Glacial landforms

Glacial landforms

Many now-familiar glacial landforms were created by the movement of huge sheets of ice called continental glaciers during the Pleistocene Epoch (more commonly called the Ice Age.)

Erosional landforms

As the glaciers expanded, due to their accumulating weight of snow and ice , they crushed and scoured surface rocks and bedrock. The resulting erosional landforms include striations, cirques, glacial horns, arêtes, U-shaped valleys, roches moutonnées, and hanging valleys.

Depositional landforms

Later, when the glaciers retreated leaving behind their freight of crushed rock and sand (glacial drift), they created characteristic depositional landforms. Examples include glacial moraines, eskers, and kames. Drumlins and ribbed moraines are also landforms left behind by retreating glaciers. The stone walls of New England contain many glacial erratics, rocks that were dragged by a glacier many miles from their bedrock origin.

Glacial lakes and ponds

Lakes and ponds can also be caused by glacial movement. Kettle lakes form when a retreating glacier leaves behind an underground or surface chunk of ice that later melts to form a depression containing water. Moraine-dammed lakes occur when a stream (or snow runoff) is dammed by glacial debris. Jackson Lake and Jenny Lake in Grand Teton National Park are examples of moraine-dammed lakes, although Jackson Lake is also enhanced by a man-made dam.

External links

* [http://www.uwsp.edu/geo/faculty/lemke/alpine_glacial_glossary/glossary.html Illustrated glossary of alpine glacial landforms]
* [http://www.physicalgeography.net/fundamentals/10af.html Landforms of glaciation]
*Diagram illustrating mechanisms of glacial landforms in [http://www.dcnr.state.pa.us/topogeo/education/es6/es6.pdf "The Ice Melts: Deposition"] on page 6 of "Pennsylania and the Ice Age" published 1999 by PA DCNR [http://www.dcnr.state.pa.us/topogo Bureau of Topographic and Geologic Survey]


Wikimedia Foundation. 2010.

Игры ⚽ Нужен реферат?

Look at other dictionaries:

  • Glacial motion — is the motion of glaciers, which can be likened to rivers of ice. It has played an important role in sculpting many landscapes. Most lakes in the world occupy basins scoured out by glaciers. Glacial motion can be fast (up to 30 m/day, observed on …   Wikipedia

  • glacial landform — ▪ geology Introduction  any product of flowing ice and meltwater. Such landforms are being produced today in glaciated areas, such as Greenland, Antarctica, and many of the world s higher mountain ranges. In addition, large expansions of present… …   Universalium

  • Glacial landform — Antique postcard shows rocks scarred by glacial erosion. Yosemite Valley …   Wikipedia

  • Glacial Lakes State Park — Geobox|Protected area name = Glacial Lakes State Park category = Minnesota State Park category iucn = V image caption = country = United States country state = Minnesota state state type = State region type = County region = Pope city type = City …   Wikipedia

  • Glacial Lake Tight — Lake Tight, named for geologist William G. Tight, was a glacial lake located in what is present day Ohio, Kentucky, and West Virginia, during the Ice Age.HistoryLake Tight s origins date to nearly 2 million years before the modern era. As the Ice …   Wikipedia

  • Ultimo Máximo Glacial — Saltar a navegación, búsqueda Mapa de los cambios de temperaturas superficiales de los oceanos y extension de los hielos durante el Ultimo Máximo Glacial segun el proyecto CLIMAP. El Último Máximo Glacial (LGM) se refiere a la época de máxima… …   Wikipedia Español

  • Último Máximo Glacial — Mapa de los cambios de temperaturas superficiales de los oceanos y extension de los hielos durante el Último Máximo Glacial según el proyecto CLIMAP. El Último Máximo Glacial (conocido por sus siglas en inglés, LGM, de Last Glacial Maximum) se… …   Wikipedia Español

  • Last Glacial Maximum — The Last Glacial Maximum (LGM) refers to the time of maximum extent of the ice sheets during the last glaciation (the Würm or Wisconsin glaciation), approximately 20,000 years ago. This extreme persisted for several thousand years. At this time,… …   Wikipedia

  • Big Rock (glacial erratic) — Big Rock Big Rock (also known as Okotoks Erratic) is a glacial erratic situated between the towns of Okotoks and Black Diamond, Alberta, Canada (18 kilometres south of Calgary). The 15,000 tonne (16,500 short ton) quartzite boulder is the world s …   Wikipedia

  • coastal landforms — ▪ geology Introduction       any of the relief features present along any coast, the result of a combination of processes, sediments, and the geology of the coast itself.       The coastal environment of the world is made up of a wide variety of… …   Universalium

Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”