广西金牙金矿床热液蚀变地质地球化学特征及与金矿化关系

基于野外地质调查,岩相学和地球化学分析结果,对金牙微细浸染型金矿床的热液蚀变作用进行了系统研究,揭示了其矿化机理,为研究区今后的进一步找矿勘探工作提供了理论依据.研究结果表明:该矿床与金矿化有关的热液蚀变类型主要有黄铁矿化、毒砂化、硅化和碳酸盐化,并划分出了3个阶段的黄铁矿化和毒砂化,以及两个阶段的硅化和碳酸盐化.矿床发育有5种主要的蚀变组合类型.同时,研究区域内蚀变岩中As含量与金矿化呈强烈的正相关关系,可作为金矿勘探的近程指示元素.

Hydrothermal Alteration Characteristic and Relationship Between Alteration and Mineralization in Jinya Gold Deposit,Guangxi

The objective of this paper is to illustrate mineralizing mechanism through investigation of hydrothermal alteration.Through field geological investigation,petrographic methods and geochemistry methods,the altered rocks were studied.The alteration related to gold mineralization was classified as pyrite-alteration,arsenopyrite-alteration,silica-alteration and carbonate-alteration.The pyrite-alteration and arsenopyrite-alteration were divided into three stages and silica-alteration and carbonate-alteration were divided into two stages,respectively.It was found out that the pyrite-alteration is directly related to the earlier stage of gold mineralization,and the arsenopyrite-alteration to the later stage of gold mineralization.The deposit develops into five kinds of altered rocks.Gold mineralization of each of the altered rocks is disparity.The fifth and first type rocks have better mineralization.In addition,the altered rock’s Fe2O3/FeO ratio and the Na2O/K2O show a positive correlation with gold mineralization.The altered rock’s arsenic contents have a strong positive correlation relation with gold mineralization.These facts can be not only used to guide the further ore body searing and exploring of Jinya deposit,but also be used as important reference of seeking of fine disseminated gold deposits which has similar geological background with this deposit.