The Lay of the Land
Hundreds of millions of years ago, what's Florida today was just a string of volcanic islands. Its landmass, a huge, mostly submerged projection known as the Floridian Plateau, separates the Gulf of Mexico from the Atlantic Ocean. Over time, the magma of these ancient volcanoes hardened, and erosion and deposits of silt and sand buried them beneath the sea. Like Venus from the sea, Florida first emerged as a sandy bar thirty million years ago. For eons its bedrock had lain beneath the warm ocean, slowly collecting sediment and forming limestone deposits that would one day become new land. Washed by pounding waves, worn by wind and rain, the mass enlarged and shrank as Ice Age glaciers to the north formed and reformed, intermittently raising and lowering the level of the sea. The tides carved out stone bluffs and terraces.
Following the Ice Age, centuries of heavy rain filled scars and caves created in the limestone crust by the changing seas. Springs burst through the surface, transforming sinkholes into marshes and lagoons. The limestone foundation became covered with sand and red clay that in some places has mixed to produce a rich sandy loam fertile enough to grow a variety of fruits and vegetables. In the extreme southern portion of Florida, peat covered the limestone, enabling lush jungle-like areas to form.
Large reptiles, mastodons, and other creatures began to roam over this new land one million years ago. And as the last Ice Age retreated in North America, the Florida peninsula took the shape it has today.