初论右江(Mz)褶皱带金矿床成矿地质条件及找矿前景

A Preliminary Discussion on Metallogenic Conditions of Gold Deposits in Youjiang (Mz) Fold Belt, South China, and Their Exploration Prospects

本文从区域背景入手,结合目前已发现的代表性典型矿床(点)实例,初步论述了黔桂滇三省(区)毗邻地区——右江(Mz)褶皱带超显微浸染型金矿的主要地质特征及区域成矿条件。笔者认为,这一地区金矿的区域成矿因素,严格受构造、岩性、热事件控制。该类型金矿床具有:赋矿层位多;构造及岩性控矿明显;热事件蚀变作用微弱;矿物组成简单,具Au—Sb—As—Hg(局部有T1)元素组合系列;金的产出性状独特,具多期次叠加成矿的特点;矿石有原生、氧化类型,品位一般偏低;矿体形态一般不复杂,矿床规模较大;氧化矿石易于选冶,经济社会效益显著;区域成矿地质条件优越,资源前景广阔等共同特征。本类型金矿与美国著名的卡林型金矿有许多相似之处,但又具有独自的特点,因此笔者建议命名为适合中国地质特色的“右江型”金矿为宜。

Based on the regional geological background and taking typical gold deposits (points) discovered at present as examples, this paper preliminarily discusses the main geological features and regional mctallogenic conditions of ultramicron type gold deposits in Youjiang fold belt adjacent to Guizhou, Guangxi and Yunnan province. The authors consider the regional metallogenic conditions of the gold deposits in this region are strictly controlled by geological structures, lithological features and hy-drothermal activities. This type of gold deposits has following features: Horizons with mineral occurrences are many; structures and lithological controlling of ores are distinct; hydrothermal erosion alterations are weak; mineral constituents are simple, with a series of element assemblages of Au-Sb - As-Hg (partially with T1); gold occurrences are unique, with piling metallogenic features; ores are of primary and oxidation types, generally with low grades; ore -body shapes are not complicated , but sizes of deposits are large; oxidized ores are easily dressed and economic and social benefits are obvious; regional metallogenic geological conditions are superior and resource prospects are bright. This type of gold deposits are similar to American famous Karlin Type Deposit, But has u-nique fcatures of its own. So it is suitable to name the deposits 'Youjiang Type Gold Deposits' so as to show the geological features of China.