 Gondwana 420 million years ago (late Silurian). View centered on the South Pole. | |
| Historical continent | |
|---|---|
| Formed | 600 Mya |
| Type | Supercontinent |
| Today part of | Africa North America South America Australia India Arabia Antarctica Balkans |
| Smaller continents | South America Africa Australia Antarctica Zealandia |
| Tectonic plates | African Plate Antarctic Plate Indo-Australian Plate South American Plate |
Gondwana ( /ɡɒndˈwɑːnə/)[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.
Gondwana was formed by the accretion of several cratons (large stable blocks of the Earth's crust), beginning c. 800 to 650 Ma with the East African Orogeny, the collision of India and Madagascar with East Africa, and culminating in c. 600 to 530 Ma with the overlapping Brasiliano and Kuunga orogenies, the collision of South America with Africa, and the addition of Australia and Antarctica, respectively.[2] Eventually, Gondwana became the largest piece of continental crust of the Palaeozoic Era, covering an area of some 100,000,000 km2 (39,000,000 sq mi),[3] about one-fifth of the Earth's surface. It fused with Euramerica during the Carboniferous to form Pangea. It began to separate from northern Pangea (Laurasia) during the Triassic, and started to fragment during the Early Jurassic (around 180 million years ago). The final stages of break-up, involving the separation of Antarctica from South America (forming the Drake Passage) and Australia, occurred during the Paleogene (from around 66 to 23 million years ago (Ma)). Gondwana was not considered a supercontinent by the earliest definition, since the landmasses of Baltica, Laurentia, and Siberia were separated from it.[4] To differentiate it from the Indian region of the same name (see § Name), it is also commonly called Gondwanaland.[5]
Regions that were part of Gondwana shared floral and zoological elements that persist to the present day.
- ^ "Gondwana". Dictionary.com. Lexico Publishing Group. Archived from the original on 3 March 2016. Retrieved 18 January 2010.
- ^ Meert & Van der Voo 1997, Abstract
- ^ Torsvik & Cocks 2013, Abstract
- ^ Bradley, D.C. (2011). "Secular Trends in the Geologic Record and the Supercontinent Cycle". Earth-Science Reviews. 108 (1–2): 16–33. Bibcode:2011ESRv..108...16B. CiteSeerX 10.1.1.715.6618. doi:10.1016/j.earscirev.2011.05.003. S2CID 140601854.
- ^ "Gondwanaland". Merriam-Webster Online Dictionary. Archived from the original on 29 October 2020. Retrieved 18 January 2010.