 | This article has multiple issues. Please help improve it or discuss these issues on the talk page . (Learn how and when to remove these template messages)
|
A crag (sometimes spelled cragg, or in Scotland craig) is a rocky hill or mountain, generally isolated from other high ground.
Crags are formed when a glacier or ice sheet passes over an area that contains a particularly resistant rock formation (often granite, a volcanic plug or some other volcanic structure). The force of the glacier erodes the surrounding softer material, leaving the rocky block protruding from the surrounding terrain. Frequently the crag serves as a partial shelter to softer material in the wake of the glacier, which remains as a gradual fan or ridge forming a tapered ramp (called the tail) up the leeward side of the crag. [1]
In older examples, or those latterly surrounded by the sea, the tail is often missing, having been removed by post-glacial erosion.
Examples of crag and tail formations include:
The Bass Rock, or simply the Bass, is an island in the outer part of the Firth of Forth in the east of Scotland. Approximately 2 km (1 mi) offshore, and 5 km (3 mi) north-east of North Berwick, it is a steep-sided volcanic plug, 107 m (351 ft) at its highest point, and is home to a large colony of gannets. The rock is uninhabited, but historically has been settled by an early Christian hermit, and later was the site of an important castle, which after the Commonwealth period was used as a prison. The island belongs to Hew Hamilton-Dalrymple, whose family acquired it in 1706, and before to the Lauder family for almost six centuries. The Bass Rock Lighthouse was constructed on the rock in 1902, and the remains of an ancient chapel survive.
Landforms are categorized by characteristic physical attributes such as their creating process, shape, elevation, slope, orientation, rock exposure, and soil type.
The Amundsen Sea is an arm of the Southern Ocean off Marie Byrd Land in western Antarctica. It lies between Cape Flying Fish to the east and Cape Dart on Siple Island to the west. Cape Flying Fish marks the boundary between the Amundsen Sea and the Bellingshausen Sea. West of Cape Dart there is no named marginal sea of the Southern Ocean between the Amundsen and Ross Seas. The Norwegian expedition of 1928–1929 under Captain Nils Larsen named the body of water for the Norwegian polar explorer Roald Amundsen while exploring this area in February 1929.
Arthur's Seat is an ancient volcano which is the main peak of the group of hills in Edinburgh, Scotland, which form most of Holyrood Park, described by Robert Louis Stevenson as "a hill for magnitude, a mountain in virtue of its bold design". It is situated just to the east of the city centre, about 1 mile (1.6 km) to the east of Edinburgh Castle. The hill rises above the city to a height of 250.5 m (822 ft), provides excellent panoramic views of the city and beyond, is relatively easy to climb, and is popular for hillwalking. Though it can be climbed from almost any direction, the easiest and simplest ascent is from the east, where a grassy slope rises above Dunsapie Loch. At a spur of the hill, Salisbury Crags has historically been a rock climbing venue with routes of various degrees of difficulty. Until recently rock climbing was restricted to the South Quarry, but access is currently banned altogether by Historic Environment Scotland.
Archaeology and geology continue to reveal the secrets of prehistoric Scotland, uncovering a complex past before the Romans brought Scotland into the scope of recorded history. Successive human cultures tended to be spread across Europe or further afield, but focusing on this particular geographical area sheds light on the origin of the widespread remains and monuments in Scotland, and on the background to the history of Scotland.
The Transantarctic Mountains comprise a mountain range of uplifted rock in Antarctica which extends, with some interruptions, across the continent from Cape Adare in northern Victoria Land to Coats Land. These mountains divide East Antarctica and West Antarctica. They include a number of separately named mountain groups, which are often again subdivided into smaller ranges.
The Axel Heiberg Glacier in Antarctica is a valley glacier, 30 nmi (35 mi) long, descending from the high elevations of the Antarctic Plateau into the Ross Ice Shelf between the Herbert Range and Mount Don Pedro Christophersen in the Queen Maud Mountains.
Marie Byrd Land (MBL) is an unclaimed region of Antarctica. With an area of 1,610,000 km2 (620,000 sq mi), it is the largest unclaimed territory on Earth. It was named after the wife of American naval officer Richard E. Byrd, who explored the region in the early 20th century.
North Berwick Law, sometimes abbreviated to Berwick Law, is a conical hill which rises conspicuously from the surrounding landscape. It overlooks the East Lothian town of North Berwick, Scotland, and stands at 613 ft (187 m) above sea level.
A volcanic plug, also called a volcanic neck or lava neck, is a volcanic object created when magma hardens within a vent on an active volcano. When present, a plug can cause an extreme build-up of high gas pressure if rising volatile-charged magma is trapped beneath it, and this can sometimes lead to an explosive eruption. In a plinian eruption the plug is destroyed and ash is ejected.
The Never Summer Mountains are a mountain range in the Rocky Mountains in north central Colorado in the United States consisting of seventeen named peaks. The range is located along the northwest border of Rocky Mountain National Park, forming the continental divide between the headwaters of the Colorado River in Rocky Mountain National Park to the local-east and the upper basin of the North Platte River to the local-west; the continental divide makes a loop in these mountains. The range is small and tall, covering only 25 sq mi (65 km2) with a north–south length of 10 mi (16 km) while rising to over 12,000 ft (3,700 m) at over ten distinct peaks. The range straddles the Jackson-Grand county line for most of its length, and stretches into Jackson and Larimer county at its northern end. A panoramic view of the range is available from sections of Trail Ridge Road in Rocky Mountain National Park. One of the northernmost peaks, Nokhu Crags, is prominently visible from the west side of Cameron Pass.
Pine Island Glacier (PIG) is a large ice stream, and the fastest melting glacier in Antarctica, responsible for about 25% of Antarctica's ice loss. The glacier ice streams flow west-northwest along the south side of the Hudson Mountains into Pine Island Bay, Amundsen Sea, Antarctica. It was mapped by the United States Geological Survey (USGS) from surveys and United States Navy (USN) air photos, 1960–66, and named by the Advisory Committee on Antarctic Names (US-ACAN) in association with Pine Island Bay.
The geology of Scotland is unusually varied for a country of its size, with a large number of different geological features. There are three main geographical sub-divisions: the Highlands and Islands is a diverse area which lies to the north and west of the Highland Boundary Fault; the Central Lowlands is a rift valley mainly comprising Palaeozoic formations; and the Southern Uplands, which lie south of the Southern Uplands Fault, are largely composed of Silurian deposits.
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.
Castle Rock is a volcanic plug in the middle of Edinburgh upon which Edinburgh Castle sits. The rock is estimated to have formed some 350 million years ago during the early Carboniferous period. It is the remains of a volcanic pipe which cut through the surrounding sedimentary rock, before cooling to form very hard dolerite, a coarser-grained equivalent of basalt. Subsequent glacial erosion was resisted more by the dolerite, which protected the softer rock to the east, leaving a crag and tail formation.
Watson's Dodd is a fell in the English Lake District, a minor rise on the main ridge of the Helvellyn range in the Eastern Fells, but a prominent shoulder on the west side of that range.
The Islands of the Forth are a group of small islands located in the Firth of Forth and in the estuary of the River Forth on the east coast of Scotland. Most of the group lie in the open waters of the firth, between the Lothians and Fife, with the majority to the east of the city of Edinburgh. Two islands lie further west in the river estuary.
Rippon Glacier is a small glacier located in Kemp Land, East Antarctica. It is close east of Seaton Glacier, flowing southward into Edward VIII Ice Shelf.
Gillies Hill is located west of Stirling and the M9, south of Cambusbarron, and north of the Bannock Burn in Central Scotland.
 | This article related to topography is a stub. You can help Wikipedia by expanding it. |
 | This glaciology article is a stub. You can help Wikipedia by expanding it. |
