The Tamiami Formation is a Pliocene marine unit comprising a wide range of rock types, including: light gray to tan fossiliferous sands, light gray to green fossiliferous sandy clays and clayey sands, and white to light gray, poorly consolidated, sandy, fossiliferous limestone. Phosphate is present in virtually all lithologies as limited quantities of sand- to gravel-sized grains. Fossils present in the Tamiami occur as molds, casts and original material. The fossils present include barnacles, mollusks, corals, echinoids, foraminifers and calcareous nannoplankton. It occurs at or near the land surface in Charlotte, Lee, Hendry, Collier and Monroe Counties in the southern peninsula.