大渡河成矿带黄金坪金矿床黄铁矿标型特征及矿床成因探讨

Typomorphic Characteristics of Pyrite and Genesis of Huangjinping Gold Deposit in Dadu River Metallogenic Belt

以大渡河金成矿带中的黄金坪金矿床作为研究对象,从黄铁矿的形态特征、主量元素和热电系数等方面进行矿物学研究,探讨该矿床中的黄铁矿标型特征及矿床成因。结果显示:该矿床中黄铁矿存在两个阶段,早期黄铁矿晶型主要呈立方体和五角十二面体,颗粒较大,晚期黄铁矿则呈立方体,颗粒较小;黄铁矿中主量元素表现出铁亏损特征,其m(S)/m(Fe)比值大于2;黄铁矿热电导型均为N型,热电系数为-390~-164μV/℃,成矿温度为173~297℃,平均温度为261℃。综合分析认为,黄金坪金矿床为与岩浆热液有关的中低温热液矿床。

This paper takes the Huangjinping gold deposit in the metallogenic belt as the research object,and carries out mineralogical research from the morphological characteristics,major elements and thermoelectric coefficient of pyrite,and discusses the typomorphic characteristics of pyrite in the deposit and the genesis of the deposit.The results show that there are two stages of pyrite in the deposit.The early pyrite crystal forms are mainly cubic and pentagonal dodecahedral,with large particles.The late pyrite is cubic and small in size.The main elements in pyrite show the characteristics of iron loss,and its m(S)/m(Fe)ratio is greater than 2.Pyrite thermal conductivity type is N-type,and thermoelectric coefficient is-390~-164μV/℃,the mineralization temperature is 173~297℃,and the average temperature is 261℃.In conclusion,it is believed that the Huangjinping gold deposit is a medium-low temperature hydrothermal deposit related to magmatic hydrothermal fluid.