Show Us Your Phosphate Fossils!

[Harry Pristis]

Phosphate is an important mineral which is mined wherever it can be found in commercially-exploitable deposits. Phosphates of that sort are biogenic, and often are deposited in a low-energy environment. Those circumstances suggest that animal hard-parts might be found preserved in some phosphates, and certainly that's the case.

From Florida's Bone Valley, and Aurora, NC, and North Africa and maybe South Africa, many fine fossils have been recovered from the local phosphate mines.

If you are lucky enough to have some of those fossils, how about showing off a few here.

Here is a pair of gomphothere (mastodont) teeth from a phosphate mine in Polk County, Florida. These are representative of the Palmetto Fauna, Late Miocene - Early Pliocene,

[Auspex]

These are four fragmentary bird bones from the phosphate mines of Khourigba, Morocco. The geologic formation is an Upper Cretaceous-eocene marine sedimentary phosphorite deposit, yielding carbonate-fluorapatite pellets. These bones came (reputedly, since I did not collect them) from the Upper Cretaceous strata (65-96 MYBP), which was deposited in a large tidal river delta. Only one of the bones has any potentially diagnostic features preserved; though I have not yet done so, ID as to family might be possible.

[Uncle Siphuncle]

Although this thread has sort of a vert slant to it, Texas has tons of phosphatized inverts as well. Bivalve, gastropod, ammonite, and nautiloid steinkerns come to mind.

[Harry Pristis]

Although this thread has sort of a vert slant to it, Texas has tons of phosphatized inverts as well. Bivalve, gastropod, ammonite, and nautiloid steinkerns come to mind.

Give us a little more info, Dan. Do you mean that the fine-grain sediment that infiltrated the tests of these ammonoids (or the cavity of an external mold) to produce the cast is some form of phosphate? I don't think I've heard that before.

I had always assumed that these steinkerns were calcitic. Here in the Ocala Group limestones (Eocene), steinkerns seem to be undifferentiated from the matrix, but these are internal casts.

What can you tell us about phosphatic steinkerns in Texas?

[Uncle Siphuncle]

Well I'm not very astute in how they are formed, but many cretaceous formations produce mollusc steinkerns ranging from white to gray to yellow to brown to black. They generally have a dull, lustrous surface patina not unlike shark tooth enamel. The black Baculites, gastopod, and bivalve examples from the Ozan formation at the North Sulphur River are perhaps the most widely known example of this mode of preservation in Texas, although it occurs in other formations such as the contact between the Austin and Pecan Gap formations, etc. The Paleocene Wills Point Clay near Mexia also presents a phosphatized fauna, most specimens being gray. The Corsicana formation of South Texas also presents some phosphatized specimens of ammonites, nautiloids, and gastropods. The white Eutrephoceras nautiloid steinkern seen in the photo banner above is one such specimen I found in the Corsicana.

[Roz]

Also some fossils near Midlothian, Texas (north-central)

can be of phosphate.. Note the 2 small clams in the pic. The ground

I took the shot on was not where the fossils were found.

These are from a recent hunt at a quarry near there.

Also a creek I loved in AR has some phosphate fossils but not all.

Not sure why some would and the fossil next to it isn't.

[Auspex]

Anyone mining phosphate commercially in Texas?

[Guest solius symbiosus]

Although this thread has sort of a vert slant to it, Texas has tons of phosphatized inverts as well.

As does Kentucky. Phosphate rich(>10% P₂O₅) limestones are in abundance around here. it can be seen as a whitish powder that precipitates on fresh surfaces, and as infill in pore spaces.

[FossilForKids]

I guess I'll post the first Bone Valley Meg Teeth.

[Harry Pristis]

Also some fossils near Midlothian, Texas (north-central)

can be of phosphate.. Note the 2 small clams in the pic. The ground

I took the shot on was not where the fossils were found.

These are from a recent hunt at a quarry near there.

Also a creek I loved in AR has some phosphate fossils but not all.

Not sure why some would and the fossil next to it isn't.

Knowing the geochemistry would be interesting. I have never seen anything like your black fossils here in the Ocala Group limestones. Honestly, you can go "snowblind" walking through those mines down here. And this is the case although there is plenty of phosphate here.

The phosphate boom (at the turn of the 19th century) started in Florida right here in my County -- hard-rock phosphate. The old mines are scattered all over. The hard-rock mining in Marion County went bust when pebble phosphate was discovered in South Florida.

[Roz]

That's a cool pic. I like abandoned quarries best. One of my favorite places in AR was an old cement plant.

Sorry, getting off topic

Here is what I found online about Texas phosphate (below)

Phosphate. Small quantities of phosphate rock are present in Paleozoic formations in West and Central Texas. Upper Cretaceous and Tertiary deposits in northeastern Texas also contain lenses of rock phosphate. No phosphate is mined in Texas, but imported phosphate rock is processed at a plant in Brownsville.

Not sure how accurate that is either..

Harry, did you dive for those mastodont teeth or on a river bank or quarry?

[Harry Pristis]

That's a cool pic. I like abandoned quarries best. One of my favorite places in AR was an old cement plant.

Sorry, getting off topic

Here is what I found online about Texas phosphate (below)

Phosphate. Small quantities of phosphate rock are present in Paleozoic formations in West and Central Texas. Upper Cretaceous and Tertiary deposits in northeastern Texas also contain lenses of rock phosphate. No phosphate is mined in Texas, but imported phosphate rock is processed at a plant in Brownsville.

Not sure how accurate that is either..

Harry, did you dive for those mastodont teeth or on a river bank or quarry?

Thanks for the research, Roz!

The gomphothere teeth are straight out of a phosphate mine. You can find them in the spoil piles, or the gun pits (they use water cannons to produce a slurry which is piped to the processing plant).

Here is a tooth that I picked out of the pebble phosphate layer, in the cut, about 40 feet below the surface.

Why the gomphothere teeth are blue and the rhino tooth is gold apparently is a matter of localized trace chemicals in the deposit.

[Uncle Siphuncle]

In many of the Eagle Ford shark tooth exposures in TX, the tooth bearing matrix is studded with phophate pellets of various colors and shapes. Sometimes these nodules can look deceivingly organic.

[mommabetts]

Most all of the bi-valves and gastropods that I have found in the NSR are the black phosphate fossils. I will post pics of them, if someone don't beat me to it, from there.

[Harry Pristis]

In many of the Eagle Ford shark tooth exposures in TX, the tooth bearing matrix is studded with phophate pellets of various colors and shapes. Sometimes these nodules can look deceivingly organic.

Is this what you are describing, Dan? The Ptychodus anonymus tooth (I think that's what it is) is 0.67" wide.

[JohnJ]

In many of the Eagle Ford shark tooth exposures in TX, the tooth bearing matrix is studded with phophate pellets of various colors and shapes. Sometimes these nodules can look deceivingly organic.

Harry, below is an example of the matrix Dan is referring to. It is studded with brown/tan phosphate pellets in addition to the shark and fish teeth.

hi res

low res

[Uncle Siphuncle]

Further to what John showed and wrote, the thin shark tooth bearing glauconitic shell hash lenses I've minedin the Eagle Ford group often have phosphate nodules from the size of a grain of rice up to 2-3 inches, some of then shaped such that novices assume they are some sort of bone or tooth. What John has shown comes from the South Bosque formation of Central Texas. Here a thin layer of shell hash, reddish when fresh, grayish when weathered, is sandwiched between limestone layers several inches thick. In north TX, the contact of the Arcadia Park (Eagle Ford Group) and Atco (Austin Group) is a gray matrix studded with black phoshpate pellets and shark teeth.

[CreekCrawler]

The black Baculites, gastopod, and bivalve examples from the Ozan formation at the North Sulphur River are perhaps the most widely known example of this mode of preservation in Texas,.

Yes they are here are a few! Slightly shaken up by the Sulphur.

[Auspex]

Nothing yet from PCS/Aurora ("Lee Creek")? Contrary to the popular notion that the mine is a shark's tooth factory, it is actually a commercial phosphate operation!

Here are some odds & ends of bird bones from there. Nothing too exciting (save for a couple verts and a phalanx ), but I thought that the range of coloration might be instructive.

[FossilForKids]

Yes they are here are a few! Slightly shaken up by the Sulphur.

Did you get those from the KFC in Aurora??

[LanceH]

some of mine

[Wim]

From the Campanian phosphatic deposits in Northern France: a Squalicorax kaupi. These deposits are nowadays used by local farmers on their fields. Sediments like these were used as a source of phosphor (=fertilizer) in Belgium also. Scalebar: 10 mm

[Harry Pristis]

From the Campanian phosphatic deposits in Northern France: a Squalicorax kaupi. These deposits are nowadays used by local farmers on their fields. Sediments like these were used as a source of phosphor (=fertilizer) in Belgium also. Scalebar: 10 mm

Fertilizer remains one of the most significant uses of naturally-occurring phosphates. In South Florida, the phosphate is converted to phosphoric acid and is shipped by tank rail-cars to chemical processors.

Are there any black fossils in the Northern France phosphates as from the Ozan Fm exposed on the North Sulphur River in North Texas?

[Harry Pristis]

Here are some Cretaceous phosphate fossils from Morocco -- teeth from the strange mosasaur, Globidens aegypticus. This tooth form is believed to be an adaptation for feeding on hard-shelled prey such as mollusks, principally cephalopods.

[Uncle Siphuncle]

Good thread - we should do this with other forms of preservation too. For instance pyritized fossils take on widely different appearance, speaking of Texas fossils alone. I'm sure there is even wider variation world wide. I for one enjoy collecting the same species in various modes of preservation - very interesting!