Occurrence state and genesis of gold in Paodaoling gold deposit, Chizhou City, Anhui Province

Journal Information

J. Hefei Univ. Tech. (Nat. Sci.), Jul.2024, Vol.47 No.7: 931-940, 947

DOI: 10.3969/j.issn.1003-5060.2024.07.011

Authors

LENG Huicong $ ^{1,2,3} $, YUAN Feng $ ^{1,2,3} $, DENG Yufeng $ ^{1,2,3} $, ZHOU Taofa $ ^{1,2,3} $, LI Yue $ ^{1,2,3} $

(1. School of Resources and Environmental Engineering, Hefei University of Technology, Hefei 230009, China; 2. Ore Deposit and Exploration Center (ODEC), Hefei University of Technology, Hefei 230009, China; 3. Anhui Province Engineering Research Center for Mineral Resources and Mine Environments, Hefei 230009, China)

Abstract and Keywords

Abstract: The Paodaoling gold deposit is located in the Anqing-Guichi ore concentration area of the metallogenic belt in the middle and lower reaches of the Yangtze River. The ore body of the deposit mainly occurs in the altered dacite porphyrite. In this paper, the petrographic analysis for the rock samples of the deposit was conducted using electron microprobe and LA-(MC)-ICP-MS. The results show that the ore minerals of the Paodaoling gold deposit are mainly pyrite, sphalerite and arsenopyrite; gangue minerals are mainly quartz, calcite and clay minerals; the main gold-bearing mineral is pyrite, followed by arsenopyrite; Au mainly exists in the above minerals in the form of silver and gold. The analysis of trace element of gold-bearing pyrite shows that Au is positively correlated with the mass fractions of As, Cu, Pb, Zn, etc., and negatively correlated with the mass fractions of Fe and S. The presence of As in pyrite lattice is conducive to Au substitution for Fe into the lattice, making Au precipitate in pyrite cracks. Electron microprobe analysis of the occurrence of gold shows that the gold in the Paodaoling gold deposit mainly exists in pyrite in the form of lattice gold, and some in the form of silver and gold in the cracks of pyrite and arsenopyrite. The sulfur in the sulfide of the deposit mainly comes from magma, and a small amount of stratum material is involved. The mixed ore-forming fluid is mainly derived from magmatic exsolution fluid.

Keywords: Paodaoling deposit; porphyry gold deposit; pyrite; silver-gold deposit; geochemistry; occurrence of gold

作者信息

冷慧聪 $ ^{1,2,3} $，袁峰 $ ^{1,2,3} $，邓宇峰 $ ^{1,2,3} $，周涛发 $ ^{1,2,3} $，李跃 $ ^{1,2,3} $

(1. 合肥工业大学资源与环境工程学院，安徽合肥 230009；2. 合肥工业大学矿床成因与勘查技术研究中心，安徽合肥 230009；3. 安徽省矿产资源与矿山环境工程技术研究中心，安徽合肥 230009)

摘要和关键词

摘要: 抛刀岭金矿床位于长江中下游成矿带的安庆—贵池矿集区, 该矿床矿体主要赋存于蚀变的英安玢岩岩体中。文章对该矿床岩石样品岩相学采用电子探针、激光剥蚀多接收电感耦合等离子体质谱仪等测试分析。结果表明: 抛刀岭金矿床的矿石矿物主要为黄铁矿、闪锌矿和毒砂等; 脉石矿物主要为石英、方解石及黏土矿物; 主要载金矿物为黄铁矿, 其次为毒砂; Au 主要以银金矿的形式存在上述矿物中。载金黄铁矿微量元素结果分析显示, Au 与 As、Cu、Pb、Zn 等质量分数呈正相关, 与 Fe、S 质量分数呈负相关, 黄铁矿晶格中 As 的存在有利于 Au 代替 Fe 进入晶格中, 使得 Au 在黄铁矿裂隙中沉淀。电子探针分析金的赋存状态显示, 抛刀岭金矿床金主要以晶格金的形式存在于黄铁矿中, 部分以银金矿的形式存在于黄铁矿和毒砂的裂隙中。矿床硫化物中的硫主要来源于岩浆, 同时有少量的地层物质参与。混染成矿流体主要为来源于岩浆的出溶流体。

关键词: 抛刀岭矿床；斑岩型金矿；黄铁矿；银金矿；地球化学；金的赋存

Funding

安徽省公益性地质调查资助项目（2021-g-2-12）；安徽省国土资源科技资助项目（2020-K-14）

合肥工业大学学报(自然科学版)

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