My first two Mazon specimens

[debivort]

I had a great, brief opportunity to collect Mazon nodules at a private site. I'm new to this deposit, but really excited to start understand the material. I've started the freeze-thaw on the bulk of specimens, and ordered my copies of the Wittry books, but will post a few specimens that were already exposed or split at the time of collection. 

Thanks for your help in advance @Nimravis @stats @RCFossils @deutscheben @Mark Kmiecik @Runner64

 

 

 

Specimen 1 (6cm nodule diameter): found as a half, already split. As a newbie, I'm not sure if this anything, but following your guidance to post everything ( @Runner64 @Mark Kmiecik : this is the specimen I thought had superficial resemblance to the example you posted in the other thread). 

 

The light region in the middle has some relief to it, as evident in D. There may be a feature that looks a bit like a flower, with a "central disc" and 3 or 4 radiating "petals" with repeating geometric patterning near one edge, visible in B on the bottom right, and in D on the right.

 

 

 

 

Specimen 2 (5.5cm on longest axis): Already quite exposed, with apparent 3d preservation. The bundle of tube-like branches converges at the bottom of A, E. F, H and J offer the view of that bottom. There maybe be a "stalk cross section" of sorts, with a pale central disc and a circumference of notches at the base (best seen in J). There are "tubercles" protruding through the matrix and on the branches (C, D, E). Between this "stalk cross section" and the tube-like branches, there seems to be a rough bark-like structure (H and J).

 

In addition to an ID, I'd love advice on if/how this should be prepped further. The matrix has a network of cracks in it. As I was handling the piece, a small corner of mostly matrix popped off (a small knob of red matrix in F and J is gone in H, revealing a bit of that bark-like structure, but also damaging it a bit, I think). Should I use consolidant to protect it? Can the large large flap of matrix in A and I be removed? Is this a job for an air scribe (which I don't have). I have the sense there may be more tube-like branches under thin regions of matrix in the C and D views (possibly all the way around? G possibly shows the ends of the black branches at the broken top of the piece).

 

 

Looking forward to hearing what you all think.

[Runner64]

32 minutes ago, debivort said:

Thanks for your help in advance @Nimravis @stats @RCFossils @deutscheben @Mark Kmiecik @Runner64

 

 

 

Specimen 1 (6cm nodule diameter): found as a half, already split. As a newbie, I'm not sure if this anything, but following your guidance to post everything ( @Runner64 @Mark Kmiecik : this is the specimen I thought had superficial resemblance to the example you posted in the other thread). 

 

The light region in the middle has some relief to it, as evident in D. There may be a feature that looks a bit like a flower, with a "central disc" and 3 or 4 radiating "petals" with repeating geometric patterning near one edge, visible in B on the bottom right, and in D on the right.

 

To me, this one looks like a combination of several different pieces of vegetation. I see the region that you are describing as a “flowers”. Flowers had not evolved quite yet, but there is Annularia, which is the leaf of Calamites. I believe @Mark Kmiecik has several great examples in his album you can reference. I don’t recognize anything else in the remainder of the nodule that can be identified.

For the second piece, it looks like a Calamites stem, nice one! Someone might be able to provide exact species. It’s possible more fossil could be preserved under the matrix. However, I would suggest leaving as is since the fossil already displays nicely. I don’t believe any additional prep needs to be done. For Mazon fossils, air scribes require lots of experience due to the delicately preserved body parts, not something I would recommend. If anything, a 80:20 Water:vinegar soak will help clean them. 

[debivort]

9 hours ago, Runner64 said:

To me, this one looks like a combination of several different pieces of vegetation. I see the region that you are describing as a “flowers”. Flowers had not evolved quite yet, but there is Annularia, which is the leaf of Calamites. I believe @Mark Kmiecik has several great examples in his album you can reference. I don’t recognize anything else in the remainder of the nodule that can be identified.

Oh for sure on the age of flowers. I was just trying to use that as an evocative descriptor so you'd see what I was seeing (thus the scare quotes). I buy that this is Annularia. It sounds like the lighter, roughly circular patch through the middle is just a mineral discoloration then (despite its slight thickness)?

 

9 hours ago, Runner64 said:

For the second piece, it looks like a Calamites stem, nice one! Someone might be able to provide exact species. It’s possible more fossil could be preserved under the matrix. However, I would suggest leaving as is since the fossil already displays nicely. I don’t believe any additional prep needs to be done. For Mazon fossils, air scribes require lots of experience due to the delicately preserved body parts, not something I would recommend. If anything, a 80:20 Water:vinegar soak will help clean them. 

I have a number of questions, hope you don't mind!

 

1) Is the vinegar mostly to remove the white mineralization? Any downside to applying it?
2) Should I use some paleobond to stabilize the fossil before any treatments?

3) Would a micro sand blaster be more effective to expose the fossil? I have a colleague who could potentially make one available.

4) Do you have any thoughts about the little tubercles?

5) Do you have a drawing of Calamites that shows where this pieces is from? I'm having trouble fully grasping its position on the plant. I have another nodule which split to reveal what I would have called a Calamites stem, with wide parallel ribbing and a bamboo-like node. Looks like many other examples I'm finding (will post a pic soon). But I'm not finding many images that are close to this specimen.

[Runner64]

On the first piece, yes I would call this a mineral discoloration.  You could try to soak it in 80:20 Water:Vinegar for about an hour and use a toothbrush to lightly brush it.

 

1.) Yes the vinegar acts to remove the calcite mineralization and other grime that might build up when exposed to the elements.  Vinegar is a strong acid so is why it is important to dilute it.  If a fossil is left in vinegar too long, it could damage the fossil, I like to keep an eye on mine as they sit in vinegar.

 

2.) I use cyanoacrylate based super glue.  

 

3.) I don't think so, you'll run into the same problems as using an air-scribe

 

4.) In C,D,E these don't look like tuburcules but rather a continuation of the Calamites sp. example seen in image A & I

 

5.). Your first specimen is Annularia which are the "leaves" of the Calamites plant.  Your second specimen is the stem.

[Mark Kmiecik]

I agree with Runner64's evaluation. The first one is assorted flora. However, because you found it already open, that tells me that it was lying around for some time exposed to the weather and it shows it. The weathering has pretty much erased all of the detail from the specimen. Once you start seeing some of the better specimens coming from those you've found you'll probably pitch this one onto the reject pile, but hold on to it now just for comparison purposes so you can appreciate the effect of exposure on the concretions when already open. Weathering also has an effect on the ones that have not yet split, but it's a complicated thing we'll get into later. You don't really develop a sense of the effect until you've opened thousands of them. The specimen may have been Annularia, but now it's just an indeterminate blob due to wear.

 

The second one is indeed a decent specimen of Calamites. This is most probably Calamites cistii. However, the nodes and their spacing are the diagnostic feature for specimens of Calamites, so this specimen at best can only be labeled Calamites sp. It is a very nice specimen -- a mid grade overall.

 

Now let's get to the questions you've asked after a short intro to freeze/thaw. You MUST soak the concretions for at least a week depending on size and porosity BEFORE you begin to freeze and thaw. The water MUST soak ALL the way through the concretion to effect the splitting of the nodule. If it only soaks part of the way through then you're just flaking away parts of the matrix nearer to the surface rather than splitting it. So, if the nodule is small-ish (less than 2" longest dimension) and composed of less dense material then a week of soaking is adequate. If it is large and dense, a month may not be enough. Bottom line is that you CAN'T soak it too long. The average is about 10 days in my opinion. Everyone has their own preference and method developed with experience and the location where they were collected. More about that later. 

 

And now, your questions:

1. Yes and yes. It removes the calcite. However, it also attacks the iron siderite matrix as well and just like the weather it begins removing detail. So, use it on some very poor specimens to gain experience with using it. You don't have any yet you say? Then forget about it until you do.

 

2. No. Most MC fossils need none. If used before freeze/thaw it will never split properly. Again, wait until you see more of what can happen. The ones that break -- a common occurence with MC material -- can be glued together with your favorite glue, cyanoacrylate, elmer's, whatever you prefer.

 

3. No. It will merely erase the fossil as the fossil and the matrix are one.

 

4. They probably exist, but there is no layer of separation between them and any other part of the specimen or the matrix, so at best exposing them is a gamble. Is it worth ruining what you have to possibly improve it? If the answer is "yes" then go for it.

 

5. The ribbing is the stem/trunk of the plant. Google calamites and look at the images. The diameter of the plant species vary dramatically, from thin to "omg".

[Mark Kmiecik]

I guess Runner64 types faster than I do.  Plus, he found a good drawing.

[debivort]

Thank you both @Mark Kmiecik and @Runner64. I'm looking forward to being so disappointed in #1 that I chuck it in the bin. I'll try the light acid soak to get a sense of that process. Hopefully the ~20 nodules I have soaking are enough to get some nice specimens. I collected about 50lb in 45 minute or so, but it was part of a fossil adventure with many friends, most of whom could not come to the private site, so 20lbs/nodules is what I took home.

Thanks for all the great answers. A couple follow-ups:

Tubercles: my question is less about prepping them, and more about their identity? Are they an organ of the Calamites (something like a sporangium, for example)? Or could they be a second species that has grown on the surface, barnacle style? Maybe a lichen or fungal sporangium? 

 

My last question about morphology still remains a bit unresolved. I'll post photos tonight hopefully, but the other Calamites I have is exactly what I'd expect from stem preservation and looks like many photos on the internet and the forum. It looks like the left drawing below. My interpretation of specimen 2 is the right drawing.

 

It seems to differ from the left morphology, in that the ribbing has a conical profile and seems to converge at a base of sorts. There may be a cylindrical feature with a bark-like texture that aligns to what looks like ~1.5cm diameter stem-like cross section. Interpreted below:

I'm wondering if I might have a transitional segment like the ones marked in this reconstruction:

 

Maybe this is too much reading of the tea leaves, but I'm a biologist professionally, so trying to understand the full organismic context is hard to resist.

[Mark Kmiecik]

It's a "primitive"? horsetail rush. So, as a biologist, anything you know or can dig up regarding extant horsetail rushes should help. As far as I know (I may be wrong) horsetail rushes are hollow, with the possible exception of the spore-bearing cone, so the transitional segment if it indeed is one (I don't see it in the photos, but that doesn't mean it's not there) would be that section, as shown in f of the drawing you presented. Also in the green area of a in the drawing, which is the same area in another species of this genus. I now understand the "tuburcules" to which have referred earlier, and no, there is no further prep necessary or even desired. MC specimens are best left as-is if you want to preserve detail. They rarely become better with prep. They may present more pleasantly, but are seldom improved.

 

It's nice to see you so interested in MC fossils. With 400 species of flora and 320 species of fuana (rough estimates), I must warn you now, it can quickly become an addiction.

 

 

 

Edited August 10, 2022 by Mark Kmiecik
added info

[debivort]

Here is the other Calamites specimen I was referring to. 10.5cm long.

 

I found this nodule with a hairline crack and opened with light hammer tapping.

[Mark Kmiecik]

Judging by the ratio of the internodal length to width I would say with about 85% probability of being correct that this specimen can be labeled Calamites cistii. I can't make out the leaf scars with any clarity, and would need a close-up of those to be 100% sure of the ID. I viewed an enlargement of the photo but there isn't enough detail in the node to see the distribution of the scars.

[debivort]

45 minutes ago, Mark Kmiecik said:

Judging by the ratio of the internodal length to width I would say with about 85% probability of being correct that this specimen can be labeled Calamites cistii. I can't make out the leaf scars with any clarity, and would need a close-up of those to be 100% sure of the ID. I viewed an enlargement of the photo but there isn't enough detail in the node to see the distribution of the scars.

Would washing with acid have any chance of revealing those features? Or better photography?

[Runner64]

1 hour ago, debivort said:

Would washing with acid have any chance of revealing those features? Or better photography?

Better photography.  I also agree with Mark's ID.  I would not clean this one with vinegar, it is preserved quite nicely!

[debivort]

2 minutes ago, Runner64 said:

Better photography.  I also agree with Mark's ID.  I would not clean this one with vinegar, it is preserved quite nicely!

Just to confirm, I should try for higher mag images across the node? Should I illuminate it for relief? 

[Mark Kmiecik]

13 hours ago, debivort said:

Would washing with acid have any chance of revealing those features? Or better photography?

 

I looked at an enlargement. I don't think the information is there. No amount of digging will bring it out in a distinguishable enough form to make a difference. In other words, you may reveal a node or two but not enough of them to see the pattern and spacing. You're looking for detail in the joint where two segmented lengths come together. There is only one node preserved in this specimen so we don't know the length of either segment. The ratios within each species are highly variable, and that accounts for the 85% degree of confidence in making an ID. The chances are very, very good that the ID is correct, though.

Edited August 11, 2022 by Mark Kmiecik

[debivort]

4 minutes ago, Mark Kmiecik said:

 

I looked at an enlargement. I don't think the information is there. No amount of digging will bring it out in a distinguishable enough form to make a difference. In other words, you may reveal a node or two but not enough of them to see the pattern and spacing. You're looking for detail in the joint where two segmented lengths come together. There is only one node preserved in this specimen so we don't know the length of either segment. The ratios within each species are highly variable, and that accounts for the 85% degree of confidence in making an ID. The chances are very, very good that the ID is correct, though.

OK cool — I was wondering if I would be able to get a better pic. I'm comfortable with uncertain IDs, so this is completely satisfactory!

[debivort]

Could Specimen 2 be the end of the root (is it a rhizoid?). This portion of the illustration:?

[Mark Kmiecik]

On 8/11/2022 at 10:46 AM, debivort said:

Could Specimen 2 be the end of the root (is it a rhizoid?). This portion of the illustration:?

I would say your specimen is from one of these areas (best guess). The pointed tip of g is just above and connected to the rhizome.

 

Edited August 12, 2022 by Mark Kmiecik

[debivort]

I found another Calamites illustration that really matches my impression of the shape (though not scale) of this piece. Reasonably close to my sketch too. But I think I'm OK say the exact position on the organism may be ambiguous:

 

I gave specimen 1 an acid wash, scrub and water soak. On board with it being a poorly preserved annularia. Here's a speculative interpretation of the features: