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Kato

Fossil (maybe) in chert

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Kato

Okay, this is way, way out there, but it's a maybe.

 

I am sitting on the fence for going real or mother nature. I was strolling around the mountains today. On an Silurian plateau I spied this piece of cherty material with what may or may not be a small crinoid. It is a bit banged up, kind of rusty looking, but seems like an immature crinoid??? Otherwise, a very interesting want-to-be.

 

Material is missing from some areas which would have been helpful and it wraps around the edge of the rock making it challenging to photograph. On the entire chunk of rock there are no other features of note.

 

Size from 8 on the ruler as it wraps around the other side comes out to about 35mm

 

image.png.a21ba1fc48f1d5d2a76a56f8afe5bd90.png

 

image.png.f88a24cc969e6f1b1cd1728337d289ca.png

Edited by Kato
corrected Ordovician to be Silurian

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Peat Burns

My guess would be septa of a rugose coral.

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Kato
9 minutes ago, Peat Burns said:

My guess would be septa of a rugose coral.

Ah....I hadn't thought of that...in other words just a portion of an internal view is showing of the some of the septa and septal grooves and it is tapering down to its apex which would be at the far left.

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ynot

I am thinking it is a sponge, but am not sure.

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Innocentx

You've definitely got something here. Could you post more angles with more MPs so can zoom in?

The sections (septa?) seem to converge in the center of your first photo.  Also there is some detail on these sections

that I can't quite see but which would be helpful to ID.

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Kato
2 hours ago, Innocentx said:

You've definitely got something here. Could you post more angles with more MPs so can zoom in?

The sections (septa?) seem to converge in the center of your first photo.  Also there is some detail on these sections

that I can't quite see but which would be helpful to ID.

This is the best I can do until tomorrow when there is daylight for other pics. Even then I am pretty much at the limit of my current tech MP-wise. Apologies the camera had trouble deciding where to focus as a close-up so the two I will post are not very good.

 

Top view as it wraps around the rock. Note the material is not chert but some kind of brown grainy material.

 

Also, this was found in Silurian and not Ordovician

 

image.thumb.png.37ef676dc345b550f4d757cb262a6892.png

 

 

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Kato

Just a full size instead of reduced image. Note the yellow ellipse. It looks like the individual strands narrow down, then I can see 'ghost images' in the chert towards the left side where it connects to a tiny pocket of quartz crystals. I can also see the ghostly remains just to the right of the ellipse where some of the strands have been worn off.

 

Also, this was found in Silurian and not Ordovician

 

image.thumb.png.71a36db3793f17e4339c0fc1b901c375.png

 

Still very uncertain. Seems it could just be a happy trick of nature. The only thing keeping me on the fence is the brown grainy matrix of the material the individual strands are composed of.

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Innocentx

When you take more photos tomorrow you can leave out the ruler. Sometimes that helps the camera focus better.

I'm interested to see the surface details of the concave area above it, and also other sides etc.

I'm kind of a sucker for fossils in chert

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abyssunder

brachiopod internal structure?

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Kato
14 hours ago, Innocentx said:

I like this idea. Here is photo of such:

http://louisvillefossils.blogspot.com/2014/04/orthospirifer-lophophore-brachiopod.html

 

We're waiting on more photos from @Kato

Apologies for the delay. I hiked back in to try and find more specimens. Here are 2 pics of the original specimen. Unfortunately, resolution limited to 8MP for now.

 

image.thumb.png.a14f779fde5658d0a240e27358129133.png

 

image.thumb.png.beb360ec1eb7945bb330e1b9c4d5fd51.png

 

I am leaning toward sponge remains. Maybe just geologic siliceous ooze.

 

Will post two pics of another specimen I picked up. Very similar ridging, yet different, clearly not brachiopod related.

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Kato

2nd specimen. These make me think sponge? Stromatoporoid?

image.thumb.png.f231c6a86f66e46e7965e966ae726bce.png

 

image.thumb.png.015fc39fd2c571b5349734a3f21984e4.png

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Kato

On the original specimen could the pinkish looking material in the void (middle/top) be fossilized sponge material?

 

image.thumb.png.c6eb3e183274fc626558d39b1a81193d.png

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JohnBrewer

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Tidgy's Dad

I'm really sorry to say, and I hope I'm wrong, but i think this is geological, calcite and deformation of the strata. 

Sorry. :(

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Kato
15 minutes ago, Tidgy's Dad said:

I'm really sorry to say, and I hope I'm wrong, but i think this is geological, calcite and deformation of the strata. 

Sorry. :(

Hi, thanks for sharing your knowledge. It has only a weak reaction to vinegar (in the grooves). The rest of the rock appears to be chert. I am fine with it being geologic and will make a nice addition to my rock garden oddity collection.

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Innocentx

@Tidgy's Dad knows way more than I do so he's probably right. I think a visit to knowledgeable people who are familiar

with the local geology, would be best answer for information on these. The type of forms appearing in this chert are quite different 

than what I have local to me.

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Kato
2 minutes ago, Innocentx said:

@Tidgy's Dad knows way more than I do so he's probably right. I think a visit to knowledgeable people who are familiar

with the local geology, would be best answer for information on these. The type of forms appearing in this chert are quite different 

than what I have local to me.

Thanks! I lived in the Flint Hills of Kansas and saw lots of chert there as well. Like you mentioned nothing like this, though. 

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Tidgy's Dad
4 minutes ago, Kato said:

Hi, thanks for sharing your knowledge. It has only a weak reaction to vinegar (in the grooves). The rest of the rock appears to be chert. I am fine with it being geologic and will make a nice addition to my rock garden oddity collection.

 

2 minutes ago, Innocentx said:

@Tidgy's Dad knows way more than I do so he's probably right. I think a visit to knowledgeable people who are familiar

with the local geology, would be best answer for information on these. The type of forms appearing in this chert are quite different 

than what I have local to me.

Thanks.

But I am far from certain, though even a weak reaction suggests calcite, but this doesn't preclude it being a fossil. 

And it's very interesting whatever it may be, well worth keeping. :)

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Kato
5 minutes ago, Tidgy's Dad said:

 

Thanks.

But I am far from certain, though even a weak reaction suggests calcite, but this doesn't preclude it being a fossil. 

And it's very interesting whatever it may be, well worth keeping. :)

haha...well, I will name it 'folded siliceous ooze' for now.

 

Just for grins, I gave it another vinegar bath and it did not fizzle so I'm guessing the dose I gave it yesterday dissolved any calcite residue on it.

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abyssunder

Definitely not sponge or stromatolite, nor brachiopod.
The new images show that it is banded chalcedony/chert.

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Innocentx
4 hours ago, abyssunder said:

banded

What might cause the bands to form/separate in this way, then leave empty spaces?

Interested in processes if you can say, thanks.

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Kato
3 hours ago, Innocentx said:

What might cause the bands to form/separate in this way, then leave empty spaces?

Interested in processes if you can say, thanks.

Thanks for asking...hopefully abyssunder will let us know. I had wondered as well but thought I would just drop the subject.

 

The only thing I could formulate, in my limited experience and imagination, was that some of the banding was of impure material (not pure enough silica like in nice agates or chalcedony) so I thought it might be causing the brown matrix material to split, perhaps as things were oozing around under pressure?

 

The brown bands do look kind of like sandy. Unfortunately, I don't have enough camera MP's or handheld glass magnification to tell if that is true.

 

Maybe this is more of a banded flint than a chalcedony?

 

'...the exact mode of formation of flint is not yet clear but it is thought that it occurs as a result of chemical changes in compressed sedimentary rock formations, during the process of diagenesis. One hypothesis is that a gelatinous material fills cavities in the sediment, such as bored by crustaceans or molluscs. This hypothesis certainly explains the shapes of flint nodules that are found. The source of dissolved silica in the media could be the spicules of silicious sponges.'

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abyssunder
13 hours ago, Innocentx said:

What might cause the bands to form/separate in this way, then leave empty spaces?

Interested in processes if you can say, thanks.

I'm not a geologist, so I'll let the specialists in this domain to explain how the banded chalcedony or agate forms. :)

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