西藏冈底斯岛弧及其铜多金属矿带的基本特征与远景评估

冈底斯岛弧带属冈底斯活动大陆边缘的组成部分。带内早自中侏罗世、晚至第三纪的中酸性火山岩以及与雅鲁藏布江结合带有成因联系的Ⅰ型中酸性岛弧陆缘碱性侵入体（40-100Ma)和陆内汇聚造山引起的S型花岗岩体（15-50Ma)广泛发育。研究证实，冈底斯岛弧带属有色金属、贵金属成矿带。主要矿种的矿床类型有：海底火山热液型或火山喷流沉积型（Cu多金属）、海底热水沉积型（Cu、Pb、Zn等）、斑岩型（Cu、Mo）以及接触交代岩浆期后地下水热液充填的复合型（Cu、Pb、Zn）等。这些多期、多阶段复合叠加成矿作用和多种矿床类型的“同带共存”格局，展示了冈底斯岛弧带的巨大找矿潜力。

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.