湖南康家湾矿区铅锌与金共生分异机制研究 ——来自单个流体包裹体LA-ICP-MS原位分析的约束

铅锌矿床常与金矿床共生或伴生，Pb-Zn-Au成矿元素组合在同一矿床中也较为常见，但这三种元素共生分异机制尚不清楚。石英及单个流体包裹体LA-ICP-MS成分分析技术能准确获取不同成矿阶段的流体组分，为示踪流体来源及演化过程，进而揭示元素共生分异机制提供了重要手段。本项目拟以铅锌金共生的大型金矿—湖南康家湾矿区为研究对象，在详细的野外调研和室内研究的基础上，系统地对不同成矿阶段的矿石矿物和脉石矿物开展单个流体包裹体LA-ICP-MS成分分析，同时辅以石英LA-ICP-MS微量元素分析、流体包裹体显微测温和稳定同位素分析，旨在查明成矿流体的性质和来源，精细刻画成矿流体演化过程及矿石沉淀机制。该项目的开展，对于进一步揭示该矿铅锌与金的共生分异机制，丰富铅锌金成矿理论，指导类似矿床的找矿，均具有十分重要的意义。

In spite of the intimate connections between the lead-zinc deposits and the gold deposits, the widely-recognized Pb-Zn-Au association in the same deposit, the paragenesis mechanisms between Pb-Zn and Au are still unclear. The chemical compositions of different-stage hydrothermal solutions can be precisely acquired by the LA-ICP-MS analysis on hydrothermal quartz and/or on the individual fluid inclusion hosted in various hydrothermal minerals, which can provide an effective tool for ascertaining the origin and the evolution of the ore-forming fluid, and further revealing the mechanism of element paragenesis and separation. The large-sized Kangjiawan Au deposit accompanying with the significant Pb-Zn mineralization, has been chosen as a studying target in this program. Based on the detailed field and indoor observation, the LA-ICP-MS analysis is systematically carried out on individual fluid inclusions hosted in different-stage ore and gangue minerals, in combination with the LA-ICP-MS analysis on quartz, and fluid and isotope researches, this study aims to reveal the characteristic of the ore-forming fluid, to trace the source of the ore-forming fluid, and to elaborately delineate the ore-forming process and the ore precipitation mechanism. This study will help to promote the further understandings for the paragenesis and separation mechanism between Pb-Zn and Au, and to enrich the metallogenic theory for the Pb-Zn mineralization and Au mineralization, and to provide theoretical guidance for the prospecting of similar deposits.