Ur (continent)
Ur is a hypothetical first supercontinent that should have formed 3 billion years ago, in the early Archean, near the equator. It is believed that it was smaller than the current Australia.
Naming
The name of Ur was proposed by John JW Rogers 1993. The name derives from the German prefix ur - for originally, from old, but also alludes to the Mesopotamian city of Ur, one of the oldest cities in the world and indicates that it is the first and oldest supercontinent. Although Ur was relatively small and the size could not compete with the later supercontinents, which is aptly named super-continent to the extent that a contiguous land mass of all or at least almost all then-existing continental nuclei arose on Earth 3 billion years ago.
Components
Ur consisted of four major cratons, the Western Dharwar and the Singhbhum craton of India, the Kaapvaal craton of South Africa and the Pilbara craton of Australia. These probably come three smaller cratons in Antarctica and possibly two smaller cratons in India, the Eastern Dharwar craton and the Bhandara craton. It is conceivable that Ur was formed from several smaller continents. So took Nelson et al. (1999) that Kaapvaal and Pilbara craton once formed a small continent due to the very similar geological history at which they called Vaalbara.
Ur as a continent
Ur was around 2500 mya by the accretion of the Zimbabwe craton to the Kaapvaal craton along the Limpopo Belt and the accretion of the Yilgarn Craton enlarged to the Pilbara craton. This continent is called extended Ur translated, referred to as "larger Ur". This enlarged by additional crustal parts continent joined after this plate tectonic model with East Antarctica, Nena and Atlantica before 1.1 to 1 billion years to the global supercontinent Rodinia together. He formed the nucleus of the later Gondwana. Today, its shares crust on the continents of Africa, Antarctica, Australia, and the Indian subcontinent are distributed.
Older crust Splitter
Since the discovery of possibly up to 4.3 billion year old Nuvvuagittuq - greenstone belt from the eastern Canadian Shield, the 4030 mya old Acasta gneisses and similar old splitter on different continents can be assumed that already existed in the Hadean continental islands. Such rock discoveries were made in Enderby Land of Antarctica, at the Sino- Korean border, in Goa, around the Greenland capital Nuuk, Brazil and Africa in Montana, Wyoming,.