Phosphate is a primary ingredient in fertilizers, and Florida mines supply 75% of the phosphate used by America's farmers. Fifteen to thirty feet beneath peninsular Florida's sandy soil is a ten to twenty foot thick layer of phosphate rock. This part of the state was once under the sea. Over millions of years, billions of phosphate particles derived primarily from dead sea life settled into layers with sand and clay. These layers were eventually covered under sandy soil as the sea retreated.
Phosphate mining in Florida dates back to 1881. Mining technologies have progressed markedly since that time, when picks and shovels and eventually mule-drawn scrapers were used to break apart the rock. Draglines were first used in the 1920s, and are still in use today. These enormous machines strip off the top layers of earth to reveal the phosphate. The phosphate is processed to separate the valuable ore from sand and clay.
Phosphate mining radically changes the landscape, and since the 1930s phosphate mining companies have become increasingly concerned with land reclamation efforts. Reclaimed land is used for agriculture, tree farms, wildlife habitats, lakes, general recreation areas, and commercial and residential development. Many of the area's parks are on reclaimed phosphate land, including parks with geocaches: Saddle Creek Park, Tenoroc Fish Management Area, and Edward Medard Park (all of which are represented photographically here...as seen from a kayak).
© April L. Gustetter