Middle Eocene

Middle Eocene

The oldest rocks exposed at the surface in Florida are limestones and dolostones that were deposited in a shallow, warm sea during the Middle Eocene age. These rocks consist of the remains of marine organisms (foraminifera, mollusks, echinoids) that died and settled to the bottom of the sea. These limestones comprise part of the Floridan aquifer system, one of the most productive aquifers in the world and the source for most of Florida’s spring water.

Main Image: Remains of marine organisms (foraminifera, mollusks, echinoids) that died and settled to the bottom of the sea 40 million years ago. © FDEP – Harley Means

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The Wacissa Spring Group lies at the northern end of the Aucilla Wildlife Management Area in Jefferson
County and forms the headwaters of the Wacissa River. Over twenty springs form a cluster that runs
along the river. A public boat ramp allows for easy access to the core of the spring cluster. This dense
core contains Log, Thomas, Wacissa #1-4, and Acuilla springs, which together form a large bowl of fast-
flowing water. Along the run, large patches of Coontail compete with beds of Hydrilla beneath the clear
water. The combined magnitude and isolation of the Wacissa springs make the location one of the most
pristine in the state, earning the system a spot on the list of OFSs despite none of the individual springs
flowing at the first magnitude.