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A supercontinent cycle is the break-up of one supercontinent and the development of another, which takes place on a global scale. [4] Supercontinent cycles are not the same as the Wilson cycle, which is the opening and closing of an individual oceanic basin. The Wilson cycle rarely synchronizes with the timing of a supercontinent cycle. [1]
Map of Pangaea with modern continental outlines. The supercontinent cycle is the quasi-periodic aggregation and dispersal of Earth's continental crust.There are varying opinions as to whether the amount of continental crust is increasing, decreasing, or staying about the same, but it is agreed that the Earth's crust is constantly being reconfigured.
The supercontinent Columbia about 1.6 billion years ago. Columbia, also known as Nuna or Hudsonland, is a hypothetical ancient supercontinent. It was first proposed by John J.W. Rogers and M. Santosh in 2002 [1] and is thought to have existed approximately (Ma), in the Paleoproterozoic era. The assembly of the supercontinent was likely ...
The Cretaceous–Paleogene extinction event killed off all dinosaurs except birds, but plant evolution in Gondwana was hardly affected. [72] Gondwanatheria is an extinct group of non- therian mammals with a Gondwanan distribution (South America, Africa, Madagascar, India, Zealandia and Antarctica) during the Late Cretaceous and Palaeogene. [ 73 ]
Continental assembly and uplift also meant increasingly arid land climates, favoring the evolution of amniote animals and seed plants, whose eggs and seeds were better adapted to dry climates. [40] The early drying trend was most pronounced in western Pangaea, which became a center of the evolution and geographical spread of amniotes.
The plant genus Nothofagus provides a good example of a taxon with a Gondwanan distribution, having originated in the supercontinent and existing in present-day Australia, New Zealand, New Caledonia, and South America's Southern Cone. Angiosperms evolved in northern Gondwana/southern Laurasia during the Early Cretaceous and radiated worldwide.
The continents that had drifted away from Rodinia drifted together again during the Paleozoic: Gondwana, Euramerica, and Siberia/Angara collided to form the supercontinent of Pangea during the Devonian and Carboniferous periods, some 350 million years ago. Pangea was a short-lived supercontinent; it began to break apart again in the early ...
The idea that a supercontinent existed in the early Neoproterozoic arose in the 1970s, when geologists determined that orogens of this age exist on virtually all cratons. [9] [failed verification] Examples are the Grenville orogeny in North America and the Dalslandian orogeny in Europe. Since then, many alternative reconstructions have been ...