Pannotia: Difference between revisions
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'''Pannotia''', first described by Ian W. D. Dalziel in [[1997]], is a hypothetical [[supercontinent]] that existed from the [[Pan-African orogeny]] about 600 [[Mya (unit)|million years ago]] to the end of the [[Precambrian]] about 540 million years ago. It is also known as the '''Vendian supercontinent'''.<ref name="palaeos">{{cite web | url = http://www.palaeos.com/Earth/Geography/Pannotia.html | title = Pannotia | work = Palaeos | accessdate = 2006-03-12}}</ref> |
'''Pannotia''', first described by Ian W. D. Dalziel in [[1997]], is a hypothetical [[supercontinent]] that existed from the [[Pan-African orogeny]] about 600 [[Mya (unit)|million years ago]] to the end of the [[Precambrian]] about 540 million years ago. It is also known as the '''Vendian supercontinent'''.<ref name="palaeos">{{cite web | url = http://www.palaeos.com/Earth/Geography/Pannotia.html | title = Pannotia | work = Palaeos | accessdate = 2006-03-12}}</ref> |
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== Formation -- |
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About 750 Ma, the previous supercontinent [[Rodinia]] [[rift (geology)|rifted]] apart into three continents: |
About 750 Ma, the previous supercontinent [[Rodinia]] [[rift (geology)|rifted]] apart into three continents: |
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Protolaurasia rotated southward toward the [[south pole]]. Protogondwana rotated counterclockwise. The Congo craton came between Protogondwana and Protolaurasia about 600 Ma. This formed Pannotia. With so much landmass around the poles, evidence suggests that there were more glaciers during this time than at any other time in [[Geologic time scale|geologic history]].<ref>{{cite web | url = http://www.fossilmuseum.net/Geological_History/PreambrianGelogicalHistory.htm | title = Precambrian Paleobiology | work = Virtual Fossil Museum | accessdate = 2006-03-12}}</ref> |
Protolaurasia rotated southward toward the [[south pole]]. Protogondwana rotated counterclockwise. The Congo craton came between Protogondwana and Protolaurasia about 600 Ma. This formed Pannotia. With so much landmass around the poles, evidence suggests that there were more glaciers during this time than at any other time in [[Geologic time scale|geologic history]].<ref>{{cite web | url = http://www.fossilmuseum.net/Geological_History/PreambrianGelogicalHistory.htm | title = Precambrian Paleobiology | work = Virtual Fossil Museum | accessdate = 2006-03-12}}</ref> |
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== A short lived supercontinent == |
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Pannotia was short-lived. The collisions that formed Pannotia were glancing collisions, and the continents composing Pannotia already had active rifting. By about 540 Ma, or only about 60 million years after Pannotia formed, Pannotia disintegrated into four continents: [[Laurentia]], [[Baltica]], [[Siberia (continent)|Siberia]] and [[Gondwana]]. Later, altered landmasses would recombine to form the most recent supercontinent, [[Pangaea]].<ref>{{cite web | url = http://evolution.berkeley.edu/glossary_entry/glossary.php?word=Pannotia | title = Pannotia | work = UCMP Glossary | accessdate = 2006-03-12}}</ref> |
Pannotia was short-lived. The collisions that formed Pannotia were glancing collisions, and the continents composing Pannotia already had active rifting. By about 540 Ma, or only about 60 million years after Pannotia formed, Pannotia disintegrated into four continents: [[Laurentia]], [[Baltica]], [[Siberia (continent)|Siberia]] and [[Gondwana]]. Later, altered landmasses would recombine to form the most recent supercontinent, [[Pangaea]].<ref>{{cite web | url = http://evolution.berkeley.edu/glossary_entry/glossary.php?word=Pannotia | title = Pannotia | work = UCMP Glossary | accessdate = 2006-03-12}}</ref> |
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Pannotia looked like a "V" that faces the northeast direction. Inside the "V" was an ocean that opened up during the break-up of [[Rodinia]], [[Panthalassic Ocean]], an ocean that will become mostly the [[Pacific Ocean]]. There is a [[mid-ocean ridge]] in the middle of the Panthalassic Ocean. Outside of the "V" was a very large, ancient ocean called [[Panafrican Ocean]] that may have surrounded Pannotia, equivalent to the future Panthalassic Ocean. |
Pannotia looked like a "V" that faces the northeast direction. Inside the "V" was an ocean that opened up during the break-up of [[Rodinia]], [[Panthalassic Ocean]], an ocean that will become mostly the [[Pacific Ocean]]. There is a [[mid-ocean ridge]] in the middle of the Panthalassic Ocean. Outside of the "V" was a very large, ancient ocean called [[Panafrican Ocean]] that may have surrounded Pannotia, equivalent to the future Panthalassic Ocean. |
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==See also== |
== See also == |
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* [[Plate tectonics]] |
* [[Plate tectonics]] |
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* [[Supercontinent cycle]] |
* [[Supercontinent cycle]] |
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Revision as of 12:41, 3 November 2006
Pannotia, first described by Ian W. D. Dalziel in 1997, is a hypothetical supercontinent that existed from the Pan-African orogeny about 600 million years ago to the end of the Precambrian about 540 million years ago. It is also known as the Vendian supercontinent.[1]
== Formation -- About 750 Ma, the previous supercontinent Rodinia rifted apart into three continents:
- Protolaurasia (Protolaurasia broke apart and eventually reformed as Laurasia)
- The continental craton of Congo
- Protogondwana (all of Gondwana except the Congo craton and Atlantica)
Protolaurasia rotated southward toward the south pole. Protogondwana rotated counterclockwise. The Congo craton came between Protogondwana and Protolaurasia about 600 Ma. This formed Pannotia. With so much landmass around the poles, evidence suggests that there were more glaciers during this time than at any other time in geologic history.[2]
A short lived supercontinent
Pannotia was short-lived. The collisions that formed Pannotia were glancing collisions, and the continents composing Pannotia already had active rifting. By about 540 Ma, or only about 60 million years after Pannotia formed, Pannotia disintegrated into four continents: Laurentia, Baltica, Siberia and Gondwana. Later, altered landmasses would recombine to form the most recent supercontinent, Pangaea.[3]
Another term for the supercontinent that is thought to have existed at the end of Neoproterozoic time is "Greater Gondwanaland", suggested by Stern in 1994. This term recognizes that the supercontinent of Gondwana, which formed at the end of the Neoproterozoic, was once part of the much larger end-Neoproterozoic supercontinent.
Pannotia looked like a "V" that faces the northeast direction. Inside the "V" was an ocean that opened up during the break-up of Rodinia, Panthalassic Ocean, an ocean that will become mostly the Pacific Ocean. There is a mid-ocean ridge in the middle of the Panthalassic Ocean. Outside of the "V" was a very large, ancient ocean called Panafrican Ocean that may have surrounded Pannotia, equivalent to the future Panthalassic Ocean.
See also
External link
- An image showing Pannotia according to Christopher Scotese. (it is referred to as the late Precambrian Supercontinent in the image).
References
- ^ "Pannotia". Palaeos. Retrieved 2006-03-12.
- ^ "Precambrian Paleobiology". Virtual Fossil Museum. Retrieved 2006-03-12.
- ^ "Pannotia". UCMP Glossary. Retrieved 2006-03-12.