Small Mississippian Ammonoid from Fayetteville Shale

[Apophis]

Howdy all,

 

I did a bit of fossil hunting in Fayetteville AK over Thanksgiving, hitting the Mississippian age black shale the area is famous for, looking for goniatites and any other ammonoids or nautaloids I could find. These concretions were dug out of the lower unit shale and many of them were large, extending over 4ft in length, flat, with an oblong appearance. 
 

This was on the surface of a concretion and unfortunately was exposed to weathering and moisture. Not sure what that is. 

 

This little guy, it’s just provided for grins and not requesting an ID. It’s way too small
 

 

This is the main fossil I’m concerned with ID’ing. When I broke the concretion, it split revealing a horizontal cross section of an ammonoid. I have both halves and it appears to be potentially well preserved. I’m attempting to prep it but it’s been a real struggle due the siderite that makes up most of the mineralization in these. It shines like metal when it’s cut or ground with a diamond bit making it very difficult to make out features and details. It all just looks like a shiny metallic mess.

 

To complicate things further, many of the fossils are pyritized. I’m sticking to mineral oil only when slabbing and making large cuts. Oil causes the dust to clump and build up further obscuring things. Im also having to wear a respirator to avoid breathing this dust and it makes a nasty mess. It’s a total pain but it’s worth the hassle to get one well preserved ammonoid, even if it’s small. 
 

I’m curious if anyone has ever worked with this shale and if any tips can be provided. I’m only attempting this kind of prep once as an experiment. If it works, I’ll do the same with the other half and glue the halves back together. Im leaving enough matrix on the bottom to provide a base to stand it upright and only removing matrix from the dorsal side. I have no clue if this will work or even how much of this thing is preserved. 
 

When slabbing excess matrix off I found a second Ammonoid below it that appears completely pyritized, though less well preserved. It’s the piece on the left and the rest of it is under the fossil on the right. Note that it’s cut like a vertical cross section and not proportionally. 
 

 

Any assistance or info is greatly appreciated. I realize that a definitive ID may be impossible without exposing the dorsal side and it’s sutures. 
 

 

 

Edited December 23, 2021 by Apophis
Clarity

[FossilNerd]

I know you originally asked to ID your specimen, but after reading through your post it seems like you might first need help with prepping in order to get any sort of ID. 
 

I’ve never worked with this material and can’t be much help in that regard, but maybe one of the admin team can move your thread over to our fossil prep section. You may get more views from preppers that way.

 

What do you think? @Fossildude19