The applicant would use the fellowship in a geological investigation of the partial melting of middle-to-lower crust and emplacement of granites in the upper crust in the Fosdick Mountains, Antarctica. The role of melt and the behavior of the crust is recorded in migmatite gneiss domes, which are culminations of exhumed gneissic rocks, and provide an exceptional opportunity to investigate the process of melting and its effect on the stabilization of the continental crust. The Fosdick Mountains are not only one of the world's best exposed gneiss domes, but also have extensive fresh outcrops of middle-to-lower crust that has been exposed by deglaciation only within the past 9000 years, and consequently has not been overprinted by subsequent events. The specific work to be done includes determining the pressure-temperature path and the rate of exhumation for rocks within and around the dome, assess the role of melting in the evolution of the dome, and determine the emplacement mechanisms for the dome. The expected results from this work will critically test the two hypotheses or the origin of gneiss domes (i.e. "active diapiric rise" and "passive response to transtension/extension"), and will make a fundamental contribution to our understanding of the significance of crustal melting in the evolution of continental crust over time.
