Balancing rock
Encyclopedia
Bedrock
In stratigraphy, bedrock is the native consolidated rock underlying the surface of a terrestrial planet, usually the Earth. Above the bedrock is usually an area of broken and weathered unconsolidated rock in the basal subsoil...
or on glacial till
Till
thumb|right|Closeup of glacial till. Note that the larger grains in the till are completely surrounded by the matrix of finer material , and this characteristic, known as matrix support, is diagnostic of till....
. Some formations known by this name only appear to be balancing but are in fact firmly connected to a base rock by a pedestal or stem. There is no single scientific definition of the term, and it has been applied to a variety of rock features that fall into one of four general categories:
- A glacial erraticGlacial erraticA glacial erratic is a piece of rock that differs from the size and type of rock native to the area in which it rests. "Erratics" take their name from the Latin word errare, and are carried by glacial ice, often over distances of hundreds of kilometres...
is a boulder that was transported and deposited by glaciers to a resting place on soil, on bedrock or on other boulders. It usually has a different lithologyLithologyThe lithology of a rock unit is a description of its physical characteristics visible at outcrop, in hand or core samples or with low magnification microscopy, such as colour, texture, grain size, or composition. It may be either a detailed description of these characteristics or be a summary of...
than the other rocks around it. Not all glacial erractics are balancing rocks; some are firmly seated on the ground. Some balancing erractics have come to be known as rocking stoneRocking stoneRocking stones are large stones that are so finely balanced that the application of just a small force causes them to rock. They are found throughout the world. Some are man-made megaliths, but others are natural, often left by glaciers.Logan or rocking stones are known in Scotland sometimes as...
s, also known as logan rocks, logan stones or logans, because they are so finely balanced that the application of just a small force may cause them to rock or sway. A good example of a rocking stone is the Logan RockLogan RockThe Logan Rock near the village of Treen in Cornwall, England, UK, is an example of a logan or rocking stone. Although it weighs some 80 tons, it was dislodged in 1824 by a group of British seamen, intent on showing what the Navy could do...
in Cornwall, England, United Kingdom; another is the Trembling Rock in Brittany, France. - A perched block, also known as a perched boulder or perched rock, is a large, detached rock fragment that most commonly was transported and deposited by a glacier to a resting place on glacial tillTillthumb|right|Closeup of glacial till. Note that the larger grains in the till are completely surrounded by the matrix of finer material , and this characteristic, known as matrix support, is diagnostic of till....
, often on the side of a hill or slope. Some perched blocks were not produced by glacial action but were the aftermath of a rock fall, landslideLandslideA landslide or landslip is a geological phenomenon which includes a wide range of ground movement, such as rockfalls, deep failure of slopes and shallow debris flows, which can occur in offshore, coastal and onshore environments...
or avalancheAvalancheAn avalanche is a sudden rapid flow of snow down a slope, occurring when either natural triggers or human activity causes a critical escalating transition from the slow equilibrium evolution of the snow pack. Typically occurring in mountainous terrain, an avalanche can mix air and water with the...
. - An erosional remnant is a persisting rock formation that remains after extensive wind, water and/or chemical erosion. To the untrained eye it may appear to be visually like a glacial erratic, but instead of being transported and deposited it was carved from the local bedrock. Many good examples of erosional remnants are seen in the Devils Marbles Conservation Reserve in the Northern TerritoryNorthern TerritoryThe Northern Territory is a federal territory of Australia, occupying much of the centre of the mainland continent, as well as the central northern regions...
of AustraliaAustraliaAustralia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...
. - A pedestal rockMushroom rocksA mushroom rock, also called rock pedestal or a pedestal rock, is a naturally occurring rock whose shape, as its name implies, strikingly resembles a mushroom. The rocks are deformed in a number of different ways: the processing of erosion and weathering, glacial action or from a sudden disturbance...
, also known as a rock pedestal or mushroom rock, is not a true balancing rock but is a single continuous rock form with a very small base leading up to a much larger crown. Some of these formations are called balancing rocks because of their appearance. The undercut base was attributed for many years to simple wind abrasion but is now believed to result from a combination of wind and enhanced chemical weathering at the base where moisture would be retained longest. Some pedestal rocks sitting on taller spire formations are known as hoodoosHoodoo (geology)A hoodoo is a tall, thin spire of rock that protrudes from the bottom of an arid drainage basin or badland. Hoodoos consist of relatively soft rock topped by harder, less easily eroded stone that protects each column from the elements...
.
Africa
Zimbabwe- The Balancing RocksBalancing RocksThe Balancing Rocks are geomorphological features of igneous rocks found in many parts of Zimbabwe, and are particularly noteworthy in Matopos National Park and near the township of Epworth to the southeast of Harare. The formations are of natural occurrence in a perfectly balanced state without...
are a geological formation found in the township of EpworthEpworth, ZimbabweEpworth is a suburb in south-eastern Harare. It is home to some famous balancing rocks.- Background :The bustling suburb is located about twelve kilometers out of the Harare City Centre. It is a high density suburb populated by mainly poor residents of Harare. It is bisected by a stream into two...
, southeast of HarareHarareHarare before 1982 known as Salisbury) is the largest city and capital of Zimbabwe. It has an estimated population of 1,600,000, with 2,800,000 in its metropolitan area . Administratively, Harare is an independent city equivalent to a province. It is Zimbabwe's largest city and its...
, the capital of ZimbabweZimbabweZimbabwe is a landlocked country located in the southern part of the African continent, between the Zambezi and Limpopo rivers. It is bordered by South Africa to the south, Botswana to the southwest, Zambia and a tip of Namibia to the northwest and Mozambique to the east. Zimbabwe has three...
. It is a formation of rocks perfectly balanced without other supports.
- The Mother and Child balancing rocks are a well-known feature in Matobo National ParkMatobo National ParkThe Matobo National Park forms the core of the Matobo or Matopos Hills, an area of granite kopjes and wooded valleys commencing some 35 kilometres south of Bulawayo, southern Zimbabwe...
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Asia and Australia
Australia- The Devils Marbles Conservation Reserve is a vast field of erosional remnants.
Europe
- England
- The Brimham RocksBrimham RocksThe Brimham Rocks are balancing rock formations located on Brimham Moor in North Yorkshire, England. The rocks stand at a height of nearly 30 metres in an area owned by the National Trust which is part of the Nidderdale Area of Outstanding Natural Beauty....
are a group of outstanding pedestal rock formations in North YorkshireNorth YorkshireNorth Yorkshire is a non-metropolitan or shire county located in the Yorkshire and the Humber region of England, and a ceremonial county primarily in that region but partly in North East England. Created in 1974 by the Local Government Act 1972 it covers an area of , making it the largest...
.
- Poland
- Chybotek – graniteGraniteGranite is a common and widely occurring type of intrusive, felsic, igneous rock. Granite usually has a medium- to coarse-grained texture. Occasionally some individual crystals are larger than the groundmass, in which case the texture is known as porphyritic. A granitic rock with a porphyritic...
balancing rock in Giant Mountains (Karkonosze) - Chybotek – granite balancing rock in Jizera MountainsJizera MountainsJizera Mountains , or Izera Mountains, are part of the Western Sudetes on the border between the Czech Republic and Poland. The major part is formed from granite, with some areas formed from basalt. The mountains got their name from the Jizera River, which rises at the southern base of Smrk...
(Góry Izerskie).
North America
Canada
- Nova Scotia
- A tall basalt stack appears to balance precariously above the water near Digby, Nova ScotiaDigby, Nova ScotiaDigby is a Canadian town in western Nova Scotia. It is the shiretown and largest population centre in Digby County.The town is situated on the western shore of the Annapolis Basin near the entrance to the Digby Gut which connects the basin to the Bay of Fundy.Named after Admiral Robert Digby, RN,...
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United States
- Arizona
- Several pedestals rocks are found within the boundaries of the Chiricahua National MonumentChiricahua National MonumentChiricahua National Monument is a unit of the National Park Service located in the Chiricahua Mountains. It is famous for its extensive vertical rock formations. The monument is located approximately southeast of Willcox, Arizona. It preserves the remains of an immense volcanic eruption that...
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- California
- A large balancing rock may be easily seen at D.L. Bliss State Park on the west shore of Lake TahoeLake TahoeLake Tahoe is a large freshwater lake in the Sierra Nevada of the United States. At a surface elevation of , it is located along the border between California and Nevada, west of Carson City. Lake Tahoe is the largest alpine lake in North America. Its depth is , making it the USA's second-deepest...
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- Colorado
- A huge sandstone boulder hangs precariously near the roadway in Garden of the GodsGarden of the GodsGarden of the Gods is a public park located in Colorado Springs, Colorado, USA.-Genesis of the park:Entrance to the park is free according to the wish of Charles Elliott Perkins, whose children donated the land to the city of Colorado Springs in 1909....
park near Colorado Springs.
- Massachusetts
- In Balance Rock Park, in Pittsfield State Forest, a field of massive boulders left on a hillside by receding glaciers is crowned by Balance Rock, a tremendous rock balancing almost unbelievably upon a smaller rock protruding from the ground.
- North Carolina
- The Devil's Head is a large boulder perched on the ledge of a cliff in the Chimney Rock State Park, North Carolina.
- Texas
- Balanced Rock (also called Window Rock) is a large boulder suspended between two pedestals in the Grapevine Hills of Big Bend National ParkBig Bend National ParkBig Bend National Park is a national park located in the U.S. state of Texas. Big Bend has national significance as the largest protected area of Chihuahuan Desert topography and ecology in the United States, which includes more than 1,200 species of plants, more than 450 species of birds, 56...
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- Utah
- One of the most visited formations in the United States is the Balanced RockBalanced RockBalanced Rock is one of the most popular features of Arches National Park, situated in Grand County, Utah, United States. Balanced Rock is located next to the park's main road, at about 9 miles from the park entrance....
in Arches National ParkArches National ParkArches National Park is a U.S. National Park in eastern Utah. It is known for preserving over 2000 natural sandstone arches, including the world-famous Delicate Arch, in addition to a variety of unique geological resources and formations....
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- Washington
- There is a large glacial erratic at the south end of Omak Lake in Okanogan County.