摘要
山西右玉火烧滩金矿床位于乌拉山—大青山矿集区东南部,了解其成矿流体特征以及金的迁移和沉积过程不仅有助于在该地区开展下一步的找矿工作,同时可为研究同类型矿床提供理论指导意义。为了解决上述问题,本文开展矿床地质特征以及石英流体包裹体的温度、压力、盐度和密度的研究。野外地质调查和工程勘查结果显示研究区矿体空间产出状态与韧性剪切带一致,矿石类型为构造蚀变岩型。流体包裹体特征显示包裹体以气液包裹体和气体包裹体为主,少量为气液固流体包裹体;成矿流体总体具有中—高温(160~400℃)、低盐度(0~10%)、低密度(0.741~1.107 g/cm^(3))的特点。此外,该矿床成矿压力均值为46.2 MPa,深度均值为3.66 km。结合本文结果和前人研究,认为金的迁移和沉淀与韧性剪切带(脆性构造)提供热液通道、总硫含量降低、温度和压力的降低、氧逸度的增加、水-岩反应、不混溶作用等因素有关。火烧滩金矿的形成与三叠纪区域性脆性伸展作用和成矿热液沿近EW展布的韧性剪切带活动有关。
The Huoshaotan gold deposit in Youyu County of Shanxi Province is located in the southeast of the Wulashan-Daqingshan gold district.The characteristics of ore-forming fluids and the gold migration and precipitation mechanisms not only play an important role in carrying out the next step of mineral exploration in the region,but also provide the theoretical guidance for studying the similar mineral deposits.To address the above-mentioned issues,we conduct the studies of the geological characteristics of mineral deposits and the temperature,pressure,salinity,and density of fluid inclusions in quartz.The results of the field geological investigation and the engineering exploration show that the attitude of the ore bodies is consistent with the ductile shear zone in the study area,and the ore type belongs to the structural altered rock type.The characteristics of fluid inclusions in quartz indicate that the inclusions consist of the gas-liquid inclusions and gas inclusions with a few gas-liquid-solid fluid inclusions.The ore-forming fluids are mainly characterized by the medium-high temperature(160-400℃),low salinity(0-10%),and low density(0.741-1.107 g/cm^(3)).In addition,the average pressure and depth of mineralization are limited to 46.2 MPa and 3.66 km,respectively.Integrated with our results and previous studies,we deem that the migration and precipitation of gold is related to the numerous factors,such as the hydrothermal channels provided by the ductile shear zones(brittle structure),the total sulfur concentration decrease,the reduction of temperature and pressure,the increase of oxygen fugacity,the fluid-rock reactions,the fluid immiscibility.The formation of the Huoshaotan gold deposit is related to the Triassic regional brittle extension and the activities of the ore-forming fluid along the ductile shear zone.
作者
陈志方
毕文军
王昊
李杰
张德会
刘宁强
白阳
谢晋强
马坤元
田毓仁
王超
CHEN Zhifang;BI Wenjun;WANG Hao;LI Jie;ZHANG Dehui;LIU Ningqiang;BAI Yang;XIE Jinqiang;MA Kunyuan;TIAN Yuren;WANG Chao(Shanxi Province Key Laboratory of Metallogeny and Assessment of Strategic Mineral Resources,Taiyuan 030006,Shanxi,China;Shanxi Institute of Geological Survey Co.,Ltd.,Taiyuan 030006,Shanxi,China;College of Geological and Surveying Engineering,Taiyuan University of Technology,Taiyuan 030024,Shanxi,China;School of Earth Science and Resources,China University of Geosciences,Beijing 100083,China;Shanxi Huaye Survey Engineering Technology Co.,Ltd.,Taiyuan 030032,Shanxi,China;Jincheng Institute of Technology,Jincheng 048009,Shanxi,China)
出处
《矿产勘查》
2025年第7期1663-1675,共13页
Mineral Exploration
基金
山西省基础研究计划(202103021223120,202303021212041)
山西省地质勘查基金项目“山西省右玉县后窑子—火烧滩金矿外围普查”(2018-3)联合资助。
关键词
火烧滩金矿床
流体包裹体
金的迁移与沉淀
Huoshaotan gold deposit
fluid inclusions
gold migration and precipitation
