西澳大利亚卡尔古丽金矿区成矿地质特征

Western Australia Kalgoorlie Gold Field Ore-forming Geological Characteristics

卡尔古丽金矿区(Kalgoorlie Gold Filed)是西澳大利亚最大的金矿产区,在大地构造上属于西澳伊尔岗(Yilgarn)克拉通东部卡尔古丽绿岩带内。矿区主要出露太古代地层,包括镁铁质-超镁铁质熔岩序列、长英质火山碎屑岩序列,以及一系列侵入的基性-超基性岩脉。区域内的主构造为北北西向,包括一对结构不对称的水平褶皱——卡尔古丽背斜和向斜,以及与向斜西翼平行的Golden Mile断层,主构造被后期走滑断层影响形成的破碎剪切带,是赋存金矿的主要构造。根据控矿构造、矿质来源和沉积时间,可以将金矿脉分为三种类型,分别是Fimiston型、Oroya型和Charlotte型。研究认为,在该地区找矿主要应从围岩、构造、地球物理、地球化学几个方面着手。通过对本区成矿地质特征的分析和研究,新发现了Eureka小型金矿,希望能对中国企业在该地区的勘探投资有所帮助。

The Kalgoorlie gold field is the largest gold production area in Western Australia, tectonically the area is within the Yilgarn craton east part Kalgoorlie greenstone belt. Mainly Archean strata outcropped in the mine area, including mafic-uhramafic lava se- quence, felsic pyroclastic rock sequence and a series of intrusive basic-ultrabasic veins. Main structure in the area is NNW structurally asymmetrical horizontal fold pair--Kalgoorlie anticline and syncline, and syncline west limb parallel Golden Mile fault; the main struc- ture fractured shear zone formed by subsequent strike-slip fault impacting is the main structure hosted the gold ore. Based on ore-con- trolling structure, material source and deposit time, can divide gold vein into three styles： Fimiston, Oroy and Charlotte respectively. The study reckoned that the prospecting in the area should start with wall rock, structure, geophysical, geochemical aspects. Through the analysis and study of the ore-forming geological characteristics, the Eureka, a small gold ore has found, we hope it will be helpful for Chinese enterprise prospecting investment in the area.