The Laboratory of geofluids and microthermometry deals with the investigation of fluid and melt inclusions in minerals, which represent relics of fluids and melts, from which the minerals crystallize. Fluid inclusions usually contain various daughter minerals, gases and liquids at room temperature. Number of the phases varies with temperature. Precisely determined temperatures of the phase transformations enable the reconstruction of chemical composition and density of the fluid, and formation conditions of the host mineral.
Microthermometric apparatus in our laboratory consists of the LINKAM FTIR600 freezing-heating stage, which enables observations of fluid inclusions in transparent minerals within the interval from -196 to 600 °C. Precision of 0.1 °C in the whole temperature range is achieved by using a platinum resistor sensor. The stage is mounted on a ZEISS Axio Scope.A1 optical microscope equipped with a QImaging MicroPublisher 5.0 RTV digital camera and a set of long-working distance lenses enabling observations of objects as small as few micrometers in size. The programmable stage is commanded by a LCD touch pad or computer using the Linksys 32 software, which precisely controls the flow of liquid nitrogen as well as the function of heating block, thus enabling the absolute control on the temperature and heating/cooling rates. The stage can also be used for acquiring Raman spectra of daughter minerals and gases (CO2, N2, CH4, H2S, H2) at room temperature, and those of gas clathrates and salt hydrates originating by the reaction of gases and salts with aqueous liquid on cooling.