Can whole continents move? It is almost impossible to believe, but without a doubt, the answer to this question seems to be yes. But how do we know, because we cannot see or feel them drifting beneath our feet?
In the early days of geology, the drifting of whole continents was certainly not considered to be a possibility, and in fact, in 1846 Dana positively asserted that continents and oceans have always been in the same place throughout geologic time. What happened, then, to change the geological mind?
It was a man called F. B. Taylor who first put forward a convincing argument for the movement of whole continents. He made this statement in the year 1910. During the following two years, H.B. Baker and perhaps most famous of all A. Wegener supported Taylor’s ideas. Since these pioneer workers first developed their startling suggestion, more and more evidence has been piling up to lend support to them.
It had been noticed 300 years ago that there was a remarkable fit between the outlines of the continents on the opposite shores of the Atlantic. It is particularly noticeable how well the coasts of South America and the Nigeria region seem to match up rather like two pieces of a jigsaw puzzle.
An even more accurate fit was discovered by Bullard in 1965. When he used a computer to try to match up these continents along the 500 fathom (900 meters) line of their shores.
Perhaps even more surprising is the correspondence of many great formations of rock which are separated by thousands of kilometers of ocean. A particularly good example is provided by sediments by ice sheets during the great Carboniferous Ice Age.
Deposits of this age can be found in South Africa, India, Australia, and Assam. Now if the ice sheet had been large enough to cover these areas as they are positioned today, there would have been a worldwide fall in temperature and other evidence proves that this simply was not so.
This means, then, that during the Carboniferous these areas must have formed one huge continent and that they have subsequently broken up and drifted apart.
There is yet more evidence provided by paleontology, which although it is not conclusive in itself, taken with all else is very convincing. Between the continents of Australia and South America, it is noticeable how there are some groups of animals and plants that are obviously very similar and closely related, while others are only found on one continent or the other.
It is now thought that the groups showing similarities had evolved before the breakup of the continents while the very different life forms had evolved separately afterwards. It is clear, then, that the map of the world has not always been the same as it is today.
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