坦桑尼亚北部维多利亚湖地区构造特征及金矿成矿时代讨论

Study on the Structural Characteristics and Metallogenic Control of Gold Deposits in Lake Victoria Area,Northern Tanzania

坦桑尼亚北部维多利亚湖地区是坦桑尼亚克拉通的重要组成部分,其中维多利亚湖东和尼安扎湖超地体内绿岩丰富,金矿床众多。坦桑尼亚克拉通大致经历了四次渐进变形事件,其中变形事件D3形成的NE向断裂和变形事件D4形成的NW向脆—韧性剪切带对金矿的形成和富集较为有利。维多利亚湖地区金矿的成矿年龄与地体的变形峰值年龄基本一致,也与全球的金成矿活动时间相吻合,为2700~2650 Ma。对该地区含矿构造的研究,有利于促进维多利亚湖绿岩带实现找矿突破。

Lake Victoria in northern Tanzania is an important part of Tanzania Craton.There are abundant greenstone and gold deposits in the East Lake Victoria and Lake Nyanza.Tanzanian craton has experienced four progressive deformation events,of which NE trending fracture formed by deformation event D3 and NW trending brittle-ductile shear zone formed by deformation event D4 are more favorable for gold deposits formation and enrichment.The metallogenic age of gold deposits in Lake Victoria area is basically consistent with the peak deformation age of the terrane.The metallogenic age of gold deposits in this area is basically consistent with the peak age of deformation of the terrain and with the time of global gold activity,ranging from 2700 to 2650 Ma.The study of ore bearing structure in this area is beneficial to the breakthrough of prospecting in the Victoria Lake greenstone belt.