An orocline — from the Greek words for "mountain" and "to bend" — is a bend or curvature of an Orogeny imposed after it was formed.[. Note that the initial formation does not have to be straight.] The term was introduced by S. Warren Carey in 1955 in a paper setting forth how complex shapes of various orogenic belts could be explained by actual bending, and that understanding this provided "the key to understanding the evolution of the continents".[.] Carey showed that in a dozen cases where such bends were undone the results were substantially identical with continental reconstructions deduced by other means.[.] Recognition of oroclinal bending provided strong support to the subsequent theory of plate tectonics.
Examples
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The Bolivian Orocline is a seaward concave bending in the coast of South America and the Andes mountains at about 18° S.
At this point the orientation of the Andes turns from Northwest in Peru to South in Chile and Argentina.[ The Andean segment north and south of the orocline have been rotated 15° to 20° counter clockwise and clockwise respectively.] The orocline area overlaps with the area of maximum width of the Altiplano. According to Isacks (1988) the orocline is related to crustal shortening. The specific point at 18° S where the coastline bends is known as the Arica Elbow.
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The Maipo Orocline or Maipo Transition Zone is an orocline located between 30° S and 38°S in the Andes with a break in trend at 33° S.
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The Arauco Orocline a subtle orocline located at 37° S in south-central Chile. It marks a seaward-convex bend in the Andes.
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Orocline
and Gibraltar Orocline,[ Faccenna C., Piromallo C., Crespo-Blanc A., Jolivet L., Federico Rossetti F.(2004) Lateral slab deformation and the origin of the western Mediterranean arcs, Tectonics, 23: (1) 1-21 [1]] Spain.
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Carpathian Orocline, Romania.
[Shaw J., Johnston S. T., The Carpathian–Balkan bends: an oroclinal record of ongoing Arabian–Eurasian collision, Journal of the Virtual Explorer, 43(4)
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Oroclines in cratons
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Bothnian oroclines in the Svecofennian Domain in Finland and Sweden.
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Inari orocline including the Lapland Granulite Belt in Finland, Norway and Russia.
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Lachlan Orocline, eastern Australia
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Dabashan Orocline, China
See also
Notes
External links