Mosaic Phosphate Mine ~ Monday, November 16

Our destination was the Mosaic phosphate mine located in Central Florida. The area we visited is known as Bone Valley because deposits often contain fossils of prehistoric creatures including mastodons, saber-tooth tigers, whales and teeth from sharks that grew up to 40 ft. The field trip began with a lecture by the staff geologists, they spoke of Mosaic’s history, the geology of phosphates and of course, fossils.

Phosphate deposits in Florida are among the richest and most accessible in the world, making Florida one of the largest exporters. Early mining was done by hand with a pick and shovel in above-water sand bars. Today, Phosphate mining  companies use draglines to remove surface soils up to 60 feet  deep over thousands of contiguous acres.

We had a chance to scavenge fossils, we left no stone unturned...

View of the surface, riddled with bones and sharks teeth galore. (shadow of hand for scale)

Phosphate rock is a general term referring to rock with high concentrations of phosphate minerals, most commonly those of the apatite family with the general formula Ca₅(PO₄CO₃)₃(F,OH,Cl). Ninety percent of phosphate mined is used to produce chemical fertilizers.

This is a 4 ft cross section of the sandy surface sediment of marine origin. Visible layers containing calcium phoshate, quartz & other minerals.

Phosphate deposits can be classified into three types. The most economically significant are marine sedimentary deposits of phosphorites which are typically argillaceous to sandy sediments containing stratified concentrations of calcium phosphate, mainly as apatite. Other deposit types are, apatite-rich igneous rocks, and modern and ancient guano accumulations.

The Sharks Teeth were of considerable size, they were definitely the most popular fossil (not surprisingly) with the boys.

I’ve actually been to dig sites located in or around the Bone Formation when I was younger. My dad brought me to a few “fossil-hunting” tours with the infamous Frank Garcia. Matter of fact, I still have a horse tooth or two in my rock collection and his autograph on a fossil Identification pamphlet (he was like a fossil rock-star when I was a kid).

Some fossils were easy to identify, such as the teeth, while others would require a trained eye.

              

Our field guide showing fossils

Fossils from mine (rusty nail for scale-top left)

 

Rusty pipes

“Fossils from Bone Valley, the phosphate mining district in Central Florida, are rare and highly-priced specimens. Due to the unique geological characteristics of the phosphate-rich region, most of the fossils are beautifully preserved with amazing detail and color. Unlike the majority of southeastern U.S. fossils retrieved from rivers and streams, Bone Valley specimens are found in dry earth and are not stained with the typical cruddy black and brown muck from rivers.” www.FossilMuseum.net, 2003

These are the types of fossils found in the phosphate deposits. Pretty neat.