REFINEMENTS IN THE NEOGENE DEFORMATION BUDGET OF WESTERN NORTH AMERICA INCORPORATING UPDATES IN REGIONAL GEOLOGICAL STUDIES AND GLOBAL PLATE CIRCUITS

Recent refinements in both global plate circuit reconstructions and regional continental tectonic reconstructions allow us to make some meaningful improvements to the Neogene deformation budgets and displacement models of western United States and northwestern Mexico. For the global circuit, we examine changes in calculated Pacific-North America tracks, giving special attention to the effects of updated scenarios for the Antarctic-African spreading history. In the continental tectonics regime, we review revised estimates of Basin and Range deformation histories (especially the timing and magnitude of the strike-slip overlay), deformation models for the interior Pacific Northwest, new data concerning partitioning of plate motion components around Baja California, and possible timing constraints for Tehachapi rotations. Finally we examine the individual and cumulative effects of these revisions upon western North American deformation models.