Show Your Strata

[Missourian]

On 11/22/2012 at 4:53 AM, Wrangellian said:

Here is a little Upper Pennsylvanian age roadcut I visited on a field trip a few weeks ago (Mt. Mark Fm, Lake Cowichan, Vancouver Isl.) Consists of alternating beds of limestone (dolomite?) and chert. Not much in the way of fossils, the only things I picked up were a couple pieces with cavities that used to be crinoid stems, bryos, etc. I didn't have a camera with me so I had to go to Google for these..

 

Those poor beds look tormented.

[Missourian]

Excelsior Springs, Missouri became a health resort in the 19th century due to its mineral spring water:

 

 

 

Today, the therapeutic water isn't so much of a draw anymore, but the limestones that produced the springs are still present, as you can imagine.

 

East of town is a rather large road cut that exposes about half of the Pennsylvanian Kansas City Group. I'd stopped here several years ago but didn't find much of anything. I visited the site again back in August. About 150 feet of strata are exposed in the 1/3-mile-long cut. (Yes, I measured it in both directions, though not on foot. ).

 

At the base is the Swope Formation. This includes the Bethany Falls Limestone, which is basically the same here as it is at the nearby Tryst Falls:

 

 

The Bethany Falls may be the source of the springs in the area.

 

The Eowaeringella zone of fusulinids is present, but they were a bit harder to find here:

 

 

The upper Bethany always has interesting lithology:

 

 

Below the Bethany is part of the Hushpuckney Shale:

 

 

Unfortunately, the highly-fossiliferous Middle Creek Limestone is buried beneath the weeds.

 

Above the Bethany is the Winterset Limestone:

 

 

The Winterset can be really good for fossils at times, but there wasn't much to find here.

[Missourian]

Above the Winterset ledge is a vast expanse of slope formed by the shales of the Cherryvale Formation:

 

 

 

These beds include the Fontana Shale, Block Limestone and Wea Shale.

 

The Block is a thin and remarkably persistent bed of limestone:

 

 

It marks the stratigraphic position of fine hash plates in the lower part of the Wea:

 

 

One plate up close:

 

 

Zounds!:

 

 

Made you look.

 

The remainder of the Wea is barren shale:

 

[Missourian]

Above the Wea is the Westerville Limestone:

 

 

I didn't spot too many fossils.

 

The top of the Westerville here is rubbly and oxidized:

 

 

This often indicates the limestone was exposed to erosion before the overlying beds were deposited. This weathered rock is often riddled with root molds:

 

 

 

The beds above the Westerville are poorly exposed:

 

 

The Nellie Bly and Quivira Shales are completely covered. The Cement City Limestone pokes out here and there:

 

 

Sometimes, it doesn't take much for the Cement City to be generous:

 

The Kozlowskia brachiopods are numerous and well-preserved here:

 

[Wrangellian]

Those poor beds look tormented.

Yes they do! Even some of the Cretaceous sediments here on the south end of the Island are affected by tectonic/hydrothermal activity - anything older is that much more likely to have been altered. As you know, the Cordillera has been thru a lot more than the central part of the continent. I'll try to get more pics of these, but the weather hasnt been too good lately (not to mention shorter days) so who knows when..

[Paleoworld-101]

This is one of the sites where i collect at, which yields complete Glossopteris leaves. As you can see by the pic, it is a great place to see the Permian-Triassic boundary, notorious for being the most devastating extinction event in the planets history (95% of life wiped out in a geological blink). It is located at Austinmer, a coastal suburb between Sydney and Wollongong.

[Missourian]

On 11/25/2012 at 12:20 AM, Paleoworld-101 said:

This is one of the sites where i collect at, which yields complete Glossopteris leaves. As you can see by the pic, it is a great place to see the Permian-Triassic boundary, notorious for being the most devastating extinction event in the planets history (95% of life wiped out in a geological blink). It is located at Austinmer, a coastal suburb between Sydney and Wollongong.

 

Very cool.

 

I just started a 'Show Your Period Boundary' thread in 'General Fossil Discussion'. You're welcome to include your P-Tr pic there.

[Paleoworld-101]

Very cool.

I just started a 'Show Your Period Boundary' thread in 'General Fossil Discussion'. You're welcome to include your P-Tr pic there.

Thanks, already did

[Missourian]

The Pleasanton Group is a 100-foot section of Pennsylvanian shale with some sandstone and very little limestone. It effectively 'bookends' the base of the Kansas City Group, which is exposed throughout the KC area:

 

 

It can be found along the slopes of large hills and ridges that mark the outcrop belt of the thicker limestones in the lower part of the KC. This escarpment is often conspicuous on topo maps:

 

 

While scouting out exposures in southeast Clay County, Missouri, I found an outcrop of the top of the Pleasanton:

 

 

The top of the group is capped by the Critzer Limestone, which here is a thin and rubbly bed:

 

 

The colors of the shale are amazing:

 

 

A paleosol is marked by maroon clay on the right.

[Missourian]

Further east, near Richmond, a spectacular section of most of the Pleasanton Group is exposed in a large railroad cut:

 

 

The sandstone in the middle may be the Knobtown 'Limestone', which is one of the few zones in the Pleasanton with marine fossils.

Notice a diagonal feature in the shale on the left?

 

 

I didn't see it until I looked through the photos. It struck me how the Knobtown ends at the feature. Is it a fault? Possibly. It could also be an erosion surface, but I don't think that is likely.

 

A couple miles to the north, I spotted a tremendouly high cut bank in the Pleasanton:

 

 

Here, the Knobtown is close to the top:

 

 

A bed poking out near the bottom could be the Exline Limestone, which is another fossil-bearing layer:

 

 

I wanted to see it up close, but I wasn't in the mood for scrapes, bruises or mud.

 

I really wanted to find outcrops of the limestones of the underlying Marmaton Group, but I'll have to go further east and south for those.

[Missourian]

More Pleasanton Group....

 

Last fall, I joined my brother and nephew at a boy scout camp-out in southeast Jackson County, Missouri. During a slow moment, I snuck away to see if anything was outcropping in the nearby creeks. I came across numerous exposures of the Pleasanton:

 

 

 

In a couple spots, plant fragments were present in the shale:

 

 

Next time, I'll see what else I can find.

[redleaf101]

Nice!

[toolbox82]

Paleocene, Midway group, Wills Point formation.

The dark marine shale holds numerous marine invertebrate fossils.

[Missourian]

On 1/8/2014 at 10:08 PM, toolbox82 said:

Paleocene, Midway group, Wills Point formation.

The dark marine shale holds numerous marine invertebrate fossils.

 

That has to be one of the finest displays of strata, sedimentary structures and in situ fossils I've seen.

 

I'll link to your other thread here if you don't mind : http://www.thefossilforum.com/index.php?/topic/41461-hello-from-texas/

[toolbox82]

Missourian,

Thank you for your comment and i do not mind. It is appreciated.

There are three more pits just like this one here and several more that have been test dug and show the same type of formation that have yet to be excavated. the shallow depth of this outcrop less that six feet in places that have been excavated is very rare for this location.

Carl

[tooth_claw]

Well as far as interesting geological features go this site is one of my favourites!

This is Pit A, about 18 meters below the surface of the Nullarbor Plains. This is the cave where complete, articulated remains of Thylacoleo carnifex were found.

Cave Palaeontology has many benefits- You are out of the wind/rain/sun, have a constant temperature/humidity and the acoustics really enhance any music that you bring down. It is a beautiful place to work!

A closer shot- imagine digging under that all day!

[squalicorax]

Here is some outcrops ive collected at in the past

This is a Maquoketa Shale outcrop in Brown County Wisconsin that exposes Ordovician brachiopods and bryozoans

Next is an exposure of Silurian Dolomite which made Door County Famous in the 1800s for commercial quarrying.

Exposure of the Duck Creek Limestone in Fort Worth Texas. Cretaceous in age.

Next is another exposure of the Maquoketa Shale in a railroad cut in North Western Illinois.

[Wrangellian]

Good shots. Is that you in each one?

Now my collecting appetite has been whetted and I can wait even less for Spring...

[PFOOLEY]

One of my favorite places to visit...

...the Kirtland/Fruitland formation... Dinosaur Country!

Edited March 4, 2014 by PFOOLEY

[Missourian]

Dinosaur country always looks like rocky road ice cream.

[Missourian]

Tonganoxie Sandstone, Pennsylvanian

Wyandotte County, Kansas

 

[squalicorax]

Is that mars?

[Missourian]

Is that mars?

Yes.

[Bullsnake]

[Missourian]