坦桑尼亚芒果金矿成矿地质特征及金赋存状态研究

Study on geological characteristics and gold occurrence of Manangu gold mine in Tanzania

太古宙卡哈马(Kahama)绿岩带为坦桑尼亚环维多利亚湖区域八大绿岩带之一,长约100 km,是坦桑尼亚重要的成矿带之一,带上分布有盖塔(Geita)、布鲁杨葫芦(Bulyanuhulu)、高登瑞德(Golden Ridge)、朱比利里夫(Jubilee Reef)等大型、特大型金矿床和众多金矿(化)点,具有很大的找矿前景。芒果(Manangu)金矿体分别赋存于矿区北西部条带状含铁建造(磁铁石英岩)与酸性火山沉积岩(凝灰岩)的上下接触带部位,矿体形态简单,具不规则层状、似层状,金属矿物自然金呈他形粒状,亮金黄色,高反射率,均质性,多属于粒间金。

Archean Kahama greenstone belt is one of the eight greenstone belts distributing around the Victoria lake region. It ex- pands about 100 Km long and is one of the important metallogenic belts in Tanzania. There are numbers of large and superlarge gold de- posits and spots （mineralization） on the belt, such as Geita, Bulyanuhulu, Golden Ridge and Jubilee Reef gold deposits etc., demon- strating that the Kahama belt have great prospect for gold exploration. Manangu gold orebody occurs in the upper and lower contact zonesbetween the banded iron formation （magnetite quartzite） in the Northwest part and the the acidic volcanic sedimentary rock con- tact zone （tuff）, which has a very simple orebody shape, irregular layered and stratified.The gold appeared asxenomorphic-granular, bright golden yellow, high reflectivity, homogeneity. Most of gold are intergranular gold.