Mazon Creek - Some Rookie Questions

[Patrick K.]

Hi all!

 

  I have a few questions from the massive amount of new info I’ve learned on here since I started collecting 3/124 at pit 11. I’d went just one time before w my dad back in probably 1982 or so, I have visions of just concretions everywhere, and hammering lots of random rocks, it’s always been a great memory in my mind. It’s been along time, and it’s juuuuust a bit harder to collect now, but I don’t mind the army crawl in the woods, and my 16 year old loves rocks and fossils, she’s having a blast with me.   

 

I’m not trying to reinvent the wheel in the freeze/thaw method or anything but I see a few different methods mentioned on here and had a question. I’ve been soaking them in single file layers in several trays(for 2 full weeks before I start the freeze), then removing the tray and draining all the water and then it goes right into the freezer. A few hours later I remove from the freezer and the tray goes right back into the water to thaw, and I rotate a new set into the freezer. 
5 trays in the freezer-

A set in the water

 

It’s a lot quicker this way and I can get several cycles a day. I can’t imagine the concretion loses any water in the brief time it takes for the outer shell to freeze - but I’d prefer to ask the question instead of assuming! So for you long time Mazon masters, is this ok?

 
Also - ok let’s say your out collecting, you find an open concretion that is obviously something more rare, not an Essexella, but it’s covered in deposits. Or one pops in freeze thaw and it is also covered in deposits. Do you just do the 25% vinegar and gently brush with cotton or something soft? I’m pretty sure I’m being too rough on some of these and am removing the remaining fauna fossil material. I’ve searched and I can’t find much detailed description on prepping anything from Mazon Creek, just bone fossils, trilobites and shale fossils etc. Anyone here have a YouTube channel where they prep/clean Mazon concretions or a book to recommend?

 

Lastly - I had an idea to ask “Take it or Leave It?” I’ve collected a lot of smaller concretions that have more of what looks like sediment layers, and are not the perfect looking concretions. The first freeze thaw has turned lots of these to mush/pieces. To the long time hunters - would you have left these? 

1

2

3 - both sides

 

4

 

Thanks for taking the time to read all that! 
 

Patrick

[Mark Kmiecik]

Most modern freezers and refrigerators have a fan system that circulates air to keep frost from forming in the compartment. This system sucks any moisture in the air inside and removes it from the freezer. Best to freeze in a sealed container (one that has a tight lid) or with the concretions covered with water. That way you can be sure they're not drying out between cycles. If you don't maintain homogenous moisture throughout the concretions they begin to crack in strange, and usually undesirable ways.

[Mark Kmiecik]

1 hour ago, Patrick K. said:

To the long time hunters - would you have left these? 

 

No. You take them all because you never know what you'll get. I agree, sometimes it seems like you've carried a lot of rock for no reason, but you won't know that unless you do, so you bring them home anyway. Sometimes one will very pleasantly surprise you.

[Patrick K.]

11 hours ago, Mark Kmiecik said:

 Best to freeze in a sealed container (one that has a tight lid) or with the concretions covered with water.

That’s a good idea, thanks Mark!

 

11 hours ago, Mark Kmiecik said:

Sometimes one will very pleasantly surprise you.

I’ll keep an optimistic outlook on the smaller ones and hopefully with time I can learn to spot the more oddball siderite lumps from the concretions. 

[deutscheben]

Leaving the concretions immersed in water while you freeze them is  important. When it becomes ice and expands, you get the combined effect of the water that has seeped into natural weaknesses along the fossil plane and that surrounds the concretions both working to crack them. 
 

One suggestion on which concretions to pick up too- it has been my experience that “tall” ones, like some of those in your picture 2, are almost never productive. 

[Patrick K.]

5 hours ago, deutscheben said:

Leaving the concretions immersed in water while you freeze them is  important. When it becomes ice and expands, you get the combined effect of the water that has seeped into natural weaknesses along the fossil plane and that surrounds the concretions both working to crack them. 
 

One suggestion on which concretions to pick up too- it has been my experience that “tall” ones, like some of those in your picture 2, are almost never productive. 

Thanks for chiming in @deutscheben! 
 

 Since it’s absolutely miserable out today here in NE IL, I managed to spend a lot of time browsing here and even watched the Esconi YouTube video from the recent past on collecting Mazon fossils, and learned about the taller more segmented siderite nodules being pretty much nothing.