矿床地质2026，Vol.45Issue(4)：825-840,16.DOI:10.16111/j.0258-7106.2026.04.006
金沙江-哀牢山造山带南段长安金矿床成矿物质来源与金属沉淀机制
Metal source and precipitation mechanism of Chang'an gold deposit,Jinshajiang Ailaoshan orogenic belt:Constraints from mineralogy and geochemistry of pyrite
摘要
Abstract
The Chang'an gold deposit is a typical Au deposit in the southern segment of the Jinshajiang-Ailaoshan metallogenic belt.Multiple-stage Cenozoic intrusions are exposed within the mining area,which are classified in-to altered diabase,unaltered diabase,syenite porphyry,and aplite.The ore bodies are hosted within siltstone and altered diabase.It remains obscure as to the relationship and the contribution between multi-stage intrusions and Au mineralization.In this study,we compared trace elements and S isotope of pyrites in these intrusions and silt-stone,respectively,to explore the source of ore metal and the contribution of intrusions to gold mineralization.The pyrites in the siltstone exhibit significant core(Fsy-1)and rim(Fsy-2)texture under BSE,and Fsy-2 is filled with amount of minerals such as arsenopyrite and galena,whereas,the pyrites in those intrusions show homoge-neous texture.The Co/Ni ratio and the large range of δ34S variation of Fsy-1 indicate that it is of sedimentary ori-gin.The Co/Ni ratio and the δ34S variation of other pyrites indicate magmatic hydrothermal genesis.Au occurs as primary nanoparticles in Fsy-11 and a few A-hly,while the rest exists in the form of solid solution in other py-rites.The content of Au,Cu,and As in Fsy-1 is much lower than that in Fsy-2,indicating that external deep fluids rich in Au,Cu,and As undergo strong fluid-rock reactions,metasomatizing sedimentary pyrite and causing Au precipitation.The As/Sb ratio of Fsy-2 and A-hly indicates that fluid boiling disrupts the stability of Au(HS)2 com-plex,which is also one of the factors causing Au precipitation.As pyrite is the main Au carrier mineral,N-hly,Zc-by and Xjy contains low Au content,and these intrusions also have very low Au content,indicating that they are not the main source of Au.The deep Au rich fluid metasomatized Fsy-1 and formed Fsy-2,accompanied by the precipitation of Au and other ore-forming elements.Overall,the ore metals of the Chang'an gold deposit mainly sourced from deep sources,and intense fluid-rock interaction behaves as a key factor controlling mineralization.The chemical composition of pyrite can effectively invert the mineralization process and can be used as a robust tool in mineral exploration.关键词
黄铁矿核边结构/水/岩反应/流体沸腾/长安金矿床/金沙江-哀牢山成矿带Key words
pyrite core-rim texture/fluid-rock interaction/fluid boiling/Chang'an deposit/Jinshajiang-Ailaoshan metallogenic belt分类
天文与地球科学引用本文复制引用
郑瑜林,周云满,贾福东,张星培,王基元,王利东,崔猛,王瑞,董云涛..金沙江-哀牢山造山带南段长安金矿床成矿物质来源与金属沉淀机制[J].矿床地质,2026,45(4):825-840,16.基金项目
本文得到云南黄金矿业集团股份有限公司博士后科研项目(编号:YNBH24004)、衢州学院博士科研启动项目(编号:KY-QD005223007)、中国有色矿业集团有限公司科技项目青年专项(编号:2023KJZX001)、"江南造山带中段锑金钨矿床找矿预测与勘查示范"(编号:2023YFC2906803)、"湖南雪峰构造带中西段金锑矿关键控矿因素厘定与找矿预测"(编号:HE2454)和"云南典型金多金属矿找矿模型构建及隐伏矿定位预测"(编号:ZKKJ202420-KT02)联合资助 （编号:YNBH24004）
