Geochemistry and Petrology
High temperature petrology and geochemistry at Illinois focuses on understanding the rates, time scales and mechanisms of melting and differentiation of the Earth’s magmas. Prof. Craig Lundstrom’s group attacks petrologic problems from multiple angles, including laboratory experiments at high pressure and temperature and high precision isotopic analysis using our newly installed multi-collector ICP-MS. One emphasis has been to use uranium series (U-series) disequilibria techniques to constrain the duration of magma ascent through the mantle as well as the changes occurring as magmas diversify their composition in the crust. For instance, one current PhD project examines how melting rates beneath convergent margin volcanoes vary with subduction rate while another recently completed project combined experiments and U-series work to understand the production of a near constant composition lava erupted continuously at Arenal volcano, Costa Rica. A recently funded NSF project breaks new ground by combining laboratory experiments examining diffusion with high precision isotopic analyses of “non-traditional isotope systems” such as Mg, Fe and Si to understand the origin of Earth’s plutonic rocks. This work thus has implications ranging from understanding the origin of Earth’s magmatic diversity to providing a new explanation for the origin of the continental crust.
Low-temperature geochemistry at Illinois focuses on reactions that take place near the Earth's surface, particularly in groundwater. Prof. Tom Johnson has been focusing on isotopic systems in groundwater, and on the behavior of contaminants both in response to physical conditions and in response to microbial activity. His research incorporates use of the Department‘s ICPMS facility. Prof. Craig Bethke developed Geochemist‘s Workbench™, a program that calculates the consequences of rock-water interaction as groundwater flows through basins. More recently, Craig has been studying how subsurface microbes control the distribution of metal and metalloid contamination.
- Prof. Steve Altaner clay mineralogy
- Prof. Craig Bethke geochemical and biogeochemical reaction-path modeling
- Prof. C.Y. Chen petrology, hotspots
- Prof. Tom Johnson isotope hydrogeology
- Prof. Craig Lundstrom uranium series disequilibria, rates of magmatic processes
- Dr. Michael Stewart Stable isotope and trace element geochemistry of basaltic systems
