9418264 Gromet The Scandinavian Caledonides provide an unusual opportunity to study events and processes associated with a continental collision because it is relatively simple, involving a single orogenic cycle, and is eroded so that both allochthonous and autochthonous rocks are exposed. This project, in conjunction with researchers in Norway and Sweden, is directed at providing improved time constraints on tectonic processes such as subduction leading to high-pressure metamorphism and assembly of a tectonostratigraphy by major thrust imbrication. Detailed geochronlogic studies will use high-precision U-Pb and other methods to directly date metamorphism and deformational fabrics in key areas. Results, along with field structural studies, will lead to more precise understanding of the development of this classic orogen.