Overdeepening
   HOME
*



picture info

Overdeepening
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 deepest continuous line (the thalweg) 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. Overdeepened fjords and lakes have significant economic value as harbours and fisheries. Overdeepened basins and valleys filled with sediment (termed tunnel valleys) are of particular interest to engineers, petroleum geologists, and hydrologists; ...
[...More Info...]      
[...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]  


picture info

Fjord
In physical geography, a fjord or fiord () is a long, narrow inlet with steep sides or cliffs, created by a glacier. Fjords exist on the coasts of Alaska, Antarctica, British Columbia, Chile, Denmark, Germany, Greenland, the Faroe Islands, Iceland, Ireland, Kamchatka, the Kerguelen Islands, Labrador, Newfoundland, New Zealand, Norway, Novaya Zemlya, Nunavut, Quebec, the Patagonia region of Argentina and Chile, Russia, South Georgia Island, Tasmania, United Kingdom, and Washington state. Norway's coastline is estimated to be long with its nearly 1,200 fjords, but only long excluding the fjords. Formation A true fjord is formed when a glacier cuts a U-shaped valley by ice segregation and abrasion of the surrounding bedrock. According to the standard model, glaciers formed in pre-glacial valleys with a gently sloping valley floor. The work of the glacier then left an overdeepened U-shaped valley that ends abruptly at a valley or trough end. Such valleys are fjords wh ...
[...More Info...]      
[...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]  


picture info

Sill (geology)
In geology, a sill is a tabular sheet intrusion that has intruded between older layers of sedimentary rock, beds of volcanic lava or tuff, or along the direction of foliation in metamorphic rock. A ''sill'' is a ''concordant intrusive sheet'', meaning that a sill does not cut across preexisting rock beds. Stacking of sills builds a sill complex . and a large magma chamber at high magma flux. In contrast, a dike is a discordant intrusive sheet, which does cut across older rocks. Sills are fed by dikes, except in unusual locations where they form in nearly vertical beds attached directly to a magma source. The rocks must be brittle and fracture to create the planes along which the magma intrudes the parent rock bodies, whether this occurs along preexisting planes between sedimentary or volcanic beds or weakened planes related to foliation in metamorphic rock. These planes or weakened areas allow the intrusion of a thin sheet-like body of magma paralleling the existing bedding pla ...
[...More Info...]      
[...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]  


picture info

Mountain Range
A mountain range or hill range is a series of mountains or hills arranged in a line and connected by high ground. A mountain system or mountain belt is a group of mountain ranges with similarity in form, structure, and alignment that have arisen from the same cause, usually an orogeny. Mountain ranges are formed by a variety of geological processes, but most of the significant ones on Earth are the result of plate tectonics. Mountain ranges are also found on many planetary mass objects in the Solar System and are likely a feature of most terrestrial planets. Mountain ranges are usually segmented by highlands or mountain passes and valleys. Individual mountains within the same mountain range do not necessarily have the same geologic structure or petrology. They may be a mix of different orogenic expressions and terranes, for example thrust sheets, uplifted blocks, fold mountains, and volcanic landforms resulting in a variety of rock types. Major ranges Most geolo ...
[...More Info...]      
[...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]  


Purcell Mountains
The Purcell Mountains are a mountain range in southeastern British Columbia, Canada. They are a subrange of the Columbia Mountains, which includes the Selkirk, Monashee, and Cariboo Mountains. They are located on the west side of the Rocky Mountain Trench in the area of the Columbia Valley, and on the east side of the valley of Kootenay Lake and the Duncan River. The only large settlements in the mountains are the Panorama Ski Resort and Kicking Horse Resort, adjacent to the Columbia Valley towns of Invermere and Golden, though there are small settlements, such as Yahk and Moyie along the Crowsnest Highway, and residential rural areas dependent on the cities of Creston, Kimberley and Cranbrook, which are located adjacent to the range. The Purcells are shown on some United States maps as the Percell Mountains, where their southern limit protrudes into the states of Idaho and Montana, abutting Lake Koocanusa, a reservoir on the Kootenai River. American geographic classification ...
[...More Info...]      
[...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]  


picture info

Selkirk Mountains
The Selkirk Mountains are a mountain range spanning the northern portion of the Idaho Panhandle, eastern Washington, and southeastern British Columbia which are part of a larger grouping of mountains, the Columbia Mountains. They begin at Mica Peak and Krell Hill near Spokane and extend approximately 320 km north (200 miles) from the border to Kinbasket Lake, at the now-inundated location of the onetime fur company post Boat Encampment. The range is bounded on its west, northeast and at its northern extremity by the Columbia River, or the reservoir lakes now filling most of that river's course. From the Columbia's confluence with the Beaver River, they are bounded on their east by the ''Purcell Trench'', which contains the Beaver River, Duncan River, Duncan Lake, Kootenay Lake and the Kootenay River. The Selkirks are distinct from, and geologically older than, the Rocky Mountains. The neighboring Monashee and Purcell Mountains, and sometimes including the Cariboo Mounta ...
[...More Info...]      
[...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]  


picture info

Kootenay Lake
Kootenay Lake is a lake located in British Columbia, Canada. It is part of the Kootenay River. The lake has been raised by the Corra Linn Dam and has a dike system at the southern end, which, along with industry in the 1950s–70s, has changed the ecosystem in and around the water. The Kootenay Lake ferry is a year-round toll-free ferry that crosses between Kootenay Bay and Balfour. The lake is a popular summer tourist destination. Geography Kootenay Lake is a long, narrow and deep fjord-like lake located between the Selkirk and Purcell mountain ranges in the Kootenay region of British Columbia. It is one of the largest lakes in British Columbia, at 104 km in length and 3–5 km in width. It is, in part, a widening of the Kootenay River, which in turn drains into the Columbia River system at Castlegar, British Columbia. Although oriented primarily in a north-south configuration, a western arm positioned roughly halfway up the length of the lake stretches 35&nb ...
[...More Info...]      
[...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]  


picture info

Okanagan Lake
Okanagan Lake ( oka, kɬúsxÌŒnítkw) is a lake in the Okanagan Valley of British Columbia, Canada. The lake is long, between wide, and has a surface area of 348 km2 (135 sq. mi.). Hydrography Okanagan Lake is called a fjord lake as it has been carved out by repeated glaciations. Although the lake contains numerous lacustrine terraces, it is not uncommon for the lake to be deep only offshore. Major inflows include Mission, Vernon, Trout, Penticton, Equesis, Kelowna, Peachland and Powers Creeks. The lake is drained by the Okanagan River, which exits the lake's south end via a canal through the city of Penticton to Skaha Lake, whence the river continues southwards into the rest of the South Okanagan and through Okanogan County, Washington to its confluence with the Columbia. The lake's maximum depth is near Grant Island (Nahun Weenox). There are three other islands: one known as Rattlesnake Island, much farther south by Squally Point. The other two are near Grant I ...
[...More Info...]      
[...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]  


Canada
Canada is a country in North America. Its ten provinces and three territories extend from the Atlantic Ocean to the Pacific Ocean and northward into the Arctic Ocean, covering over , making it the world's second-largest country by total area. Its southern and western border with the United States, stretching , is the world's longest binational land border. Canada's capital is Ottawa, and its three largest metropolitan areas are Toronto, Montreal, and Vancouver. Indigenous peoples have continuously inhabited what is now Canada for thousands of years. Beginning in the 16th century, British and French expeditions explored and later settled along the Atlantic coast. As a consequence of various armed conflicts, France ceded nearly all of its colonies in North America in 1763. In 1867, with the union of three British North American colonies through Confederation, Canada was formed as a federal dominion of four provinces. This began an accretion of provinces an ...
[...More Info...]      
[...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]  


picture info

British Columbia
British Columbia (commonly abbreviated as BC) is the westernmost province of Canada, situated between the Pacific Ocean and the Rocky Mountains. It has a diverse geography, with rugged landscapes that include rocky coastlines, sandy beaches, forests, lakes, mountains, inland deserts and grassy plains, and borders the province of Alberta to the east and the Yukon and Northwest Territories to the north. With an estimated population of 5.3million as of 2022, it is Canada's third-most populous province. The capital of British Columbia is Victoria and its largest city is Vancouver. Vancouver is the third-largest metropolitan area in Canada; the 2021 census recorded 2.6million people in Metro Vancouver. The first known human inhabitants of the area settled in British Columbia at least 10,000 years ago. Such groups include the Coast Salish, Tsilhqotʼin, and Haida peoples, among many others. One of the earliest British settlements in the area was Fort Victoria, established ...
[...More Info...]      
[...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]  


picture info

Moraine
A moraine is any accumulation of unconsolidated debris (regolith and rock), sometimes referred to as glacial till, that occurs in both currently and formerly glaciated regions, and that has been previously carried along by a glacier or ice sheet. It may consist of partly rounded particles ranging in size from boulders (in which case it is often referred to as boulder clay) down to gravel and sand, in a groundmass of finely-divided clayey material sometimes called glacial flour. Lateral moraines are those formed at the side of the ice flow, and terminal moraines were formed at the foot, marking the maximum advance of the glacier. Other types of moraine include ground moraines (till-covered areas forming sheets on flat or irregular topography) and medial moraines (moraines formed where two glaciers meet). Etymology The word ''moraine'' is borrowed from French , which in turn is derived from the Savoyard Italian ("mound of earth"). ''Morena'' in this case was derived from Provenà ...
[...More Info...]      
[...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]  


Coniston Watermap
Coniston may refer to: Australia *Coniston (Northern Territory), a cattle station **Coniston massacre, 1928 *Coniston, New South Wales ** Coniston railway station, New South Wales * Coniston, Tasmania, a town in the Derwent Valley United Kingdom *Coniston, East Riding of Yorkshire *Coniston Cold, North Yorkshire *Coniston, Cumbria, a village *Coniston Fells, a chain of hills and mountains in the Furness Fells, in the Lake District **Coniston Old Man (also called the Old Man of Coniston), the highest peak in the Coniston Fells *Coniston Water, a lake in the Lake District *Coniston Limestone, the sedimentary rock formation around Coniston, Cumbria. *Coniston Group, a lithographic group named after Coniston, Cumbria. United States * Coniston, California * ''Coniston'' (novel), by American writer Winston Churchill Canada *Coniston, Ontario, Canada See also *Conistone Conistone is a small village in the Craven district of North Yorkshire, England. It lies north of Grassingto ...
[...More Info...]      
[...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]