Reikum is an ancient ocean located between Gondwana ( Africa , Australia , Antarctica and South America ) and Lavrussia ( Lawrence , Fennosarmatia and Avalonia ). It bordered on the Tethys Ocean, which is why it is sometimes regarded as its western part. [1] Today, its sutures extend over 10 thousand km from Mexico to Turkey . Closing of the ocean occurred during the formation of Pangea , accompanied by the formation of Hercynian , Allegan folding and folding Ushito . [2]
Etymology
The ocean, located between Gondwana and Lavrentia in the early Cambrian period , was named Iapetus in honor of the ancient Greek god Iapetus , the father of Atlant , since it was actually the predecessor of the Atlantic Ocean . In turn, the ocean, located between Gondwana and Lavrussia in the late Cambrian period and the early Ordovician period , was named Reikum in honor of Rhea , sister of Iapetus. [2] [3]
Ocean History
At the beginning of the Paleozoic era (540 million years ago) around the southern pole of the Earth was the largest mainland, Gondwana . The two smaller continents, Lawrence and Fennosarmatia , were separated from Gondwana by the ocean of Yapetus . During the Ediakar period (635 - 541 million years ago) on the northern edge of Gondwana , Kadom folding , leading to the formation of a volcanic arc of the Cordelier type in the place where the oceanic crust was subduced under Gondwana. When the mid-ocean ridge was subducted at an oblique angle, extensional Russian basins appeared along the northern edge of Gondwana . [4] During Late Cambrian and Early Ordovician, they led to rifts along the northern edge of Gondwana . [5] [6] The rift , in turn, turned into a mid-ocean ridge , which is small continental fragments, such as Avalonia and Carolina , separated from Gondwana.
As soon as the united Avalon-Carolina began its movement north of Gondwana , the Reikum Ocean was formed. In the Silurian period, it reached its maximum width of 4 thousand km. The ocean of Iapetus at that time was closed during the collision of Avalon-Carolina and Lavrentia , which led to the formation of Allegan folding in . [five]
From the early Devonian to the early Carboniferous period , the Reikum ocean closed, culminating in the collision of Gondwana and Lavrentia in Pangea and leading to the formation of the largest Paleozoic folds: Hercynian and Alleganian between the West African part of Gondwana , the southern edge of Fennosarmatia and the eastern edge of Lavrentia , as well as the folding of Ushito between the Amazonian part of Gondwana and the southern edge of Lawrence . [five]
Notes
- ↑ History of the oceans on the site of Igor Garshin
- ↑ 1 2 Nance RD, Gutiérrez-Alonso G., Keppie JD, Linnemann U., Murphy JB, Quesada C., Strachan RA, Woodcock NH Introduction // Evolution of the Rheic ocean . - 2nd ed. - Gondwana Research, 2010 .-- T. 17 .-- S. 2.
- ↑ Murphy JB, Gutierrez-Alonso G., Nance RD, Fernandez-Suarez J., Keppie JD, Quesada C., Strachan RA, Dostal J. Introduction // Origin of the Rheic Ocean: Rifting along a Neoproterozoic suture? . - 5th ed. - Geology, 2006.- T. 34. - S. 325.
- ↑ Scenario from Linnemann U., Pereira F., Jeffries TE, Drost K., Gerdes A. The Cadomian Orogeny and the opening of the Rheic Ocean: The diacrony of geotectonic processes constrained by LA-ICP-MS U – Pb zircon dating ( Ossa-Morena and Saxo-Thuringian Zones, Iberian and Bohemian Massifs). - Tectonophysics, 2008. - T. 461. - S. 21–43.
- ↑ 1 2 3 Murphy JB, Gutierrez-Alonso G., Nance RD, Fernandez-Suarez J., Keppie JD, Quesada C., Strachan RA, Dostal J. Introduction // Origin of the Rheic Ocean: Rifting along a Neoproterozoic suture? . - 5th ed. - Geology, 2006. - T. 34. - S. 325–328.
- ↑ Linnemann, U., Gerdes, A., Drost, K., Buschmann, B. The continuum between Cadomian Orogenesis and opening of the Rheic Ocean: constraints from LA-ICP-MS U – Pb zircon dating and analysis of plate-tectonic setting (Saxo-Thuringian Zone, NE Bohemian Massif, Germany) // The Evolution of the Rheic Ocean: from Avalonian – Cadomian Active Margin to Alleghenian – Variscan Collision / Linnemann U., Nance D., Kraft P., Zulauf G. .. - Geological Society of America, 2007. - T. 423. - S. 61–96. - (Special Paper).