Identification Request

[BLT]

This is another fossil which I would like to have identified. Can anyone tell me what the area circled in red would be? The rock is from my yard in middle Tennessee. (Mississippian, St. Louis Limestone & Warsaw Limestone) 

[ynot]

I can not see any defining features in these pieces.

Could be shark or fish teeth, or could be shell fragments, or could be bone fragments.

If You can expose one better it may help.

 

Maybe @TNCollector can help with this.

[BLT]

3 minutes ago, ynot said:

I can not see any defining features in these pieces.

Could be shark or fish teeth, or could be shell fragments, or could be bone fragments.

If You can expose one better it may help.

 

Maybe @TNCollector can help with this.

Gotcha. Will try to do that. Thanks!

[TNCollector]

Yeah I see the object you are talking about, but can’t see enough detail to make out what is there. Some better pictures would help shed some light on this.

 

What county was this found in, if you don’t mind me asking?

[BLT]

5 minutes ago, TNCollector said:

Yeah I see the object you are talking about, but can’t see enough detail to make out what is there. Some better pictures would help shed some light on this.

 

What county was this found in, if you don’t mind me asking?

This was found in Warren County. (McMinnville) I am going to try to get clearer pics later.

[Fossildude19]

I think this is a piece of a branching bryozoan, much like the one next to the shell. (Circled in red. ) 

The shell covered the bryozoan bit, and then broke over it when the overburden got too heavy. 

Looks like you can see the pores on one side of the piece.

 

 

 

 

 

[Innocentx]

Yes, it looks like the shell was pressed over something and deformed over it.

[BLT]

27 minutes ago, Fossildude19 said:

I think this is a piece of a branching bryozoan, much like the one next to the shell. (Circled in red. ) 

The shell covered the bryozoan bit, and then broke over it when the overburden got too heavy. 

Looks like you can see the pores on one side of the piece.

 

 

 

 

 

Oh, gotcha. And yes, pores are visible on that one side. Thank you!

 

14 minutes ago, Innocentx said:

Yes, it looks like the shell was pressed over something and deformed over it.

Thanks!

[BLT]

Although I am content with the previous identification, I wanted to post this pic which shows a bit more detail. It does appear to have multiple layers/textures. @TNCollector

[fossilcrazy]

Looks like shell material from Ordovician Brachiopod Rafinesquina sp.

[BLT]

2 minutes ago, fossilcrazy said:

Looks like shell material from Ordovician Brachiopod Rafinesquina sp.

I had to do a quick google search. Some of the photos online actually look identical to what I am seeing on my rock, but cannot photograph well enough with my iPhone camera. However, my area is mostly Mississippian. 

[BLT]

Several pieces crumbled off the opposite side of the large hash plate in this post. Can anyone tell me which type of brachiopod this is? 

[BLT]

Another piece from the same hash plate:

[TNCollector]

I believe that I was quoted in this topic in case it was fish/shark material, however the new pictures show that it definitely is not. I agree that it is a brachiopod that has been compressed on top of a branching bryozoan. @JimB88 may be of more help.

 

Are you 100% certain that you are in the Mississippian? There are many outcrops of Ordovician in that county and sometimes it can be hard to determine what you are collecting in. Have you found any Archimedes at the site? That would be a tell-tale sign that you are searching the Mississippian.

[BLT]

8 minutes ago, TNCollector said:

I believe that I was quoted in this topic in case it was fish/shark material, however the new pictures show that it definitely is not. I agree that it is a brachiopod that has been compressed on top of a branching bryozoan. @JimB88 may be of more help.

 

Are you 100% certain that you are in the Mississippian? There are many outcrops of Ordovician in that county and sometimes it can be hard to determine what you are collecting in. Have you found any Archimedes at the site? That would be a tell-tale sign that you are searching the Mississippian.

I see. Thank you!  Yes, I am certain that my property is in the Mississippian. I have found several Archimedes here. 

[Innocentx]

5 hours ago, BLT said:

this pic which shows a bit more detail.

Now I can see the shell may be scrunched over a bryozoan, as @Fossildude19 said earlier. Cool.

[GavySwan]

I’d agree with Bryozoan. I see a lot of them up here in the Ordovician. 

I don’t know a lot about Bryozoans but I don’t think being in the Mississippian rules them out—they’re still abundant today, after all!

Gavy

[Paciphacops]

13 hours ago, TNCollector said:

Are you 100% certain that you are in the Mississippian? There are many outcrops of Ordovician in that county and sometimes it can be hard to determine what you are collecting in.

Warren County is all Mississippian and Pennsylvanian. The closest outcrops of Ordovician are in neighboring Cannon County, along the Highland Rim escarpment below Short Mountain. However, some of the fossils found and posted by @BLT appear to be Ordovician, so some of her finds must have been transported there, so Ordovician can't be ruled out.

 

The Geologic map below shows Warren County. Mississippian strata are blue, Pennsylvanian are green/brown and Ordovician are red/pink.

[BLT]

53 minutes ago, GavySwan said:

I’d agree with Bryozoan. I see a lot of them up here in the Ordovician. 

I don’t know a lot about Bryozoans but I don’t think being in the Mississippian rules them out—they’re still abundant today, after all!

Gavy

Gotcha. Thanks!

~ Tracey

5 minutes ago, Paciphacops said:

Warren County is all Mississippian and Pennsylvanian. The closest outcrops of Ordovician are in neighboring Cannon County, along the Highland Rim escarpment below Short Mountain. However, some of the fossils found and posted by @BLT appear to be Ordovician, so some of her finds must have been transported there, so Ordovician can't be ruled out.

 

The Geologic map below shows Warren County. Mississippian strata are blue, Pennsylvanian are green/brown and Ordovician are red/pink.

I do not live near Short Mountain. (My children grew up going to camp there every Summer, so I am quite familiar with the area.) But yes, a neighbor has confirmed that a few of the rocks which I posted a couple of months ago were transported here from a nearby county.  

[TNCollector]

8 hours ago, Paciphacops said:

Warren County is all Mississippian and Pennsylvanian. The closest outcrops of Ordovician are in neighboring Cannon County, along the Highland Rim escarpment below Short Mountain. However, some of the fossils found and posted by @BLT appear to be Ordovician, so some of her finds must have been transported there, so Ordovician can't be ruled out.

 

The Geologic map below shows Warren County. Mississippian strata are blue, Pennsylvanian are green/brown and Ordovician are red/pink.

 

The creek bottoms along the western edge of Warren county are mostly Ordovician. The geological maps do not always take this into account.

[Paciphacops]

18 hours ago, TNCollector said:

The creek bottoms along the western edge of Warren county are mostly Ordovician. The geological maps do not always take this into account.

I have been exploring this area for nearly 30 years and I have hiked most of those creek bottoms.  Some of the exposures are relatively close to the western edge, but not in Warren County. The map I posted is from the East Central sheet, and not the highest resolution available, and the strata does extend a bit further upstream than indicated. However, it would have to be off by miles to extend into Warren County, which lies entirely on or above the Highland Rim plateau. There are high resolution detailed 7.5 minute geologic topo maps for all of TN, and they show that all of the Ordovician exposures near the western edge of Warren County are only in the head water tributaries of the Stones River. None of these tributaries extend into Warren County. I've actually hiked most of these creeks. The purpose of these hikes was to investigate extensive karst systems in Cannon County. When water drains off the Highland Rim plateau, which is capped by the Mississippian Fort Payne formation, it crosses the Chattanooga Shale (Mississippian and Devonian) and sinks almost immediately into the Ordovician limestone. This makes the Ordovician/Devonian/Mississippian contact extremely easy to spot.

 

Below is a section of the Short Mountain geologic topo. I have marked the exposures of Ordovician strata closest to Warren County in red circles (about 1.5 miles from the county line). I have been to both of the marked contacts, and I have also been to many of the other contacts. I have found the 7.5 minute maps to be quite accurate.

[TNCollector]

@Paciphacops

 

Yes Warren County is almost completely Mississippian, and like you I have done extensive collecting in the area, including in the Ordovician Leipers Formation where I have done an extensive collection of brachiopods.

 

The USGS site notes that this formation is indeed found in Warren County, regardless of the fact that they do not show these formations on their map.. See this link: https://mrdata.usgs.gov/geology/state/sgmc-unit.php?unit=TNOu%3B8

 

The maps are good measures of where the listed strata should be, but only evaluation by eye can really tell you what is there. There have been many instances where I have found outcrops of formations that should not be where they are, especially in the Appalachians where the tectonic forces that made these mountain ranges crumpled the ground like a piece of paper.