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KimTexan

Matoaka Beach iron concretions?

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KimTexan

I found these on Matoaka Beach, Maryland a week ago. I found some of these that have bone and shell in them. I also found turtle shell fragments and other bone fragments. I think they are just iron concretions of some sort, but since I found bone in some I question whether there may be something else to them.

4CB5305E-5CD0-472A-AF13-7954BBC32399.thumb.jpeg.fe2770e13f3910d01d40278e7e9b963e.jpeg

 

Any thoughts?

 

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KimTexan

EB7D321B-DD83-433C-9C65-BC433E922975.jpeg

F661EFDF-7713-428E-9571-D52233DF630B.jpeg

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daves64

3rd pic looks sort of like a Mars orbiter view. 

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Rockwood

My first thought is of how cold the wind sifting through the beach cabin was about this time of year in 2010.

Second thought; ironstone, aka bog iron.

IMG_1630 a.jpg

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WhodamanHD

Yeah, iron. 

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KimTexan

Yes, it is iron, but there are bone and shells in some of it. Some of the patterns remind me of this from the museum. If I removed the iron from them the pieces may look more similar to these turtle shell fragments on the bottom. I even have some with long ridges like these, but the pattern doesn’t look exactly like that.

The underlying material on mine is dark brown to black like these. Can you see similarities? Ugh, sorry about the underline. I can’t get it to turn off!

 

90AC5C8F-1C5B-4958-90BC-387825E59F6D.thumb.jpeg.1672fcc1a2fabbc4495c073b758bce4b.jpeg

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Rockwood
53 minutes ago, KimTexan said:

but there bone and shells in some of it

Isn't that a bit like arguing that it is matrix rather than fossil ? :)

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KimTexan
10 minutes ago, Rockwood said:

Isn't that a bit like arguing that it is matrix rather than fossil ? :)

My point in saying that is that the iron concretion material does have fossils found in it. Many times iron concretions or any concretions have no fossilized material in them. You cal look at hundreds or thousands of them and find nothing. Fossils are found in these layers thus increasing the likelihood these could be something.

 

That said I don’t know the geology in the area. There may be beds of this type of material that spread across larger areas with this morphology, which would completely rule out the any prospect of them being turtle shell fragments. 

 

When I went looking for turtle shell patterns in the area I found others as well. I don’t know for certain that this is turtle, but it is a bone fragment. The under side of this is clearly bone.3E896E60-59A3-467E-B45B-BB0CFE9A69B0.thumb.jpeg.2c10feba0c315e64715edf305f94a0f3.jpeg

There is also this pattern from sturgeons which has some similarities as well to some of the pieces I found. I have a number more pieces.

819E2856-E845-4D67-8136-2D1BB67B18C5.thumb.jpeg.b1825a79582caa90f75bbfc9d4772805.jpeg

 

I think the one on the right (which appears to have some fossilized material in it, possibly bone) bears some similarities to the crock material below on the right on display at the museum.

4CB5305E-5CD0-472A-AF13-7954BBC32399.thumb.jpeg.fe2770e13f3910d01d40278e7e9b963e.jpeg

B4D11A90-E8A5-4495-9144-833A4411834E.jpeg.26ad80c2b5e6eec3f2530bb66ac04382.jpeg

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WhodamanHD

It’s just bog iron, usually doesn’t have anything in it. Sometimes there is a fine grained Pliocene iron that I’ve seen have starfish in it, and down the Potomac Marco Sr. And Dr. Weems work on Pleistocene Bog Iron with mammal footprints in it. 

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KimTexan

@abyssunder or @doushantuo You two often seem to come up with relevant papers to shed light upon matters. Do either of you have any ideas on the topic from Maryland, Chesapeake Bay, the Potomac and Patuxant Rivers are nearby? 

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Rockwood

I think the key to it is texture. It's not quite the same.

When you see color as poorly as I do you pick up on things like that. ;)

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KimTexan
1 hour ago, WhodamanHD said:

It’s just bog iron, usually doesn’t have anything in it. Sometimes there is a fine grained Pliocene iron that I’ve seen have starfish in it, and down the Potomac Marco Sr. And Dr. Weems work on Pleistocene Bog Iron with mammal footprints in it. 

I understand some could be just bog iron, but there is iron material I picked up at the same time in the same place which has fossil material in it. Most of this was from one spot on the beach. Some have very deteriorated bone in them.

One key to this is the grainy yellow/orange clay material present with them. Clay is often a common component which marine fossil material is found in. 

These are a few examples of the material I found with fossil material in them. So there are definitely fossils in the bog iron as you call it. I have many more pieces. If I had not seen the fossils I would have thought just a concretion. Then I saw the yellow clay material, which raised my curiosity.

I had a large conglomerate of shell material I chose to leave behind. It was too big.

 

There are 3 imprints of shell fossils on this piece.

96C2B5A7-B65D-4346-9A10-47F6B8EF638C.thumb.jpeg.fe60d2a1100dcd84cbf39a634c7a9d7b.jpeg

 

This is another. The color is very off on this because I couldn’t capture the details because the material is a dark brown with some orange. The lighting makes it look light and green.

6C8BE4BA-FB94-45B7-A4A9-8060524AA05F.thumb.jpeg.f780af60163ab3ad40f5815d48464820.jpeg

The other side looks like a scallop possibly.

BE8153D9-FCF3-415B-815C-4185034CBE0E.thumb.jpeg.9e2960ad6d268aad75faeb719c1b7c1b.jpeg

 

These 2 bone fragments as well as another I found had the yellow orange clay material seen in the groves of the first pictures posted. I have cleaned the clay off.

The darker one looks like a turtle shell fragment to me.

Side one

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Side 2

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The edge. The top one doesn’t look like bone from the edge, but it is the edge of the bottom one in the previous pic.

E3165825-724A-4DAE-9E1C-0D527CDBC494.thumb.jpeg.2f7d37001d419e4046fc35668e66cc14.jpeg

 

This piece has 3 shell imprints I can see in it. Only 2 in this pic. The color is a bit off on this too.

5033A29E-8827-4643-A483-B21CA9353D5F.thumb.jpeg.0e298450422a418d86e9e91e50d73042.jpeg

I’ll work on cleaning my bumpy pieces up and see if I can see other details that may give more clues about them.

 

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Rockwood

I think bog iron sort of consumes these in it's path. That's my impression of the way it forms, as opposed to nucleation. 

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MarcoSr
5 hours ago, KimTexan said:

I think the one on the right (which appears to have some fossilized material in it, possibly bone) bears some similarities to the crock material below on the right on display at the museum.

4CB5305E-5CD0-472A-AF13-7954BBC32399.thumb.jpeg.fe2770e13f3910d01d40278e7e9b963e.jpeg

B4D11A90-E8A5-4495-9144-833A4411834E.jpeg.26ad80c2b5e6eec3f2530bb66ac04382.jpeg

 

 

I see lots of bog iron in Virginia with patterns like your bog iron piece on the right.  So many pieces that I almost didn't pick up the croc dermal armor  (4.5” by 3.5”), frozen in the beach with some sand on it, shown in the pictures below, thinking it was just bog iron.

 

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Marco Sr.

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abyssunder
8 hours ago, KimTexan said:

@abyssunder or @doushantuo You two often seem to come up with relevant papers to shed light upon matters. Do either of you have any ideas on the topic from Maryland, Chesapeake Bay, the Potomac and Patuxant Rivers are nearby? 

I think, ironstone (a sedimentary rock) with differential erosion, or bioeroded ferruginous hard substrate, may be similar to the specimens in question.

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KimTexan

I found a piece today in the Eagle Ford group that looked a little bit like some of this material. We don’t call it bog iron though. We don’t have bogs in this part of Texas.

 

@MarcoSr Thank you for commenting. What do you think this is from?

The first 2 pics are same side different angles. The bottom is smooth dark brown. It looks very similar in color, shape and size to some turtle shell fragments, but the texture is totally different. This is dark brown so the color here is distorted, because I shined bright light on it to illuminate the details.

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This is the edge. It is also dark brown, not tan.

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ynot
5 minutes ago, KimTexan said:

We don’t have bogs in this part of Texas.

Not now, but what about 1000 or 10000 or a million years ago? Everything changes over time.

 

9 minutes ago, KimTexan said:

What do you think this is from?

Maybe a piece of skull bone(?).

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WhodamanHD

I still think that’s a partial epiphysis.

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MarcoSr
11 hours ago, KimTexan said:

I found a piece today in the Eagle Ford group that looked a little bit like some of this material. We don’t call it bog iron though. We don’t have bogs in this part of Texas.

 

@MarcoSr Thank you for commenting. What do you think this is from?

The first 2 pics are same side different angles. The bottom is smooth dark brown. It looks very similar in color, shape and size to some turtle shell fragments, but the texture is totally different. This is dark brown so the color here is distorted, because I shined bright light on it to illuminate the details.

 

 

This is the edge. It is also dark brown, not tan.

C4C1140B-2B26-4821-BFAB-A7853B37D56D.thumb.jpeg.eed06a98b10f916041cafe5cf747b753.jpeg

 

The bog iron that I see is layered and solid in the middle and not porous in the middle like your piece.  Your piece does look like bone.  Turtle shell is porous like that but I don't recognize the patterns/texture on the one side either.

 

Marco Sr.

 

Edited by MarcoSr
clarification

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DPS Ammonite
On 10/13/2018 at 9:32 PM, KimTexan said:

 

4CB5305E-5CD0-472A-AF13-7954BBC32399.thumb.jpeg.fe2770e13f3910d01d40278e7e9b963e.jpeg

 

Hello Kim. The textures might be suggestive of bone. What you need to do is see what they are made of bone or iron rich sediment. I would clean them well and look at them with a handlens. If there is bone it should be visible on the narrow edges of the pieces. Do you see bone? I would then scratch them or break a small piece off. Bone looks different than iron rich silt and clay. Let us know if you see any bone. 

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WhodamanHD

I’ve seen hundreds of pieces like this, it is definitely iron.

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KimTexan
10 hours ago, kelliloan said:

Some very nice finds!!!!!!!!! :) those iron concretions look like the Chesapeake bay bio minerals possibly.  https://www.irocks.com/chesapeake-biominerals-hazen-article

Thank you so much for sharing that article!!!

 It was very interesting. I picked up a lot of that stuff and I did find a limonite burrow with the manganese mineral included that is hollow.

Yes, from reading that article that is what they are.

I picked up a few pieces that were beautiful limonite finely layered concretions.

 

Years ago there was an Arkenstone exhibit at a small nature preserve museum near here. I went to see it. It was the best crystal and mineral exhibit I have ever seen before or since. Even better than that at the Perot Museum. I have never purchased anything from them though.

 

@DPS Ammonite

I did extract 3 pieces of bone from the limonite. 2 I believe are turtle shell fragments. I guess that still counts as bone, kind of.

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