- Valais Ocean
The Valais Ocean is a disappeared piece of
oceanic crust which was situated between the continentEurope and themicrocontinent Iberia or so calledBriançonnais microcontinent [ [http://www.dinodata.org/Golonka/GLOSSARY.pdf http://www.dinodata.org - Glossary of Plate Tectonic and Paleogeographic Terms] ] . The Valais Ocean is together with other small disappeared oceanicbasin s often called the Alpine or WesternTethys Ocean .Tectonic history
After the breakup of
Pangaea in the earlyMesozoic age the continents Africa,South America , Europe andNorth America began to move away from each other. The breaking up orrift ing was not a process that happened along one clear line. At the southern edge of the European plate the microcontinent Iberia began also to break away from Europe. In the western part of the rift that separated the two landmasses oceanic crust was formed in what is at present theGulf of Biscay , while in the eastern part the Valais Ocean was formed.When in the
Cretaceous period Africa began to move towards Europe again the Valais Ocean was sandwiched between the two continents. To the east the Valais oceanic crust, together with a piece of Iberiancontinental crust (called the Briançonnais terrane) subducted beneath theApulian plate , a part of the Africantectonic plate that had begun to move independently. This process eventually lead to the formation of theAlps . To the west no subduction took place, but the Iberian plate moved along and against the European plate along a largetransform fault , which lead to the formation of thePyrenees .Fragments of Valais oceanic crust have been obducted and can be found as
ophiolite s in thePenninic nappes of the Alps.Name
The Valais Ocean is named after the Swiss canton
Valais .References
ee also
*
Piemont-Liguria Ocean
*Pannonian Sea
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