island-arc belt.This belt is a nonferrous metal and no-ble metal metallogenic belt.The deposit types of main minerals include the submarine volcanic-hydrother-mal type or volcanic exhalation-sedimentary type(Cu polymetallic ore deposits),submarine hydrothermal-sedimentary type(Cu ,Pb,Zn etc.),porphyry type(Cu and Mo )and contact metasomatic and post-magmatic subsurface hydrothermal fluid filling compound type(Cu ,Pb and Zn ).The pattern of the exis-tence of these polyphase and multi-stage telescoping mineralizations and many deposit types in the same belt shows the great ore potentials in the Gangdise island-arc belt.