Editing Rodinia (section)

==Geodynamics==
===Paleogeographic reconstructions===
[[File:Rodinia 900Ma.jpg|thumb|right|Rodinia at 900 Ma. "Consensus" reconstruction of Li et al. 2008.]]
The idea that a supercontinent existed in the early Neoproterozoic arose in the 1970s, when geologists determined that [[orogen]]s of this age exist on virtually all [[craton]]s.<ref>{{Harvnb|Dewey|Burke|1973}}; the name 'Rodinia' was first used in {{Harvnb|McMenamin|McMenamin|1990}}</ref>{{Failed verification|date=February 2016|reason="supercontinent" not mentioned in Dewey & Burke 1973}} Examples are the [[Grenville orogeny]] in North America and the [[Dalslandian orogeny]] in Europe. Since then, many alternative reconstructions have been proposed for the configuration of the cratons in this supercontinent. Most of these reconstructions are based on the correlation of the orogens on different cratons.<ref>See for example the correlation between the North American Grenville and European Dalslandian orogenies in {{Harvnb|Ziegler|1990|p=14}}; for the correlation between the Australian [[Musgrave orogeny]] and the Grenville orogeny see {{Harvnb|Wingate|Pisarevsky|Evans|2002|loc=Implications for Rodinia reconstructions, pp. 124–126; fig. 5, p. 127}}</ref> Though the configuration of the core cratons in Rodinia is now reasonably well known, recent reconstructions still differ in many details. Geologists try to decrease the uncertainties by collecting geological and paleomagnetical data.{{Life timeline}}
Most reconstructions show Rodinia's core formed by the North American Craton (the later [[paleocontinent]] of [[Laurentia]]), surrounded in the southeast with the [[East European craton|East European Craton]] (the later paleocontinent of [[Baltica]]), the [[Amazonian craton|Amazonian Craton]] and the [[West African craton|West African Craton]]; in the south with the [[Río de la Plata craton|Río de la Plata]] and [[São Francisco craton]]s; in the southwest with the [[Congo craton|Congo]] and [[Kalahari craton]]s; and in the northeast with [[Australia (continent)|Australia]], [[Indian subcontinent|India]] and eastern [[Antarctica]]. The positions of [[Siberia (continent)|Siberia]] and [[North China craton|North]] and [[South China craton|South China]] north of the North American craton differ strongly depending on the reconstruction:<ref>For a comparison of the SWEAT, AUSWUS, AUSMEX, and Missing-link reconstructions see {{Harvnb|Li|Bogdanova|Collins|Davidson|2008|loc=Fig. 2, p. 182}}.  For a comparison between the "consensus" Rodinia of {{Harvnb|Li|Bogdanova|Collins|Davidson|2008|}} and the original proposal of {{Harvnb|McMenamin|McMenamin|1990}} see {{Harvnb|Nance|Murphy|Santosh|2014|loc=Fig. 11, p. 9}}.</ref><ref>Examples of reconstructions can be found in {{Harvnb|Stanley|1999|pp=336–337}}; {{Harvnb|Weil|Van der Voo|Mac Niocaill|Meert|1998|loc=Fig. 6, p. 21}}; {{Harvnb|Torsvik|2003|loc=Fig. 'Rodinia old and new', p. 1380}}; {{Harvnb|Dalziel|1997|loc=Fig. 11, p. 31}}; {{Harvnb|Scotese|2009|loc=Fig. 1, p. 69}}</ref><ref>{{cite journal |last1=Wang |first1=Chong |last2=Peng |first2=Peng |last3=Wang |first3=Xinping |last4=Yang |first4=Shuyan |date=October 2016 |title=Nature of three Proterozoic (1680 Ma, 1230 Ma and 775 Ma) mafic dyke swarms in North China: Implications for tectonic evolution and paleogeographic reconstruction |url=https://www.sciencedirect.com/science/article/abs/pii/S0301926816303801 |journal=[[Precambrian Research]] |volume=285 |pages=109–126 |doi=10.1016/j.precamres.2016.09.015 |bibcode=2016PreR..285..109W |access-date=17 December 2022|url-access=subscription }}</ref>
*[[SWEAT (hypothesis)|SWEAT]]-Configuration (Southwest US-East Antarctica craton): Antarctica is southwest of Laurentia, and Australia is north of Antarctica.<ref>{{Harvnb|Moores|1991}}; {{Harvnb|Goodge|Vervoort|Fanning|Brecke|2008}}</ref>
*AUSWUS-Configuration (Australia-western US): Australia is west of Laurentia.
*AUSMEX-Configuration (Australia-Mexico): Australia is at the location of current day Mexico relative to Laurentia.
*The "Missing-link" model by {{Harvnb|Li|Bogdanova|Collins|Davidson|2008|}} which has South China between Australia and the west coast of Laurentia.<ref>{{Harvnb|Li|Bogdanova|Collins|Davidson|2008|loc=Fig. 4, p. 188; fig. 8, p. 198}}</ref> A revised "Missing-link" model is proposed in which Tarim Block serves as an extended or alternative missing-link between Australia and Laurentia.<ref>{{Cite journal|last1=Wen|first1=Bin|last2=Evans|first2=David A. D.|last3=Li|first3=Yong-Xiang|date=2017-01-15|title=Neoproterozoic paleogeography of the Tarim Block: An extended or alternative "missing-link" model for Rodinia?|journal=Earth and Planetary Science Letters|volume=458|pages=92–106|doi=10.1016/j.epsl.2016.10.030|bibcode=2017E&PSL.458...92W}}</ref>
*Siberia attached to the western US (via the [[Belt Supergroup]]), as in {{Harvnb|Sears|Price|2000}}.<ref name="Others" />

Little is known about the paleogeography before the formation of Rodinia. Paleomagnetic and geologic data are only definite enough to form reconstructions from the breakup of Rodinia<ref name="Others">{{cite web
 | title = Other Reconstructions for Rodinia based on sources for Mojavia
 | publisher = Department of Geological Sciences, University of Colorado Boulder | date = May 2002
 | url = http://www.colorado.edu/GeolSci/Resources/WUSTectonics/mojavia/others.html | access-date = 20 September 2010}}</ref> onwards. Rodinia is considered to have formed between 1.3 and 1.23 Ga and broke up again before 750 Ma.<ref name="Torsvik2003">{{Harvnb|Torsvik|2003|p=1380}}</ref> Rodinia was surrounded by the [[superocean]] [[Mirovia]].

According to J.D.A. Piper, Rodinia is one of two models for the configuration and history of the [[continental crust]] in the latter part of [[Precambrian]] times. The other is [[Paleopangea]], Piper's own concept.<ref>{{Harvnb|Piper|2010}}</ref> Piper proposes an alternative hypothesis for this era and the previous ones. This idea rejects that Rodinia ever existed as a transient supercontinent subject to progressive break-up in the late [[Proterozoic]] and instead that this time and earlier times were dominated by a single, persistent "Paleopangaea" supercontinent. As evidence, he suggests an observation that the palaeomagnetic poles from the continental crust assigned to this time conform to a single path between 825 and 633 Ma and latterly to a near-static position between 750 and 633 Ma.<ref name=Piper>{{Harvnb|Piper|2013}}</ref> This latter solution predicts that break-up was confined to the [[Ediacaran]] period and produced the dramatic environmental changes that characterised the transition between the Precambrian and [[Phanerozoic]]. However, this theory has been widely criticized, as incorrect applications of paleomagnetic data have been pointed out.<ref name="li2009">{{cite journal |last1=Z.X |first1=Li |title=How not to build a supercontinent: A reply to J.D.A. Piper |journal=Precambrian Research |date=October 2009 |volume=174 |issue=1–2 |pages=208–214 |doi=10.1016/j.precamres.2009.06.007|bibcode=2009PreR..174..208L }}</ref>

===Breakup===
In 2009 UNESCO's [[International Geoscience Programme]] project 440, named "Rodinia Assembly and Breakup," concluded that Rodinia broke up in four stages between 825 and 550 Ma:<ref>{{Harvnb|Bogdanova|Pisarevsky|Li|2009|loc=Breakup of Rodinia (825–700 Ma), pp. 266–267}}</ref>
* The breakup was initiated by a [[superplume]] around 825–800 Ma whose influence—such as crustal arching, intense bimodal magmatism, and accumulation of thick rift-type sedimentary successions—has been recorded in South Australia, South China, Tarim, Kalahari, India, and the Arabian-Nubian Craton.
* Rifting progressed in the same cratons 800–750 Ma and spread into Laurentia and perhaps Siberia. India (including Madagascar) and the Congo–São Francisco Craton were either detached from Rodinia during this period or simply never were part of the supercontinent.
* As the central part of Rodinia reached the Equator around 750–700 Ma, a new pulse of magmatism and rifting continued the disassembly in western Kalahari, West Australia, South China, Tarim, and most margins of Laurentia.
* 650–550 Ma several events coincided: the opening of the [[Iapetus Ocean]]; the closure of the Braziliano, [[Adamastor Ocean|Adamastor]], and Mozambique oceans; and the [[Pan-African orogeny]]. The result was the formation of [[Gondwana]].

The Rodinia hypothesis assumes that [[rift]]ing did not start everywhere simultaneously. Extensive lava flows and volcanic eruptions of Neoproterozoic age are found on most continents, evidence for large scale rifting about 750 Ma.<ref name="mcmenamin" /> As early as 850 to 800 Ma,<ref name="Torsvik2003" /> a rift developed between the continental masses of present-day Australia, East Antarctica, India and the Congo and Kalahari cratons on one side and later Laurentia, Baltica, Amazonia and the West African and Rio de la Plata cratons on the other.<ref>{{Harvnb|Torsvik|2003|loc=Fig. 'Rodinia old and new', p. 1380}}</ref> This rift developed into the Adamastor Ocean during the [[Ediacaran]].

Around 550 Ma, near the boundary between the Ediacaran and Cambrian, the first group of cratons fused again with Amazonia, West Africa and the Rio de la Plata cratons<ref>See for example reconstructions in {{Harvnb|Pisarevsky|Murphy|Cawood|Collins|2008|loc=Fig. 4, p. 19}}</ref> during the Pan-African orogeny, which caused the development of Gondwana.

In a separate rifting event about 610 Ma, the Iapetus Ocean formed. The eastern part of this ocean formed between Baltica and Laurentia, the western part between Amazonia and Laurentia. Because the timeframe of this separation and the partially contemporaneous Pan-African orogeny are difficult to correlate, it might be that all continental mass was again joined in one supercontinent between roughly 600 and 550 Ma. This hypothetical supercontinent is called [[Pannotia]].