湘东大垄铅锌矿床成矿机理

摘要

Dalong Pb-Zn deposit is located in the southeast of the middle Fanglou NNE structural belt of Neocathaysian structural system and the north head of the Dengfuxian composite granite. Ore occurrence is controlled by south-north faults. Through the electron microprobe analysis, fluid inclusions and S, Pb, H, O isotope characteristics research, the source of ore-forming materials, ore-forming physicochemical conditions were analyzed, and the ore deposit genesis and metallogenic process were discussed. The results indicate that the formation of ore bodies is closely related to the Yanshanian magmatic activity; the ore-forming materials have the feature of crust-mantle mixing; the ore-forming fluid is mainly derived from magmatic water, but with the mixing of atmospheric precipitation; the metallogenetic temperature is low-medium temperature; the ore-forming fluid is weak alkali, weak oxidizing environment, and late it transforms to low temperature and low oxygen fugacity of low sulfur fugacity environment; the metallogenetic depth is shallow-moderate depth. Dalong Pb-Zn deposit belongs to low-medium temperature magmatic hydrothermal deposit relating to the Yanshanian magmatic activity.%大垄铅锌矿床位于湘东新华夏构造体系中坊楼北北东向构造带中部南东侧,邓阜仙复式岩体北端,矿体受南北向断裂控制.通过电子探针、流体包裹体和 S、Pb、H、O 同位素研究,分析矿床的成矿物质来源、成矿物理化学条件,探讨矿床成因及成矿过程.结果表明:矿床的形成与燕山期岩浆活动密切相关,成矿物质具有壳幔混合的特征,成矿流体主要源于岩浆水,有大气降水的加入;成矿温度属于中低温,成矿初期流体处于弱碱性、弱氧化的环境,后期向低温、低氧逸度、低硫逸度的环境转换,成矿深度为中深成.综合认为大垄铅锌矿床属于与燕山期岩浆活动有关的中低温热液铅锌矿床.