云南西邑MVT型铅锌矿床地质特征与硫化物电子探针分析

发布时间：2018-06-06 10:48

本文选题：铅锌矿 + MVT型　；参考：《地质与勘探》2017年01期

【摘要】：云南保山西邑铅锌矿位于保山地块中北部,是实现隐伏铅锌矿找矿重大突破的典型矿床。矿体赋存于下石炭统香山组灰岩地层中,受NE向断裂及次级断裂构造控制,矿体与围岩界线清晰且受到一定地层层位控制;矿体形态变化较大,主要呈脉状、网脉状、透镜状、层状;金属矿物组合为闪锌矿、方铅矿±黄铁矿±毒砂。矿体主要为产于似层状含炭质褪色灰岩中的似层状铅锌矿体,以V3号矿体为代表,其Zn/Pb值平均为1.6,含较多的方铅矿,成矿温度相对较低;次为穿切岩层的破碎带型铅锌矿体,其Zn/Pb值平均为24.9,以铁闪锌矿为主,方铅矿少见,成矿温度相对较高。电子探针分析(EMPA)测定结果显示,西邑铅锌矿区闪锌矿中的Zn平均值为60.0%,S平均为32.9%,含Fe平均达6.2%(大于6%),为铁闪锌矿,是中-低温下析出的产物;方铅矿的Pb/S平均为1.01,接近理论值;黄铁矿的Fe平均为46.0%,S平均值为52.8%,S/Fe值为2.0,Co/Ni值平均为1.1,表现出热液成因黄铁矿的特点。这些数据表明,云南保山西邑铅锌矿具有MVT型矿床的特征。
[Abstract]:Baoshan Xiyi lead-zinc deposit in Yunnan Province is located in the central and northern part of Baoshan massif and is a typical deposit to achieve a major breakthrough in prospecting for concealed lead-zinc deposits. The orebody occurs in the limestone strata of Xiangshan formation of Lower Carboniferous, controlled by NE trending fault and secondary fault structure, the boundary between orebody and surrounding rock is clear and controlled by certain stratigraphic position, the shape of orebody is changed greatly, it is mainly vein-like, reticulate and lenticular. The metallic mineral assemblage is sphalerite, galena 卤pyrite 卤arsenopyrite. The ore bodies are mainly layered lead-zinc orebodies occurring in decolorized carbonaceous limestone, represented by the V3 orebody, with an average Zn/Pb value of 1.6, containing more galena and relatively low metallogenic temperature, followed by the fractured zone-type lead-zinc orebody with penetrating strata. The average Zn/Pb value is 24.9, mainly of sphalerite, galena is rare, and the ore-forming temperature is relatively high. The results of electron microprobe analysis show that the average value of Zn in sphalerite in Xiyi lead-zinc mine is 60.00.The average value of Zn in sphalerite is 32.9, the average iron content is 6.2cm (> 6%), which is the product of sphalerite precipitated at medium-low temperature, the average Pb/S of galena is 1.01, which is close to the theoretical value. The average Fe value of pyrite is 46.0 and the average value of S / S is 52.80.The average value of S / Fe is 2.0 Co / Ni = 1.1, which shows the characteristics of hydrothermal pyrite. These data indicate that the Baoshan Xiyi Pb-Zn deposit has the characteristics of MVT type deposit.
【作者单位】：中国地质大学(北京)地球科学与资源学院;中国地质大学地质过程与矿产资源国家重点实验室;云南省地质矿产勘查院;
【基金】：中国地质调查项目(12120114014001) 国家自然科学基金项目(41572062、U1303292)联合资助
【分类号】：P575.1;P618.4

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