Wednesday, October 13, 2010

Palaeoclimates (ancient climates)

Being a meteorologist, Wegener was interested in the climate that earth experienced during Paleozoic times. He found evidence for dramatic global climate differences. Wegener found that glacier sheets aged between 220 and 300 million years old covered large areas of the Southern Hemisphere. Layers of glacial deposits were found in southern Africa, South America, Australia and India. Below these deposits are scratched layers of bedrock from expanding ice.

Certain types of minerals and rocks can only be created under specific conditions. One example of this is coal is formed from organic material deposited in warm, swampy areas. Antarctica has coal deposits dated to the same age as the glacial deposits, so that rules out the question could the earth have been cold enough to be completely covered in ice?

As Antractica has coal deposits and other parts of the Southern Hemisphere were covered in glaciers, the only explination for the differing in the climate of today is that the world was once joined as the super continent, Pangea.

If South Africa was centered over the South Pole, the conditions would be appropriate to form large glaciers over what is today's Southern Hemisphere and would place the northern landmasses near the tropics, resulting in coal deposits.


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