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Pangaea was C-shaped, with the bulk of its mass stretching between Earth's northern and southern polar regions and surrounded by the superocean Panthalassa and the Paleo-Tethys and subsequent Tethys Oceans. Pangaea is the most recent supercontinent to have existed and the first to be reconstructed by geologists.
They split in two groups, with one returning to Gondwana (and stayed there after Pangaea split) while the other staying in Laurasia (until further descendants switched to Gondwana starting from the Jurassic). In the early Eocene, a peak in global warming led to a pan-Arctic fauna with alligators and amphibians present north of the Arctic Circle.
Location of the Hercynian-Alleghenian mountain belts in the middle of the Carboniferous period.Present day coastlines are indicated in grey for reference. [1]The Variscan orogeny, or Hercynian orogeny, was a geologic mountain-building event caused by Late Paleozoic continental collision between Euramerica (Laurussia) and Gondwana to form the supercontinent of Pangaea.
Gondwana formed part of Pangaea for c. 150 Ma [31] Gondwana and Laurasia formed the Pangaea supercontinent during the Carboniferous. Pangaea began to break up in the Mid-Jurassic when the Central Atlantic opened. [32] In the western end of Pangaea, the collision between Gondwana and Laurasia closed the Rheic and Paleo-Tethys oceans.
In North America it shows as later phases of the Acadian orogeny. This was happening at around the Equator during the later Carboniferous, forming Pangaea with Avalonia near its centre but partially flooded by shallow sea. [14] In the Jurassic, Pangaea split into Laurasia and Gondwana, with Avalonia as part of Laurasia. [15]
Pangaea's supercontinent cycle is a good example of the efficiency of using the presence or lack of these entities to record the development, tenure, and break-up of supercontinents. There is a sharp decrease in passive margins between 500 and 350 Ma during the timing of Pangaea's assembly.
[5] The second major phase of breakup began in the Early Cretaceous. The South Atlantic Ocean opened around 140 million years ago as Africa separated from South America, and about the same time, India separated from Antarctica and Australia, forming the central Indian Ocean. [citation needed]
Valentine & Moores 1970 were probably the first to recognise a Precambrian supercontinent, which they named "Pangaea I." [5] It was renamed "Rodinia" by McMenamin & McMenamin 1990, who also were the first to produce a plate reconstruction and propose a temporal framework for the supercontinent.