Continental Drift Theory
Habish Ribin Haneef
Continental drift theory is an interesting theory that will surely make you think in depth. Presently, we know about 7 continents and you may be living in any one of these, right? But have you ever imagined how these 7 continents formed? The continental drift theory details this interesting phenomenon. The theory was first put forward by Abraham Ortelius in 1596. According to Ortelius, earthquakes and floods tore the Americas apart from Europe and Africa. He also suggested that if someone brings the world map and observe the coasts of the Americas, Europe, and Africa carefully, the vestiges of the rupture can be spotted clearly. However, this theory was completely developed by Alfred Wegener in 1912. Wegener suggested that all the continents were one single continental mass known as Super Continent and a mega ocean surrounded this supercontinent. He called this supercontinent as “Pangaea” and the mega ocean as “Panthalassa”. According to Wegener’s continental drift theory, Pangaea started to split about two hundred million years back. Pangaea split into two big continental masses- Gondwanaland and Laurasia. The Gondwanaland and Laurasia formed the southern and northern modules respectively. Then, these two big continental masses started to split again into several smaller continents which we see today.
Evidence of Continental Drift Theory:
Alfred Wegener explained his theory of continental drift with the help of some examples. The first one was the fossils of Mesosaurus, an ancient reptile that was only one meter long. The fossils of these reptiles are only found in Southern Africa and South America. How is this possible? Anyways, Mesosaurus can’t swim through the Atlantic ocean. The possibility is that these reptiles might have a single habitat with numerous lakes and rivers. Another piece of evidence of Wegner’s continental drift theory is the plant fossils of the frigid Arctic archipelago of Svalbard, Norway. These plants are not enough suited to survive in the Arctic climatic conditions of Norway. These plants’ fossils clearly indicate that they are suited for tropical conditions characterised by warmer and humid environments. Yes, Svalbard once had a tropical climate! Now, the next piece of evidence will surely astonish you. The east coast of South America and the west coast of Africa fits perfectly like a jigsaw puzzle, i.e, South America and Africa have similar geology. Wegner also pointed that the Appalachian mountains of the eastern United States are also geologically similar to the Caledonian Mountains of Scotland. Wegener believed that all these strange incidents have something to prove and these are not just a case of a coincidence.
Is Continental Drift Theory true?
The continental drift theory proposed by Alfred Wegener had all the elements that will make a person curious. But, there was one area the theory was lacking and due to that scientists didn’t accept Wegener’s continental drift theory. Why did the continents split? How did they split and what pattern did they follow? Wegener told that it may be the rotation of the Earth that caused the continents to drift. But this suggestion from Wegener was wrong. Actually, the continents lies on huge slabs of rocks known as tectonic plates. These plates are moving and interacting. This process is called plate tectonics. Plate tectonics are more common in seafloor spreading zones and giant rift valleys. In seafloor spreading, molten rocks rises from within the Earth and adds new seafloor to the edges of the old. Underwater mountain ranges known as mid-ocean ranges are the most dynamic sites for seafloor spreading. The continents on the opposite sides of the ridge move away from each other according to the seafloor becomes more wider. For example, the North American and the Eurasian tectonic plates are separated by the Mid-Atlantic Ridge. It is evident that the two continents are moving from each other about 2.5 centimetres per year. Giant rift valleys, however, are locations where continental landmasses are ripping themselves apart. For example, Africa will eventually split along the Great Rift Valley System. A single continent will now be split into two halves- the African plate and the smaller Somali plate. The Somali continent will largely be oceanic, with the horn of Africa and Madagascar as its largest land masses. The mechanism of tectonic plates was not well discovered before the 1960s and this was the reason behind the Continental Drift Theory proposed by Alfred Wegener.
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Check your knowledge
Answer. The Continental Drift Theory was first put forward by Abraham Ortelius in 1596.
Answer. Continental Drift Theory was completely developed by Alfred Wegener in 1912.
Answer. The continents lies on huge slabs of rocks known as tectonic plates. These plates are moving and interacting. This process is called plate tectonics.
Answer. Wegener suggested that all the continents were one single continental mass known as Super Continent and a mega ocean surrounded this supercontinent. He called this supercontinent as “Pangaea” and the mega ocean as “Panthalassa”.