Wednesday, October 13, 2010

Glacial Deposits

Glacial deposits are the result of ice and glaciers spreading over large regions outwards from the poles and scratching smooth rock and depositing unsorted sediments that can be identified and dated. About 300 million years ago the Palaeozoic glaciation left its mark on rocks now found on several continents that are as far away from the poles as the equator.
These features only fall into place perfectly when the continents are alligned in the jig-saw style and moved near the south pole, as demonstrated in the following diagram.

The widespread distribution of Permo-Carboniferous glacial sediments in South America, Africa, Madagascar, Arabia, India, Antarctica and Australia was one of the major pieces of evidence for the theory of continental drift.

Advancements in technology have allowed scientists to study these glacial deposits, working together with the knowledge of past climates to give us a mapping out of glacial sediments created towards the south pole, on continents that are now found on the equator. This evidence compells us to believe that these continents were once joined near the south pole, with the effects of continental drift moving them apart towards the equator.

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