The tectonic history of the Canada Basin is poorly understood and the Mesozoic history of the Arctic margin of Alaska & NW Canada is critical to this problem. Magnetic data from the oceanic crust of Canada Basin are ambiguous and cannot distinguish between (1) anticlockwise oroclinal rotation of the northern margin of Alaska away from the Canadian Arctic Islands about a pole of rotation new the MacKenzie delta, and (2) a major left-lateral transform fault to permit the southerly migration of northern Alaska. The two models predict different structural regimes for the eastern Brooks Range, MacKenzie delta, and Black River-Oglivie Mountains regions during the Mesozoic this project will address the problem by structural and kinematic studies along the Porcupine River fault system and adjacent areas. Spatial variations in the geometry of superposed structures will be documented from Precambrian through Cenozoic rocks, and ages of deformation all be established from stratigraphic and igneous intrusion relationships. The results of this study will improve our understanding of the tectonic evolution of the Canada Basin and the adjacent Arctic region, and will also have relevance to oil exploration in the area.