Much of Florida’s landscape is composed of “karst” landforms. A karst terrain is a land surface produced by water dissolving the bedrock and is characterized by sinkholes, cavern systems and disappearing streams and springs. The Alafia River watershed is a textbook example of karst topography.

Florida lies atop a platform of sedimentary rocks many thousands of feet thick. In geologic terms, it was formed 25 to 60 million years ago, when the region was underwater.

The platform is composed of the fossilized remains of sea creatures, mostly tiny invertebrates, which died and sank to the ocean floor. Over millions of years, as the geologic ages passed, the shell remains were compacted into layers of whitish carbonate rock known as limestone.

karst geologic formation Karst geologic formations are visible near a spring; photo by Richard Gant

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