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兰坪盆地西部发育大量沉积岩容矿的Cu-Ag-Pb-Zn多金属矿床,矿体的分布受逆冲推覆系统控制。逆冲推覆系统根部带主要发育脉状Cu-Ag(Mo)矿床(包括金满Cu-Ag、连城Cu-Mo及一系列脉状Cu矿床);前锋带主要发育Pb-Zn-Ag(±Cu)矿床(包括白秧坪Pb-Zn-Ag-Cu多金属矿集区及一系列小型的Pb-Zn矿床)。文章系统分析了盆地西缘Cu-Ag(±Pb-Zn)多金属矿床流体包裹体及C、H、O同位素特征进行了根部带Cu和前锋带Pb-Zn矿床成矿流体的对比研究,探讨了盆地西缘Cu-Ag(±Pb-Zn)多金属矿床成矿流体的性质、来源及演化。研究表明,根部带的CuAg(Mo)多金属矿床成矿流体主要为与围岩充分交换的深循环大气降水,具有富CO2、中高温(集中在280~340℃)、中低盐度w(Na Cleq)(1%~4%)的特点;前锋带Pb-Zn-Ag(±Cu)多金属矿床成矿流体则主要为源于大气降水的盆地卤水,具有贫CO2、中低温(集中在160~240℃)、中高盐度w(Na Cleq)(集中于22.0%~24.0%)的特点。
Large amounts of sedimentary-graded Cu-Ag-Pb-Zn polymetallic deposits are developed in the western Lanping basin. The distribution of orebodies is controlled by the thrust-nappe system. The main belt of the thrust-nappe system is mainly composed of Cu-Ag (Mo) deposits (including Jinman Cu-Ag, Liancheng Cu-Mo and a series of vein Cu deposits) Cu deposits, including the Pb-Zn-Ag-Cu polymetallic ore deposits in Baiyangping and a series of small Pb-Zn deposits. This paper systematically analyzes the fluid inclusions and C, H, O isotopic characteristics of the Cu-Ag (± Pb-Zn) polymetallic deposits in the western margin of the basin. The Characteristics, Origin and Evolution of Ore-forming Fluids in Cu-Ag (± Pb-Zn) Polymetallic Deposits in the Western Margin of the Basin. The results show that the ore-forming fluid of CuAg (Mo) polymetallic deposits in the root zone is mainly the deep-cycle atmospheric precipitation which is fully exchanged with the surrounding rock and has rich CO2, medium and high temperature (concentrated at 280 ~ 340 ℃) Na Cleq) (1% ~ 4%). The Pb-Zn-Ag (± Cu) polymetallic deposits in the foreland are mainly derived from basin brine derived from atmospheric precipitation, 160 ~ 240 ℃) and Na Cleq (22.0% ~ 24.0%).