Pannotia: Difference between revisions

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The formation of Pannotia began during the [[Pan-African orogeny]] when the [[Congo Craton|Congo continent]] got caught between the northern and southern halves of the previous supercontinent [[Rodinia]] some 750 Ma. The peak in this mountain building event was around 640–610 Ma, but these continental collisions may have continued into the Early Cambrian some 530 Ma. The formation of Pannotia was the result of Rodinia turning itself inside out.<ref name="Scotese-2009-Pannotia">{{Harvnb|Scotese|2009|loc=Reconstruction of Pannotia, pp. 71–72}}</ref>
 
When Pannotia had formed, Africa was located at the centre surrounded by the rest of Gondwana: South America, Arabia, Madagascar, India, Antarctica, and Australia. Laurentia, which 'escaped' out of Rodinia, Baltica, and Siberia, kept the relative positions they had in Rodinia. The Cathaysian and [[Cimmeria (continent)|Cimmerian terranes]] (continental blocks of southern Asia) were located along the northern margins of east Gondwana. The [[Avalonia]]n-[[Cadomian Orogeny|Cadomian]] terranes (later to become central Europe, Britain, the North American east coast, and Yucatán) were located along the active northern margins of western Gondwana. This orogeny probably extended north into the [[Ural Mountains|Uralian]] margin of Baltica.<ref name="Scotese-2009-Pannotia" />
 
Pannotia formed by subduction of exterior oceans (a mechanism called extroversion)<ref>{{Harvnb|Murphy|Nance|2013|loc=Introduction, pp. 185–187}}</ref> over a [[geoid]] low, whereas Pangaea formed by subduction of interior oceans (introversion) over a geoid high<ref>{{Harvnb|Murphy|Nance|2013|loc=Discussion, p. 191}}</ref> perhaps caused by [[superplume]]s and [[Supercontinent#Supercontinents and volcanism|slab avalanche events]].<ref>{{Harvnb|Murphy|Nance|2013|loc=Conclusions, p. 192}}</ref>