新洲金矿床的地质特征及其成因

广东新洲金矿床产于褶皱式推覆构造外来系统——震旦系乐昌峡群变质地层之中.金矿床主要属碎裂石英脉型,次为蚀变糜棱岩型.成矿作用早期形成糜棱岩型金矿,为韧性剪切成矿期;晚期形成碎裂石英脉型金矿、属韧-脆性和脆性成矿期.成矿溶液为浅成中低温变质-混合岩化热液,成矿物质来源于震旦系,属褶皱式逆冲推覆-剪切带型金矿床.

THE GEOLOGICAL CHARACTERISTICS AND FORMATION MECHANISM OF XINZHOU GOLD DEPOSIT IN NORTHERN GUANGDONG PROVINCE

Xinzhou Au deposit and ore bodies occur as veins in the metamorphic Sinian Lechangxia Group in the allochthon of the fold-thrust nappe. The Au deposit is dominantly cataclastic quartz-vein type, secondly altered mylonite type. The early stage the mineralization is of ductile shearing, which formed the mylonite-type Au deposit. The later stage of mineralization is of ductile-brittle shearing and brittle shearing, which formed cataclastic quartz-vein type Au deposit. The ore solution is a metamorphosed and migmatized hydrothermal fluid formed in hypabyssal moderate-to low-temperature conditions and that the ore-forming materials come mainly from the metamorphic Sinian strata.Consequently, the Xinzhou gold deposit is considered to be a fold-thrust-shear zone type gold deposit.