This award will support collaborative research between Dr. David Crerar, Princeton University, and Dr. Jacques Schott, Laboratoire de Geochimie, University of Paul Sabatier, France. The objective of this research is to study the dissolution rates and reaction mechanisms of minerals such as calcite, fluorite, quartz and feldspar in water from 25 degrees to over 400 degrees Centigrade. In this joint project, the hydrothermal laboratories at Princeton University will be used to measure mineral reaction rates, and their variation with solution composition and degree of crystal strain. The reacted crystals will then be analyzed by surface spectroscopic techniques in Toulouse and affiliated French laboratories to provide detailed information on reaction processes at mineral surfaces and the kinetic mechanisms of mineral reactivity. This work has application to understanding formation of mineral deposits under non-equilibrium conditions typical of upper crystal processes and should provide insight into the behavior of fluids and mineral in projected radwaste repositories. The research by the Princeton and Toulouse groups has been complementary, with Princeton concentrating on hydrothermal dissolution rates and processes, and Toulouse on lower-T surface reaction mechanisms. This project will combine their expertise in mineral reaction kinetics and allow the U.S. group to use high technology surface spectroscopic and analysis facilities not otherwise available to them.
