The Pacific northwest consists of a number of exotic terranes that were accreted to the continental margin beginning in the Cretaceous, however the tectonics and timing of the assembly is controversial. This renewal of a collaborative project will address the mechanics and processes of mid- Cretaceous Orogeny in the southeast Coast Plutonic Complex of British Columbia and its extension in the Crystalline Core of the North Cascades of Washington. Models of orogenesis to be tested include bulk shortening, transpressive thrusting, contractional thrusting and magmatic accretion. Evaluation of these models will utilize mineral thermobarometry, fabric analysis and U-Pb Zircon geochronology and pertains to a larger view of the orogen as either a collisional welt related to terrane accretion, or as a complex Andean-type magmatic arc developed on the edge of the North American craton.
