9805009 Bickford This project is an attempt to follow the process by which collisional orogens become cratonized. The study will focus on plutons and paragneisses from the internal subdivision of the Trans-Hudson orogen. The project will benefit from the Canadian Lithoprobe Seismic transect and will involve extensive isotopic age dating using minerals with various closure temperatures. Results will allow construction of time-temperature cooling curves for the several terranes and the bordering Archean cratons.