中文摘要:新疆哈图金矿床赋存往石炭系基性火山岩-火山碎屑岩中,矿体受古火山口断裂系控制。矿脉内流体包裹体较为丰富,主要为气液相\JaCl-H2O)包裹体和少量的NaCl-CO2-H2O包裹体。成矿热液中富含CO2、N2、Na+、K+、Cl-和SO42+,而所含的成矿元素以Au-As-Ag-Sb组合为特征。成矿热液为低盐度流体,丰成矿阶段的盐度为4.1 wt%~6.3 wt% NaCl,密度为0.88~0. 80 g/cm3,fO2为10-35~10-31Pa,Eh为0. 60~0.80 eV,为还原环境。金沉淀成矿的最佳温度为230~260℃。哈图金矿成矿热液不是典型的岩浆热液,而是受到了古大气水混入的火山晚期热液。流体不混溶、水-岩反应及占人气水的混入是造成本区金沉淀成矿的主要因素。
Abstract:The Hatu gold deposit is located in western Junggar of Xinjiang, adjacent to Kazakhstan, lying in north limb of Dalabute synclinorium of Junggar Hercynian folding belt. Wall rocks of the deposit arc lower Carboniferous basalt-pyroclastic rocks. Orcbodies are controlled by fault system of the old crater. Two ore types, quartz vein and altered rock, have been found in the mine. The ore veins contain abundant fluid inclusions, which are mainly two phase gas-liquid NaCl-H2O and three phase NaCl-CO2-H2O with liquid CO2, Ore-forming fluids are rich in CO2, N2, Na+, K+, Cl- and SO42-, but merely contain simple ore-forming elements characterized by Au-As-Ag-Sb. Ore-forming fluids are of low salinity. In the main mineralizing stage , salinity is 4.1 wt% - 6.3 wt% NaCl equiv., density 0.88 g/cm3. fO2 10-35~10-31 Pa, and Eh 0.60~0.80 eV. The fluids in the inclusions have a wide range of homogenization temperatures from 160℃ to 360℃, but the best temperature range for gold deposition is from 230℃ to 260℃. Quartz from auriferous veins has δ18O values ranging from 15.4‰ to 17.5‰. Calculated δ18O andδD values for the ore-forming fluids range from 6.0‰ to 11.7‰ and -86‰ to -111‰, respectively, suggesting derivation from later volcanic fluids mixed with meteoric water. Fluid immiscibility and fluid-rock interaction may be the main causes for gold deposition in the mine.
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基金项目:国家305项目(85-902-02-01)
引用文本:
范宏瑞, 金成伟, 沈远超.1998.新疆哈图金矿成矿流体地球化学[J].矿床地质,17(2):135~149.1998.Ore-forming fluid geochemistry of the Hatu gold deposit in Xinjiang northwest China[J].Mineral Deposits17(2):135~149
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