My research primarily involves field-based studies of Precambrian igneous and metamorphic rocks, including application of petrologic and geochemical information to deduce the typically complex evolution of such rocks and the terranes in which they occur. My current work involves field and petrologic studies of Mesoproterozoic basement rocks and Neoproterozoic metavolcanic rocks exposed near Mount Rogers in southwestern Virginia. Investigations include detailed field mapping, petrologic and geochemical characterization, and in situ trace-element geochemical analyses of zircons dated by U-Pb isotopic methods. These studies are undertaken in collaboration with colleagues from the U.S. Geological Survey. A recent focus of our work involves detailed SHRIMP (sensitive high resolution ion microprobe) analysis of trace-element compositions in Precambrian zircons that have been dated using standard SHRIMP isotopic techniques. These studies are designed to elucidate the geochemical and petrologic mechanisms of zircon formation in polymetamorphosed rocks of igneous origin. Undergraduate students play an active and key role in all of my research-related activities.