Exam Question 40 Mark – Plate Tectonics – Is the Theory Valid

1621 Words7 Pages
Plate Tectonics is the theory that explains the structure and motion of the Earth’s lithosphere. The theory states that the Earth’s crust is split into large sections called tectonic plates, and these move relative to one another creating boundaries at which plates converge, diverge and move past each other. As far back as 1620, Francis Bacon noticed that the west coast of Africa and the east coast of South America looked as if it would fit together. Between then and 1912 others identified further similarities but it was only that year when Alfred Wegener published a theory and subsequent evidence to explain why the earth appeared to be a huge jigsaw puzzle. He suggested that all continents were once a huge supercontinent, called Pangaea- which drifted apart. He suggested that Pangaea had split into fragments like pieces of ice floating on a pond and that the continental fragments had slowly drifted to their present locations. But Wegener’s main problem was that he could not find a mechanism with which such movement was possible to his ideas was largely dismissed. Alfred Wegener pioneered the theory of continental drift in the early 1900s which he supported with multiple pieces of evidence. Perhaps the earliest indicator of the theory was the apparent fit of some of the Earth’s continents; analysis of these coastlines, notably the eastern edge of South America and the western edge of Africa, has shown that they are very similar geologically suggesting that at some point in the Earth’s history the landmasses were joined together. In addition to this, Wegener found Coal had been found in the Antarctic, but coal only forms under warm, wet conditions. Coal forming in more tropical conditions suggests Britain once lay closer to the equatorial regions of the world. Thus he believed that the land moved after the coal was produced. Another indicator that the continents
Open Document