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. Ice is a Solid phase, usually crystalline, of a Non-metalic substance that is liquid or gas at Room temperature, such as Ammonia "Glacial" and "Glaciation" redirect here For the geological periods see Glacial period. The Pleistocene ('plaɪstəsin is the epoch from 18 million to 10000 years BP covering the world's recent 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 )
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Erosional landforms
As the glaciers expanded, due to their accumulating weight of snow and ice , they crushed and scoured surface rocks and bedrock. "Snowfall" redirects here For other uses see Snow (disambiguation or Snowfall (disambiguation. Ice is a Solid phase, usually crystalline, of a Non-metalic substance that is liquid or gas at Room temperature, such as Ammonia In Geology, rock is a naturally occurring aggregate of Minerals and/or Mineraloids The Earth's outer solid layer the ‘ Lithosphere Bedrock is the native consolidated rock underlying the surface of a terrestrial planet usually the Earth. The resulting erosional landforms include striations, cirques, glacial horns, arêtes, U-shaped valleys, roches moutonnées, and hanging valleys. Glacial striations or glacial grooves are scratches or gouges cut into Bedrock by process of glacial abrasion. A cirque ( French for " Circus " is an Amphitheatre -like Valley, or valley head formed at the head of a Glacier by A pyramidal peak, or sometimes in its most extreme form called a glacial horn, is a Mountaintop that has been modified by the action of Ice during This article is about a glacial landform See Arete for other meanings In Geology, a valley (also called a vale, dale, glen or strath and near or in Appalachia, a draw) is In Glaciology, a roche moutonnée (or sheepback) is a Rock formation created by the passing of a Glacier. In Geology, a valley (also called a vale, dale, glen or strath and near or in Appalachia, a draw) is
Depositional landforms
Later, when the glaciers retreated leaving behind their freight of crushed rock and sand (glacial drift), they created characteristic depositional landforms. In Geology, rock is a naturally occurring aggregate of Minerals and/or Mineraloids The Earth's outer solid layer the ‘ Lithosphere Examples include glacial moraines, eskers, and kames. Moraine refers to any glacially formed accumulation of unconsolidated glacial debris (soil and rock which can occur in currently glaciated and formerly glaciated regions such as those An esker is a long winding ridge of Stratified Sand and Gravel, examples of which occur in glaciated and formerly glaciated regions of A kame is a geological feature an irregularly shaped Hill or Mound composed of Sand, Gravel and Till that accumulates Drumlins and ribbed moraines are also landforms left behind by retreating glaciers. A drumlin (Irish droimnín, a little hill ridge is an elongated whale-shaped Hill formed by glacial action A ribbed moraine (also called a Rogen moraine is a type of Moraine formed subglacially (i The stone walls of New England contain many glacial erratics, rocks that were dragged by a glacier many miles from their bedrock origin. A glacial erratic is a piece of rock that deviates from the size and type of rock native to the area in which it rests the name " erratic " is based on the Bedrock is the native consolidated rock underlying the surface of a terrestrial planet usually the Earth.
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. A kettle (or kettle hole) is a shallow sediment-filled body of water formed by retreating glaciers or draining floodwaters Moraine-dammed lakes occur when a stream (or snow runoff) is dammed by glacial debris. A moraine-dammed lake occurs when a terminal moraine has prevented some Meltwater from leaving the valley 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. Jackson Lake is a Lake located in north western Wyoming in Grand Teton National Park. Jenny Lake is located in Grand Teton National Park in the US state of Wyoming. Grand Teton National Park is a United States National Park located in northwestern Wyoming, south of Yellowstone National Park.
External links
- Illustrated glossary of alpine glacial landforms
- Landforms of glaciation
- Diagram illustrating mechanisms of glacial landforms in The Ice Melts: Deposition on page 6 of "Pennsylania and the Ice Age" published 1999 by PA DCNR Bureau of Topographic and Geologic Survey
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