滇西大坪金矿流体包裹体特征及其地质意义
Fluid Inclusion Characteristics and Geological Significance of the Dianxi Daping Gold Deposit

大坪金矿床是赋存于闪长岩体中的含金多金属硫化物热液石英脉型金矿，矿体呈脉状，三家河断裂、小新街断裂、小寨–金平断裂控制着矿区地层岩性。成矿过程可划分为3个阶段：1) 白钨矿–石英脉阶段；2) 团块状多金属硫化物阶段；3) 碳酸盐–石英脉阶段。石英脉中流体包裹体分为富液相CO₂包裹体、富气相CO₂包裹体、CO₂型包裹体，以CO₂-H₂O包裹体为主。CO₂-H₂O包裹体的完全均一温度236.5℃~379.2℃，盐度为1.74~18.63 wt% NaCl，成矿流体具有中–高温、中–低盐度、富含CO₂并且含有少量N₂的特征，属于CO₂-H₂O-NaCl ± N₂体系，且成矿流体的温度逐渐降低。成矿流体来源复杂，为深源的壳幔混合流体，即成矿流体的主体为深源的流体，后期有浅部的混合流体加入。大坪金矿矿区北部属于造山型金矿，南部属于浅成低温热液型金矿。
The Daping gold deposit is a hydrothermal quartz vein-type gold deposit containing gold-bearing polymetallic sulfides hosted in a diorite intrusion. The ore bodies occur as veins, with the regional stratigraphy and lithology controlled by the Sanjiahe Fault, Xiaoxinjie Fault, and Xiaozhai-Jinping Fault. The mineralization process can be divided into three stages: 1) Scheelite-quartz vein stage, 2) Massive polymetallic sulfide stage, and 3) Carbonate-quartz vein stage. Fluid inclusions in the quartz veins can be classified into liquid-rich CO₂ inclusions, vapor-rich CO₂ inclusions, and CO₂-H₂O inclusions, with CO₂-H₂O inclusions being predominant. The homogenization temperatures of CO₂-H₂O inclusions range from 236.5？C to 379.2？C, and their salinities range from 1.74 to 18.63 wt% NaCl equivalent. The ore-forming fluids are characterized by medium-to-high temperatures, medium-to-low salinities, CO₂ enrichment, and the presence of small amounts of N₂, belonging to the CO₂-H₂O-NaCl ± N₂ system. The temperature of the ore-forming fluids gradually decreased over time. The ore-forming fluids have a complex origin, derived from deep-seated crust-mantle mixed fluids. The main component of the ore-forming fluids is deep-sourced, with later contributions from shallow mixed fluids. The northern part of the Daping gold deposit is classified as an orogenic gold deposit, while the southern part belongs to the epithermal low-temperature hydrothermal gold deposit type.