豫西骆驼山硫多金属矿床的成因——来自纹层状矿石中硫化物LA-ICP-MS微量元素证据

发布时间：2018-02-23 16:14

本文关键词： 地球化学硫化物原位微区分析纹层状矿石岩浆热液成因海底喷流沉积成因豫西　出处：《矿床地质》2017年01期 　论文类型：期刊论文

【摘要】：骆驼山硫多金属矿床位于豫西栾川钼多金属矿集区,矿体主要呈似层状和透镜状产于新元古界栾川群三川组和南泥湖组的层间断裂带内的矽卡岩中,受NWW向层间断裂带的控制。该矿床在成因方面的争论的焦点在于:是否存在元古代的喷流沉积成矿作用?具有纹层状构造的硫化物矿石以往被认为是喷流沉积成因矿床的关键证据,但这种矿石结构也可能为热液交代成因。通过详细的野外地质观察,纹层状矿石在空间上主要产于矽卡岩与致密块状硫化物矿石之间,在透辉石长英角岩、矽卡岩及大理岩等围岩中也有分布,纹层状矿石交代了矽卡岩。针对纹层状矿石中的金属硫化物开展LA-ICP-MS原位微区分析,结果表明:(1)闪锌矿形成于中高温环境,其微量元素以富Fe、Mn、In、Co(均值分别为8.5%、6144×10~(-6)、321×10~(-6)和28.54×10~(-6)),贫Ga、Ge、Tl(均值分别为4.31×10~(-6)、0.98×10~(-6)和0.0476×10~(-6))等元素为特征;(2)磁黄铁矿和黄铁矿的微量元素组成均具有富Co(均值分别为57.75×10~(-6)和2787.68×10~(-6))、贫Ni(均值分别为19.24×10~(-6)和11.29×10~(-6))的特征,二者的Ni-Co关系图指示其与岩浆热液密切相关。以地质现象为基础,结合硫化物原位微区分析数据,笔者认为骆驼山硫多金属矿床中的纹层状矿石属于岩浆热液成因。
[Abstract]:The Luohumushan sulfur polymetallic deposit is located in Luanchuan molybdenum polymetallic ore concentration area in western Henan Province. The orebody is mainly stratiform and lenticular in skarn rocks in the interlaminar fault zones of Sanchuan formation and Nannihu formation of the Luanchuan Group in the Neoproterozoic. Controlled by the NWW interlaminar fault zone, the dispute over the genesis of the deposit is focused on: is there Proterozoic exhalation mineralization? Sulphide ores with lamellar structures were previously considered to be the key evidence of exhalative sedimentary genetic deposits, but this ore structure may also be hydrothermal metasomatic origin. The laminated ore mainly occurs between skarn and dense massive sulphide ore in space, and is also distributed in the surrounding rocks such as diopside feldspar, skarn and marble. The LA-ICP-MS in-situ microanalysis of metallic sulfides in laminated ores shows that the sphalerite was formed in a medium and high temperature environment. The trace element compositions of pyrrhotite and pyrite are characterized by rich in Fe _ 2O _ 2 (mean value is 8.5144 脳 10 ~ (-1) ~ (-6)), 28.54 脳 10 ~ (10) ~ (-6) and 28.54 脳 10 ~ (10) ~ (-6), (the mean values are 4.31 脳 10 ~ (-1) -6 (0.98 脳 10 ~ (-6)) and 0.0476 脳 10 ~ (10) ~ (-6)). The trace element compositions of pyrrhotite and pyrite have the characteristics of rich in Co-rich (57.75 脳 10 ~ (-6)) and 2787.68 脳 10 ~ (10) ~ (-6), Ni-poor (the mean values are 19.24 脳 10 ~ (-6)) and 11.29 脳 10 ~ (10) ~ (6), respectively. The trace element compositions of pyrrhotite and pyrite have the characteristics of rich in Co (the mean values are 57.75 脳 10 ~ (-6)) and 2787.68 脳 10 ~ (10) ~ (-6), respectively. The Ni-Co diagram of the two shows that they are closely related to magmatic hydrothermal fluid. Based on the geological phenomena and the data of in-situ analysis of sulphide, the authors consider that the laminated layered ore in Luohumushan sulfur polymetallic deposit belongs to magmatic hydrothermal origin.
【作者单位】：中国地质科学院矿产资源研究所国土资源部成矿作用与资源评价重点实验室;内蒙古自治区地质调查院内蒙古自治区岩浆活动与找矿重点实验室;中国地质大学地球科学与资源学院;河南省栾川众鑫矿业有限公司;成都地质矿产研究所;
【基金】：中央级公益性科研院所基本科研业务费专项资金(编号:K1308) 栾川铅锌矿集区成岩、成矿系统的时空结构专题研究(编号:2011BAB04B06)联合资助
【分类号】：P618.2

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