LOCALIZED STRAIN ORIENTATIONS EXPOSED IN FOOTWALL SYNCLINE OF BIG BEND NATIONAL PARK

Dog Canyon of Big Bend National Park in Brewster County, Texas exposes a cross section of the footwall syncline of a Laramide backthrust fault. The hinge zone of the syncline is almost entirely exposed and therefore provides a record of zone-specific strain that is atypically complete. Micro- and meso-scale structures at ground level reveal localized strain orientations but the structures exposed higher than ground level allow a complete interpretation of the range of strain ellipses in the rest of this hinge zone. These are for the first time accessed and mapped via top-roping and rappelling, and presented for both sides of the same drainage exposure.