Small-scale landforms of glacial erosion—usually less than 1 m in width and depth—on glaciated bedrock surfaces. Sichelwannen are sickle-shaped bedrock depressions, with an open end pointing in the direction of ice flow, and are the most common (Glasser and Bennett (2004) PPG 28, 1). See Shaw (1994) Sed. Geol. 91. The term ‘s-form’ applies if a glacial meltwater origin can be established.