This study will focus on the regional metamorphism and deformation of Precambrian basement rocks in the central Transantarctic Mountains of Antarctica. These rocks are significant because they comprise some of the only high-grade basement terrains exposed in the Transantarctic Mountains which represent a part of the ancient East Antarctic craton. As such, their petrogenesis and tectonic evolution are important for a better understanding of how the paleo-Antarctic craton evolved and how the supercontinent Gondwana formed. The position of these rocks near the edge of cratonal West Antarctica provides a unique opportunity to study the relation between the tectonic elements of the Archaen and Proterozoic shield, and younger crustal elements formed along a convergent Antarctic plate boundary. This integrated study of deformed Precambrian metamorphic terrains will involve: 1) detailed field geologic mapping and sampling; 2) structural, microstructural, kinematic and fabric analysis; 3) metamorphic petrology and quantitative geothermobarometry involving both major element exchange and oxygen isotope techniques; and 4) isotopic geochronometry. The duration of the proposed project is three years, including field seasons during the first two years.