湖南老鸦巢隐爆角砾岩型金矿床地质特征及找矿标志

摘要

Laoyachao gold deposit is located in the famous Shuikoushan orefield,the exposed strata are the upper Devonian to lower Cretaceous,the lithology is carbonate,paralic clastic rocks and terrigenous clastic rock.The Indosinian fold and the SN trending fracture are developed,magmation is rather strong.The ore-forming material enriched in the axle of the overturned anticline,the fault zone and surrounding the rock.Laoyachao gold deposit occurs in cryptoexplosive breccia pipe,which is controlled by F1 fault and No.4 granodiorite,alteration of the wall rock is developmend,silicification,pyritization,zinc mineralization has a close relationship with mineralization. Gold mainly exists as native gold,distribute in the gaps of quartz,pyrite,sphalerite and the particle clearances. Mineralization can be divided into skarn stage,hydrothermal stage and supergene stage,hydrothermal stage is the main mineralization stage.Quartz-pyrite-sphalerite-native gold stage is the main stage of mineralization.The main prospecting mark is cryptoexplosive breccia,silicification,sphalerite and pyritization is closely associated with mineralization.%老鸦巢金矿床位于我国著名的水口山矿田中部，出露地层为上泥盆-下白垩统海相碳酸盐岩、海陆交互相碎屑岩和陆相碎屑岩。老鸦巢金矿赋存于受F1断层及4号花岗闪长岩体控制的隐爆角砾岩筒中，矿体围岩蚀变发育，以硅化、闪锌矿化和黄铁矿化与成矿关系最为密切。金以自然金为主，呈显微和次显微粒状分布于石英、黄铁矿和闪锌矿等矿物的颗粒中或晶隙中。成矿期大致可分为矽卡岩期、热液期和表生期，其中，热液期为主成矿期。石英-黄铁矿-闪锌矿-自然金阶段是主要的成矿阶段。隐爆角砾岩为主要的找矿标志，硅化、闪锌矿化和黄铁矿化为主要的矿化蚀变标志。