澳大利亚Mt.Wills金矿床地质特征与找矿预测

在全面收集和梳理矿区已有地质资料的基础上,通过开展地质剖面测量、野外调研、老探槽清理、老坑道编录和钻探等一系列工作,系统总结了澳大利亚Mt.Wills金矿矿床地质特征和控矿因素,认为该矿床是含金石英脉型矿床,矿体位于Omeo变质杂岩与Wills山花岗岩的接触带上,受脆-韧性断层控制,主要赋存在于南北向和北北东向断层中,北西向断层和北东东向断层在成矿期的力学性质为压性,不能提供理想的容矿空间,在物性差异明显的不同岩性接触带上,控矿构造膨大,常出现富矿段。围岩蚀变为中低温热液蚀变,影响范围有限,围岩蚀变主要有硅化、绢云母化、绿泥石化、碳酸盐化、黄铁矿化和毒砂化等。矿石矿物种类较多,主要有黄铁矿、毒砂、方铅矿、闪锌矿、黄铜矿、辉锑矿、自然金和自然银等,自由金主要以细粒形式存在。在对该矿床地质规律的研究和对矿区勘查的基础上,提出了Centre Country、控矿构造倾角发生变化部位等是下一步勘查工作的优选靶区。

Geological characteristics and target prospecting of Mt.Wills gold deposit of Australia

Based on comprehensive collection and analysis of existing geological data, through geological profile survey, field investigation, old trenches and underground workings reclogging and drilling, geological characteristics of the deposit and ore controlling factors are summarized. It is considered that Mr. Wills is auriferous quartz vein type, and it is situated in contact zone of Omeo Complex and Mt. Wills granite. The ore bodies controlling by Brittle-ductile fault are limited in NNE and N-strike fault, while NEE and NW-strike faults can not supply ideal host space as E - W compression during metallogenic epoch. Faults and ore bodies expand in the transition zone of different lithologies. Wall rock alteration whose extent limited is a kind of low to moderate temperature hydrothermal alteration, including siliconization, sericitization, chloritization, carbonatization, pyritization and arsenopyritization. There are lots kinds of ore minerals, such as pyrite, arsenopyrite, galena, sphalerite, chalcopyrite, stibnite, native gold and silver etc. Free gold mainly exist in fine grain. Based on degree of exploration, several preferred targets such as Centre Country are put forward according to geology and mineralizing regularities.