Florida's Geologic History and Formations

Florida has unique origins. What would become the basement rocks of Florida were once part of other continents. During the early part of the Cenozoic Era, Florida was submerged under a warm, shallow, ocean which explains why our entire state has hundreds to thousands of feet of limestone beneath it! Land emerged from the ocean as sea level fell during the Oligocene Epoch.  During the later part of the Cenozoic Era, quartz sand and clays were transported to Florida, via rivers and marine currents, from the Appalachian Mountain belt as it eroded over millions of years.    

Florida geologic strata are divided into formations.  Formations are the basic rock units used in stratigraphy, the branch of geology that deals with the layers of sedimentary rock that have accumulated over geologic time.   The following are select formations that can be found in the state. Visit our page about Florida's Rocks and Minerals for more information about individual components, or take a visual tour of Florida’s tectonic and depositional history through geologic time long before the Atlantic Ocean existed with our ESRI Story Map of Florida's Geologic History.

Formations of Florida

Formation	Photo	Composition	Extent
Alum Bluff Group Miocene & Pliocene	Image View More Photos	Clays, sands, and shell beds; characterized by molluscan fauna	Panhandle
Anastasia Formation late Pleistocene More information	Image View More Photos	Coquinoid limestone (coquina) and unconsolidated shelly sand	Eastern Florida Coast
Arcadia Formation (Hawthorn Group) late Oligocene to early Miocene More information	Image View More Photos	Dolomite, limestone, and quartz sands; characterized by high percentage of phosphate	Central Peninsular Florida
Avon Park Formation middle Eocene More information	Image View More Photos	Limestone and dolostone with gypsum infill	Peninsular Florida
Bridgeboro Limestone early Oligocene More information	Image View More Photos	Fossiliferous limestone containing rhodoliths (coralline red algae)	Panhandle along the western flank of the Gulf Trough
Caloosahatchee formation early Pleistocene More information	Image View More Photos	Quartz sand and shelly limestone	South Florida
Cedar Keys Formation Paleocene to early Eocene More information	Image	Recrystalized limestone and dolostone with gypsum, quartz and chert infill	Peninsular Florida
Chattahoochee Formation early Miocene More information	Image View More Photos	Silty, sandy dolostone	Panhandle
Chipola formation (Alum Bluff Group) early Miocene More information	Image View More Photos	Clayey, sandy fossiliferous carbonates and shelly sand	Panhandle
Citronelle Formation Pliocene to Pleistocene More information	Image View More Photos	Quartz sand, gravel and clay	Panhandle
Cypresshead Formation Pliocene to Pleistocene More information	Image View More Photos	Quartz sands	Northeast Florida
Hawthorn Group Oligocene to Pliocene	Image View More Photos	Limestone and siliciclastics; characterized by presence of phosphates	Peninsular Florida
Jackson Bluff Formation late Pliocene More information	Image View More Photos	Fossiliferous clayey sands and sandy clays; molluscan fauna	Panhandle
Key Largo Limestone late Pleistocene More information	Image View more Photos	Coralline limestone	South Florida
Marianna Limestone early Oligocene More information	Image View More Photos	Fossiliferous, argillaceous limestone	Panhandle
Miami Limestone late Pleistocene More information	Image View More Photos	Oolitic and brozoan limestone	South Florida
Miccosukee Formation Pliocene to Pleistocene	Image View More Photos	Interbedded and cross-bedded siliciclastics with a high clay content	Panhandle
Ocala Limestone late Eocene More information	Image View More Photos	Highly permeable fossiliferous limestone	Peninsular Florida & Eastern Panhandle
Oldsmar Formation early Eocene	Image View More Photos	Recrystalized limestone and dolostone with gypsum infill	Peninsular Florida
St. Marks Formation early Miocene More information	Image View More Photos	Fossiliferous limestone	Panhandle
Suwannee Limestone early Oligocene More information	Image View More Photos	Micro-fossiliferous and crystalline limestone	North and Central Peninsular Florida
Tamiami Formation Pliocene More information	Image View More Photos	Slightly phosphatic sandy limestone	South Florida
Torreya Formation (Hawthorn Group) early Miocene More information	Image View More Photos	Quartz sands and fine-grained limestone with phosphate	Panhandle