河北丰宁银多金属矿床黄铁矿热电性特征及其指示意义

Thermoelectric Characteristics of Pyrite from the Fengning Ag Polymetallic Deposit, Hebei Province and Its Implications

丰宁银多金属矿床位于华北克拉通北缘冀北成矿区内,是该地区重要的银多金属矿床之一。为了更好地探究矿床成因并进行矿区深部、外围找矿预测,对丰宁银多金属矿床牛圈银(金)矿区不同成矿阶段矿石中黄铁矿热电性标型特征进行了研究。结果表明该矿床黄铁矿热电系数变化范围为26~367μV·℃^(-1),主要集中在200~330μV·℃^(-1)范围内,黄铁矿热电导型全部为P型,热电系数平均值为267μV·℃^(-1)。从1190 m到1110 m范围内约80 m的垂直空间内,热电系数变化梯度为0.74μV·℃^(-1)·m^(-1),变化梯度较小。综合来看,目前牛圈银(金)矿区所揭露的仅为浅部矿体,深部矿体还没有披露,并且矿体剥蚀较浅,深部尚有很大找矿远景。另外,利用黄铁矿热电系数与其形成温度的经验公式计算得出本区黄铁矿的形成温度范围为147~281℃,主要集中在180~280℃,与流体包裹体均一测温结果的变化范围基本一致,表明该矿床为中低温矿床。

The Fengning Ag polymetallic deposit is one of the most important Ag polymetallic deposits located in northern Hebei metallogenic area,north margin of North China Craton.In order to better explore the genesis of the deposit and make predictions for deep and peripheral mineralization of the mining area,the thermoelectric typomorphism of pyrite in different mineralization stages of the Niujuan Ag(Au)mining area of the Fengning Ag polymetallic deposit was studied.The results show that the pyrite thermoelectric coefficient ranges from 26-367μV·℃^(-1),mainly in the range of 200-330μV·℃^(-1).The pyrite thermoelectric conductivity type is all P type,and the average value of thermoelectric coefficient is 267μV·℃^(-1).The gradient of thermoelectric coefficient is 0.74μV·℃^(-1)·m^(-1) in the vertical space of about 80 m from 1,190 m depth to 1,110 m depth.In summary,only the shallow ore body has been disclosed in the Niujuan silver(gold)mining area,and the deep ore body has not been disclosed,and the erosion of the ore body is shallow,so there is a great prospect for deep ore prospecting.In addition,the pyrite formation temperature ranges from 147℃to 281℃,mainly concentrated in 180℃to 280℃,which is basically consistent with the variation range of fluid inclusion homogenization temperature measurement results,indicating that this deposit is a medium-low temperature deposit.