Fluid inclusion analysis has the potential to provide some of the clearest data regarding the chemical and physical processes that result in mineral growth, deformation, and recrystallization. The purpose of this chapter is, first, to briefly introduce microthermometry, the most common analytical technique used to gain information from fluid inclusions and second, to discuss how to model and interpret the analytical data. The well-informed user must understand both how the data are gathered and how calculations are made. A detailed summary and critique of various analytical techniques and the thermodynamic data for the various chemical systems is beyond the scope of this chapter. The interested reader will need to follow up on the references throughout the text. However, what follows provides a solid basis to evaluate and interpret publications that use fluid inclusion data to constrain geochemical, geological and geophysical processes.
In the previous chapter, Shepherd and Rankin reviewed a variety of analytical techniques to determine the chemical and isotopic composition of either individual fluid inclusions or whole populations of inclusions in a sample. In this chapter, I will review microthermometry, the most widely used technique, and discuss how to interpret the data obtained with this method. The following Glossary defines several phase equilibria terms and abbreviations used in the sections that follow.