Drumlin in Cato, New York

Drowned drumlin in Clew Bay, County Mayo

Drumlin at Withrow Moraine and Jameson Lake Drumlin Field National Natural Landmark, Washington state

A drumlin (Irish droimnín, a little hill ridge) is an elongated whale-shaped hill formed by glacial action. Cato New York may refer to either Cato (town New York, located in Cayuga County Cato (village New York, located within the towns Clew Bay ( Irish Cuan Mó) is a natural ocean Bay in County Mayo, Ireland. The Withrow Moraine and Jameson Lake Drumlin Field is a National Park Service designated privately-owned National Natural Landmark located in Douglas County Washington ( is a state in the Pacific Northwest region of the United States. "Glacial" and "Glaciation" redirect here For the geological periods see Glacial period. Its long axis is parallel with the movement of the ice, with the blunter end facing into the glacial movement. Drumlins may be more than 45 m (150 ft) high and more than 0. 8 km (½ mile) long, and are often in drumlin fields of similarly shaped, sized and oriented hills. A drumlin field is a cluster of dozens to hundreds of similarly shaped sized and oriented Drumlins also called a drumlin swarm. Drumlins usually have layers indicating that the material was repeatedly added to a core, which may be of rock or glacial till. In Geology, rock is a naturally occurring aggregate of Minerals and/or Mineraloids The Earth's outer solid layer the ‘ Lithosphere Till is unsorted glacial sediment Glacial drift is a general term for the coarsely graded and extremely heterogeneous Sediments of glacial origin

There are many theories as to the exact mode of origin and plenty of controversy among geologists interested in geomorphology. The word theory has many distinct meanings in different fields of Knowledge, depending on their methodologies and the context of discussion. Geomorphology (from Greek: γη ge, "earth" μορφή morfé, "form" and λόγος Logos, "knowledge" Some consider them a direct formation of the ice, while a theory proposed since the 1980s by John Shaw and others postulates creation by a catastrophic flooding release of highly pressurized water flowing underneath the glacial ice. ^[1] Either way, they are thought to be a waveform (similar to ripples of sand at the bottom of a stream). waveformogg|right|a sine square and sawtooth wave at 440 hz]] Waveform means the shape and form of a signal such as a Wave moving in a solid liquid or gaseous It is also poorly understood why drumlins form in some glaciated areas and not in others. They are often associated with ribbed moraines. A ribbed moraine (also called a Rogen moraine is a type of Moraine formed subglacially (i

Drumlins are common in New York, the lower Connecticut River valley, eastern Massachusetts, the Monadnock Region of New Hampshire, Minnesota, Wisconsin, Southern Ontario, Nova Scotia, Poland, Estonia, around Lake Constance north of the Alps, Ireland, Denmark, Finland and Patagonia. New York ( is a state in the Mid-Atlantic and Northeastern regions of the United States and is the nation's third most populous The Connecticut River is the largest River in New England, flowing south from the Connecticut Lakes in northern New Hampshire, along the border The Commonwealth of Massachusetts ( is a state located in the New England region of the northeastern United States. The Monadnock Region is a region in southwestern New Hampshire. New Hampshire ( is a state in the New England region of the northeastern United States of America. Minnesota ( Native Americans demonstrated the name to early settlers Wisconsin ( or wɪˈskɑnsɨn (French Ouisconsin) is one of the fifty United States of America, located in the north central part of the United States Southern Ontario is the portion of the Canadian province of Ontario lying south of the French River and Algonquin Park. Nova Scotia (ˌnəʊvəˈskəʊʃə ( Latin for New Scotland; Alba Nuadh Nouvelle-Écosse is a Canadian province located on Canada 's Poland (Polska officially the Republic of Poland Estonia, officially the Republic of Estonia ( Eesti or Eesti Vabariik) is a Country in Northern Europe in the Baltic region Under the designation Lake Constance or Lake of Constance ( German Bodensee) one summarizes the three independent bodies of water Obersee Ireland (pronounced /ˈaɾlənd/ Éire) is the third largest island in Europe, and the twentieth-largest island in the world Finland, officially the Republic of Finland ( is a Nordic country situated in the Fennoscandian region of northern Europe. Llao LLaojpg|thumb|250px| Lake Nahuel Huapi, near Bariloche, Argentina Those in North America are regarded as a creation of the last Wisconsin ice age. "Last glacial" redirects here For the period of maximum glacier extent during this time see Last Glacial Maximum The last glacial period An ice age is a period of long-term reduction in the Temperature of the Earth 's surface and atmosphere resulting in an expansion of continental Ice sheets

The islands of Boston Harbor Islands National Recreation Area are drumlins that became islands when sea levels rose as the glaciers melted. The Boston Harbor Islands National Recreation Area is a National Recreation Area situated among the islands of Boston Harbor of Boston, Massachusetts Clew Bay in Ireland is a good example of a 'drowned drumlin' landscape where the drumlins appear as islands in the sea, forming a 'basket of eggs' topography. Clew Bay ( Irish Cuan Mó) is a natural ocean Bay in County Mayo, Ireland. Ireland (pronounced /ˈaɾlənd/ Éire) is the third largest island in Europe, and the twentieth-largest island in the world Drumlins are typically aligned parallel to one another, usually clustered together in numbers reaching the hundreds or even thousands.

Drumlin formation has recently been observed for the first time in Antarctica in the Rutford Ice Stream. ^[2]

A similar formation, with a more resilient (generally composed of igneous or metamorphic rock) core, is a crag. Igneous rocks (etymology from Latin ignis, fire are rocks formed by solidification of cooled Magma (molten rock A crag (sometimes spelled cragg, or in Scotland craig) is a rocky hill or mountain generally isolated from other high ground

Drumlin soil classification consists of a thin A soil horizon and a thin Bw horizon. A soil horizon is a specific layer in the Soil which measures parallel to the soil surface and possesses physical characteristics which differ from the layers above and The C horizon is close to the surface, allowing parent material to emerge to the surface through weathering

See also

• Landform
• Glacial landforms
• Lincoln Hills
• Ribbed moraines
• Roche moutonnée
• Sediment
• Geology

References

• Tarbuck, Edward J. Parent material, in Soil science, means the underlying geological material (generally Bedrock or a superficial or drift deposit in which Soil horizons Weathering is the decomposition of earth rocks, Soils and their Minerals through direct contact with the planet's Atmosphere. Many now-familiar glacial Landforms were created by the movement of huge sheets of Ice called continental Glaciers during the Pleistocene Epoch The Lincoln Hills extend along the Mississippi River starting about 40 miles northwest of St A ribbed moraine (also called a Rogen moraine is a type of Moraine formed subglacially (i In Glaciology, a roche moutonnée (or sheepback) is a Rock formation created by the passing of a Glacier. Sediment is any particulate matter that can be transported by fluid flow and which eventually is deposited as a layer of solid particles on the bed or bottom of a body of Geology (from Greek γη gê, "earth" and λόγος Logos, "speech" lit ; Frederick K. Lutgens (2002). Earth: An Introduction to Physical Geography. Upper Saddle River, New Jersey: Prentice Hall, 347-350. ISBN 0-13-092025-8.  
• Trenhaile, Alan (2007). Geomorphology: A Canadian Perspective. Don Mills, Ontario: Oxford University Press, 183-6. ISBN 0-19-542474-3.  

Footnotes

External links

• Diagrams of an idealized drumlin
• Douglas E. Cox, "Drumlins and subglacial meltwater floods"
• Douglas E. Cox, "The role of vortices in drumlin formation" Introductions to the current dialogue.