豫西陆院沟蚀变岩型金矿床黄铁矿标型研究

Typomorphic characteristics of Au-bearing pyrites from Luyuangou altered gold deposit,western Henan Province

陆院沟破碎蚀变岩型金矿床主成矿期载金黄铁矿存在原生、改造、增生、新生以及多型叠加等结构类型,这种单期黄铁矿显示复杂成矿过程的现象说明对黄铁矿的形态结构分类和原位测试是极为必要的。在宏观期次研究的基础上,对成矿期黄铁矿进行形态结构分类和原位分析,结果显示,载金黄铁矿是预富集期、主成矿期和晚成矿期3个阶段的产物,3个阶段普遍显示富S亏Fe、富Ni亏Co的沉积型特征,晚期显示了亏硫富铁的变质型叠加特征。综合研究认为,黄铁矿的形态、结构和成分标型是不同成因及演化过程的产物,对矿床成因判别和找矿勘探具有重要的指示意义。

A diversity of morphological structures of Au-bearing pyrites exists during the main metallogenic stage.These structures include the corrosion metasomatic,proliferation,directed modification,dissemination and veined types.The phenomenon that multiple morphological structures exist in sole metallogenic epoch indicates that the morphological structural classification and in-situ pyrite testing are desperately needed.The present study conducted research on these two topics based on macroscopic examinations.The results show that gold-bearing pyrites were the products of the pre-enrichment,the main-metallogenic and the postmetallogenic stages.All three periods embodied depositional characteristics that the pyrites were rich in S and poor in Fe,and rich in Ni and deficient in Co.In addition,post-metallogenic stage embodied the metamorphism superposition characteristics that the pyrites were rich in Fe and deficient in S.It is believed by a comprehensive study that the morphological,textural and constitutional typomorphism of pyrites indicate different origin and complex evolutionary process;these typomorphic characteristics can be significant in genesis discrimination,exploration and prospecting of gold deposits.