河南桐柏老湾金矿床地质特征及成因探讨

Geological features and genesis of the Laowan gold deposite in the Tongbai region, Henan

老湾金矿属剪切带型金矿床。矿体的分布受Riedel剪切裂隙系统控制 ,成矿流体具低盐度、弱碱性及较高矿化度的混合水特点。区内的龟山岩组是原始矿源层 ,燕山期老湾花岗岩提供了部分热源、水源及成矿物质。Au主要是以Au S、Au Si配合物形式迁移 ,其次是被硅胶吸附呈胶体状态迁移 ,而成矿流体的温度、压力、pH值降低 。

The Laowan deposit belongs to shear zone type gold deposit, which is controlled by Riedel shear-fissure system. The ore-forming liquid is the mixed water of lower salinity and alkalinity, higher mineralization. The Pt 2-3 g s is the primary source bed, the Laowan granite of Yanshanian provided part of heat source, water source and metallogenic material. Gold is mainly transferred in the form of gold-sulphur and gold-silicon complex compands and secondly in the form of silicon colloids. The drop in temperature, pressure, pH value and variation in Eh of the metallogenic fluid and gelification of the silicon colloids caused by electrilyte adding are important factors resulting in precipitation of gold.