Missouri Stark and Galesburg Shale Collection

[Petalodus12]

1 hour ago, Titan said:

@Petalodus12 Thanks, I'll look forward to it! No worries about the preservation, I'm trying to get my eyes on as many different types of fossils as possible in an effort to better identify them. After seeing specimens others post on here I've gone back through my discard pile a few times and found specimens that I missed because I thought they were nothing.

Good idea. I often re-examine my material too because so much of the vertebrate diversity is preserved in microfossils, and they can easily be missed. I’ve been meaning to ask, is the shale that you have collected from a freshwater or marine depositional environment?

[DPS Ammonite]

21 hours ago, Petalodus12 said:

I’ll send you a PM soon with pictures of the plants, and some conchostracans too. At first I thought they were just sulfur dilemma, but when I looked at them under the microscope I realized that it was pyrite. They all are poorly preserved though

If you have pyrite then the powdery yellow minerals might be iron oxides and oxy-hydroxides such as limonite which are breakdown products of pyrite.

 

https://en.m.wikipedia.org/wiki/Ochre

Edited July 21, 2020 by DPS Ammonite

[Petalodus12]

1 hour ago, DPS Ammonite said:

If you have pyrite then the powdery yellow minerals might be iron oxides and oxy-hydroxides such as limonite which are breakdown products of pyrite.

 

https://en.m.wikipedia.org/wiki/Ochre

I think that’s what it is, for at least some of the pieces. Others, when viewed under the microscope, show a crystalline microstructure similar to non-oxidized pyrite. Thanks for the help!

[Titan]

@Petalodus12 My understanding is that the Stark shale is a deep water marine deposit. Everything I've read has said that the rock laid down below the Quaternary stuff in Kansas City is from a shallow sea however on further investigation it isn't so simple. The way I'm understanding it presently is that repetitive cycles of sea level rise (transgression) and fall (regressions) laid down shale and then limestone respectively with intermittent river deltas laying down sandstone and occasional coal layers. I'm not sure how to find information on which specific layers represent marine or non-marine deposits beyond what I've found below. 

http://geospectra.net/lewis_cl/geology/bedrock.htm

http://www.kgs.ku.edu/Publications/Bulletins/Sub12/Heckel/index.html

http://www.kgs.ku.edu/Publications/Bulletins/58/05_cycl.html

[Titan]

@DPS Ammonite Awesome, thanks for the info! It may very well be the explanation. Would such a breakdown of pyrite sandwiched between shale form honeycomb structures though?

[Titan]

@DPS Ammonite I have an example of what I think may be the process you described. It's the largest specimen I've found so far so I call it 'blob.' It's an unknown for me because I can't find any identifying markers beyond what I believe to be cartilage. It is mostly pyritized and has gone through some of the breakdown process which would explain why there are the yellowish mounds present.

 

[Petalodus12]

1 hour ago, Titan said:

@Petalodus12 My understanding is that the Stark shale is a deep water marine deposit. Everything I've read has said that the rock laid down below the Quaternary stuff in Kansas City is from a shallow sea however on further investigation it isn't so simple. The way I'm understanding it presently is that repetitive cycles of sea level rise (transgression) and fall (regressions) laid down shale and then limestone respectively with intermittent river deltas laying down sandstone and occasional coal layers. I'm not sure how to find information on which specific layers represent marine or non-marine deposits beyond what I've found below. 

http://geospectra.net/lewis_cl/geology/bedrock.htm

http://www.kgs.ku.edu/Publications/Bulletins/Sub12/Heckel/index.html

http://www.kgs.ku.edu/Publications/Bulletins/58/05_cycl.html

Interesting. I obviously hunt Pennsylvanian deposits too which were deposited in a similar manner of transgression/regression. The main difference is that the rocks that I hunt (Conemaugh group) are mostly freshwater deltaic deposits with intermittent nearshore marine deposits, so I do not have access to the same type of deep water marine shales that you do. However the main shale that I hunt (shale above the Duquesne Limestone, which is freshwater), is representative of a deep, anoxic freshwater lake. I’ve had to piece together a lot about the lake deposit by myself, but with help with @jdp because there has been little research done into it, although the limestone itself has been subject to study. This can be frustrating at times but more so it is exciting because there are definitely discoveries to be made. Mostly wondering about depositional environment because I know that it can affect diagenesis

[Titan]

@Petalodus12 That is fantastic that you've figured out the shale you hunt was from a deep lake. I agree 100% with the excitement in something that isn't as widely studied. There's a post recently by @Missourian that is incredibly informative on our environment (I'm not sure how I missed this thread to begin with!) here in Kansas City. He has a graph posted on page 24 that may be of interest to you as it shows the stratigraphy linked with sea level. It's the one of the coolest graphs I've ever seen.

 

[Titan]

Here is another one that I think is a jumble of shark dermal denticles. Its around 20x20 cm. They start at the top of the specimen and are laid 'flat' and continue about halfway through it at the split (around 3.8 cm) down.

I'm not sure about the black wavy material. Once I get my prepping station set up after moving I'll get some of the yellow material out as it is very soft and hopefully be able to see what the black material is.

'top' section with the denticles laid flat.

 

 

 

 

[Titan]

Here is an assortment of spines, most likely acanthodian. They are by far what I find the most of.

#1

#2

#3

#4

 

[Titan]

And last post for a while as everything is packed away. The Listracanthus denticles!

[deutscheben]

Thanks for sharing, it’s fascinating to compare yours to what I find in Illinois black shale- very similar spines. The preservation is very nice on yours though!  Have you found any bivalves or brachiopods in your shale?

[Titan]

@deutscheben Happy to provide something to the community! I haven't found any bivalves or brachiopods in the fissile shale but the mud/clay stone layer is filled with them. I've found a few Derbyia sp.? But only find them on the very top layer of the mudstone.

 

I've also found two of these that I have yet to identify:

 

And the most common are these:

But the mud stone specimens are so fragile it's hard to imagine prepping them without them being damaged or destroyed. I've saved quite a few that I will try my hand at.

 

 

[Nathan5]

That gray shale with the plant and the snail shell you circled in blue- do you think that is Galesburg Shale? (I see now that you wrote it is)

Edited November 1, 2021 by Nathan5
I noticed you answered my question in the post above