Drumlin

Drumlins around Horicon Marsh, Wisconsin, in an area with one of the highest concentration of drumlins in the world. The curved path of the Laurentide Ice Sheet is evident in the orientation of the various mounds.
Elongate and forested drumlins south of Puerto Williams, Chile. Flow direction here was at time of formation from west to east (left to right on picture).

A drumlin, from the Irish word droimnín ("little ridge"), first recorded in 1833, in the classical sense is an elongated hill in the shape of an inverted spoon or half-buried egg[1][2] formed by glacial ice acting on underlying unconsolidated till or ground moraine. Assemblages of drumlins are referred to as fields or swarms;[3][4] they can create a landscape which is often described as having a 'basket of eggs topography'.[5]

  1. ^ Menzies(1979) quoted in Benn, D.I. & Evans, D.J.A. 2003 Glaciers & Glaciation, Arnold, London (p431) ISBN 0-340-58431-9
  2. ^ Bryce, James (1838). "On the evidences of diluvial action in the north of Ireland". Journal of the Geological Society of Dublin. 1: 34–44. hdl:2027/mdp.39015035541435. Originally presented in 1833 by Irish geologist James Bryce (1806–1877). From p. 37: "This peculiar form is so striking that the peasantry have appropriated an expressive name to such ridges; while Knock, Sleive, Ben, have each their peculiar significations, the names Drum and Drumlin (Dorsum) have been applied to such hills as we have been describing."
  3. ^ Benn, Douglas I.; Evans, David J.A. (2003). Glaciers and Glaciation (First ed.). London: Arnold. p. 434. ISBN 0340584319.
  4. ^ "Glacial Landforms". Bitesize. BBC. Archived from the original on 21 June 2020. Retrieved 28 March 2021.
  5. ^ "Cavan" (PDF). Geoschol – Geology for schools in Ireland. Archived (PDF) from the original on 2021-11-22.