Fluid Inclusion Microscope
Fluid inclusions at The University of Auckland are studied using a Fluid-Inc. adapted USGS heating and freezing stage, mounted on an Olympus BX51IR microscope that is capable of transmitted, infrared, and ultraviolet microscopy. Sample viewing is via the binocular microscope or through a video camera connected to a computer with video capture. The stage is used both to heat (up to 400°C) and freeze (as low as 196°C) the fluid inclusions. Heating of a fluid inclusion determines the temperature of homogenisation (Th), the temperature at which either the liquid or vapour phase homogenises to a monophase liquid or vapour and reflects the minimum trapping temperature of the fluid inclusion. Freezing of the fluid inclusion and measuring the final ice melting temperature (Tm) is used to determine the apparent salinity of the trapped fluid.
The fluid inclusion set up has transmitted, infrared (IR) and ultraviolet (UV) capacities. Transmitted light allows the study and measurement of fluid inclusions in minerals such as quartz and calcite. Infrared permits the measurement of inclusions in sulphide minerals such as sphalerite, stibnite, enargite, tetrahedrite and some wolframite and pyrite. Ultraviolet light is used to identify hydrocarbons in fluid inclusions.
