1. How were the Florida Keys Formed? What natural events caused the formation of the keys?
2. The Ancient Coral Reef About 2-3 million years ago during the Pleistocene Epoch large sand shoals appeared in the oceans. What are shoals? About 500 million years ago a large coral reef began to grow on these shoals, one in particular was around the location of Florida today.
3. Climate Change About 100,000 to 125,000 years ago the Earth’s temperature began to cool. Ice caps began to form and expand over the North and South poles removing fresh water from the oceans. The ocean level dropped by as much as 300-400 ft. The coral reefs were exposed and died.
4. More Climate Change! About 26,000 years ago the Earth began to warm and the ice caps began to shrink, glaciers disappeared. The oceans began to rise slowly again. 20,000 years later the oceans had risen back to nearly where they were, but some land areas were still exposed. Namely the Florida Keys!
6. Questions What are the Florida Keys made of? The upper and middle keys which are generally larger and longer are made of limestone. The limestone is the remnants of the ancient coral reefs. What are coral reefs? What is limestone? The lower keys are made of oolite. What is oolite?