Photos of flow breccia in Central Plateau Member rhyolites in Yellowstone National Park

Photos of flow breccia in Central Plateau Member rhyolites in Yellowstone National Park. A) Flow breccia observed in a drill core from the Lower Geyser Basin. The angular, light-colored clasts are fragments of the original lava carapace, broken and incorporated into the flow as it advanced. B) Flow breccia exposed in a road cut along Firehole Canyon Drive. The size of the breccia blocks varies significantly between both of these examples, illustrating the diversity of size and texture produced during emplacement. Photographs by Drew White (Colorado State University), taken in January 2025 (A) and Lauren Harrison (Colorado State University), taken in May 2024 (B).