A day studying the Weber Sandstone

Today we headed back into Utah to drive through the Sheep Creek Geological Loop, with its magnificent rock exposures ranging from the Uinta Mountain Group (Precambrian) to the Mancos Shale (Cretaceous). I think I counted seventeen formations that we passed through. We made our way to the base of the cross-bedded Weber Sandstone (Pennsylvanian-Permian). The upper part of this unit is thought to be eolian in origin and the lower part a mixture of eolian and marine. We spent some time sampling the Weber at intervals from the bottom to the top of the section. Having completed that task, we travelled on to Dinosaur National Monument, where the Weber Sandstone is again exposed. Although we didn’t have permits to collect in the national park, we did take a short hike along Box Canyon Trail, where we were able to photograph some extraordinary soft sediment deformation in the Weber. The photograph (above) shows some of these deformation features in Box Canyon.