RECONSTRUCTING THE PROPAGATION OF DEFORMATION WITHIN THE CANADIAN ROCKY MOUNTAIN FOLD-THRUST BELT USING LOW TEMPERATURE THERMOCHRONOLOGY

The eastern Canadian Cordillera is the best studied example of a thin-skinned thrust belt and is foundational to our understanding of cordilleran orogenesis. Despite the eastern Canadian Cordillera’s prominence for orogenic models, fault timing and magnitude along the Rocky Mountain fold-thrust belt remains poorly resolved with Late Jurassic to Miocene exhumation identified. We present preliminary zircon fission-track and zircon (U-Th)/He analyses across major thrusts along an E-W transect at the latitudes of Jasper National Park to determine 1) a detailed record of timing and magnitude of fault-associated exhumation and 2) assess whether the fold-thrust belt experienced pulsed or continuous propagation of deformation. Existing low-temperature thermochronological analyses (apatite [U-Th-Sm]/He and fission-track) have identified that the eastern Canadian Cordillera experienced Eocene-Miocene exhumation associated with widespread glaciation, suggesting a need for higher temperature thermochronometers to assess earlier exhumation associated with oceanic slab subduction. Previous studies have applied illite 40Ar/39Ar analysis to fault gauge samples and support four distinct minimum-age pulses of propagation within the Rocky Mountain fold-thrust belt. By creating a multidimensional exhumational evolution, our findings will provide valuable insight into growth of Cordillera systems globally and the debate around deformation propagation.