The White Cliffs of Dover

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• The famous white cliffs of Dover on the coast of Dover, England, are "chalk" with streaks of black flint.
• The chalk is composed of millions of skeletons of very small protozoans (coral, sponges and other small sea creatures).
• The white cliffs of Dover were at one time part of the ocean floor but they were raised above the sea during past geologic times.
• The chalk itself is very soft and easily eroded by the tidal forces. The cliff face continues to erode at an average rate of one centimeter per year.