Evidence that large continental blocks have been subducted to depths in excess of 100 km, poses a challenge to present geodynamic and geochemical paradigms, and understanding the exhumation of ultrahigh pressure rocks in orogenic belts is also not well understood. This project will examine ultrahigh pressure rocks in the Scandanavian Caledonides where subsequent tectonic overprints have not obscured the high pressure history, existing and new tectonic models will be evaluated by constructing pressure-temperature-deformation-time histories of key thrust nappes and their bounding faults. In combination with data from other ultrahigh pressure examples, results of this work are expected to help clarify the phenomena of deeply subducted continental crust and its return to the surface in the context of subduction geodynamics. ***
