|Vanessa Di Benedetto
Plate Tectonics Unit
How did Alfred Wegener prove that at one point the earth was one giant supercontinent? Even though all the continents formed one super continent 4.8 billion years ago, nobody realized this until Alfred Wegener proved it by using evidence in his plate tectonic theory. In the year 1912 Alfred Wegener realized that the continents all fit together but he only begun to convince the public in 1940 with he famous plate tectonic theory (Alfred Wegener’s concept, pbs.org). His theory was that all the continents have a good fit, the exact same species fossilized remains have been found on different continents and that there are matching mountain ranges that are nowhere near each other.
First of all, Alfred Wegener pointed out that all the continents made a good fit. He said all the continents could have started off as one supercontinent which he called Pangaea. In Gwandanaland, which is half of the supercontinent Pangaea, was South America, Africa, India, Antarctica and Australia. The east coast of South America and the west coastline of Africa could interlock together and touch; they then could have broken away from each other millions of years later (Plate Tectonics: The history of a rocky idea. berkeley.edu). Australia, India and Antarctica were all connected to each other. At one point Eurasia – Asia and Europe- were connected to Greenland.
Besides this, Alfred Wegener realized that fossilized remains of identical fauna and flora were found in different continents. The fossilized remain of a land reptile called the Cynognathus were found in South-eastern Argentina near Bahia Blanca and near Cape Town in South-western South Africa. This means that the Cynognathus reptiles were able to move from continent to continent that nowadays are separated from an ocean(Pangaea evidence. moorlandschool.co.uk). This means the reptile could only travel on connected parts of land, therefore, South America and Africa had to be connected at one point. Another extinct animal found in South America –East Brazil- and West Africa –Cameroon- was the freshwater reptile, the Mesosaurus (Pangaea evidence. moorlandschool.co.uk). The Glossopteris, a fossilized fern was found in Oates coast and Harold Coast in Antarctica, in South-eastern Australia and at the southern tips of India and Madagascar (Pangaea evidence. moorlandschool.co.uk.).
In addition to this, he found that identical rock layers from the same time periods were found on different continents. In Norway, Britain, Canada and Greenland a red sandstone band that passes through each of them (The history of the continental drift- Alfred Wegener, bbm.me.uk.) On the South American coastline and Western Africa coastline is an identical mountain range from the same time period. In South America and Africa two identical mountain ranges were found. Although Alfred Wegener was mainly right when giving evidence about the plate tectonic theory, he had made a few mistakes about identical rock layers as bbm.me.uk pointed out (The history of the continental drift- Alfred Wegener). He thought that all mountains were almost the same age but it was known even while Alfred was alive that mountains ages were very unique, due to radioactive dating evidence.
Furthermore, coal was found in areas where coal could not naturally be made anymore. Coal was found in Antarctica even though coal is only found in countries close to the equator because coal only grows in hot, humid places (Plate tectonics, Wikipedia.org). If naturally made coal was found in Antarctica that would mean at one point Antarctica was a warm, humid place near the equator although nowadays Antarctica is at the South Pole. Another part of evidence was that identical coal fields found in Belgium, Britain and in North America near the Appalachian Mountains.
In conclusion, Alfred Wegener created a theory for plate tectonics with the main reasons: all the continents have a good fit, identical fossils have been found on different continents, coal was found in places where nowadays it could not grow naturally there and matching mountain ranges have been found on other continents.
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Hilma “The History of the Continental Drift” Date modified: 29/1/03. Bbm.me.uk. Date viewed: 22/9/09 <http://www.bbm.me.uk/portsdown/PH_061_History_b.htm>
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