The open pit PCS Mine lies on the south shore of the Pamlico Sound, adjacent to the small town of Aurora, NC.  The mining process requires removal of approximately 112 feet of overburden.  The top and most recent part is composed of sedimentary silts from the past 15,000 years.  bulldozers and bucketwheel machines are used to remove the first 40 feet (12 meters) of Holocene and Pleistocene deposits.  The next 60-69 feet (18-21 meters) of overburden is removed using draglines to expose the phosphate ore.  This phosphate came from several sources, including marine invertebrates that secrete calcium phosphate shells and the bones and teeth of vertebrates.  Typical deposits contain about 30% phosphorus pentoxide - P₂O₅ and several other compounds of phosphate.  The ore is mixed with water to form a slurry which is pumped to the main plant for processing into livestock feed, fertilizer, acid production and to be used in carbonated drinks.

Millions of years ago this area was part of the Aurora Embayment (system of bays) which in turn was part of the vast Albermarle Embayment.  During the same time period, to the north, lay the Salisbury Embayment - now known as Chesapeake Bay.  The shallow, warm waters were favourites among the numerous marine mammals for calving.  Unfortunately for the whales and porpoises, most of the area sharks were drawn here to take advantage of the relatively slow, tender sources of food.

The first major fossil formation uncovered is the Croatan (James City) Formation which was deposited during the Early Pleistocene Epoch.  The next layer down is the Chowan River Formation which occurred during the Late Pliocene (2 Million Years Ago).  The Yorktown Formation underlies the Chowan River and occurred during most of the rest of the Pliocene Epoch.  The Pungo River Formation is the last major formation uncovered and contains the phosphate.  This formation was deposited during the Miocene Epoch.  The underlying Eocene Epoch, Castle Hayne Formation is largely limestone (bedrock) and left undisturbed.

It may have occurred to the more astute reader to question why a 4.5 million year old formation lies adjacent to a 14.8 million year old formation and a 20.5 million year old formation lies adjacent to a 41 million year old formation.  What happened to the interlayering millions of years of dirt?  For a detailed explanation of these interruptions in the normal time-sequence of deposition of sediment layers see our new WebPage:

Lee Creek Mine Stratigraphy

Starting at the surface about 37 feet of sand and clay is removed.  Next comes 5 feet or so of Croatan Formation "shell beds".  A thin "boulder bed" is exposed and removed about 42 feet down.  The draglines now break through the Chowan River Formation into the phosphate poor Yorktown Layer.  The next 50 feet of overburden is composed of mostly clays which are removed to expose the thin layer of "Coquina Beds" which are part of the Upper Pungo River Formation.  The High Grade Ore and Phosphate Ore layers are then exposed and mined from the 112 foot to 145 foot level.  Below this is a thin layer of sandstone, a thin layer of low grade ore and then the Castle Hayne aquifer and bedrock.  The sandstone or "caprock" layer marks the end of the mining operation.  The Low Grade Ore layer below is not economically feasible to mine.

In recent years PCS has intermittently allowed Fossil Clubs and individuals into the mine to search for fossils during weekends in Spring and Fall.  Collection was not allowed during 1999 and 2000.  The season was terminated prematurely in 2001 to allow for reclamation and water storage.  Starting in 2003 many of the best slots went to "Friends of the Aurora Fossil Museum".  As a result fewer and fewer slots were available to Fossil Clubs.  Email us for insider information on getting the best collecting date and how to find fossils once you get an invitation.

The photo above was taken from the top of the Spoil Pile known as Block 26A.  This 1/2 mile mound of fossil bearing material in 2003 had been bulldozed about half way up in an effort to expose more fossils.  The "Better Half" (in the yellow hard-hat) can be seen on bulldozed road on the left side of the photo.  She is busy picking up fossil shark teeth that I walked right by.  The "White Stuff" in the foreground is broken fossil shell and coral.  The strip mine pit can be seen on the right.

By far the best find of the day was David Sanderson's 4 inch megalodon.

For the past 12 years fewer and fewer large size Carcharocles megalodon shark teeth have been found.  This has been largely blamed on the fact that the mining area has moved further south.  (The same movement south to smaller teeth is occurring in the Florida Phosphate mines.)  The largest C. megalodon teeth were found in the Early Pliocene deposits of the Yorktown Formation - the Unit 1 / Unit 2 boundary, which occurs in the northern area of the mine near the sound.  Smaller C. megalodon, C. chubutensis and C. subauriculatus teeth are found in the earlier Yorktown Formation base of Unit 1.  Carcharodon Carcharias (Great White) teeth are not found in the Pungo Formation, rarely in the Yorktown Formation and uncommonly in the Croatan Formation.  These teeth are relatively rare and generally black in color.  This coloration tells us that these teeth were part of a Reformulation Cycle which occurred during the Ocean Transgression that formed the boundaries between formations and formation units.  Megalodon teeth of over 6 3/4" were found during the "Good Old Days" and were generally black.  In the current location 5" teeth are rare as the mining operation moves further away from the water.

We at MegMawL have been fortunate to have a good supply of these extremely rare and beautiful fossils.  Their beautiful tan, blue, and brown coloration is due to the unique impurities in the surrounding sediment.  The black coloration of some teeth indicates either Oceanic or River Reformulation in water rich in manganese.

If you are ever in the area, please visit the Aurora Fossil Museum.  For more information see:          Aurora Fossil Museum

For more information about becoming a "Friend of the Museum" contact the Museum:

Telephone: (252) 322-4238

Each year in late May, the town of Aurora holds a Fossil Festival.  For more information contact the Museum at the number above.

Contact us if we can help with information about dates, directions, places to stay, etc.
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