The Appalachians record is a classic example of mountain building, and there is present agreement that they owe this existence to accretion of fragments of continents and island arcs to North America during the Paleozoic. However, critical aspects of the evolution of the range remain enigmatic or controversial, especially the actual timing of various events. This project, conducted by workers at the University of Tennessee and Vanderbilt University, aims to provide new timing constraints for events using new techniques that have the potential of producing age data from regions having complex, high-temperature growth episodes. These overprints can not be resolved with conventional techniques, but new ion probes dating of overgrowths on zircon crystal appear to be successful. These new data are expected to answer or constrain several major uncertainties in the Southern Appalachians.
