9804712 Selverstone The assembly of continental crust of the American west during the proterozoic involves successive accretion of arc material from north to south, with early collision between the Colorado province and the Wyoming province, as marked by 1.4 Ga thrusting. However, new evidence for even earlier polymetamorphism and strike slip translation has raised the possibility of significant complications to these accretion events. This project will pursue these issues with an integrated kinematic, petrologic, geochronologic and isotopic study of the northern Front Range. Results are expected to clarify early accretionary tectonics between the Colorado and Wyoming provinces.