<P> The later Malagasy orogeny at about 550--515 Mya affected Madagascar, eastern East Africa and southern India . In it, Neoproterozoic India collided with the already combined Azania and Congo--Tanzania--Bangweulu Block, suturing along the Mozambique Belt . </P> <P> The 18,000 km (11,000 mi) - long Terra Australis Orogen developed along Gondwana's western, southern, and eastern margins . Proto - Gondwanan Cambrian arc belts from this margin have been found in eastern Australia, Tasmania, New Zealand, and Antarctica . Though these belts formed a continuous arc chain, the direction of subduction was different between the Australian - Tasmanian and New Zealand - Antarctica arc segments . </P> <P> Gondwana and Laurussia formed the Pangaea supercontinent during the Carboniferous . Pangaea began to break up in the Mid-Jurassic when the Central Atlantic opened . </P> <P> In the western end of Pangaea, the collision between Gondwana and Laurussia closed the Rheic and Palaeo - Tethys oceans . The obliquity of this closure resulted in the docking of some northern terranes in the Marathon, Ouachita, Alleghanian, and Variscan orogenies, respectively . Southern terranes, such as Chortis and Oaxaca, on the other hand, remained largely unaffected by the collision along the southern shores of Laurentia . Some Peri-Gondwanan terranes, such as Yucatán and Florida, were buffered from collisions by major promontories . Other terranes, such as Carolina and Meguma, were directly involved in the collision . The final collision resulted in the Variscan - Appalachian Mountains, stretching from present - day Mexico to southern Europe . Meanwhile, Baltica collided with Siberia and Kazakhstania which resulted in the Uralian orogeny and Laurasia . Pangaea was finally amalgamated in the Late Carboniferous - Early Permian but the oblique forces continued until Pangaea began to rift in the Triassic . </P>

How long ago did one single supercontinent stretching from pole to pole exist on earth