Shale Question From A Newbie

[shorty]

Hello!

So, first of all, I'm definitely an over enthusiastic newbie with little knowledge. I apologize in advance if this is a ridiculous question.

I've read the old posts about shale, and the potential for fossils. This shale is from the Francis Creek Shale that Mazon Creek concretions are found in (near Braidwood, IL.) I usually find leaves and stems in the shale. But this is different and maybe nothing.

The picture below looks like part of a fin to me, but I have an over active imagination.

My question is 2 part - Could impressions of fins be preserved in this type of shale?

and is that what this is?

Thanks for your time!

Kim

[Auspex]

To me, it looks more like a water-born stain that infiltrated the bedding plane.

[jkfoam]

To answer your question, yes fins or fin prints can be preserved in shale. But, IMO I think you have a print of part of a pinnule of the plant Neuropteris sp.

Shorty, no questions here can even be remotely considered rediculous.

JKFoam

[tracer]

auspex nailed it, methinks. when you say "could" a fin be preserved in that type of shale, i'd say the answer is yes. but are there any is another question, and the answer is if you're close to mazon creek, and you want to know what all you might find in that area, there's tons of info out there on mazon creek fossils... i'm not sure if fish had been invented yet in that part of the country back then.

(you'll have to excuse tracer - he's always saying weird snarge like that)

p.s. - a fast googling revealed that yeah, it's possible, cuz here's a fish scale in a mazon creek nodule

scale

[Guest Nicholas]

To answer your question, yes fins or fin prints can be preserved in shale. But, IMO I think you have a print of part of a pinnule of the plant Neuropteris sp.

Shorty, no questions here can even be remotely considered rediculous.

JKFoam

I support this statement and the possible id.

[Guest solius symbiosus]

Much too large for Nueropteris. Auspex nailed it. It is manganese oxide stains. Look closely and you can see the plumose structures associated with the stress that caused the fracture.

[shorty]

Thanks for all the replies and the support for asking potentially silly questions!

Mineral stain explains why I couldn't find the rest of a monster fish or shrimp that the fin belonged to!

solius symbiosus - I'm going to have to google this, "plumose structures associated with the stress that caused the fracture." and see if I can figure it out it!

I've recently gone back to college to become a science teacher someday - so I've clearly got a lot to learn!

Ok - just so you all don't think I'm just finding water born stains in shale - below are a couple photos of some of the real things I've found!

By the way, I have a question about that broken tully monster in the first photo, if anyone has time. I'll start a new question.

Thanks again for all the help!

Kim

[Auspex]

Tullies! He's got Tullies!

One of the most enigmatic fossils out there; we may never know even the basics about the critter.

[shorty]

Tullies! He's got Tullies!

One of the most enigmatic fossils out there; we may never know even the basics about the critter.

Yep, Tullies I do have! But I'm a she, not a he!

Here's the tully inventory list: A whole, but broken tully. 1 that's missing his jaws. A big, colorful tully tail & some assorted tully tummies and eyebars. Not a tully museum yet, but I'm working on it!

Kim

[Auspex]

...But I'm a she, not a he!

I had a hunch, just from your word-style, but decided to go generic; sorry

[crinus]

Hi Kim,

Before I got interested in echinoderms, I spent a LOT of time collecting in Will and Grundy counties. While fossils can occur in the shale, I personally have never found anything in the shale itself (or at least I can't remember finding anything in the shale). I agree with everyone else that you have some kind of water markings and nothing else.

This past few weeks I have been adding a Mazon Creek section to my web page. All of that stuff was collected in the 80's. I haven't been collecting in your area in 20 years. I am curious where you are collecting that you can still find shale. I didn't think there were any active mining sites and any exposed shale from the old days would have broken up by now.

If you want to talk tully's bring up your questions.

Visit My Website

crinus

[shorty]

Hi Kim,

Before I got interested in echinoderms, I spent a LOT of time collecting in Will and Grundy counties. While fossils can occur in the shale, I personally have never found anything in the shale itself (or at least I can't remember finding anything in the shale). I agree with everyone else that you have some kind of water markings and nothing else.

This past few weeks I have been adding a Mazon Creek section to my web page. All of that stuff was collected in the 80's. I haven't been collecting in your area in 20 years. I am curious where you are collecting that you can still find shale. I didn't think there were any active mining sites and any exposed shale from the old days would have broken up by now.

If you want to talk tully's bring up your questions.

Visit My Website

crinus

Crinus,

Hello!

Thanks for the response! I'll definitely check out your website!

The shale & most everything else I've found is from the state park "Mazonia South Unit." The shale is mounded up in those big strip mine spoil hills. (I'm sure you know that, though!) There's one hill that has spots with out vegetation. After heavy rains, there are sometimes washouts and areas that collapse. (If you're ever out this way, I'd be happy to show you where!) The shale is soo soft, that I just pull it open with my hands. Most of it doesn't have fossils, but every so often that hill has a big pocket of shale with leaves & stems.

Everyone else is walking around looking for concretions, and I end up fascinated by leaves in the shale that will probably not survive the trip home.

Where did you hunt when you were in the area?

Kim

[crinus]

Where did you hunt when you were in the area?

Kim

I hunted the area before the nuclear power plant. They were still working Pit #11. Once the power plant went up I lost interest in the area. You needed a boat to get to the good spots. At that time Braidwood Lake was completely fenced in. Based on map you gave, I am not sure if that is the case now. What you are calling Mazonia South was accessable but highly picked over. The locals always got there early. It is a 4 hour drive for me. I eventually gave up on it and became interested in crinoids.

Crinus

[shorty]

I hunted the area before the nuclear power plant. They were still working Pit #11. Once the power plant went up I lost interest in the area. You needed a boat to get to the good spots. At that time Braidwood Lake was completely fenced in. Based on map you gave, I am not sure if that is the case now. What you are calling Mazonia South was accessable but highly picked over. The locals always got there early. It is a 4 hour drive for me. I eventually gave up on it and became interested in crinoids.

Crinus

There's a fence around the power plant's area & the lake (Braidwood Lake), but access to the islands & fishing in the lake is allowed from the state park. See the Kankakee boat ramp on the map. I've heard you're allowed to hunt those islands if you put a sign on your boat that says Fossil Hunter.

The rest of the area to the south of the cooling lake is now a state park. There are several access points and you're free to walk around & look for fossils from March til September. The trouble is most of it's overgrown with vegetation.

I've heard that years ago the concretions were abundant & just laying around everywhere. That hasn't been my experience now.

There are definitely 'locals' who know just where to go & get there early. I'm not one of those. I'm still trying to figure out which area of the park will yield worms and other interesting stuff.