气液包裹体气相色谱分析及其地质意义

矿物中气液包裹体的气体成分的研究,对于了解岩石矿床的形成条件及指导找矿有重要意义。为此我们改造了国产SP2305型气相色谱仪,使它适用于包裹体的气体分析,得到较好的效果。用这种设备,我们曾对几个火山岩铁矿、变质铁矿和热液矿床进行了研究,并获得初步结果。

GAS CHROMATOGRAPHIC ANALYSIS OF FLUID INCLUSIONS AND THEIR GEOLOGICAL SIGNIFICANCE

This paper introduces a technique of measuring gases and water from inclusions by Sp 2305 gas chromatograph made in China.According to the studies of gas composition of inclusions in some volcanic and sedimentary-metamorphie iron ores and hydrothermal deposits,the results obtained are reflected in following there exist two extreme types of inclusions,of which one is high in content of CO,H₂ and CH₄ and the other is poor or little in CO,CH₄ and or H₂.The former formed in the reductive atmosphere and the latter is the oxidative atmosphere.Under a reductive condition,the variable valence elements are hardly to give high-oxidized minerals,such as hematite,whereas under a oxidative condition,they hardly to form low-oxidized minerals,such as magnetite.It is proposed that reduction parameter can be used as a scale measuring the reduction capability.The reduction parameters are defined as a proportion of total reducible gas (Mol) to CO₂ Mol.The greater the proportion,the higher the reduction capability and vice versa The relationship between reduction parameters and ore-forming depth and associated mineral is also discussed herein.