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Mazon Creek Bonanza


Mediospirifer

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I recently (2 weeks agos) started freeze/thaw treating some Mazon Creek nodules purchased through the Forum. So far, I've had 13 split, and a lot of small pieces spall off.

Of the split nodules, 2 have recognizable fossils:

Here's a fern leaflet (I don't know the species):

post-12648-0-73256000-1397620691_thumb.jpg

And here's something that I don't know:

post-12648-0-62356800-1397620687_thumb.jpg

This one looks like it has something, but I don't know what. If anyone is interested, I could take a photo through my microscope to see if it becomes recognizable:

post-12648-0-88393300-1397620820_thumb.jpg

This one has a suggestive mineral stain, but I'm not sure whether it's a fossil or not:

post-12648-0-65261600-1397620825_thumb.jpg

So far, the other splitters are fairly nondescript. Some split on a plane offset from the center, others have a ragged split. The most visible features on the cleanly split ones are vague, amorphous stains of a different color from the reddish matrix. If anyone wants me to, I'll post photos, but these four are the most interesting to me so far.

As I get more of them split, I'll post pictures. I have a lot more waiting for treatment! :D

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I had a lot of the same experience with mine, not much recognizable either.. That 2nd one looks to me like a fern, either not well preserved or not well split (which would be odd, as I thought the fossil would always be the plane of weakness)

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I had a lot of the same experience with mine, not much recognizable either.. That 2nd one looks to me like a fern, either not well preserved or not well split (which would be odd, as I thought the fossil would always be the plane of weakness)

It does look like it split next to the fossil. I'm tempted to put a little superglue on that bit (what looks like a thin layer of matrix still covering the fossil), put the two halves back together, and freeze it again! What could possibly go wrong? :P

I can easily see that as a piece of fern. I can also easily see that as a flattened earthworm...

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You might be able to apply the glue and then just pry it apart manually (Not sure what the freeze-thaw process would do to the glue.. wonder what others think)

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The glue and pry apart idea has worked for me...and as a nodule whacker i would get a lump hammer on those unproductive nodules just incase you never know what might be still in there.

A whacked nodule..... Bellinurus.

post-7909-0-95057900-1397758774_thumb.jpg

John

Edited by t-tree

Be happy while you're living for you're a long time dead.

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Nice piece, t-tree! I'd love to find one of those.

So you'd recommend the glue-and-pry rather than glue-and-freeze? I could try that. There's another nodule that I took out of the freezer last night that needs similar treatment. There's definitely something in there, but the split is irregular enough that I can't tell more than that.

Is superglue the best adhesive for this purpose, or can anyone recommend something better? I'm willing to take my time with this, so a long-setting glue that works better is OK with me, as long as I can get my hands on some without too much expense.

Also, for hammering, do you recommend putting a stone, metal, or wooden platform under the nodule? Or does it matter? What about using a chisel?

These are my first attempts at splitting nodules, and I want to do it right!

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Superglue is fine....Split on a hard suface with a heavy hammer....don't use a chisel as it would make it split unnaturally.

John

Be happy while you're living for you're a long time dead.

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I am thinking that if the stubborn layer you want to peel off is thin enough, it might come apart just with a screwdriver prying the 2 halves apart again, after gluing. I wouldn't think it should put up so much resistance that you would need a hammer. Just make sure you glue it well, and only on the part that you want to transfer from one side to the other (if possible! I know superglue/crazy glue is tricky to work with, I hate it. Just a couple drops, not even enough to cover the whole surface of what you want to transfer, it should spread once you squeeze it together). Superglue dries fast but maybe clamp it with a spring clamp and wait longer than you normally would, just to be sure it's bonded.

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Yes just pry apart .......i only mentioned using the hammer for the unproductive nodules.

John

Be happy while you're living for you're a long time dead.

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I'll try supergluing and prying. I just haven't got to it yet.

The objects I have that most closely resemble spring clamps are clips for closing potato chip bags, or else binder clips. I was thinking of wrapping a large rubber band around the nodule and using a binder clip to tighten it. I'll leave it to set overnight before attempting to reopen it.

Now I just need to find some superglue around here!

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Might work, but with superglue you might not have time to fiddle with a rubber band (which might cause trouble because it squeezes in all directions whereas the clip just squeezes perpendicular to the plane of gluing which is what you want).. not sure, just a hunch there.

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Might work, but with superglue you might not have time to fiddle with a rubber band (which might cause trouble because it squeezes in all directions whereas the clip just squeezes perpendicular to the plane of gluing which is what you want).. not sure, just a hunch there.

Oh, I'd hold it in hand until it feels like it's started to set (10 seconds or so, maybe a minute), then wrap the rubber band. If circular compression is a potential problem, I could use a pair of small board sections to surround the rock, and wrap the band around those. I have some 1x2s around here somewhere...

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I would think the clip would be quicker and more effective, but whatever you try I'm sure it'll work and if not, it's probably not the most valuable fossil to screw up! (I am betting it's a fern) Good luck.

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Jim:

Thank you! That set of directions looks very useful. For one thing, it tells me that I've been doing this wrong... ;) Not too far wrong, and I don't think I've damaged anything, but I've been wondering why my nodules are mostly being stubborn!

There are a few that I'll tap on with a hammer and see if anything opens. We'll see what happens!

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A friend of mine made this little document a few years ago specifically for opening Mazon concretions. Hope it is helpful.

Jim Fairchild

Wow, I've been doing it (somewhat) wrong too...

Q1: Will the likelihood a nodule will produce a fossil decrease with the increasing number of f/t cycles it takes to open it?

Q2: Does tapping with hammer, after any number of f/t cycles, produce as much flaked-off debris as repeated f/t cycles without tapping?

Q3: Does the size of the nodule have any bearing on its likelihood to produce a fossil?

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Keep in mind that my experience is with 100+ 5 gallon buckets some maybe 20 years old. It is easy to be patient when you have lots of material.

Q1: I would say a conditional yes. Some concretions are highly mineralized and may take a long time before they open if ever. Some are too soft and crumble away. How easily it opens is a function of the plane of weakness, so something like a large jellyfish may open easiest. I have had great fossils open after a decade or more in the bucket.

Q2: Probably more. Tap, don't whack between cycles. Flake off debris like the rind of an orange is just a less mineralized transition between the shale and the concretion. No worries. If you get a divot like flake after a freeze-thaw examine it closely as some things like coprinoscolex are usually preserved near the top of the concretion. Sometimes, the best way is to drop the concretion from about 4 feet elevation into the bucket. I always get some openings that way.

Q3: Shape more than size determines the outcome. Rounded edges and not too thick are usually best.

Jim

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Yes, some good points in that PDF. I hadn't ever bothered to let them dry between some freeze/thaws like they describe in the PDF. Maybe I should start trying that.

Somewhere, something incredible is waiting to be known.–Carl Sagan

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I let my current set of nodules being treated dry out overnight, then tapped with a knife handle on all of them that had visible cracks. Here are the ones that opened. I don't know what any of them are!

This one is obviously something:

post-12648-0-77758700-1398301704_thumb.jpg

This doesn't show color, but the structure can be seen:

post-12648-0-04869000-1398301699_thumb.jpg

I'm not sure whether there's anything beyond a lumpy mineral stain here:

post-12648-0-74665100-1398301700_thumb.jpg

This one split unevenly. I'm contemplating putting it back in the freezer:

post-12648-0-89089800-1398301702_thumb.jpg

This one also split unevenly, but there's a corner of something visible:

post-12648-0-66774500-1398301706_thumb.jpg

I have the unopened nodules (and a bunch more) soaking in water, and I'll put them back in the freezer tomorrow. I think I'll be doing a week-long cycle: three days in the freezer, one day with the nodules spread out to dry, an evening of tapping to see what splits, then soak for the rest of the week.

It's going to take me a while to work through all of my nodules (the box of rocks had more than 300!), but so far things are looking interesting. :D

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