Giant's kettle

From Wikipedia, the free encyclopedia
Jump to navigation Jump to search
Glacial pothole in Bloomington on the St. Croix River at Interstate State Park, Wisconsin, U.S.

A giant's kettle, also known as either a giant's cauldron, moulin pothole, or glacial pothole, is a typically large and cylindrical pothole drilled in solid rock underlying a glacier either by water descending down a deep moulin or by gravel rotating in the bed of subglacial meltwater stream.[1]

The interiors of potholes tend to be smooth and regular, unlike a plunge pool. An example is the large pothole found in Archbald, Pennsylvania, in Archbald Pothole State Park.

Formation[edit]

Giant's kettle illustration
Collection of pebbles shaped in giant's kettles

Giant's kettles are formed while a bedrock surface is covered by a glacier. Water, produced by the thawing of the ice and snow, forms streams on the surface of the glacier, which, having gathered into their courses a certain amount of morainic debris, finally flow down a crevasse as a swirling cascade or moulin; the sides of the crevasse are abraded, and a vertical shaft is formed in the ice.[2] The erosion may be continued into the bed of the glacier; and, the ice having left the district, the giant's kettle so formed is seen as an empty shaft, or as a pipe filled with gravel, sand, or boulders; such cavities and pipes afford valuable evidence as to the former extent of glaciers.

Similar potholes are encountered in riverbeds and the Channeled Scablands scoured by glacial outburst floods.[3]

Notable giant's kettle[edit]

Giant's kettle in Rovaniemi, Finland

The GletscherGarten of Lucerne (Switzerland) is famous for its giant's kettles, having 32 in number, the largest being 8 m (26 ft) wide and 9 m (30 ft) deep, they are also common in Germany, Norway (jettegryte), Sweden (jättegryta), Finland (hiidenkirnu; hiisi's churn), and Moss Island in the United States.

See also[edit]

References[edit]

  1. ^ Neuendorf, K.K.E., J.P. Mehl, Jr., and J.A. Jackson, eds. (2005) Glossary of Geology (5th ed.). Alexandria, Virginia, American Geological Institute. 779 pp. ISBN 0-922152-76-4
  2. ^ Bulletin of the Massachusetts Archaeological Society (PDF). XIV (4): 112. July 1953 http://library.bridgew.edu/exhibits/BMAS/pdf/MAS-v14n04.pdf. Retrieved 12 July 2010. Missing or empty |title= (help)
  3. ^ Baker, Victor (2010). Migon, Piotr (ed.). Channeled Scablands: A Megaflood Landscape, in Geomorphological Landscapes of the World. Springer. pp. 21–28. ISBN 9789048130542.

External links[edit]

 This article incorporates text from a publication now in the public domainChisholm, Hugh, ed. (1911). "Giant's Kettle". Encyclopædia Britannica (11th ed.). Cambridge University Press.