de Geer moraine A type of moraine landscape that consists of a series of separate, narrow ridges trending parallel to a former ice front, and which can form annually. The ridges may be up to 300 m apart and up to 15 m high. Each ridge consists typically of a till core, capped by a layer of partly rounded boulders. This landscape may have formed beneath the grounded part of an ice sheet that extended into a lake or sea. It was first described by the Swedish geologist Gerard Jacob de Geer (1858–1943).

de Geer moraine A type of moraine landscape that consists of a series of separate, narrow ridges trending parallel to a former ice front, and which can form annually. The ridges may be up to 300 m apart and up to 15 m high. They consist typically of a till core, capped by a layer of partly rounded boulders. This landscape may have formed beneath the grounded part of an ice sheet that extended into a lake or sea. It is named after an early Swedish geologist.