Central Pangean Mountains
{{Short description|Major feature of the supercontinent}}
The Central Pangean Mountains were a massive prehistoric mountain range, trending northeast to southwest, in the central portion of the supercontinent Pangaea during the Carboniferous, Permian and Triassic periods. These were formed as a result of continental crust collision (convergence) between the large continents of Euramerica (also known as Laurussia) in the north, and Gondwana in the south. This collision closed the Rheic Ocean, leading to their connection and the formation of the Pangean supercontinent. At its greatest elevation during the early part of the Permian period, it was comparable in height and length to the present Himalayas. Parts of the range attained elevations around 8,000 to 10,000 meters above sea level, as evidenced by extensive erosion (an estimated 1 million cubic kilometers of rock eroded) caused by the flow of equatorial glaciers.{{Cite journal |last1=Pfeifer |first1=Lily S. |last2=Soreghan |first2=Gerilyn S. |last3=Pochat |first3=Stéphane |last4=Van Den Driessche |first4=Jean |date=2021-01-01 |title=Loess in eastern equatorial Pangea archives a dusty atmosphere and possible upland glaciation |journal=GSA Bulletin |language=en |volume=133 |issue=1–2 |pages=379–392 |bibcode=2021GSAB..133..379P |doi=10.1130/B35590.1 |issn=0016-7606 |doi-access=free |hdl-access=free |hdl=11244/325416}} Remnants of the massive mountain range include the Appalachian Mountains and Ouachita Mountains of North America, as well as the Bohemian Massif and Massif Central of Europe.
A number of mountain building episodes were involved in forming the Central Pangean Mountains, the most notable ones being the Acadian, Caledonian, Alleghenian, Mauritanide and Variscan orogenies, each responsible for separate regions and time periods of mountain generation, leading to various currently present ranges and plateaus. For example, the Caledonian (490-390 Ma) orogeny formed the precursors of the Scottish Highlands and the Scandinavian Mountains; the Appalachians are highly eroded (highest point ~2,000 meters) remnants of the Acadian orogeny.
The eastern portions of the range are also sometimes denoted the Variscan Mountains.
Formation and decline
File:Mollweide Paleographic Map of Earth, 285 Ma (Artinskian Age).png
The Central Pangean Mountains were formed during the collision of Euramerica and northern Gondwana as part of the Variscan and Alleghanian orogenies, which began during the Carboniferous approximately 340 million years ago, and complete by the beginning of the Permian around 295 million years ago, when the range was at its maximum elevation. During the Permian, the mountain range was subjected to intense physical and mechanical weathering, reducing the peaks to around half their original size by the Late Permian (Lopingian) and creating numerous deep intermontane valleys. By the Middle Triassic, the Central Pangean mountains had been substantially reduced in size, and by the earliest Jurassic around 200 million years ago the Pangean range in Western Europe had been reduced to a few upland areas surrounded by deep marine basins, having been rifted apart into channels through mid-continental tectonic divergence and infilling by the sea.{{Citation|last1=Scotese|first1=C.R.|title=Late Permian-Early Jurassic Paleogeography of Western Tethys and the World|date=2017|url=https://linkinghub.elsevier.com/retrieve/pii/B9780128094174000045|work=Permo-Triassic Salt Provinces of Europe, North Africa and the Atlantic Margins|pages=57–95|publisher=Elsevier|language=en|doi=10.1016/b978-0-12-809417-4.00004-5|isbn=978-0-12-809417-4|access-date=2021-03-15|last2=Schettino|first2=A.}}
File:Mollweide Paleographic Map of Earth, 190 Ma (Pliensbachian Age).png
Climate
Climate modeling suggests that the Central Pangean Mountains contributed to the deposition of vast quantities of coal in the late Carboniferous. During the period, the Central Pangean Mountains lay directly beneath the equatorial rainy belt, and in the way of north and western traveling winds from seas.. The mountains created an area of year-round heavy precipitation, reaching approximately 4,000 mm/year and comparable with that of the modern Amazonian rainforest, with no dry season typical of a monsoon climate. This is necessary for the preservation of peat in coal swamps, as it prevented oxidation by air infiltrating into the carbon-sediment rich soil. Consequently, it created to the north a corresponding rain shadow, by blocking the damp air arriving from the Southern Hemisphere, thus contributing to the formation of vast deserts and savannas, leading to what would become the immense Zechstein salt deposits in Europe over geological times. In addition, data from the loess deposits of the Salagou Formation in France, dating to the Permian, indicates that the areas near the peak of the Central Pangean Mountains were likely glaciated, despite being located directly on the equator.
References
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{{Major African geological formations}}
Category:Mountain ranges of Africa
Category:Mountain ranges of Europe
Category:Mountain ranges of North America
Category:Triassic paleogeography
Category:Triassic United States
Category:Appalachian Mountains
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