I don't know where to start to ID this one. Fossil or something else?

[Plantgrogu]

I've come across several similar shapes in pieces of shale and could use some help with ID. All have a rounded end and in one specimen I see a lot of tiny round indentations to evenly spaced to be random or weathering, in the bulbous round end. Found in the Finger Lakes Region, NY. Matrix is shale in the Hamilton group and in natural light the fossils have a silver sheen to them. (Quite striking) When I uncovered one sample, shown in pictures 2 - 4, a dark red solution drained from around the fossil when it came in contact with water. Can you point me in the right direction? Picture one is a different sample than in pictures 2 - 4.

[Fossildude19]

Concretions, I believe.

[Plantgrogu]

On 3/25/2022 at 10:16 PM, Fossildude19 said:

Concretions, I believe.

Thank you for your response  I took additional photos to better show the two structures of interest and took some measurements as I'm not convinced these are "random"  but am hoping my mind is not playing tricks on me either. LOL 

What I found:

Both pieces of shale were found in different locations, but appear to be from the same formation.

The large stone has several of these same structures throughout and some curious silver (definitely not white) colored possibly very worn brachipods and yet to be identified fossils in the same layer. 

The bulbous end of each of the two items of interest measure 7 - 8 mm each and I can see segmentation, restrictions, or indentations in both samples. 

After flipping through my first field guide for Devonian fossils of the Finger Lakes (so excited about this book), I came across Ceratodictya annulata and am wondering what you think! Could it be part of a sponge?

[Fossildude19]

Any idea which formation it is that you are finding these in?

[Fossildude19]

Ceratodictya annulata is from the Upper Devonian, Chemung Facies, West Falls Group. 

[Plantgrogu]

6 minutes ago, Fossildude19 said:

Any idea which formation it is that you are finding these in?

At this time, I only know that it's in the Hamilton Group. There is an outcrop of Tully limestone that is above the shale layers upstream of where these were found. I have to dig into my geology books for this group asap.

[Plantgrogu]

3 minutes ago, Fossildude19 said:

Ceratodictya annulata is from the Upper Devonian, Chemung Facies, West Falls Group. 

Very curious indeed. I need to hit that geology book!!

[Plantgrogu]

There's another possibility! Many of the streams and tributaries here have massive stone brought in to stabilize the shores. Between the glaciers and human activity,  who knows what I'll find!

[Fossildude19]

My gut is telling me these are concretions or possibly burrow traces. 

 

[Plantgrogu]

2 minutes ago, Fossildude19 said:

My gut is telling me these are concretions or possibly burrow traces. 

 

Thank you 

[Ludwigia]

Whatever they are, they appear to be either pyritized or limonitized.

[doushantuo]

Radish concretion, possibly, vide wetzel et al..

Which I will post, soonest.

 

 

edit:

(10 MB,RECOMMENDED!!!!)

 

Sedimentology (2022) 69, 750–774

Radish concretions, grown in mud during compaction
ANDREAS WETZEL and MACIEJ BOJANOWSKI

495364462_Sedimentology-2021-Wetzel-Radishconcretionsgrowninmudduringcompaction.pdf

[caterpillar]

Nodule of marcasite or pyrite for me, as in many deposits

[Plantgrogu]

6 hours ago, Ludwigia said:

Whatever they are, they appear to be either pyritized or limonitized.

Thank you! I'll read up on these terms

 

[Plantgrogu]

42 minutes ago, caterpillar said:

Nodule of marcasite or pyrite for me, as in many deposits

Thank you. I'll read up on these

59 minutes ago, doushantuo said:

radish concretion ,possibly ,vide wetzel et al.

which i will post,soonest

 

 

edit:

(10 MB,RECOMMENDED!!!!)

 

Sedimentology (2022) 69, 750–774

Radish concretions, grown in mud during compaction
ANDREAS WETZEL and MACIEJ BOJANOWSKI

495364462_Sedimentology-2021-Wetzel-Radishconcretionsgrowninmudduringcompaction.pdf 10.2 MB · 2 downloads

Thank you! Looks like a great article and I will read it soon.  Very interesting! At a glance, Wetzel, et., al describe the radish concretions as forming vertically. If I'm looking at the stone correctly, these structures are predominately horizontal. They look very similar though. While looking at the paper you shared, I found another that describes vertical concretions and bioturbation formations that also look similar. See page 2451 of  this paper. 2021 Jean-Philippe Blouet et., al. What makes seep carbonates ignore self-sealing and grow vertically: the role of burrowing decapod crustaceans

[Plantgrogu]

3 minutes ago, Plantgrogu said:

radish concretion 

There is SO much to learn and the the examples in Wetzel, et., al look very similar to my find. Although they may not be Radish concretions, I'm now convinced that what I have found is certainly a concretion and can understand how they could be formed. Thank you!

[Plantgrogu]

Thank you everyone for the great discussion. I have learned a lot and will read up on the terminology you've shared along with the informative articles. I'm convinced it's a concretion and you've helped me to rule out other possibilities.

Edited March 29, 2022 by Plantgrogu
grammar

[Plantgrogu]

3 hours ago, caterpillar said:

Nodule of marcasite

I found this photo of "Iron pyrite marcasite" online when I searched for marcasite nodules and am seeing many similarities between those in the photos and the two that I found! The photo came from an appraisal site and specimens were found in chalk. "These were found at the foot of the white cliffs of Beachy Head, Seven Sisters, South coast of England. They form in the chalk, as as the cliff erodes, these fall out onto the beach."