- Tor
A tor is a rock outcrop formed by
weathering , usually found on or near the summit of ahill . In the South West of England, where the term originated, it is also a word used for the hills themselves – particularly the high points ofDartmoor inDevon andBodmin Moor inCornwall .Name
The word 'tor' is also used in southern
Wales , particularly on the rocky coastlines such as theVale of Glamorgan and theGower peninsula ; on the Gower one of the sandy beaches nearOxwich Bay is called "Tor Bay" because the beach is framed by a huge outcrop ofcarboniferous limestone . Tor (Cornish "tor",Old Welsh "twrr", Scots Gaelic "tòrr") is notable for being one among a mere handful of Celtic loan-words to be borrowed into vernacular English prior to the modern era – such borrowings are mainly words of a geographic or topographical nature, also includingcrag andAvon ("river"). This origin of the word and the very fact it has survived hints at the places' special meaning to the Celtic peoples, often being centres of ritual and beliefs in the mystic and spiritual – a belief which in some cases carries on to today.Fact|date=August 2008Tors are composed usually of
granite ormetamorphic rock s. Tors can also be found around any previously erupted volcanoes (althoughDevonian andCarboniferous outcrops are also found), though occasionally of other hard rocks such asquartzite , and are the result of millions of years ofweathering . In prehistoric times, when the land was covered in forest, rain water seeped into the ground and gradually weathered the bedrock through its natural cracks, or joints. Once the land became exposed, the weathering was accelerated, particularly during theIce age when freezing water expanded in the cracks. The result can be seen today in dramatic rock formations.Weathering has also given rise to circular "rock basins'" formed by the accumulation of water and the repeated freezing and thawing – a fine example is to be found at
Kes Tor on Dartmoor.As the weathering of the tors continues, the rock is broken down into ever smaller sizes. Many hillsides are covered with loose rocks, known as clitter, which have provided ready building materials for thousands of years. Eventually the granite is weathered down to a level equivalent to sandy
gravel , known as growan, which consists of individual crystals.The most distinctive granite landform in temperature countries is the tor and in tropical regions, the inselbergs. Both suggest the removal of material by solifluction and hence lead to the opinion that tors and inselbergs are relict features.
Tors on Dartmoor
Dartmoor represents one of the largest areas of exposed granite in the
United Kingdom , covering an area of 241 square miles (625 square kilometres). [Source: Dartmoor National ParkFact|date=February 2007] It is part of a chain of granite stretching through Cornwall, as far as theIsles of Scilly .Some of the more durable granite survived to form the rocky crowns of Dartmoor tors. One of the best known is at
Haytor , on the eastern part of the moor, whose granite is of unusually fine quality and was quarried during the 19th and early 20th centuries. Its stone was used to construct the pillars outside theBritish Museum inLondon , and to buildLondon Bridge (now inArizona ). The last granite to be quarried there was used to buildExeter War Memorial in 1919.Ten Tors is an annual weekend hike on Dartmoor.For a full list of Dartmoor's tors see
List of Dartmoor tors and hills .Other tors
British Isles
*Black Tor,
Derwent Edge (538m)
*Brent Tor
*Dovestone Tor, Derwent Edge (505m)
*Glastonbury Tor
*Great Tor, Bamford,Peak District
*Howshaw Tor, overlookingSheffield
*Ladybower Tor,Upper Derwent Valley
*Low tor
*Mam Tor (517m)
*Shining Tor
*Stiperstones ,Shropshire Hills
*Over Owler Tor (375m)
*Higgar Tor (384m)
*Whinstone Lee Tor
*White Tor, Derwent Moors (487m)
*The Barns of Bynack, Granite tors onBynack More in theCairngorms
*The Salt Cellar, Gritstone tor onDerwent Edge in thePeak District
* Tor Heard,Long Whatton North America
* Angel Rocks north of
Fairbanks, Alaska , USAAfrica
*
Kit-Mikayi , Kenyaee also
*
List of peaks of the Peak District
*The bookRed Shift (novel) the Mow Cop Tor at the centre of its plot.External links
* [http://www.richkni.co.uk/dartmoor/tors.htm Pictures of Dartmoor tors]
Notes
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