山西刁泉银铜矿地质特征及矿床成因

Genesis and Prospecting Criteria of Niujuan Hot spring Type Ag(Au) Deposit in Fengning County,Hebei Provine

刁泉矿床为产在大理岩和花岗斑岩接触带中的大型ＡｇＣｕ矿床。成矿作用分为两期，具有强的围岩蚀变。岩石和硫化物的微量元素、地球化学特征表明：成矿流体为内生热液。稳定同位素研究表明：３４Ｓ明显富集，均为正值，塔式效应明显。矿石铅和黑云母石英二长岩的铅同位素具有相似和相对稳定的组成，二者可能从下地壳产生的。碳、氧同位素组成显示了岩浆热液的特征。包裹体测温给出了１８５～４００℃的成矿温度；含盐度为４０～４６ｗｔ％。认为刁泉为一中低温热液ＡｇＣｕ矿床。本文建立了成矿模式。

Niujuan Ag(Au)deposit is one of important Ag deposits found recently in the north of Heibei Province.Basing on the works of predecessors and many geologic observtions by the authors,the ore forming stages are divided into sericitization stage,silicatization stage,sulfide rich stage,pyrite quartz stage,purple fluorite stage,white fluorite stage and kaolinization stage.The deposit has slightly high temperature,low pressure and low salinity,with meteoric water in fluid,and the ore forming materials were originated from the metamorphic rocks and granites of Hongqiyengzi Group.As a main ore bearing geologic body,the siliceous breccia is neither tectonic origin nor magmatic crypto explosion origin,so the authors consider the deposit is of hot spring crypto explosion type.