金成矿的物理化学条件研究进展

本文介绍了G.Friedrich等将矿相学、蚀变岩相学、流体包裹体和硫化物矿物相等研究紧密结合起来，来解释含金溶液来源和沉淀条件的方法，他们首先根据矿石组构及矿物交生关系准确划分成矿阶段及矿物生成顺序，并测定类质同象矿物的成分，再根据流体包裹体、矿石矿物组合、蚀变带矿物组合确定成矿温度，计算各阶段pH值变化范围；在loga （O₂）一pH和loga （S₂）-loga （O₂）图解上就可以确定每个矿化阶段的物化条件及整个矿化过程物化条件的演变。据此，他们在西班牙Rodalquilar金矿研究后提出浅成热液中金以Au （HS）^-₂形式搬运，在近地表金因pH值、总硫活度降低及氧速度增加而沉淀的成矿模式。

RECENT DEVELOPMENT OF THE STUDY OFPHYSICO- CHEMICAL CONDITIONS DURINGGOLD MINERALIZATION

he paper shows the means that G. priedrich and other economic geologists explain thesources and precipitation conditions of gold bearing solution according to the studys onmineragraphy, alteration petrography, fluid inclusions and sulfide phases. The parageneticstudies of the gold occurrences document the stages of mineralization. Based on the fluid in-clusions and mineral assemblages in ores, the temperatures and the pH value ranges of thestages can be identified. By using of loga (O_2) -pH and loga (S_2)-loga (O_2) diagrams thephysicochemical conditions of gold mineralization can be detuced. Based on the study Ro-dalquilar gold deposit Spain, they proposed that gold in epithermal gold deposits has beentransported as Au(HS)-1 by fluids of moderate pH and reducing properties. The reason forgold precipitation in the near surface environment must have a rapid decrease in pH and totalsulfur activity and an increases in oxygen activity.