Kai Kristiansen: Pressure Solution - the importance of electrochemical surface potentials
Kai Kristiansen, from the University of California Santa Barbara, will tell us of their results on electrochemical processes in pressure solution using the surface forces apparatus.
“Pressure solution” is a phenomenon that is frequently found in illitic sandstone and is characterized by enhanced quartz dissolution at inter-grain contacts. The origin of pressure solution and many other related dissolution processes remains elusive. We have found an intimate relationship between dissolution rate and the surface potential difference across interfaces of dissimilar materials through experiments using a surface forces apparatus. Based on these results we have developed a electrochemical model of pressure solution phenomena that explains why negatively charged mica surfaces enhances quartz dissolution as observed in various samples of rock diagenesis. Our findings demonstrate that (at low temperature) pressure solution and many other mineral dissolution phenomena are also an electrochemical process rather than a solely pressure-driven process.