To Be Mazon Or Not To Be Mazon?

[dudeman]

Here is a good cross section of my "Mazon Creek" fossils, if you find yourself second guessing the "Mazon Creek" please post. I purchased these, I did not find them myself, so they could be mislabeled. I am self taught, so I could very well have all of my ID's wrong.

This will have to be a 4 part message, due to the fact I can only upload 8 pics at one time.

[dudeman]

Part 2...

[dudeman]

Part 3....

[dudeman]

Part 4....

[dudeman]

Part 5....

The fossil are "Mazon Creek" found in 1910? Lot 11? Again, I did not personally find these fossils and I am self taught in ID. So here we go, I think some of the ferns are;

Odontopteris

Pecopteris

Asterophyllites

Neuropteris

Some of the ferns are sitting on petrified wood and seed pods?

Ad some petrified wood...

[Wrangellian]

I can't help much with your IDs, but they do look like the typical Mazon Ck material - Pennsylvanian (Moscovian (st)age, ~310 million yrs), Francis Creek Shale. By 'Lot 11' maybe it was meant 'Pit 11' near Braidwood, IL?

[piranha]

I can't help much with your IDs, but they do look like the typical Mazon Ck material - Pennsylvanian (Moscovian (st)age, ~310 million yrs), Francis Creek Shale. By 'Lot 11' maybe it was meant 'Pit 11' near Braidwood, IL?

Hi Eric, Just a heads-up FYI the Moscovian stage is equivalent to European Russia and eastern Europe (Moscow Basin).

In this case the Desmoinesian is preferable to describe the North American stage. LINK

[Wrangellian]

You're right, I was going to add that once I had referred to my North Amer scale but got distracted... anyway I thought there was an effort to go to an Int'l scale but apparently not outside of the Int'l Comm. on Stratigraphy!

[piranha]

Logical though and a sensible solution to regionalize the stages for clarity of discussion. Thankfully the computer relieves the strain on my ability to memorize the large volumes of data that need sorting...

[Wrangellian]

Is it in fact Desmoinesian? because I have always read that the Mazon was Middle Penn. which would be equivalent to the Moscovian, while the Desmoinesian barely overlaps with the Moscovian for 1 million years, but correlates more with the Kasimovian above it. Then I see on the wikipedia entry for 'Mazon Creek' that the deposits are about 300my - I dont know if that is just a really rounded figure and the actual date is more like 305 or 310, but 300 would make it Virgilian, at the very top of the Penn.! (according to current ICS dates). All too confusing.

Edited November 21, 2011 by Wrangellian

[Wrangellian]

Here's a site that apparently made the same induction I did (just below the scrolling pics) - not that this one is authoritative:

http://mazoncreekfossils.typepad.com/

But if it's both Moscovian and Desmoinesian, the current ICS date puts it around 308.5my without much wiggle room!

Here's one that seems to confirm us both (Desmoinesian and Moscovian/Westphalian D), and corrects my name for the formation - it's the Carbondale Fm, Francis Creek Shale Member:

http://fieldmuseum.o...ast-and-present

Edited November 21, 2011 by Wrangellian

[Wrangellian]

Yes computers have helped a lot... I think - But usually I find the Wikipedia articles on this type of topic are fairly on top of things. For example, recently the ICS named a stage in the Cambrian and the wikipedia article containing the Cambrian divisions was quickly updated with that name!

For my labels I usually go System: Series: Stage (or just Series: Stage if the Series is 'Upper', 'Middle' or 'Lower' something), followed by the date in m.y. if known. I would think the Int'l stages could be used alongside the regional ones, but the regional stages from another region should not be used (eg. Westphalian for North America or Desmoinesian for Europe). If there is something that doesn't jive, it will be corrected later.. I know the geologists are always tweaking and refining things, and I'm trying to put it all together in my Time Scale compilation http://www.thefossil...gic-time-scale/

Glad you put that jpg up, now I know that the Cantabrian is a substage - I was confused about that!

Edited December 12, 2011 by Wrangellian

[RCFossils]

Your fossils are definately from the Mazon Creek deposit. The fossils in the lighter colored rocks appear to be from the creek itself while some of the other specimens are from the strip mines. My guess is these fossil were collected relatively recently.

[miraspis]

Autunia sp. (probably conferta)

[JimB88]

Your fossils are definately from the Mazon Creek deposit. The fossils in the lighter colored rocks appear to be from the creek itself while some of the other specimens are from the strip mines. My guess is these fossil were collected relatively recently.

Not sure how could make that statement. Ironstone nodules with plant material which look like Mazon creek stuff are quite common. Especially in southern Illinois. And I find marine inverts in iron stone nodules here in Tennessee that look like Mazon material.

[Texas-Tunnel Rat]

Yeah I can attempt and put a vote out there its Mazon or one of the lower portions of the same stuff,

some of the stuff looks like it came out of the "Mazon Creek Starter Kit" that is sometimes sold to boost collections. Not discrediting or anything but it looks too familar to the stuff.

But thats my .02.

But then again what we are mostly trying to ID are common pantformes that can be found just about everywhere the enviroment can call for so determining "Mazon" vs "Not Mazon" on the same plant that is abundant in that part and in same rock types is confusing. Now if an Index and or a keystone critter was presented that could shift the thoughts.

[RCFossils]

Not sure how could make that statement. Ironstone nodules with plant material which look like Mazon creek stuff are quite common. Especially in southern Illinois. And I find marine inverts in iron stone nodules here in Tennessee that look like Mazon material.

Hi Jim,

Having collected this material most of my life, i have become very familiar with the concretions found at different locations in the Mazon Creek deposit and throughout Illinois. i am also very familiar with material from several of the surrounding states and some overseas locations. Each of these locations have color and texture variations to the concretions along with the differences in flora and fauna. you can see a lot of variation just in the concretions that are posted in this thread. Even though these fossils were collected within a few miles of each other, there is enough variation for me to distinguish with a fairly high degree of certainty where they were found. The telltale sign for me is the fossils from the creek. They have a color and texture that differs from concretions that i have seen from any other site.

I would agree with texas Tunnel Rat that judging by the material, this was probably sold on Ebay as a "Mazon Creek Starter Kit"

[dudeman]

Yes RCFossils, this was an Ebay purchase. That is why there was a question if they are "true" Mazon Creek, as you know some Ebay seller can not be trusted. I have found some really good Ebay shops over the years.

[dudeman]

This lot also included some jellies, a leech, a large fern tree top, a crab, seed pods, ferns, wood, bark, etc...

[Sharkbyte]

Hello Dudeman,

I love plant fossils and you have a great collection. Thanks for sharing the pictures.

Bobby

[Missourian]

The yellowish nodules look similar to the material that came out of Knob Noster, Missouri.