大兴安岭南段黄岗矽卡岩型铁锡多金属矿床蚀变矿化特征及其成因  

Alteration, Mineralization and Genesis of Huanggang Skarn Iron-Tin Polymetallic Deposit, Southern Great Xing’an Range

作　　者：梅微[1] 吕新彪[1,2] 王祥东 范谢均 魏巍[1] Mei Wei;LüXinbiao;Wang Xiangdong;Fan Xiejun;Wei Wei(Institute of Geological Survey,China University of Geosciences,Wuhan 430074,China;School of Earth Resources,China University of Geosciences,Wuhan 430074,China;Wuhan Center of Geological Survey,CGS,Wuhan 430205,China)

机构地区：[1]中国地质大学地质调查研究院,湖北武汉430074 [2]中国地质大学资源学院,湖北武汉430074 [3]中国地质调查局武汉地质调查中心,湖北武汉430205

出　　处：《地球科学》2020年第12期4428-4445,共18页Earth Science

基　　金：中国地质调查局项目(No.DD20160101)。

摘　　要：大兴安岭南段黄岗铁锡多金属矿床具有明显的蚀变-矿化特征,对于研究矽卡岩型矿床的成矿过程具有重要的意义.因此对该矿床中具有代表性的蚀变矿物以及金属矿物开展电子探针研究,结果指示研究区的热液演化经历了4个阶段:在进变质矽卡岩阶段(Ⅰ),矿物以含有钙铁榴石GrtⅠ核的钙铝榴石GrtⅡ和钙铁辉石为主;在退变质矽卡岩阶段(Ⅱ),矿物以富铁榴石GrtⅡ、浸染状磁铁矿以及含水矿物为代表;氧化物阶段(Ⅱ)的矿物以大量磁铁矿、锡石以及少量钙铁榴石GrtⅣ和透辉石为主;在硫化物阶段(Ⅳ),磁铁矿逐渐被硫化物交代,最后形成毒砂、黄铁矿、黄铜矿、铁闪锌矿、浅色闪锌矿-黄铜矿-方黝锡矿固溶体、锑黝铜矿等,表明黄岗铁多金属矿床的流体来源从岩浆水、交代流体最后演化为大气降水的加入,流体成分变化复杂,流体演化具体表现为温度逐渐降低,水岩比值逐渐升高,具有还原性→氧化性→还原性等特点.The Huanggang iron-tin polymetallic deposit in the southern Great Xing’an Range is characterized by alterationmineralization features, which is of great significance to study the ore-forming process of skarn deposit. In this paper, it makes the Electron Probe Micro-analysis(EPMA) on typical alteration minerals and metallic minerals. The results indicate that hydrothermal evolution in the study area has experienced four stages. The prograde skarn stage(Ⅰ): the minerals are mainly grossular(GrtⅡ) with the andradite(GrtⅠ) core and hedenbergite. The retrograde skarn stage(Ⅱ): the minerals are mainly Fe-rich garnet(GrtⅢ),disseminated magnetite and hydrated minerals. The oxide stage(Ⅲ): the minerals are represented by a large amount of magnetite,cassiterite, a small amount of andradite(GrtⅣ) and diopside. The sulfide stage(Ⅳ): the minerals are a small amount of magnetites which are replaced by later sulfides, developing arsenopyrite, pyrite, chalcopyrite, iron-rich sphalerite, light-colored sphaleritechalcopyrite-isostannite solid solution, and antimony-bearing tetrahedrite. It makes clear that the source of main metallogenic stage from the Huanggang skarn iron polymetallic deposit is magmatic fluid, metasomatic fluid to mixing of meteoric water, fluid compositions change complex, fluid evolution is characterized by the temperature decreased, the water/rock ratio increases gradually, and reducing to oxidizing to reducing.

关 键 词：大兴安岭南段 黄岗矿床 矽卡岩型 矿物学 电子探针 矿床成因 

分 类 号：P611[天文地球—矿床学]