drumlin

Long streamlined hill created in formerly glaciated areas. Debris (till) is transported by the glacial icesheet and moulded to form an egg-shaped mound, 8–60 m/25–200 ft in height and 0.5–1 km/0.3–0.6 mi in length. Drumlins commonly occur in groups on the floor of glacial troughs, producing what is called a ‘basket-of-eggs’ landscape.

Drumlins are important indicators of the direction of ice flow, as their blunt ends point upstream, and their gentler slopes trail off downstream.