Abrasion and quarrying are significant processes of subglacial erosion for ice masses in direct contact with hard substrates, yet their relative efficacy and spatio-temporal variability is unclear. Here, we investigate the glacial impact of these processes on a 70 m by 60 m bedrock surface at Moel Ysgyfarnogod in the Rhinog Mountains, Wales, using a combination of high-resolution digital photographs, ...