THE ROLE OF FLUIDS IN GEOLOGICAL PROCESSES

The role and behavior of fluids in hydrothermal and magmatic environments have been studied. Experimental studies have been carried out to determine fluid properties, in natural environments and in both synthetic and natural fluid and melt inclusions. One of these studies dealt with the effect of composition on the critical P-T-X properties of aqueous salt solutions approximated by the H2O-NaCl-KCl-CaCl2 system. The results indicate a systematic variation in critical properties as a function of composition over the range of P-T-X studied. A technique for analyzing individual H2O-CO2 inclusions using Raman spectroscopy has also been developed. The resulting empirical equation relating Raman intensities and composition is valid for compositions ≤50mol % CO2. The technique has been applied to H2O-CO2 inclusions from the Butte, MT Porphyry Cu-Mo deposit and the results agree with compositions estimated from microthermometric and petrographic observations. The aim of another study was to study water loss from melt inclusions durin