Jean Louis Rodolphe Agassiz FRS (For) FRSE was a Swiss-born American biologist and geologist who is recognized as a scholar of Earth's natural history.
Till or glacial till is unsorted glacial sediment.
A glacial erratic is glacially deposited rock differing from the type of rock native to the area in which it rests. Erratics, which take their name from the Latin word errare, are carried by glacial ice, often over distances of hundreds of kilometres. Erratics can range in size from pebbles to large boulders such as Big Rock in Alberta.
The Clearwater River is located in the Canadian provinces of Saskatchewan and Alberta. It rises in the northern forest region of north-western Saskatchewan and joins the Athabasca River in north-eastern Alberta. It was part of an important trade route during the fur trade era and has been designated as a Canadian Heritage River.
The Driftless Area, also known as Bluff Country, the Blufflands, the Paleozoic Plateau, and the Coulee Region, is a topographical and cultural region in the Midwestern United States that comprises southwestern Wisconsin, southeastern Minnesota, northeastern Iowa, and the extreme northwestern corner of Illinois. The Driftless Area is a USDA Level III Ecoregion: Ecoregion 52. The Driftless Area takes up a large portion of the Upper Midwest forest–savanna transition.
Glacial landforms are landforms created by the action of glaciers. Most of today's glacial landforms were created by the movement of large ice sheets during the Quaternary glaciations. Some areas, like Fennoscandia and the southern Andes, have extensive occurrences of glacial landforms; other areas, such as the Sahara, display rare and very old fossil glacial landforms.
Glacial striations or striae are scratches or gouges cut into bedrock by glacial abrasion. These scratches and gouges were first recognized as the result of a moving glacier in the late 18th century when Swiss alpinists first associated them with moving glaciers. They also noted that if they were visible today that the glaciers must also be receding.
Prof Otto Martin Torell HFRSE was a Swedish naturalist and geologist.
An outcrop or rocky outcrop is a visible exposure of bedrock or ancient superficial deposits on the surface of the Earth.
In glaciology, a roche moutonnée is a rock formation created by the passing of a glacier. The passage of glacial ice over underlying bedrock often results in asymmetric erosional forms as a result of abrasion on the "stoss" (upstream) side of the rock and plucking on the "lee" (downstream) side. Some geologists limit the term to features on scales of a metre to several hundred metres and refer to larger features as crag and tail.
Plucking, also referred to as quarrying, is a glacial phenomenon that is responsible for the weathering and erosion of pieces of bedrock, especially large "joint blocks". This occurs in a type of glacier called a "valley glacier". As a glacier moves down a valley, friction causes the basal ice of the glacier to melt and infiltrate joints (cracks) in the bedrock. The freezing and thawing action of the ice enlarges, widens, or causes further cracks in the bedrock as it changes volume across the ice/water phase transition, gradually loosening the rock between the joints. This produces large pieces of rock called joint blocks. Eventually these joint blocks come loose and become trapped in the glacier.
U-shaped valleys, also called trough valleys or glacial troughs, are formed by the process of glaciation. They are characteristic of mountain glaciation in particular. They have a characteristic U shape in cross-section, with steep, straight sides and a flat or rounded bottom. Glaciated valleys are formed when a glacier travels across and down a slope, carving the valley by the action of scouring. When the ice recedes or thaws, the valley remains, often littered with small boulders that were transported within the ice, called glacial till or glacial erratic.
The geology of Minnesota comprises the rock, minerals, and soils of the U.S. state of Minnesota, including their formation, development, distribution, and condition.
The Withrow Moraine and Jameson Lake Drumlin Field is a National Park Service–designated privately owned National Natural Landmark located in Douglas County, Washington state, United States. Withrow Moraine is the only Ice Age terminal moraine on the Waterville Plateau section of the Columbia Plateau. The drumlin field includes excellent examples of glacially-formed elongated hills.
Abrasion is a process of erosion which occurs when material being transported wears away at a surface over time. It is the process of friction caused by scuffing, scratching, wearing down, marring, and rubbing away of materials. The intensity of abrasion depends on the hardness, concentration, velocity and mass of the moving particles. Abrasion generally occurs in four ways: glaciation slowly grinds rocks picked up by ice against rock surfaces; solid objects transported in river channels make abrasive surface contact with the bed and walls; objects transported in waves breaking on coastlines; and by wind transporting sand or small stones against surface rocks.
Schoonmaker Reef, also known as Wauwatosa Reef, Schoonmaker Quarry, Raphu Station or Francey Reef is a 425 million year-old fossilized reef in Wauwatosa, Wisconsin. It was discovered in 1844 by Increase A. Lapham and Fisk Day on the site of a quarry owned by the Schoonmaker family. Geologist James Hall declared its significance in 1862. It was the first ancient reef described in North America, and among the first described in the world. It is located North of W. State St., between N. 66th St. and N. 64th St. extended, in Wauwatosa. It was declared a National Historic Landmark in 1997.
New England is a region in the North Eastern United States consisting of the states Rhode Island, Connecticut, Massachusetts, New Hampshire, Vermont, and Maine. Most of New England consists geologically of volcanic island arcs that accreted onto the eastern edge of the Laurentian Craton in prehistoric times. Much of the bedrock found in New England is heavily metamorphosed due to the numerous mountain building events that occurred in the region. These events culminated in the formation of Pangaea; the coastline as it exists today was created by rifting during the Jurassic and Cretaceous periods. The most recent rock layers are glacial conglomerates.
Overdeepening is a characteristic of basins and valleys eroded by glaciers. An overdeepened valley profile is often eroded to depths which are hundreds of metres below the lowest continuous surface line along a valley or watercourse. This phenomenon is observed under modern day glaciers, in salt-water fjords and fresh-water lakes remaining after glaciers melt, as well as in tunnel valleys which are partially or totally filled with sediment. When the channel produced by a glacier is filled with debris, the subsurface geomorphic structure is found to be erosionally cut into bedrock and subsequently filled by sediments. These overdeepened cuts into bedrock structures can reach a depth of several hundred metres below the valley floor.
Grafton Notch State Park is a public recreation area in Grafton Township, Oxford County, Maine. The state park occupies 3,129 acres (1,266 ha) surrounding Grafton Notch, the mountain pass between Old Speck Mountain and Baldpate Mountain. The park is abutted by the eastern and western sections of the Mahoosuc Public Reserved Land, which total 31,807 acres (12,872 ha). The park is managed by the Department of Agriculture, Conservation and Forestry.
The Edaga Arbi Glacials are a Palaeozoic geological formation in Tigray and in Eritrea. The matrix is composed of grey, black and purple clays, that contains rock fragments up to 6 metres across. Pollen dating yields a Late Carboniferous to Early Permian age.
