The development of the theory of plate tectonics from Continental Drift
The development of the theory of plate tectonics from Continental Drift to the present
The theory of continental drift first came to be in 1915 when Alfred Wegener first proposed his belief that 300 billion years ago there was one single supercontinent, Pangaea. At the time, most did not believe it was true as he had no proof or idea of how the masses of land would move. However, new evidence was put forward over time that fit with Wegener’s beliefs.
The first key piece of evidence is the shape of each continent. On a map of the earth, it is clear that, if moved together, the continents would fit together very well due to the similarities of coastlines such as those of east South America and West Africa; with the best fit being around1000 metres below sea level. Although they do not fit together perfectly, any irregularities can be explained. Gaps form due to the erosion of coastlines by the sea by abrasion and hydraulic action and areas where land overlaps are due either to volcanic activity creating new land when eruptions occur or changes in sea or land levels since the continents were separated.
In addition, there is also the idea of a geological fit. South America and West Africa, when mapped, showed that many rock outcrops, some over 2000 million years old, continued across the two continents, implying that that both were once in the same place. This could also explain how parts of England can house coal or sandstone despite being in the wrong climate.
Furthermore, there are many examples of fossils found on separate continents and nowhere else. This suggests that they were once joined as it would be almost impossible for an animal to swim thousands of miles in order to breed as this contradicts the theory of evolution.
Fragments of old fold mountain belts, aged between 400-450 million years old, are found on widely spread continents in the present. For example, pieces of the Caledonian fold mountain belt can be found in many different areas
The theory of continental drift first came to be in 1915 when Alfred Wegener first proposed his belief that 300 billion years ago there was one single supercontinent, Pangaea. At the time, most did not believe it was true as he had no proof or idea of how the masses of land would move. However, new evidence was put forward over time that fit with Wegener’s beliefs.
The first key piece of evidence is the shape of each continent. On a map of the earth, it is clear that, if moved together, the continents would fit together very well due to the similarities of coastlines such as those of east South America and West Africa; with the best fit being around1000 metres below sea level. Although they do not fit together perfectly, any irregularities can be explained. Gaps form due to the erosion of coastlines by the sea by abrasion and hydraulic action and areas where land overlaps are due either to volcanic activity creating new land when eruptions occur or changes in sea or land levels since the continents were separated.
In addition, there is also the idea of a geological fit. South America and West Africa, when mapped, showed that many rock outcrops, some over 2000 million years old, continued across the two continents, implying that that both were once in the same place. This could also explain how parts of England can house coal or sandstone despite being in the wrong climate.
Furthermore, there are many examples of fossils found on separate continents and nowhere else. This suggests that they were once joined as it would be almost impossible for an animal to swim thousands of miles in order to breed as this contradicts the theory of evolution.
Fragments of old fold mountain belts, aged between 400-450 million years old, are found on widely spread continents in the present. For example, pieces of the Caledonian fold mountain belt can be found in many different areas