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Gondwana (/ ɡ ɒ n d ˈ w ɑː n ə /) [1] was a large landmass, sometimes referred to as a supercontinent. The remnants of Gondwana make up around two-thirds of today's continental area, including South America, Africa, Antarctica, Australia, Zealandia, Arabia, and the Indian Subcontinent.
Because the formation of Gondwana encompassed several continents and extended from the Neoproterozoic to the early Palaeozoic, Pan-African could no longer be considered a single orogeny, [4] but rather an orogenic cycle that included the opening and closing of several large oceans and the collisions of several continental blocks.
The notion that Gondwana was assembled during the Late Precambrian from two older fragments along the Pan-African Mozambique Belt was first proposed in the early 1980s. [3] A decade later this continental collision was named the East African Orogeny, but it was also realised that this was not the simple bringing together of two halves.
Pannotia was centred on the South Pole, hence its name. Pannotia (from Greek: pan-, "all", -nótos, "south"; meaning "all southern land"), also known as the Vendian supercontinent, Greater Gondwana, and the Pan-African supercontinent, was a relatively short-lived Neoproterozoic supercontinent that formed at the end of the Precambrian during the Pan-African orogeny (650–500 Ma), during the ...
The extreme cooling of the global climate around 717–635 Ma (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. [8]
In the Neoproterozoic most of the Earth's landmasses were united in the Rodinia supercontinent.The majority of its bulk consisted of the landmass of Gondwana. [Note 1] Near the end of the Neoproterozoic, during the breakup of this supercontinent, Laurentia [Note 2] and Baltica [Note 3] rifted from the western (Amazonian craton) and northern (African) margins of Gondwana respectively.
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.
About 180 million years ago, a mantle plume under southern Gondwana caused bulging of the continental crust in the area that would later become southern Africa. [2] Within 10–20 million years, rift valleys formed on either side of the central bulge and flooded to become the proto-Atlantic Ocean and proto-Indian Ocean more or less along the present southern African coastline and separating ...