NATR - Phosphate Mine EarthCache

The Natchez Trace Parkway is a 444-mile drive through exceptional scenery and 10,000 years of North American history. Used by American Indians, "Kaintucks," settlers, and future presidents, the Old Trace played an important role in American history. Today, visitors can enjoy not only a scenic drive but also hiking, biking, horseback riding, and camping. For more information about the Natchez Trace Parkway visit:
Website: www.nps.gov/natr
Facebook: www.facebook.com/NatchezTraceParkwayNPS
Phone: 1-800-305-7417.

The posted coordinates will take you to the parking area and trailhead of Phosphate Mine on the beautiful Natchez Trace Parkway in central Tennessee. I hope you learn about the area and enjoy your hike to this very neat and historical place.

This EarthCache will take you on a short trail that dead-ends on the backside of Phosphate Mine. As you make your way down the short trail, you will see that the National Park Service has placed signs where you will learn about the history and use of phosphate ore, and how it was transported from this area. You will also be able to see the entrance to the mine and what type of earth the mine was dug into.

I hope you have a pleasant experience upon the completion of this EarthCache, and enjoy the beautiful scenery that the Natchez Trace Parkway has to offer.

To get credit for the find, simply answer the following five questions and send them to me in a message:

Question #1: When did the production of phosphate rock in Tennessee end?

Question #2: How many possible openings do you see that lead into the mine? (please stay on the designated walk-ways)

Question #3: Without disturbing the soil, how would you describe the composition of the earth around the opening of the mine?

Question #4: Where did the phosphate ore at this location come from, and approximately when?

Question #5: Approximately what year did man learn of the importance of phosphate ore?

Once you have sent the answers to the five questions in a message, please post a photograph of yourself with the Phosphate Mine sign behind you. The photograph is NOT required.

A little historic information for you....

The trail that you walk down to complete this EarthCache is actually an abandoned railroad bed where “dinkey” engines on miniature tracks hauled small pushcarts of blue phosphate ore to a washer near Gordonsburg, Tennessee. Over 1000 miles of track have been abandoned in Tennessee because the resources have been exhausted.

Phosphate Statistics

The principal commercial deposits of phosphate rock exist in Florida, North Carolina, and Idaho, and to a lesser degree in Montana and Utah. Production of phosphate rock in Tennessee ended in 1991. Phosphate rock is mined, beneficiated, and either solubilized to produce wet-process phosphoric acid or smelted to produce elemental phosphoric acid or smelted to produce elemental phosphorous. Phosphoric acid is reacted with phosphate rock to produce the fertilizer triple superphosphate or with anhydrous ammonia to produce the ammonium phosphate fertilizers. Elemental phosphorus is the base for furnace-grade phosphoric acid, phosphorus pentasulfide, phosphorus pentoxide, and phosphorus trichloride. Approximately 90% of phosphate rock production is used for fertilizers and animal feed supplements and the balance for industrial chemicals.

U.S. phosphate rock production increased from 18 million metric tons in 1960 to 35 million metric tons in 1970 and peaked at 54 million metric tons in 1980. Consumption in 1990 was 44 million metric tons. Increasing tonnage of phosphate rock is used to produce higher value phosphatic fertilizers for the export market. Phosphate rock exports peaked in 1980 at 14 million metric tons and has declined to 6 million metric tons in 1990. Phosphate rock imports have historically been a minor factor in supply; however, in addition to small quantities of low-fluorine materials, phosphate rock imports in recent years increased to the .5-million-metric-ton level.

Phosphate rock prices in the 1960's were in the $5 to $6 per metric ton range, f.o.b. mine, and increased to the $20 to $25 per metric ton range, f.o.b. mine, in the 1980's.

The demand for phosphate rock as a nutrient for food production will vary throughout the world. The overall demand is forecast to increase in the 1%-to-2%-per-year range; however, in the agriculturally mature countries, the increase in demand will be closer to 1% per year.

The supply of phosphate rock is forecast to decline in the United States as existing mines in Florida are mined out and unfavorable economics discourage new mine development. World supply will be maintained from quality deposits in North Africa.