Formations in Peace River

[Max-fossils]

Hey everyone,

I was recently looking through some of my older fossils and found the shark teeth I had found in the Peace River around 2 years ago on a trip kindly organized by @Sacha. I noticed I hadn't included a Formation tag on my labels, so I went to do some research. I googled 'Peace River formation' and found a formation carrying the name of the river; I also remembered that some of my shark teeth had Bone Valley-like coloration, and if I remember correctly the Bone Valley and the Peace River essentially represent the same fauna. 

 

According to Wikipedia, the Peace River Formation covers this age range:

Quote

Epoch: Miocene to Pliocene
Faunal stage: Arikareean through Hemphillian, ~23.03–4.9 mya, calculates to a period of ~18.13 million years

But Wikipedia also says that it's "a Late Oligocene to Early Miocene geologic formation in the west-central Florida peninsula."

 

If you then take a look at the entry for the Bone Valley Member/Formation, this is what you get: 

Quote

Epoch: Middle Miocene to Early Pliocene
North American land mammal age: Barstovian to Hemphillian

They also say that "The Bone Valley Formation includes a diverse assemblage of vertebrate fossils. These include remains of sea turtles, equines, felines, peccaries, and others."

However I'm looking for the info for my shark teeth, not land animals. 

Overall, I'm a bit confused as to what information I need to take into account. Wikipedia is generally good in my opinion for scientific stuff, but in this case it didn't help me much.

 

So essentially, my question is this: from what formation do my Peace River shark teeth come from and exactly how old are they? And what exactly is the stratigraphy of the Peace River like?

I can post a picture of the shark teeth in question if necessary (or if you just wanna look at them ). 

 

Hopefully someone has a clear answer to this  

 

Best regards,

 

Max

[Scylla]

1 hour ago, Max-fossils said:

 

So essentially, my question is this: from what formation do my Peace River shark teeth come from and exactly how old are they? And what exactly is the stratigraphy of the Peace River like?

I can post a picture of the shark teeth in question if necessary (or if you just wanna look at them ). 

 

Hopefully someone has a clear answer to this  

 

Best regards,

 

Max

Yes I have a clear answer: Yes I want to see your shark teeth.

[Max-fossils]

17 minutes ago, Scylla said:

Yes I have a clear answer: Yes I want to see your shark teeth.

Lol, here they are: 

So on top, from left to right: a group of lemon sharks (Negaprion eurybathrodon), bull/dusky sharks (Carcharhinus sp.), and ray plates (yes I know, not sharks, but same age and cool anyways). Then on the bottom, a hammerhead (Sphyrna zygaena), a mako (Isurus oxyrhinchus), a big tiger shark (Galeocerdo cuvier), a false tiger (Physogaleus contortus), and 3 snaggletooth sharks (Hemipristis serra). The ones with nice colors are from a Bone Valley clay bank in the river I believe. 

 

Btw, you don't need to quote my whole topic, quoting just the relevant sentence is better (that way we don't have to scroll down a bunch of already-read text again)  

[Scylla]

Ok, edited

[Bone Daddy]

It has always been my understanding that the majority of the Peace River basin resides in the Bone Valley Formation, which is now called the "Bone Valley Member" according to the official nomenclature.

 

For locality labeling, I usually label my Peace River finds as :

Fossil Specimen XXXX

Miocene/Pliocene/etc

Peace River, Zolfo Springs, Hardee County, FL

Bone Valley Member, Hawthorn Group

 

 

 

[Harry Pristis]

Here it is:

 

[Shellseeker]

Let me look at it slightly differently:

https://www.wikiwand.com/en/Polk_County,_Florida_paleontological_sites

Polk County Florida includes Fort Meade and a section of the Peace River:  I might be confused but this is saying that for the last 2 mya since Megs went extinct, Polk county has been DRY land. Wow!! I did not realize that....

 

Then this picture, indicating a little salt water in the upper left.  So, understanding the depth of salt water over the eons could help us understand which sharks dropped teeth When....

I am curious about Sand Tigers ( Carcharhinus taurus ). They are in the Bone Valley Polk County mines--- (and other places in LARGE numbers)

 

Quote

By about 12 million years ago, most of the coastline of Florida probably looked much like it does today in many coastal areas. In those times, however, the shoreline was located up to 60 miles further inland. In the shallow waters offshore a layer of clay and sandy limestone was deposited. Today this layer is known as the Hawthorn Formation.

Rivers and streams flowed down to the sea, carrying material washed from the land. This material was deposited in shallow lagoons and bays along the coast, forming deposits of sand and clay. These deposits contain the remains of land animals brought in by the rivers and streams, and also marine creatures that inhabited the coastal waters. These deposits are so rich in fossils, the term scientists use for evidence of ancient life, that they are known as the Bone Valley Formation. In Central Florida, the Bone Valley Formation is found on top of the Hawthorn Formation and is under about 20-40 feet of sand.

Fossils from the sedimentary deposits of the Bone Valley Formation are often uncovered in the process of phosphate mining and give us a glimpse of Florida’s prehistoric past. Bone Valley is the heart of Florida’s phosphate mining area.

 

Fort Meade is about 65 miles inland today. That seems to mean  that the Megs we are finding were laid down in Fort Meade 10-12 myas ????  That is sort of the question.  Hopefully , many will add to this discussion...

[Shellseeker]

48 minutes ago, Shellseeker said:

Let me look at it slightly differently:

https://www.wikiwand.com/en/Polk_County,_Florida_paleontological_sites

Polk County Florida includes Fort Meade and a section of the Peace River:  I might be confused but this is saying that for the last 2 mya since Megs went extinct, Polk county has been DRY land. Wow!! I did not realize that....

Found a new chart that has me thinking. Fort Meade is on top of that Central Highland, 25 miles South of Lakeland... It probably has very different characteristics of other cities (Bowling Green, Wauchula, Zolfo Springs, Arcadia, Nocatee) on the way down the Peace River to the Gulf of Mexico. Throughput the ages, it had higher ground...

 

The ocean level is thought to have fallen as much as 300 to 450 feet at its lowest levels. The high seawater level occurred about 125,000 years ago, the low was about 20,000 years ago and the outer reefs went under water about 6,000 years ago. This shown in the drawing at the right: The blue is Florida 125,000 before present (BP), the pink Florida 26,000 BP and the gray is today. What today we call the Keys were the very high points of a very wide peninsular.

[minnbuckeye]

1 hour ago, Shellseeker said:

Let me look at it slightly differently:

 

I will add my 2 cents. Elevation of the river  IN METERS at Bartow is 28, Ft Meade 23, Bowling Green 20, Wauchula 18, Zolof 12, Gardner 10, Brownville 7, Arcadia 5 and Nocatee 3. If one knows the thickness of the formations, It would be easy to calculate where a formation likely ends as the river heads to the sea. Just a thought. I must be bored!!

 

 Mike

[Shellseeker]

45 minutes ago, minnbuckeye said:

 

I will add my 2 cents. Elevation of the river  IN METERS at Bartow is 28, Ft Meade 23, Bowling Green 20, Wauchula 18, Zolof 12, Gardner 10, Brownville 7, Arcadia 5 and Nocatee 3. If one knows the thickness of the formations, It would be easy to calculate where a formation likely ends as the river heads to the sea. Just a thought. I must be bored!!

 

 Mike

Mike,  Thanks for playing the game.  If we add enough pieces, in addition what we learn about the new piece, it may lead us to an answer !!! Here are some pieces... Contortus lived 15-18 million ago. Predominately I find Contortus teeth upstream of Bowling Green and rarely downstream. So, during the period Contortus lived, it dropped its teeth in Fort Meade on the central highlands... DEEPER Salt Water  !!!!! G. cuvier came along later in the late miocene-pliocene.

 

Then this photo: of HemiPristis... How did the creator know that HemiPristis was in SW Florida 3-10 mya?  and a different geological range at the Lee Creek Mine? Time to ask @siteseer @MarcoSr on dating a current hunting location by the shark teeth you do and do not find there....

[Al Dente]

Here is a graph of global sea level change that I pulled off the internet. This shows eustatic sea-level change which is change that occurred globally. You also have to account for isostatic sea level change which is local change in land surface relative to sea level for various reasons such as land movement or sediment loading and compaction and other reasons. The different ages for the Hemipristis is because they are found in different formations. Pungo River is Miocene only, so if you find one in the Pungo, you know it is Miocene, but Hemipristis serra lived into the Pliocene so you can have H. serra that are younger in other formations.

 

 

[Al Dente]

Here’s a brief pamphlet that describes Florida through time- https://www.stetson.edu/other/gillespie-museum/media/Florida Formations EXHIBIT TEXT-FULL for website.pdf

[Bone Daddy]

Here is a larger version of the Pleistocene sea level graphic that Jack posted. This one shows the sea levels during the Pliocene and Miocene as well.

 

From left to right : Miocene, Pliocene, Pleistocene.

 

 

 

 

 

[MarcoSr]

9 hours ago, Shellseeker said:

 

Then this photo: of HemiPristis... How did the creator know that HemiPristis was in SW Florida 3-10 mya?  and a different geological range at the Lee Creek Mine? Time to ask @siteseer @MarcoSr on dating a current hunting location by the shark teeth you do and do not find there....

 

 

I can only comment on the dating that I've been involved with.  We collect matrix samples from a marine formation of interest.  These samples go to the USGS for analysis.  The USGS can use three different methods of dating them , pollen, dinoflagellates and/or calcareous nannoplankton.  They make up sample slides from the matrix and compare what is on the slides to pollen or dinoflagellate or nannoplanton known zonation standards to get a time period.  Truthfully I don't know how these standards were created or verified.  We then create a vertebrate fauna list of all of the vertebrate species from the formation that we collected and have been previously collected from the formation like shark species using their fossil teeth for species identification.  Using the USGS zonation for the formation we can place a specific species in the formation into a specific time-frame.  You can use the fauna lists for different formations in combination with their zonations to start building the overall species time-frames for different vertebrate species like sharks.  To be accurate, a similar methodology should have been used to estimate the 3-10 mya time-frame for Hemipristis in SW Florida.

 

Marco Sr.    

[Shellseeker]

On 6/2/2020 at 2:35 PM, Max-fossils said:

So essentially, my question is this: from what formation do my Peace River shark teeth come from and exactly how old are they? And what exactly is the stratigraphy of the Peace River like?

Well,  This seems simple , but is a very complicated question as evidenced by the great materials that TFF members provided to address an aspect of your question.

How about your 3rd question.  Here is a picture from 1991 research Paper and both @Bone Daddy and @Harry Pristis gave you some good info on it.  Here is a Research Paper with a layered picture. https://www.researchgate.net/figure/Revised-stratigraphic-column-for-central-and-south-Florida-after-Galloway-et-al-1991_fig2_222709721. This is good enough, but there are LOTS of research papers on this topic.

For what it's worth, the Peace River flows on top, cutting into the formations below it getting shark teeth from many formations below it. When identifying Shark Teeth, I generally say Peace River Fm for shark teeth that came from the river and Bone Valley Formation from shark teeth coming from the Phosphate Mines.

How about your 1st question: What Formation do my Peace River Teeth come from?

Depends.  The Peace River flow thru and over multiple different formations heading for the Gulf of Mexico. The easiest example is the Bone Valley Formation which terminates some where below Hardee county (Zolfo Springs).  Think about where you and John were digging when you found these teeth? @minnbuckeye helped with the data that the Peace River is flowing downhill heading for the Gulf. You can believe that there are different shark teeth in different sections of the Peace River.

@Al DenteGave us two great documents and insights!!!! Sea levels over the last 15 myas (about the age of the Bone Valley Phosphate mines). 15 MYA .. middle miocene and lots of salt water over Bartow, Fort Meade,  and maybe 12 MYA  ,, no so much.  Also the AGE when Hemipristis serra were laid down in Florida was 3-10 mya but Pungo River is miocene only  .. not the age of the shark but the age of the teeth and when they were dropping.   The insight here is that although Megs were extinct 2 mya or so, it has been at least 5 or 12 mya, since Fort Meade had enough sea water to allow a Meg to swim there.

So your middle question.. In order to date the Shark teeth you found in the Peace River, we must date the formation they fell into!!!! and here @MarcoSr provides the scientific background on a way to date the formation.

 

I have hunted the Peace River for more than 10 years.  Thru experience on what shark teeth I find, I know where the big and little Megs are more and less numerous. Same for all types of tigers, duskys, bulls...  Lemons seem to be everywhere.. I know where the Makos and GW have tended to show up. 

 

I went hunting Wednesday.  Light colors because most of the teeth are being protected from tanic accid that create the black and brown colors in shark teeth from this area.  So lots of Lemons, Dusky, Bulls... many fewer Hemipristis, G. cuvier, ... no GWs, single numbers of mako, older tiger species,  except  Sand Tigers!!! I find 10-20 Sand Tiger teeth every time out which is more than any other location I have hunted.

 

Because of that contortus and the hemis,  I would guess that your teeth might have been dropped 2-3 mya in the Pliocene. 

 

Thanks to all the TFF experts for their thoughts and contributions.

[Harry Pristis]

It's not so difficult.  The last great inundation of South Florida was in the Early Pliocene, and the presumption should be that shark teeth from the Peace River Member are Pliocene in age.  There is always the chance that the river cuts into the Late Miocene portion of the P.R.Member, but the fauna is similar.  This is why I like to label many of my marine fossils from the river "Mio-Pliocene."  The idea of separating Miocene Hemipristis from Pliocene Hemipristis from the Peace River is making a distinction without a difference.

 

 

[siteseer]

Just a general comment...it's not really possible to identify the formation when you find fossils in a river that cuts through at least two formations especially when the taxa collected have chronologic ranges that bridge the ages of those formations.  We have the same problem with fossils found in the South Carolina rivers with fossils from the Oligocene to Pleistocene being found in them.

 

Shark teeth are generally not great time indicators but land mammals are.  I don't know what the oldest land mammal fossils found in the Peace are but the oldest Bone Valley Formation fossils I know of are Middle Miocene - specifically roughly Early Barstovian, using the North American Land Mammal Ages scale. or also roughly 16-17 million years old.  One of the early Mercychippus or Merychippus-like species of horse is found in the Upper Bone Valley.  I would assume something of that age would be quite rare in the Peace (those horse teeth are very rare in the Bone Valley) or perhaps the river has not cut that deep into the formation.  These teeth would resemble the classic Bone Valley horse teeth from the phosphate mines but they are shorter.  @fossillarry could provide more details.  

 

Jess

 

[Max-fossils]

@Bone Daddy @Harry Pristis @Shellseeker @minnbuckeye @Al Dente @MarcoSr @siteseer

 

Thank you all for your very interesting contributions to this discussion! The answer is a lot less straightforward than I had anticipated. (Sorry for the late reply btw, I forgot to pay much attention to this topic until today.)

 

Anyways, I'm going to attempt to 'summarize' the main answer. Feel free to correct anything I may have misunderstood. As extra info, we met up near Zolfo Springs.

 

I feel like Harry's and Jess' point of it not being a single age is probably best suited for labeling purposes. As such, we should put 'Mio-Pliocene', as this covers the whole possible range and we can't go wrong, given it's a mixed sediment with different formations present, that the Peace River all cuts through. It may not be a satisfying, accurate answer, but it's the only way we can be certain to not get it wrong. And as many of the shark species were present for a long time, it's impossible to pinpoint most species to a specific age or formation. With other locations, like quarries, often only a single formation is present, and it becomes very easy to just attribute all fossils to that formation and the corresponding age, but unfortunately we do not have that easy privilege in the Peace River. Which isn't all bad, because it does mean we get a nicer variety of fossils  

--> A decent 'proof' of there being several different ages is the fact that I have found both Galeocerdo cuvier and Physogaleus contortus in the same spot. And if the info on the picture of the Physogaleus frame that John provided is true, these two species did not live together and hence cannot be of the same age. 

 

Oh also, to add on to the complexity of the different layers present, I also found a three-toed horse tooth and glyptodont scutes (John found those) that same day. And while I'm not sure if a massive glyptodont would float or sink, I do know that it did not like to live next to some big ol' sharks in the open sea. So these land mammal fossils come from a time in the Mio-Pliocene where the Earth was a bit colder (and hence the landmass larger / lower sea-levels). Yet another layer to add to the mix! These are probably more easy to pinpoint to a specific age using the NALMA system mentioned by Jess, but do make the whole Peace situation even more complex. 

[siteseer]

On 6/18/2020 at 3:07 AM, Max-fossils said:

@Bone Daddy @Harry Pristis @Shellseeker @minnbuckeye @Al Dente @MarcoSr @siteseer

 

Thank you all for your very interesting contributions to this discussion! The answer is a lot less straightforward than I had anticipated. (Sorry for the late reply btw, I forgot to pay much attention to this topic until today.)

 

Anyways, I'm going to attempt to 'summarize' the main answer. Feel free to correct anything I may have misunderstood. As extra info, we met up near Zolfo Springs.

 

I feel like Harry's and Jess' point of it not being a single age is probably best suited for labeling purposes. As such, we should put 'Mio-Pliocene', as this covers the whole possible range and we can't go wrong, given it's a mixed sediment with different formations present, that the Peace River all cuts through. It may not be a satisfying, accurate answer, but it's the only way we can be certain to not get it wrong. And as many of the shark species were present for a long time, it's impossible to pinpoint most species to a specific age or formation. With other locations, like quarries, often only a single formation is present, and it becomes very easy to just attribute all fossils to that formation and the corresponding age, but unfortunately we do not have that easy privilege in the Peace River. Which isn't all bad, because it does mean we get a nicer variety of fossils  

--> A decent 'proof' of there being several different ages is the fact that I have found both Galeocerdo cuvier and Physogaleus contortus in the same spot. And if the info on the picture of the Physogaleus frame that John provided is true, these two species did not live together and hence cannot be of the same age. 

 

Oh also, to add on to the complexity of the different layers present, I also found a three-toed horse tooth and glyptodont scutes (John found those) that same day. And while I'm not sure if a massive glyptodont would float or sink, I do know that it did not like to live next to some big ol' sharks in the open sea. So these land mammal fossils come from a time in the Mio-Pliocene where the Earth was a bit colder (and hence the landmass larger / lower sea-levels). Yet another layer to add to the mix! These are probably more easy to pinpoint to a specific age using the NALMA system mentioned by Jess, but do make the whole Peace situation even more complex. 

 

Glyptodonts didn't migrate north from South America until the formation of the Isthmus of Panama during the Pliocene.

 

Jess

 

[Max-fossils]

7 hours ago, siteseer said:

 

Glyptodonts didn't migrate north from South America until the formation of the Isthmus of Panama during the Pliocene.

 

Jess

 

Ah ok then, some of the (land) mammal stuff is quite a bit younger then. Good to know!

[Harry Pristis]

Bison didn't arrive in North America until the Rancholabrean, the North American Land Mammal Ages chronology (NALMA), typically set from less than 240,000 years to 11,000 years BP.