一、区域地质概况伊尔岗地块(Yilgarn Block)位于西澳大利亚地盾的南部,是地盾的两个太古代古陆核(nucleii)(伊尔岗和皮里巴拉)之一。这两个古陆核间被不同程度变质和形变了的元古代盆地隔开,周围被宽阔的元古代变质岩和深成岩的线形岩带或称活动带包围着。伊尔岗地块的东南部边缘以变质作用年令为13亿年的阿尔巴尼弗雷塞省(Albany I. Regional Geological Profile The Yilgarn Block is located in the southern part of the Western Australian Shield and is one of the two Archean ancient nuclei (Ilgan and Pirbala). The two ancient continental cores are separated by varying degrees of metamorphic and deformed metamorphic metamorphic Paleozoic, surrounded by broad metamorphic and plutonic linear rock belt or activity belt. Albany, on the southeastern margin of the Ilgan block,