河南省罗山县皇城山银矿床矿物标型特征及其找矿意义

Mineral typomorphism characteristic and prospecting significance of Huangchengshan silver deposit in Luoshan county,Henan province

本文基于对罗山县皇城山银矿矿化蚀变、矿物标志及方铅矿、闪锌矿、黄铁矿矿物标型特征分析的基础上,认为皇城山银矿床类型为浅成火山低温热液矿床中的高硫化型矿床。皇城山银矿以发育多孔状石英岩的硅化带和高级泥化带特征,矿石中主要为黄铁矿+铜蓝+辉铜矿硫化物组合,表明其具有高硫型浅成热液矿床蚀变及矿物组合特点;银矿石中闪锌矿具贫Fe、富Tl的低温型闪锌矿特征,方铅矿的Sb/Ag比值,黄铁矿Co/Ni比值及Ni-Co图,均表明皇城山银矿具火山低温热液矿床特征。皇城山银矿石中黄铁矿热电效应表现为P、P-N型、N^P型,结合深部勘查工作,判断矿体剥蚀深度小于300 m,矿体剥蚀程度属于上部或近中部,其下一步深部勘查工作难度较大,矿体基本接近尾部。

On the basis of mineralization alteration,mineral signs,typomorphism analysis of galena,phalerite and pyrite in Huangchengshan silver deposit,Luoshan county,Henan province,the Huangchengshan silver deposit is considered to belong to high sulphidation deposit of shallow-seated volcanic low temperature hydrothermal deposit.Huangchengshan silver deposit has characteristics of developing silicified zone of cellular quartzite and advanced argillization zone,from the combination of pyrite＋ covellite＋chalcocite sulfide in silver ore,it shows mineral assemblage characteristics of high sulphidation shallowseated hydrothermal deposit;sphalerite shows significant characteristic of low temperature sphalerite as poor Fe,rich Tl,and galena Sb/Ag ratio,pyrite Co/Ni ratio and Ni-Co figure in silver ore,which suggests Huangchengshan silver deposit has characteristic of volcanic hydrothermal deposit;Pyrite thermoelectric effect of Huangchengshan silver ore shows P,P-N type,N-P type.With deep exploration work,it can be judged that erosion level of orebody is less than 300 m,denudation extent of ore body belongs to upper or submedian.It is relatively difficult for next deep exploration work,and ore body is basically approaching rear.