| 还原性矽卡岩型金矿床基本特征、研究现状及在中国前景 |
| Received:October 17, 2023 Revised:December 01, 2023 点此下载全文 |
| 引用本文：LIU Jun,WANG XiaoTong,HE JunCheng,LI TieGang.2024.Reduced skarn gold deposits: Basic characteristics, current understanding, and perspectives in China[J].Mineral Deposits,43(1):1~28 |
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| Author Name | Affiliation | | LIU Jun | MNR Key Laboratory of Metallogeny and Mineral Assessment, Institute of Mineral Resources, Chinese Academy of Geological Sciences, Beijing 100037, China | | WANG XiaoTong | MNR Key Laboratory of Metallogeny and Mineral Assessment, Institute of Mineral Resources, Chinese Academy of Geological Sciences, Beijing 100037, China
School of Earth Sciences and Resources, China University of Geosciences(Beijing), Beijing 100083, China | | HE JunCheng | School of Earth Sciences and Resources, China University of Geosciences(Beijing), Beijing 100083, China | | LI TieGang | MNR Key Laboratory of Metallogeny and Mineral Assessment, Institute of Mineral Resources, Chinese Academy of Geological Sciences, Beijing 100037, China |
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| 基金项目:本文得到中央级公益性科研院所基本科研业务费项目（编号：KK2205、KK2106）、国家自然科学基金项目（编号：41672066、41820104010）和中国地质调查局地质调查项目（编号：DD20230287）联合资助 |
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| 中文摘要:还原性矽卡岩型金矿以独立金矿形式赋存于钙质沉积岩中，以金品位高（5~15 g/t）著称。目前，该类型金矿的总体研究程度较低，在成矿背景、还原性岩浆源区及成因、金高效富集机制等方面仍缺乏理解。笔者对该类型金矿的地质特征、时空分布规律、成矿机理、找矿标识等方面进行了系统梳理，探讨了该类金矿的研究难点及其在中国的成矿潜力和找矿前景。还原性矽卡岩型金矿具有以下特征：① 独特的Au-Bi-Te-As±Co元素组合，缺乏Cu等贱金属；② 矽卡岩以钙铁辉石为主，其次为石榴子石？③ 成矿岩体属于还原性钛铁矿系列，包括辉长闪长岩、闪长岩和花岗闪长岩等；④ 代表性低硫逸度的金属矿物，包括斜方砷铁矿、黑铋金矿、贫S的Te-Bi矿物。关键问题或薄弱环节主要有：① 还原性岩浆存在温度、盐度、氧逸度、硫逸度、含水量、还原性组分类型及含量等多种属性，这些属性对还原性矽卡岩型金矿的形成有哪些影响？② Au可能以氯络合物、硫络合物、Bi-Te熔体、纳米絮状物等多种方式运移，还原性岩浆流体中Au的高效迁移及富集方式有哪些；③ 还原性成矿岩浆的氧化-还原性质有争议，部分学者认为岩浆始终为还原性，另一些学者认为母岩浆为氧化性，后期混入还原性物质；④ 存在深部W-Mo矿化、浅部Au-Sb-Bi矿化的金属元素分带现象，这种分带规律受哪些因素控制？总之，还原性矽卡岩型金矿在中国有着良好的成矿潜力和找矿前景，其中中国东部W/Sn成矿区（带）和Au成矿区（带）的叠加区域、西部还原性岩体分布区是该类金矿的有利勘探区。 |
| 中文关键词:还原性岩浆 矽卡岩 金矿床 岩浆成因 成矿机制 |
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| Reduced skarn gold deposits: Basic characteristics, current understanding, and perspectives in China |
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| Abstract:Reduced skarn gold deposits (RSGD) occur at calcareous sedimentary rock and have been famous for independent deposits with high gold grade (5~15 g/t). Now, the studies of RSGD are poor. Some important questions lack enough understanding, e.g., metallogenic background, source and genesis of reduced magma, and efficient gold enrichment mechanism. This paper systematically reviews the geological characteristics, spatiotemporal distribution, metallogenic mechanism, and prospecting indicator, discusses research difficulties and metallogenic potential and prospecting prospect in China. The RSGD shows some characteristics:① unique Au-Bi-Te-As±Co element group, lacking base metals such as Cu; ② The skarn consists of hedenbergite with minor garnet; ③ The ore-related intrusive rock belongs to the reduced ilmenite series, including gabbro diorite, diorite, and granodiorite; ④ Representative metal minerals with low sulfur fugacity, have lollingite, maldonite, and S-poor Te-Bi minerals. The key issues or poor research mainly include:① the reduced magmatic fluid shows many attributes, e.g., temperature, salinity, oxygen fugacity, sulfur fugacity, water content, type and content of reduced component, which attribute plays key effect during RSGD formation? ② Au could migrate in various ways, e.g., chloride complexes, sulfur complexes, Bi-Te melt, and nanometer-flocs. Which mechanism is the most efficient for gold migration and enrichment in reduced magmatic fluid? ③ The oxidation-reduced properties of reduced ore-forming magma have been controversial. Some scholars believe that the primary magma is always reduced, but others indicate that the primary magma is oxidized and later mixed with reduced materials; ④ There is a phenomenon of metal element zoning, showing W-Mo mineralization in deep and Au-Sb-Bi mineralization at shallow. Which factor controls the zoning pattern? In conclusion, the RSGD shows favorable mineralization potential and prospecting prospects in China. The superposition area of W/Sn and Au mineralization regions (belts) in the eastern China, as well as the distribution region of reduced intrusive rocks in the western China, could be favorable exploration area for RSGD. |
| keywords:reduced magma skarn gold deposit magma genesis ore-forming mechanism |
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