Backyard Trip

[Missourian]

Traces can be identified by behavior rather than by the type of creature that produced them. Most often, there aren't enough details to id the culprit. It's still fun to speculate, though.

 

 

[Missourian]

Just trying to visualize the multiple Pennsylvanian cyclothems of the area and how they relate to sea level variation:

 

(The image can be expanded to a really large size.)

 

I flipped the column on its side to better fit the screen and to show it as a 'time line'.

 

At top is the 1) stratigraphic nomenclature, followed by the 2) lithology, as observed in the 'backyard', 3) presence of plant fossils, 4) relative sea level estimates based on stratigraphic position and lithology, and 5) the names of the cyclothems.

 

The lithology is color-coded at key points:

 

Purple - Maximum depth, with black, platy shale (indicating anoxic conditions)

Blue - Maximum depth, with gray shale

Gray - Maximum depth, with limestone

Aqua - Very shallow depth, with evidence of shoaling (e.g. oolitic limestone)

Orange - Subaerial exposure (erosion surface, paleosol, oxidation, plants, root molds, tidal flat with mud cracks, etc.)

Yellow - Uncertain, arbituary point of minimun depth (or exposure with no visible evidence)

 

This is based on interpretations of cyclothems by Philip Heckel (example: http://www.kgs.ku.edu/Publications/Bulletins/GB2/ )

[KCMOfossil]

Very nice!  Lots of information clearly displayed.  It really opens a window on what is happening in the Pennsylvanian.

 

Russ

[KCMOfossil]

1 hour ago, Missourian said:

interpretations of cyclothems by Philip Heckel (example: http://www.kgs.ku.edu/Publications/Bulletins/GB2/ )

Thanks for this link.  In the document I found Heckel's "basic vertical sequence of individual 'Kansas Cyclothem'" to be helpful in clarifying, in general terms, what a cyclothem is. 

 

[Missourian]

1 hour ago, KCMOfossil said:

Thanks for this link.  In the document I found Heckel's "basic vertical sequence of individual 'Kansas Cyclothem'" to be helpful in clarifying, in general terms, what a cyclothem is. 

 

Thanks. That chart is what I had in mind. 

[Nimravis]

On 12/1/2011 at 1:36 PM, Missourian said:

At a creek exposure (now covered over) near my childhood home, the sandstones had trace fossils and some amazing ripple marks:

Love the ripple marks.

[Missourian]

Over eight years after I posted this: 

 

http://www.thefossilforum.com/index.php?/topic/25424-backyard-trip/&do=findComment&comment=285787

 

I happened to revisit the site yesterday. The scene has noticeably changed. Apparently, a landslide has cleared some of the forest canopy and brought down some large slabs of limestone from overlying beds.

 

The Cement City Limestone is still well exposed here:

 

 

Is the prominent groove in the middle of the beds fossiliferous?:

 

 

Yes it is. The large rugose coral Caninia is present, as well as brachiopods and crinoid debris:

 

 

I didn't have any tools with me at the time. I plan to return to collect the big coral.

[Monica]

What a bounty of fossils!  Congrats! 

[JimB88]

wow..those are nice! Definitely go back and get that coral! Is that formation Pennsylvanian?

[Missourian]

23 hours ago, JimB88 said:

wow..those are nice! Definitely go back and get that coral! Is that formation Pennsylvanian?

 

Thanks, and indeed.

 

Yes, Pennsylvanian.

 

More specifically: Pennsylvanian, Missourian Stage (Kasimovian Stage), Kansas City Group, Linn Subgroup, Dewey Formation (formerly Drum Fm.), Cement City Limestone Member.

[JimB88]

1 hour ago, Missourian said:

 

Thanks, and indeed.

 

Yes, Pennsylvanian.

 

More specifically: Pennsylvanian, Missourian Stage (Kasimovian Stage), Kansas City Group, Linn Subgroup, Dewey Formation (formerly Drum Fm.), Cement City Limestone Member.

 I forgot how well you knew the formations over there 

[Missourian]

This summer, the city began to improve a stretch of road in the 'backyard'. I was hoping they would cut into the Muncie Creek Shale as they graded the slope. As work progressed, it became apparent that they hit pay dirt.

 

After the workers finished for the day, I walked up to the exposure. The Chanute Formation can be seen on the left, the lower Iola Formation is in the center, and slabs of Iola limestone are on the right:

 

Apparently, this area was excavated for the new utility poles that are visible in the image. All the beds on the left will be removed for the new road.

 

The lower Iola, a little closer:

 

The Muncie Creek is the black, platy shale between the Paola Limestone below and the crinoidal bed of the lower Raytown Limestone above. This distinctive sandwich-like arrangement of beds makes the Muncie Creek easy to spot wherever it is exposed:

 

There is one thing better than an outcrop of Muncie Creek. That would be an area of Muncie Creek that has been stripped off and cast aside. Here, several slabs of the Paola and the crinoidal bed have been piled up:

 

I soon found many concretions on the slabs and in the mixed-up shale around them. They can be found embedded in both the Paola and the crinoidal bed. At this site, they tended to be associated more with the crinoidal bed, as can be seen here:

 

This concretion on the slab contains a cross-section of fish bone, possibly a cranium:

 

I plan to return and extract it with hammer and chisel. Unfortunately, the crinoidal limestone is very durable, and the concretion may not survive the attempt.

[Missourian]

Above the 'sandwich' beds is the upper portion of the Raytown Limestone:

 

The Liberty Memorial Formation above often produces crinoids, but unfortunately the shale here is either covered or has been graded.

 

Below the Iola is the Chanute Formation. This shale contains some thin-bedded sandstone:

 

These sandstone slabs contain trace fossils, and in some cases, plant debris:

 

I brought home quite a few Muncie concretions on two outings. Here is my first haul:

 

I haven't yet popped any open. This already-split concretion containing shark cartilage will serve as a sneak preview for now:

 

A stratigraphic chart of the outcrop:

 

[JimB88]

Holeeee! Shark cartilage and fish bones! That would be heaven for me! Cant wait to see what you get! 

[Missourian]

One more specimen....

 

This crusher tooth, probably Sandalodus sp., was lying loose on the ground. It almost certainly came from one of the limestones of the Iola:

 

 

The surface of the tooth is covered with some kind of white material. Are these mineral deposits, or some kind of encrusting fossils? I had to check it out under the microscope:

 

 

These are encrusting forams, possibly Tolypammina sp. Additionally, several parallel abrasion marks cover the surface, providing some evidence of the feeding habits of the shark.

 

I may have to place more of my teeth under the scope.

[JimB88]

Thats a great tooth! And since the forams are over the scratches, the latter must have happened before it was buried..could be feeding wear or could be evidence of scavenging or predation on the shark. With the scratches all going in the same direction, you could be correct, but its hard to say for certain.

[Missourian]

5 hours ago, JimB88 said:

Thats a great tooth! And since the forams are over the scratches, the latter must have happened before it was buried..could be feeding wear or could be evidence of scavenging or predation on the shark. With the scratches all going in the same direction, you could be correct, but its hard to say for certain.

 

Thanks, and indeed. The forams and scratches remind me of calcite deposits on glacially striated rock.

 

Plus, it is interesting how this tooth is both a body fossil and a substrate for other body and trace fossils.

[Titan]

@Missourian I don't know how I missed this thread but it's amazing. Thank you for sharing so much detailed information as well as your finds.  

[Samurai]

On 7/14/2020 at 1:38 AM, Missourian said:

This concretion on the slab contains a cross-section of fish bone, possibly a cranium:

Wonderful finds!

[Missourian]

They say not to count your chickens before they hatch. I beg to differ. As of today, I've collected almost 1400 Muncie Creek concretions of all shapes and sizes:

 

 

 

I don't know when I'll start to crack through them, but a few have naturally opened on their own. This one is showing a bit of shark cartilage:

 

 

These two contain fish bones or spines:

 

 

At first, I thought the one on the left was a large crinoid stem covered in mud.

 

This one appears to contain an orthocone nautiloid:

 

 

Only a few percent of these concretions will contain really nice fossils, so the more found, the better.

[Missourian]

I have collected Muncie Creek concretions at two sites in close proximity. Here is the second one:

 

 

Something to note about concretions is that the most prolific collecting sites can be quite underwhelming in appearance. I probably have collected more here than at the site described in the posts above. In this case, the work crew probably cut into the formation to install utilities along the road, and then dumped and leveled the material back into the excavation. (Edit: This material was likely excavated from the other site and dumped here for when they eventually raise the road level.) The Muncie Creek Shale is mixed together with other shales, limestones and soil. Fortunately, it is likely this site will be left in its current state for an extended period of time. At every opportunity, I plan to scan the ground for newly exposed concretions after each decent rainfall. (Edit: This spot has been covered with debris.)

[Missourian]

While continuing to collect Muncie Creek concretions, I came across this:

 

 

This was unexpected. While I frequently see concretions imbedded in the base of this crinoidal limestone, I have never seen them in the middle of the bed. This seems to indicate that these phosphatic concretions formed in the shale before the overlying crinoidal debris was deposited. In this case, the concretion probably became dislodged from the Muncie Creek mud by sea-floor currents and was subsequently mixed in with the crinoid fragments.

 

Here is a closer look at the concretion, shown at full resolution:

 

There is no discernible crinoid material within the concretion, which seems to confirm that it did not form in this bed.

 

[Missourian]

This concretion, at the base of the crinoidal bed, isn't lying flat as would be expected if it had formed after all the sediments were deposited:

 

 

Instead, it appears to have been imbricated as it was put into place by currents. (Happily, I managed to pop this one out.)

 

Additionally, these concretions can be found in the black, platy shale in the lower portion of the Muncie Creek. These can be revealed as deformations in the shale:

 

 

General distribution of phosphatic concretions in the lower Iola formation:

 

[Missourian]

Some trace and plant fossils found in the Chanute Formation at the site mentioned a few posts above....

 

Trails. These may have been made by gastropods:

 

 

Rusophychus, a trilobite trace:

 

 

I'm not sure how these formed:

 

 

A degraded fern frond:

 

 

The Calamites-like fragment in the upper left is from a recent plant.

 

[Missourian]

A few more fossils found at the construction site....

 

An unidentified cephalopod in the crinoidal bed at the base of the Raytown Limestone:

 

 

Sponge in the Paola limestone. This is either Amblysiphonella or Girtycoelia:

 

 

I examined this close up. Porous structure confirmed it as a sponge:

 

 

Wood in the base of the crinoidal bed, just above the Muncie Creek Shale:

 

 

I was surprised to find plant material associated with phosphatic concretions. This, along with the crinoidal debris, indicate an agitated environment.