Mazon Creek ID pls

[Yah Hey Der]

Greetings Fossil Mavens!

 

I discovered the Mazon Creek Lagerstätte earlier this month while searching for caves to explore near Chicago [Caves->Coal Mines->Strip Mines->Fossils->Obsession].
I live about 60 minutes north of Braidwood and have visited the South Mazonia area and Pit 11 four times in the past month. As a nascent fossil enthusiast I have much to learn, and I'm glad to be here.

 

I'm freeze-thawing what I believe are a handful of smaller nodules that I'll share if they produce anything. I have two large stones that I'd like to share first for ID and advice on approaches to expose what's inside.

 

STONE 1 - has the well-defined iron ring and crystals in the matrix. I found it as a half, already cleaved open. I tapped along a small crack which exposed what you see here. There is an obvious crack forming. I plan to continue to freeze-thaw.
STONE 2 - looks like a red bird head :-) Found like this. Could have been peanut shaped at one time. Is this shape indicative of anything? The substrate is pretty thin and I'm nervous about approaching with the hammer. No obvious cracks to follow.

 

THANK YOU!

[Fossildude19]

Sorry, I'm not seeing any fossils here. First item looks like a septarian nodule, and the second looks like a concretion, or some sort of sedimentary structure in sandstone or mudstone.

 

Certainly not any kind of bird fossil.

[Mark Kmiecik]

I don't see any fossils at this point. The first one may yield something with additional freezing.

 

Concretions with this general shape are low-percentage candidates for containing fossils. When viewed from the edge these appear to be a rather thin-nish section of the whole of which it was once part. In other words, the part of the concretion that had the fossil in it is the part you don't have. It appears to be the right kind of material, iron siderite, but you need to collect concretions that are mostly still intact. If you search Mazon Creek on this forum you'll find many hundreds if not thousands of examples. If you haven't yet, join ESCONI (earth sciences club of nothern illinois). You'll see tons of MC material at their meetings and get to handle it personally.

 

Basically, you got the wrong shape of the right stuff. Seriously, spend some time searching this forum. And make sure to soak any nodules you plan to freeze/thaw for at least a week so the water soaks all the way through. The forming ice can't push from the inside out unless the water has gottern all the way inside.

[Yah Hey Der]

Thanks guys. I appreciate your thoughts, pointers, and advice. I’ll join the local ESCONI Chicago club and get active. I’m headed to the Chicagoland Gem and Mineral show today and tomorrow. Hope to meet some of you there!

 

Jeff

[Mark Kmiecik]

4 hours ago, Yah Hey Der said:

Thanks guys. I appreciate your thoughts, pointers, and advice. I’ll join the local ESCONI Chicago club and get active. I’m headed to the Chicagoland Gem and Mineral show today and tomorrow. Hope to meet some of you there!

 

Jeff

 

Ask the people you see there if they are Fossil Forum members. You should run into about 1/2 dozen of our members attending the show, and ESCONI might have a table there. Have fun. If you buy stuff, post photos.

 

P.S. -- You may be able to find unopened MC concretions there.

 

 

 

Edited May 25 by Mark Kmiecik
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