Research Associates

Paul A. Giesting

Eveline Bowley

Ph.D., 2006 University of Notre Dame, South Bend, IN

Room 3152 SES
Phone (312) 413-1853
giesting@uic.edu

I study crystal chemistry of a variety of minerals and mineral-like crystals.  The physical and chemical consequences of crystal chemistry are varied and sometimes subtle changes have significant effects.

At UIC, I am working with Steve Guggenheim and A.F. Koster van Groos to study the interaction between clay minerals and carbon dioxide, as well as serpentine minerals and carbon dioxide.  We will be using the environmental chambers they have developed to examine clay properties in situ, at conditions of moderately elevated pressure and temperature.  This research could shed substantial light on the feasibility of carbon sequestration in underground reservoirs.  It also represents a significant contribution to clay mineralogy in general, as it has been difficult in the past to study clay properties as they really are under conditions that differ significantly from surface temperature and pressure.

In the past, I have worked on uranyl complex chemistry with Peter Burns at Notre Dame.  My goal was to take and classify crystal structure data in order to make the insights inherent in that data more readily available to geochemists.  Several hundred crystal structures of uranyl complexes with organic ligands have been published.  This data represents a rich resource for geochemists to consider for a variety of questions, notably those involving transport of uranium in groundwater containing organics.  I also synthesized several new uranyl oxalate phases at hydrothermal conditions.  Oxalate is a rectangular ligand that can easily form polymeric complexes, and this tendency appears to be enhanced at somewhat elevated temperatures and pressures.  The sheet-structured complexes I discovered are unlike the looser chain structures that form from solutions at room conditions.

My earliest work was with Anne Hofmeister at Washington University in St. Louis, where we used infrared spectroscopy to estimate the thermal conductivity of garnets.  The peak widths in an IR spectrum are related to the disorder in the crystal caused by, among many things, random distribution of cations on particular sites.  Since garnet-structured phases are major components of the Earth's mantle, the ability to estimate the thermal conductivity of these phases provides valuable evidence for geodynamic models of mantle convection.