Fluid Inclusion Microthermometry
The determination of temperatures of phase changes within fluid inclusions during heating and cooling of samples is termed microthermometry. The technique is invaluable for discovering the temperatures at which minerals form, the thermal history a rock has experienced, and the compositions of the fluids that traversed a rock in its history. The fundamental principles upon which microthermometry is based are the principles of phase equilibria introduced in Chapter 3. And, as explained in Chapter 6, it is best to first spend a considerable amount of time and effort to characterize the fluid inclusion petrography prior to attempting microthermometry. This chapter elucidates useful philosophical approaches and important practical procedures that, if learned and employed, will ensure successful and efficient microthermometric studies. Also, phase changes for some simple but potentially applicable fluid systems common in the diagenetic realm will be described.