Реферат на тему The Theory Of The Continental Drift Essay
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The Theory Of The Continental Drift Essay, Research Paper
In my opinion, continental drifting definitely occurred. I believe there is plenty of evidence proving that, evidence that anyone could see just by looking at a map. Almost everyone who has looked at a world map or globe has noticed that the continents of South America and Africa seem to fit together fairly well. An even better fit is seen if continental margins (the underwater edge of the continent) are used. Other “fits” like this can be assembled as well, such as the way the coastal outlines of North and South America seem to fit with those of Africa and Europe.
Evolutionists believe that continental drifting took place over millions of years, and that the split up of North and South America from Africa and Europe is only the most recent example that proves their theory. According to geologists, continental drifting definitely occurred, but they’re just not sure how. It is somewhat of a mystery. Apparently it has something to do with solid “plates” of material floating on top of liquid magma deep below the earth’s crust.
Continental drifting is taking place even now, at the rate of a few inches per year. If this rate was the same since the continents all were one, it would have taken millions of years.
Alfred Wegener, a German meteorologist, decided to look for such evidence. He thought that if South America and Africa had been joined at some earlier time, both continents would have the same geological formations such as like mountains. Also, both continents would have almost the same fossils of extinct animals and plants.
Wegener led many expeditions to prove his ideas. Mountains, plants, and fossils were proven to be similar on both continents. It seemed like Africa and South America had been joined. Since they are not now joined, they must’ve drifted apart, which has come to form the term, “continental drift.” Wegener also came up with the term “Pangaea’, which is the name of the continents when they were a whole. Wegener’s theory, though understandable, was not accepted by the public as a rational theory. People just couldn’t imagine a continent moving. Not only is it a very large object, but it would have to plow through miles of solid rock on the floor of the ocean.
When measurements of the magnetism of rocks began to take place, it led to the further development of Wegener’s theory. When measurements were made of the Earth’s magnetic field, it was found that either the poles of the Earth were moving, or the continents were. This helped with Wegener’s theory, but it still was not proven.
Eventually, studies of the ocean floor were carried out. A ridge, with a valley in the middle, was found at the center of each major ocean. This was a fact that proved that continents could’ve moved through the ocean floor, which proves Wegener’s theory . . . . . . or does it?