投稿时间：2024-01-12
修订日期：2024-06-12
网络发布日期：2024-08-23
中文摘要:金盆梁是南秦岭柞水-山阳矿集区勘查的一处微细浸染型金矿床，矿床成因与成矿机制尚不清楚。矿体产于上泥盆统桐峪寺组粉砂质板岩和钙质板岩中，以浸染状、脉状金锑矿化为主，成矿过程可划分为3个阶段：毒砂-黄铁矿-硅化阶段（Ⅰ）、石英-辉锑矿-白铁矿±锑氧化物阶段（Ⅱ）和方解石-石英阶段（Ⅲ）。流体包裹体及C-H-O-S-Pb同位素研究结果显示，Ⅱ阶段主要为金锑矿化，以H2O-NaCl两相包裹体占绝对优势，成矿流体属于中温（200~290℃）、低盐度（w(NaCleq)为0~6.0%）、低密度（0.64~0.99 g/cm3）的H2O-NaCl±CO2体系，以循环大气降水为主。无矿化的Ⅲ阶段主要发育H2O-NaCl两相包裹体，含少量CO2-H2O-NaCl±CH4、纯CO2±CH4及含子晶多相包裹体，流体以中低温（140~280℃）、低盐度（w(NaCleq)为2.0%~8.0%）、低密度（0.68~1.02 g/cm3）的富CO2-H2O-NaCl±CH4体系为主，或存在少量高温、高盐度、高密度H2O-NaCl体系的岩浆热液混入。硫化物δ34S值为较大负值（−12.50‰~−10.20‰），Pb同位素组成具上地壳源铅特征，成矿物质主要来源于围岩地层。综合研究表明，金盆梁金矿的成因类型属于卡林型金矿，水-岩反应（围岩硫化作用）是金富集沉淀的主要机制。
中文关键词:矿床成因 流体包裹体 C-H-O-S-Pb同位素 金盆梁金矿床 南秦岭
Abstract:The Jinpenliang is an explored micro-disseminated gold deposit in the Zhashui-Shanyang ore cluster area, South Qinling. To date, its ore genesis and metallogenic mechanism are still unclear. These Au-Sb orebodies at Jinpenliang deposit are hosted by the silty slate and calcareous slate of the Upper Devonian Tongyusi Formation, occurring as disseminated and veinlet mineralization. The ore-forming process can be classified into three stages, namely, arsenopyrite-pyrite-silicification stage (Ⅰ), quartz-stibnite-marcasite±antimony oxide stage (Ⅱ), and calcite-quartz stage (Ⅲ). Fluid inclusion and C-H-O-S-Pb isotope studies indicate that inclusions in stage Ⅱ quartz (Au and Sb mineralization) are dominated by the H2O-NaCl two-phase inclusions. The metallogenic fluid is characterized by a medium-temperature (200~290℃), low-salinity (w(NaCleq)=0~6.0%), and low-density (0.64~0.99 g/cm3) H2O-NaCl±CO2 system, predominately originated from meteoric water. Besides the H2O-NaCl two-phase inclusions, there are a small amount of CO2-H2O-NaCl±CH4 inclusions, pure CO2±CH4 inclusions, and daughter mineral-bearing multiphase inclusions identified in quartz of stage Ⅲ barren veins. This nonmetallogenic fluid primarily belongs to a medium to low-temperature (140~280℃), low-salinity (w(NaCleq) 2.0%~8.0%), and low-density (0.68~1.02 g/cm3) CO2-H2O-NaCl±CH4 system, with a high-temperature, high-salinity, and high-density H2O-NaCl system of magmatic water mixed in. The δ34S values of sulfides range from −12.50‰ to −10.20‰, and the Pb isotopic compositions have the characteristics of the upper crust, implying that the ore-froming materials were mainly derived from wall rocks. Comprehensive studies show that the Jinpenliang deposit can be classed as a typical Carlin-type gold deposit, and the water-rock reaction (sulfidation) is the crucial mechanism for gold precipitation.
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基金项目:本文得到陕西省自然科学基础研究计划资助项目（编号：2023-JC-QN-0284, 2024JC-YBQN-0349）、国家自然科学基金重点项目（编号：42130804）、中国地质调查局项目（编号：DD20220966、DD20230060、DD20230378）、新疆维吾尔自治区重点研发计划项目（编号：2023B03016）和新疆维吾尔自治区“天池英才”引进计划项目联合资助
引用文本：
葛战林,顾雪祥,章永梅,高永宝,郝迪,郑艳荣,刘明,王辉.2024.南秦岭柞水-山阳矿集区金盆梁金矿床成因——来自流体包裹体及C-H-O-S-Pb同位素的制约[J].矿床地质,43(4):877~898GE ZhanLin,GU XueXiang,ZHANG YongMei,GAO YongBao,HAO Di,ZHENG YanRong,LIU Ming,WANG Hui.2024.Genesis of Jinpenliang gold deposit in Zhashui-Shanyang ore cluster area, South Qinling: Constraints from fluid inclusions and C-H-O-S-Pb isotopes[J].Mineral Deposits43(4):877~898
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