U.S.-China Cooperative Research (Geol.): Geochemical Studiesof the Massive Sulfide Gold Deposits of the Tongling District, Anhui, China

“安徽铜陵地区块状硫化物金矿床地球化学研究”，由中国地质大学地质与地质研究所博士主持。美国弗吉尼亚理工学院和州立大学的James R. Craig和Robert J. Bodnar以及中国冶金工业部华东地质勘探公司的LIN Gen Fan和WAN Xin先生是由美国国家科学基金会和中国冶金工业部联合主办的。本联合研究旨在对中国中东部一个重要但鲜为人知的成矿省——安徽省铜陵地区的矿床进行详细的地质调查。本区有大量矽卡岩和层控块状硫化物矿床，含可开采或潜在可开采量的贱金属和金，特别是铜金矽卡岩矿床、层控铜金矿床和粗砂岩金矿床。研究人员试图确定这些沉积物形成的条件，并确定这两种不同的沉积物类型是否在基因上相关。为了实现这一目标，对矿石和脉石矿物进行详细的岩石学和电子显微分析将确定矿床内的矿物学和矿物化学，并寻求建立一个全面的共生序列。同时，详细的流体注入研究，包括标准显微测温和激光拉曼分析，将确定矿化流体的组成和物理状态。对不同地质背景和成因的金矿床的研究为发现地球化学运输和金的沉积提供了新的机会。具体而言，通过探索与火成岩活动（如夕卡岩）明显相关的矿床与完全赋存于沉积物（层控矿床）且在空间上与侵入体无关的矿床之间的关系，对这些矿床的研究可以为含金热液系统的演化提供有价值的信息。这项研究对金矿成因的新认识可能会带来对美国和中国都有用的新勘探策略和技术。

This proposal on "Geochemical Studies of the Massive Sulfide Gold Deposits of the Tongling District, Anhui Province, China," between Drs. James R. Craig and Robert J. Bodnar of the Virginia Polytechnic Institute and State University and Messrs. LIN Gen Fan and WAN Xin of the East China Geological Exploration Company of the Chinese Ministry of Metallurgical Industry (MMI), is jointly sponsored by NSF and by the Chinese MMI. This joint research aims at a detailed geological investigation into the ore deposits of a major, but little known, metallogenic province in east central China, the Tongling area of Anhui province. This area contains a large number of skarn and stratabound massive sulfide deposits that contain mineable or potentially mineable quantities of base metals and gold, specifically copper gold skarn deposits, stratabound copper gold deposits, and gossan gold deposits. The investigators seek to define the conditions under which these deposits formed and to determine if the two different deposit types are genetically related. To achieve this, detailed petrographic and electron microprobe analyses of ore and gangue minerals will define the mineralogy and mineral chemistry within the deposits and seek to establish a comprehensive paragenetic sequence. At the same time, detailed fluid infusion studies, including standard microthermometry and laser Raman analyses, will define the composition and physical state of the mineralizing fluids. This study of gold deposits in distinctly different geological settings and apparent genesis provides an opportunity to discover new aspects of the geochemical transport and deposition of gold. Specifically, study of these ore deposits may provide valuable information about the evolution of gold bearing hydrothermal systems, by exploring the relationship between deposits that are clearly related to igneous activity, such as the skarns, and those that are hosted entirely in sediments (the stratabound deposits) and spatially unrelated to an intrusive body. The new insight into gold ore genesis promised by this research could lead to new exploration strategies and techniques useful both in the United States and in China.