Fluid inclusions are the only direct records of paleo-fluids, and provide insight into the physical and chemical feature of geological process. In research of hydrothermal ore deposits, fluid inclusions are the best tools to reveal the features of ore-forming fluids. Regular studies of fluid inclusion in hydrothermal deposits are focused on gangue minerals which are transparent under visible light, however, fluid inclusions in ore minerals are thought to record ore-forming fluids more directly and accurately. Considering most ore mineral are opaque in visible light,fluid inclusions studies of them need to use the microscope with infrared imaging system. In recent 20 years, there has been much progress in the research of infrared microthermometry of fluid inclusions in opaque minerals, but some problems that remain unresolved limit the develop of it. Meanwhile it is still at initial stage in China now, without much research examples and systematic discussion, although several infrared microscopes having been established. Therefore, it is necessary to summarize the research and discuss the existing problems to promote its development in China. This paper introduces the infrared microscope,basic principles and sample preparation at first. Then it summarizes the factors that influence the transparency of opaque minerals under infrared light. Moreover, discussions of the main problems and predicaments encountered in previous studies are given and a feasible test method that can solve the difficulty of determining of phase change during microthermometry and avoid the possible devotion of temperature of phase changes caused by infrared light is proposed. Finally, this paper states the current situation and prospects of application of the infrared microscope in ore deposits researches.
Peng Hongwei Fan Hongrui Qiu Zhengjie Liu Xuan . Infrared microthermometry of fluid inclusions in opaque minerals：Progress，existing problems and solutions[J]. Chinese Journal of Geology, 2017, 52(3): 895-914.