Peace River trip January 22nd

[Shellseeker]

With the Peace River water depth coming down, and easing on the cooler temperatures. I was out hunting Wednesday, Friday, Sunday... basically checking various locations.

It was a little cool, so I wore a 5 mm wetsuit.  There were numerous places waist deep with some gravel..

A newer layer had moved in with small colored teeth, but almost everything we found were marine fossils and not very numerous. But there are always some interesting finds.

 

A few were larger, some even complete

 

There were a couple of types of urchin spines , one much more common than the other,

 

Then some shell material transformed to silica...

 

This last one had a silica cave complete with Botryoidal Chalcedony globes.

Finally,  a tooth, more likely Croc than gator....

 

All sorts of little treasures....

[Meganeura]

I love the silica bits! Really don't find much like that in the northern areas of the Peace!

[Tidgy's Dad]

Beautiful gastropod! 

[digit]

The silicified gastropod is truly a little gem!

 

 

Cheers.

 

-Ken

[Shellseeker]

5 minutes ago, digit said:

The silicified gastropod is truly a little gem!

Cheers.

 

-Ken

I am very curious about that one..

It has been a long time since we had a salt water environment in the Peace River. Just another data point if it could be IDed as Pliocene versus  Pleistocene. I'll search Pliocene gastopods for a likely match...

[Top Trilo]

The gastropod, the Hemis, the Tiger Shark, all really nice finds!

[Praefectus]

Nice finds!

[Fossildude19]

Great report and finds, Jack!

Thanks for the reveal!

[Sacha]

1 hour ago, Shellseeker said:

I am very curious about that one..

It has been a long time since we had a salt water environment in the Peace River. Just another data point if it could be IDed as Pliocene versus  Pleistocene. I'll search Pliocene gastopods for a likely match...

 

I'm guessing more Miocene Jack as are the rest of my silica replaced inverts in the Peace.

[Shellseeker]

Just poking around in @MikeR Pleistocene/Pliocene Gallery... One of  many possibilities

 

Hindsiclava perspirata is an extinct species of sea snail, a marine gastropod mollusc in the family Pseudomelatomidae, the turrids and allies.^[1]

 

I was hunting in Polk County, so I have to consider the formations...

 

Geologic units in Polk county, Florida

Reworked Cypresshead sediments (Pliocene/Pleistocene) at surface, covers 34 % of this area

Undifferentiated reworked Cypresshead Formation- This unit is the result of post depositional reworking of the Cypresshead siliciclastics. The sediments are fine to coarse quartz sands with scattered quartz gravel and varying percentages of clay matrix.

Hawthorn Group, Peace River Formation, Bone Valley Member (Miocene/Pliocene) at surface, covers 22 % of this area

The Bone Valley Member (originally the Bone Valley Formation of Matson and Clapp, 1909), Peace River Formation occurs in a limited area on the southern part of the Ocala Platform in Hillsborough, Polk and Hardee Counties. Throughout its extent, the Bone Valley Member is a clastic unit consisting of sand-sized and larger phosphate grains in a matrix of quartz sand, silt and clay. The lithology is highly variable, ranging from sandy, silty, phosphatic clays and relatively pure clays to clayey, phosphatic sands to sandy, clayey phosphorites (Webb and Crissinger, 1983). In general, consolidation is poor and colors range from white, light brown and yellowish gray to olive gray and blue green. Mollusks are found as reworked, often phosphatized casts. Vertebrate fossils occur in many of the beds within the Bone Valley Member. Shark's teeth are often abundant. Silicified corals and wood are occasionally present as well. The Bone Valley Member is an extremely important, unique phosphate deposit and has provided much of the phosphate production in the United States during the twentieth century. Mining of phosphate in the outcrop area began in 1888 (Cathcart, 1985) and continues to the present.

Undifferentiated sediments (Pleistocene/Holocene) at surface, covers 21 % of this area

Undifferentiated Quaternary Sediments - Much of Florida's surface is covered by a varying thickness of undifferentiated sediments consisting of siliciclastics, organics and freshwater carbonates. Where these sediments exceed 20 feet (6.1 meters) thick, they were mapped as discrete units. In an effort to subdivide the undifferentiated sediments, those sediments occurring in flood plains were mapped as alluvial and flood plain deposits (Qal). Sediments showing surficial expression of beach ridges and dunes were mapped separately (Qbd) as were the sediments composing Trail Ridge (Qtr). Terrace sands were not mapped (refer to Healy [1975] for a discussion of the terraces in Florida). The subdivisions of the Undifferentiated Quaternary Sediments (Qu) are not lithostratigraphic units but are utilized in order to facilitate a better understanding of the State's geology. The siliciclastics are light gray, tan, brown to black, unconsolidated to poorly consolidated, clean to clayey, silty, unfossiliferous, variably organic-bearing sands to blue green to olive green, poorly to moderately consolidated, sandy, silty clays. Gravel is occasionally present in the panhandle. Organics occur as plant debris, roots, disseminated organic matrix and beds of peat. Freshwater carbonates, often referred to as marls in the literature, are scattered over much of the State. In southern Florida, freshwater carbonates are nearly ubiquitous in the Everglades. These sediments are buff colored to tan, unconsolidated to poorly consolidated, fossiliferous carbonate muds. Sand, silt and clay may be present in limited quantities. These carbonates often contain organics. The dominant fossils in the freshwater carbonates are mollusks.

Cypresshead Formation (Pliocene) at surface, covers 15 % of this area

The Cypresshead Formation named by Huddlestun (1988), is composed of siliciclastics and occurs only in the peninsula and eastern Georgia. It is at or near the surface from northern Nassau County southward to Highlands County forming the peninsular highlands. It appears that the Cypresshead Formation occurs in the subsurface southward from the outcrop region and similar sediments, the Long Key Formation, underlie the Florida Keys. The Cypresshead Formation is a shallow marine, near shore deposit equivalent to the Citronelle Formation deltaic sediments and the Miccosukee Formation prodeltaic sediments. The Cypresshead Formation consists of reddish brown to reddish orange, unconsolidated to poorly consolidated, fine to very coarse grained, clean to clayey sands. Cross bedded sands are common within the formation. Discoid quartzite pebbles and mica are often present. Clay beds are scattered and not areally extensive. In general, the Cypresshead Formation in exposure occurs above 100 feet (30 meters) above mean sea level (msl). Original fossil material is not present in the sediments although poorly preserved molds and casts of mollusks and burrow structures are occasionally present. The presence of these fossil "ghosts" and trace fossils documents marine influence on deposition of the Cypresshead sediments. The permeable sands of the Cypresshead Formation form part of the surficial aquifer system.

Dunes (Pliocene/Pleistocene) at surface, covers 4 % of this area

Tertiary-Quaternary Dunes - The dune sediments are fine to medium quartz sand with varying amounts of disseminated organic matter. The sands form dunes at elevations greater than 100 feet (30 meters) msl.

There is more.....

I love those words.... at the surface.  How come it is so hard to find Pliocene at the surface... ? I am thankful for the Peace River...

[Shellseeker]

7 minutes ago, Sacha said:

I'm guessing more Miocene Jack as are the rest of my silica replaced inverts in the Peace.

Thanks John.  Your insight is helpful...

[Harry Pristis]

"The Early Miocene (25mybp) Tampa Formation [now the Tampa Member of the Arcadia Formation in the Hawthorn Group] underlies much of Florida.   It is composed of soft, highly-fossiliferous limestones intermixed with sand and clay.  There are several widely-separated exposures of the Tampa limestones which produce silicified corals and mollusks, the best known of which is Ballast Point on Tampa Bay.  Nearby exposures of the same formation, such as at Sixmile Creek on Tampa Bay, may produce only calcareous specimens.
"Many of the corals, mollusks, and other taxa of the Tampa Formation with shells or skeletons of calcium carbonate have been subjected to complete or partial silicification.  This replacement has produced specimens of considerable beauty and sometimes of faithfully reproduced pseudomorphs.  Most often the original calcareous structure has been partially or wholly dissolved, and the replacing silica obscures identification of the taxon."

[Shellseeker]

1 hour ago, Harry Pristis said:

Most often the original calcareous structure has been partially or wholly dissolved, and the replacing silica obscures identification of the taxon."

Yes, Harry.... too true, too true

I am likely on a path that might identify a family that has examples within the Miocene and Pliocene and Pleistocene of Florida and the key differentiators are erased in the silicification process.  I just needed a reason to go search.

 

[MikeR]

18 hours ago, Shellseeker said:

Just poking around in @MikeR Pleistocene/Pliocene Gallery... One of  many possibilities

 

Hindsiclava perspirata is an extinct species of sea snail, a marine gastropod mollusc in the family Pseudomelatomidae, the turrids and allies.^[1]

 

That is a pretty shell.  It isn't Hindsiclava perspirata which is a Plio-Pleistocene species.  We had a discussion before on the silicified fauna occasionally found in the Peace River area.  I think it is from the Tampa Member of the Arcadia Formation.  Definitely a turrid, so probably the family Pseudomelatomidae assignment is correct.  It isn't in Mansfield's Tampa/Suwannee monograph, FL Bulletin 15.  I am hesitant to say so as it is a term used much too often, but could be an undescribed species.

 

Mike

Edited January 24, 2023 by MikeR

[Sacha]

18 hours ago, Shellseeker said:

Thanks John.  Your insight is helpful...

 

My other insight is that Roger Portell may have some resource that Mike doesn't have, but if you show it to him, you know he will hope you will donate it!

[Yoda]

@Shellseeker

 

Nice finds.

Especially the shark teeth 

[Shellseeker]

 

I donated the Silica Turrid.... Not all my donations manage to get into the UF Database, so I am extra pleased.

 

https://en.wikipedia.org/wiki/Pseudomelatomidae

[Coco]

Good ! You should put it in the "Paleopartner" section

 

Coco