ABSTRACT

The Tampa Formation of west-central Florida historically has been defined on biostratigraphic and geochronologic criteria. Formation definitions based on these criteria are not in accordance with the American Code of Stratigraphic Nomenclature. Furthermore, a type section of the Tampa Formation has never been established. Currently, the Tampa Formation is recognized by ill-defined and conflicting criteria. Boundaries are vague. At the originally described localities on Tampa Bay, there is an interval of rocks that is mappable, has recognizable boundaries, and is capable of being defined in accordance with the Code. It is proposed here that this unit be formally designated. The unit is generally a quartz sandy limestone, having at least 10% quartz sand and less than 1% phosphate. The boundary with the units above the Tampa Formation is defined by the occurrence of phosphate bearing (5%-50%) dolomites, clays and quartz sands. The lower boundary is marked by the occurrence of a relatively pure carbonate unit containing only trace phosphates or quartz sands. The Tampa Formation has been correlated indirectly with the Oligocene Chickasawhay Stage of the Gulf Coast. A type section for the Tampa Formation is established in the Ballast Point core taken at Tampa Bay, Florida, and housed by the Florida Bureau of Geology.