Thermal convection: diffuse upwelling, slab suction, slab pull. 1 INRODUCTION HISTORICAL PERSPECTIVE Continental Drift - Abraham Ortelius (1596) He was the first to note the similarity between coastlines of the. ![]() Arthur holmes: early supporter of weg(cid:374)er(cid:859)s continental drift theory, earth(cid:859)s (cid:373)a(cid:374)tle co(cid:374)tai(cid:374)s co(cid:374)(cid:448)ectio(cid:374) cells due to radioacti(cid:448)e heat, plates driven by convection currents. 2 tectonic plates are spreading apart along the mid-atlantic ridge. Explaining the opening of atlantic ocean and east africa rift. Formally proposed by american geologist harry h hess. Paleomagnetism: reconstructed locations of continents, 200 ma continents joined together, more importantly, lead to sea floor spreading theory. Increase lunar gravitation: geophysical force caused by earth rotation (now known too small) Radioactive dating: the absolute age of rocks, look at layer sediments to help. Similar geology: type, age, structure of mountain ranges. Alfred wegener: german climatologist, continents moved (concept, wrote a book about this, pangaea, gondwana, laurasia, found that continents actually stay together. Plate Tectonics accepts the existence of Pangaea and related landmasses, but it gives a different explanation for the causes of drifting.Ĭonclusion: On various grounds, it was criticized but the Wegener’s theory is a significant milestone, the theory was incorporated into the theory of Plate Tectonics.Idea that continents and other landmasses have shifted: used to be together, but drifted apart.The hypothesis that continents 'drift' was rst put forward by Abraham Ortelius in 1596 and was fully developed by Alfred Wegener. The tidal currents, Buoyancy, and gravity are weak forces and these are not able to move continents. Continental drift Plates in the crust of the earth, according to the plate tectonics theory From Wikipedia, the free encyclopedia Continental drift is the movement of the Earth's continents relative to each other. The hypothesis that continents drift was first put forward by Abraham Ortelius in 1596 and was fully developed by Alfred Wegener in 1912 when he noticed.He took proofs mostly based on assumptions that are generalist.It only considers continents but not oceans.Alfred Wegener considered drifting only in the Mesozoic era, he failed to explain why drifting did not begin before.According to Wegener, Earth’s Gravity, the buoyancy of seas, and tidal currents were the main factors that caused the drift.Although most Scholars found these forces to be insufficient. So the forces of the moon to less extent but the forces of the sun played a major role. The Westward movement of continents was due to the tidal force of the moon and the sun. The hypothesis that continents drift was introduced by Abraham Ortelius in 1596 and was completely prepared by Alfred Wegener in 1912.The drifting was towards the equator due to the centrifugal effect.According to Wagener, the Drift was in two directions due to centrifugal force and tidal currents.The fossil of the seed fern Glossopteris was also found on the continent side by side. ![]() The lemurs that occur in India, Madagascar, and Africa led to consider the contiguous landmass ‘Lemuria’ which connects these three landmasses.The remains of Mesosauraus a freshwater reptile (- 286 to 258 million years ago) are found in southern Africa and Eastern South America (Travers formation of Brazil). Identical species of flora and fauna (plants and animals) adapted to live on land or in Aquatic habitat – Freshwater, are found on either side of the marine barriers.So the gold deposits of Ghana are derived from The Brazil Plateau when the two continents lay side by side. The plentiful placer deposits of gold found at Ghana’s coast (in west Africa) do not have source rock in the region but the sources are in Brazil.These all were previously a part of Gondwana as it gives clear evidence for paleoclimates and the drifting of continents. It is found in the Gondwana system in India, Africa, Falkland, Madagascar, Antarctica, and Australia. ![]()
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