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RODINIA (from the Russian "Родина", _ródina_, meaning "The Motherland") is a Neoproterozoic supercontinent that was assembled 1.3–0.9 billion years ago and broke up 750–633 million years ago. Valentine & Moores 1970 were probably the first to recognise a Precambrian supercontinent, which they named ' Pangaea I'. It was renamed 'Rodinia' by McMenamin ">

Rodinia broke up in the Neoproterozoic with its continental fragments reassembled to form Pannotia 633–573 million years ago. In contrast with Pannotia, little is known yet about the exact configuration and geodynamic history of Rodinia. Paleomagnetic evidence provides some clues to the paleolatitude of individual pieces of the Earth\'s crust , but not to their longitude , which geologists have pieced together by comparing similar geologic features, often now widely dispersed.

The extreme cooling of the global climate around 717–635 million years ago (the so-called Snowball Earth of the Cryogenian Period ) and the rapid evolution of primitive life during the subsequent Ediacaran and Cambrian periods are thought to have been triggered by the breaking up of Rodinia or to a slowing down of tectonic processes.

CONTENTS

* 1 Geodynamics

* 1.1 Paleogeographic reconstructions * 1.2 Break up

* 2 Influence on paleoclimate and life * 3 See also

* 4 References

* 4.1 Notes * 4.2 Bibliography

* 5 External links

GEODYNAMICS

Life timeline view • discuss • edit -4500 — – -4000 — – -3500 — – -3000 — – -2500 — – -2000 — – -1500 — – -1000 — – -500 — – 0 — _WATER _ Single-celled life _PHOTOSYNTHESIS _ EUKARYOTES Multicellular life LAND LIFE DINOSAURS MAMMALS FLOWERS ← Earliest Earth (−4540 ) ← Earliest water ← Earliest life ← LHB meteorites ← Earliest oxygen ← Atmospheric oxygen ← Oxygen crisis ← Earliest sexual reproduction ← Ediacara biota ← Cambrian explosion ← Earliest humans P h a n e r o z o i c

P r o t e r o z o i c

A r c h e a n H a d e a n Pongola Huronian Cryogenian Andean Karoo Quaternary Axis scale : millions of years . Orange labels: known _ICE AGES_. Also see: _ Human timeline _ and _Nature timeline _

PALEOGEOGRAPHIC RECONSTRUCTIONS

The idea that a supercontinent existed in the early Neoproterozoic arose in the 1970s, when geologists determined that orogens of this age exist on virtually all cratons . 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. 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.

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 (the later paleocontinent of Baltica ), the Amazonian craton ("Amazonia") and the West African craton ; in the south with the Río de la Plata and São Francisco cratons ; in the southwest with the Congo and Kalahari cratons ; and in the northeast with Australia , India and eastern Antarctica . The positions of Siberia and North and South China north of the North American craton differ strongly depending on the reconstruction:

* SWEAT -Configuration (Southwest US-East Antarctica craton): Antarctica is on the Southwest of Laurentia and Australia is at the North of Antarctica. * AUSWUS-Configuration (Australia-western US): Australia is at the West of Laurentia. * AUSMEX-Configuration (Australia-Mexico): Australia is at the location of nowadays Mexico relative to Laurentia. * The "Missing-link" model by Li et al. 2008 which has South China between Australia and the west coast of Laurentia. A revised "Missing-link" model is proposed in which Tarim Block serves as an extended or alternative missing-link between Australia and Laurentia. * Siberia attached to the western US (via the Belt Supergroup ), as in Sears the closure of the Braziliano, Adamastor, and Mozambique oceans; and the Pan-African orogeny. The result was the formation of Gondwana.

The Rodinia hypothesis assumes that rifting 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 million years ago. As early as 850 and 800 million years ago, 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. This rift developed into the Adamastor Ocean during the Ediacaran.

Around 550 million years ago, on the boundary between the Ediacaran and Cambrian, the first group of cratons eventually fused again with Amazonia, West Africa and the Rio de la Plata cratons. This tectonic phase is called the Pan-African orogeny . It created a configuration of continents that would remain stable for hundreds of millions of years in the form of the continent Gondwana .

In a separate rifting event about 610 million years ago (halfway in the Ediacaran period), the Iapetus Ocean formed. The eastern part of this ocean formed between Baltica and Laurentia, the western part between Amazonia and Laurentia. Because the exact moments of this separation and the partially contemporaneous Pan-African orogeny are hard to correlate, it might be that all continental mass was again joined in one supercontinent between roughly 600 and 550 million years ago. This hypothetical supercontinent is called Pannotia .

INFLUENCE ON PALEOCLIMATE AND LIFE

Unlike later supercontinents, Rodinia would have been entirely barren. Rodinia existed before complex life colonized dry land. Based on sedimentary rock analysis Rodinia's formation happened when the ozone layer was not as extensive as it is today. Ultraviolet light discouraged organisms from inhabiting its interior. Nevertheless, its existence did significantly influence the marine life of its time.

In the Cryogenian period the Earth experienced large glaciations , and temperatures were at least as cool as today. Substantial areas of Rodinia may have been covered by glaciers or the southern polar ice cap .

Low temperatures may have been exaggerated during the early stages of continental rifting. Geothermal heating peaks in crust about to be rifted; and since warmer rocks are less dense , the crustal rocks rise up relative to their surroundings. This rising creates areas of higher altitude, where the air is cooler and ice is less likely to melt with changes in season, and it may explain the evidence of abundant glaciation in the Ediacaran period.

The eventual rifting of the continents created new oceans and seafloor spreading , which produces warmer, less dense oceanic lithosphere . Due to its lower density, hot oceanic lithosphere will not lie as deep as old, cool oceanic lithosphere. In periods with relatively large areas of new lithosphere, the ocean floors come up, causing the eustatic sea level to rise. The result was a greater number of shallower seas.

The increased evaporation from the larger water area of the oceans may have increased rainfall, which, in turn, increased the weathering of exposed rock. By inputting data on the ratio of stable isotopes 18O:16O into computer models, it has been shown that, in conjunction with quick weathering of volcanic rock , this increased rainfall may have reduced greenhouse gas levels to below the threshold required to trigger the period of extreme glaciation known as Snowball Earth .

Increased volcanic activity also introduced into the marine environment biologically active nutrients, which may have played an important role in the development of the earliest animals.

SEE ALSO

* Columbia for one possible reconstruction of an earlier supercontinent * List of supercontinents * Supercontinent cycle

REFERENCES

NOTES

* ^ "Research paper suggests East Antarctica and North America once linked". _The Antarctic Sun_. United States Antarctic Program. 26 August 2011. Retrieved 15 November 2012. Reconstruction originally published in Goodge et al. 2008 , Fig 3A, p. 238; research paper mentioned is Loewy et al. 2011 . * ^ Redfern 2001 , p. 335 * ^ Li et al. 2008 , Abstract * ^ Li et al. 2008 , Introduction, p. 180 * ^ Meert 2012 , Supercontinents in Earth history, p. 998 * ^ Zhao et al. 2002 ; Zhao et al. 2004 * ^ _A_ _B_ Piper 2013 * ^ Dewey the name 'Rodinia' was first used in McMenamin for the correlation between the Australian Musgrave orogeny and the Grenville orogeny see Wingate, Pisarevsky fig. 5, p. 127 * ^ For a comparison of the SWEAT, AUSWUS, AUSMEX, and Missing-link reconstructions see Li et al. 2008 , Fig. 2, p. 182. For a comparison between the "consensus" Rodinia of Li et al. 2008 and the original proposal of McMenamin & McMenamin 1990 see Nance, Murphy Weil et al. 1998 , Fig. 6, p. 21; Torsvik 2003 , Fig. ' Rodinia old and new', p. 1380; Dalziel 1997 , Fig. 11, p. 31; Scotese 2009 , Fig. 1, p. 69 * ^ Moores 1991 ; Goodge et al. 2008 * ^ Li et al. 2008 , Fig. 4, p. 188; fig. 8, p. 198 * ^ Wen, Bin; Evans, David A. D.; Li, Yong-Xiang (2017-01-15). " Neoproterozoic paleogeography of the Tarim Block: An extended or alternative "missing-link" model for Rodinia?". _ Earth and Planetary Science Letters_. 458: 92–106. Bibcode :2017E&PSL.458...92W. doi :10.1016/j.epsl.2016.10.030 . * ^ _A_ _B_ "Other Reconstructions for Rodinia based on sources for Mojavia". Department of Geological Sciences, University of Colorado Boulder. May 2002. Retrieved 20 September 2010. * ^ Scotese 2009 ; Torsvik, Gaina & Redfield 2008 * ^ _A_ _B_ Torsvik 2003 , p. 1380 * ^ Piper 2010 * ^ Bogdanova, Pisarevsky & Li 2009 , Breakup of Rodinia (825–700 Ma), pp. 266–267 * ^ _A_ _B_ McMenamin ">

BIBLIOGRAPHY

* Bogdanova, S. V.; Pisarevsky, S. A.; Li, Z. X. (2009). "Assembly and Breakup of Rodinia (Some Results of IGCP Project 440)" (PDF). _Stratigraphy and Geological Correlation_. 17 (3): 259–274. Bibcode :2009SGC....17..259B. ISSN 0869-5938 . doi :10.1134/S0869593809030022 . Retrieved 7 February 2016. * Dalziel, I. W. (1997). "Neoproterozoic-Paleozoic geography and tectonics: Review, hypothesis, environmental speculation". _Geological Society of America Bulletin_. 109 (1): 16–42. Bibcode :1997GSAB..109...16D. doi :10.1130/0016-7606(1997)1092.3.CO;2 . * Dewey, J. F. ; Burke, K. C. (1973). "Tibetan, Variscan, and Precambrian basement reactivation: products of continental collision". _Journal of Geology_. 81 (6): 683–692. Bibcode :1973JG.....81..683D. JSTOR 30058995 . doi :10.1086/627920 . * Donnadieu, Y.; Goddéris, Y.; Ramstein, G.; Nédélec, A.; Meert, J. G. (2004). "A \'snowball Earth\' climate triggered by continental break-up through changes in runoff" (PDF). _Nature_. 428 (6980): 303–306. Bibcode :2004Natur.428..303D. PMID 15029192 . doi :10.1038/nature02408 . Retrieved 29 January 2016. * Goodge, J. W.; Vervoort, J. D.; Fanning, C. M.; Brecke, D. M.; Farmer, G. L.; Williams, I. S.; Myrow, P. M.; DePaolo, D. J. (2008). "A positive test of East Antarctica– Laurentia juxtaposition within the Rodinia supercontinent" (PDF). _Science_. 321 (5886): 235–240. Bibcode :2008Sci...321..235G. ISSN 0036-8075 . PMID 18621666 . doi :10.1126/science.1159189 . Retrieved 4 February 2016. * Li, Z. X.; Bogdanova, S. V.; Collins, A. S.; Davidson, A.; De Waele, B.; Ernst, R. E.; Fitzsimons, I. C. W.; Fuck, R. A.; Gladkochub, D. P.; Jacobs, J.; Karlstrom, K. E.; Lul, S.; Natapov, L. M.; Pease, V.; Pisarevsky, S. A.; Thrane, K.; Vernikovsky, V. (2008). "Assembly, configuration, and break-up history of Rodinia: A synthesis" (PDF). _ Precambrian Research_. 160: 179–210. doi :10.1016/j.precamres.2007.04.021 . Retrieved 6 February 2016. * Loewy, S. L.; Dalziel, I. W. D.; Pisarevsky, S.; Connelly, J. N.; Tait, J.; Hanson, R. E.; Bullen, D. (2011). "Coats Land crustal block, East Antarctica: A tectonic tracer for Laurentia?" (PDF). _Geology_. 39 (9): 859–862. doi :10.1130/G32029.1 . Retrieved 24 January 2016. Lay summary (August 2011). * McMenamin, M. A. ; McMenamin, D. L. (1990). _The emergence of animals: the Cambrian breakthrough_. Columbia University Press. ISBN 0-231-06647-3 . * Meert, J.G. (2012). "What\'s in a name? The Columbia (Paleopangaea/Nuna) supercontinent" (PDF). _ Gondwana Research_. 21 (4): 987–993. doi :10.1016/j.gr.2011.12.002 . Retrieved 6 February 2016. * Meert, J.G.; Torsvik, T.H. (2003). "The making and unmaking of a Supercontinent: Rodinia revisited" (PDF). _Tectonophysics_. 375: 261–288. Bibcode :2003Tectp.375..261M. doi :10.1016/S0040-1951(03)00342-1 . * Moores, E. M. (1991). "Southwest US-East Antarctic (SWEAT) connection: a hypothesis" (PDF). _Geology_. 19 (5): 425–428. doi :10.1130/0091-7613(1991)0192.3.CO;2 . Retrieved 21 February 2016. * Nance, R. D.; Murphy, J. B.; Santosh, M. (2014). "The supercontinent cycle: a retrospective essay" (PDF). _Gondwana Research_. 25 (1): 4–29. doi :10.1016/j.gr.2012.12.026 . Retrieved 6 February 2016. * Piper, J. D. A. (2010). "Palaeopangaea in Meso-Neoproterozoic times: The palaeomagnetic evidence and implications to continental integrity, supercontinent form and Eocambrian break-up" (PDF). _Journal of Geodynamics_. 50 (3): 191–223. doi :10.1016/j.jog.2010.04.004 . Retrieved 24 January 2016. * Piper, J. D. A. (2013). "A planetary perspective on Earth evolution: lid tectonics before plate tectonics" (PDF). _Tectonophysics_. 589: 44–56. doi :10.1016/j.tecto.2012.12.042 . Retrieved 1 February 2016. * Pisarevsky, S. A.; Murphy, J. B.; Cawood, P. A.; Collins, A. S. (2008). "Late Neoproterozoic and Early Cambrian palaeogeography: models and problems" (PDF). _Geological Society of London, Special Publications_. 294 (1): 9–31. Bibcode :2008GSLSP.294....9P. doi :10.1144/SP294.2 . Retrieved 6 February 2016. * Redfern, R. (2001). _Origins: The Evolution of Continents, Oceans and Life_. University of Oklahoma Press. ISBN 0-8061-3359-7 . Retrieved 6 February 2016. * Scotese, C. R. (2009). "Late Proterozoic plate tectonics and palaeogeography: a tale of two supercontinents, Rodinia and Pannotia" (PDF). _Geological Society, London, Special Publications_. 326 (1): 67–83. doi :10.1144/SP326.4 . Retrieved 29 November 2015. Lay summary (February 2001). * Sears, J. W.; Price, R. A. (2000). "New look at the Siberian connection: No SWEAT". _Geology_. 28 (5): 423–426. Bibcode :2000Geo....28..423S. ISSN 0091-7613 . doi :10.1130/0091-7613(2000)282.0.CO;2 . * Stanley, S. M. (1999). _ Earth System History_. W. H. Freeman & Co. ISBN 0-7167-2882-6 . * Torsvik, T. H. (2003). "The Rodinia Jigsaw Puzzle" (PDF). _Science_. 300 (5624): 1379–1381. PMID 12775828 . doi :10.1126/science.1083469 . Retrieved 24 January 2016. * Torsvik, T. H.; Gaina, C.; Redfield, T. F. (2008). " Antarctica and Global Paleogeography: From Rodinia, through Gondwanaland and Pangea, to the birth of the Southern Ocean and the opening of gateways" (PDF). In Cooper, A. K.; Barrett, P. J.; Stagg, H.; Storey, B.; Stump, E.; Wise, W.; the 10th ISAES editorial team. _Antarctica: A Keystone in a Changing World. Proceedings of the 10th International Symposium on Antarctic Earth Sciences_. Washington, DC: The National Academies Press. pp. 125–140. doi :10.3133/of2007-1047.kp11 . Retrieved 30 January 2016. * Valentine; Moores, E. M. (1970). "Plate-tectonic Regulation of Faunal Diversity and Sea Level: a Model". _Nature_. 228: 657–659. PMID 16058645 . doi :10.1038/228657a0 . * Weil, A. B.; Van der Voo, R.; Mac Niocaill, C.; Meert, J. G. (1998). "The Proterozoic supercontinent Rodinia: paleomagnetically derived reconstructions for 1100 to 800 Ma" (PDF). _ Earth and Planetary Science Letters_. 154 (1): 13–24. Bibcode :1998E&PSL.154...13W. doi :10.1016/S0012-821X(97)00127-1 . Retrieved 6 February 2016. * Wingate, M. T. D.; Pisarevsky, S. A.; Evans, D. A. D. (2002). " Rodinia connections between Australia and Laurentia: no SWEAT, no AUSWUS?" (PDF). _Terra Nova_. 14 (2): 121–128. doi :10.1046/j.1365-3121.2002.00401.x . Retrieved 1 February 2016. * Ziegler, P. A. (1990). _Geological Atlas of Western and Central Europe_ (2nd ed.). Shell Internationale Petroleum Maatschappij BV . ISBN 90-6644-125-9 . * Zhao, G.; Cawood, P. A.; Wilde, S. A.; Sun, M. (2002). "Review of global 2.1–1.8 Ga orogens: implications for a pre-Rodinia supercontinent" (PDF). _Earth-Science Reviews_. 59 (1): 125–162. Bibcode :2002ESRv...59..125Z. doi :10.1016/S0012-8252(02)00073-9 . Retrieved 3 February 2016. * Zhao, G.; Sun, M.; Wilde, S. A.; Li, S. (2004). "A Paleo-Mesoproterozoic supercontinent: assembly, growth and breakup" (PDF). _Earth-Science Reviews_. 67 (1): 91–123. Bibcode :2004ESRv...67...91Z. doi :10.1016/j.earscirev.2004.02.003 . Retrieved 3 February 2016.

EXTERNAL LINKS

_ Look up RODINIA _ in Wiktionary, the free dictionary.

* Scotese Animation: Breakup of Rodinia

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