Backyard Trip

[Plantguy]

How about sending a railroad car full of those rock outcrops and fossils to Florida! Its just too stinking flat down here and geologically young! Love seeing the stratigraphy and different rock types---fossiliferous or not. Thanks for sharing! Regards, Chris

[RomanK]

Since my local excursions have been turning up empty fossil-wise, I will tide you over with some specimens from the Winterset Limestone found around the Kansas City metro....

I shall start out with the trilobite Ameura. Here is its head:

And its tail:

Cephalopods can be found in the oolitic beds. Here is Metacoceras:

Liroceras:

Stenodomatoceras:

I've had this specimen for 24 years, and just tonight, I learned its genus name.

Alongside the cephalopods are many types of gastropods. Here is Strobeus:

And Euconospira:

Pelecypods are plentiful as well. These large pectens are clustered together:

This Aviculopecten is in dolomitized limestone:

Mollusks of all kinds can be found in the bands in this rock:

Crinoids are present too. Here is a calyx of an Ethelocrinus magister, along with some stems and plates:

Plants are often encountered in the Winterset. The strap-like leaves of Cordaites are the most common:

Cordaites may have formed mangroves along the coastline.

And in a few isolated spots, ferns can be found. This is Pecopteris:

Well, that's all for now.

Like your Cordaites!

Pecopteris looks rather like Mariopteris, check that, I may be wrong

[Missourian]

On 10/27/2012 at 9:15 AM, RomanK said:

Like your Cordaites!

Pecopteris looks rather like Mariopteris, check that, I may be wrong

 

Thanks. The Winterset Cordaites have always fascinated me.

 

As much as the plant names change over the years, I may have to scrap all my labels and hit the library some day.

[Missourian]

On 10/27/2012 at 9:05 AM, Plantguy said:

How about sending a railroad car full of those rock outcrops and fossils to Florida!

 

As long as you can send Sanibel Island in exchange.

 

Yeah. It's just not the same when you can't climb all over the stuff.

[Indy]

Bump !!

Outstanding archives like this one deserve a bump from time to time for interest

and shouldn't fall into back pages to be seldom seen again

[Missourian]

On 12/3/2012 at 6:37 PM, Indy said:

Bump !!

Outstanding archives like this one deserve a bump from time to time for interest

and shouldn't fall into back pages to be seldom seen again

 

Agreed!

 

It is recon season again, i.e. no poison ivy, bugs, obscuring vegetation, etc. I have several potential outcrops on the back burner....

[Ludwigia]

I agree with Indy, so I'm bumping to finally get in on it.

[Indy]

Post 16

Fossil-bearing phosphatic concretions

Image: Link

Absolutely beautiful and fascinating Eye Candy grouping !!

The robust preservation is fascinating.

I see some familiar friends ... found in the Lake Neosho here in Missouri.

Goodies hiding in these phosphatic concretions has always been of interest.

I have about a thousand unopened nodules.

I don't see any obvious markings indicating these were opened

by tapping on them with a small hammer. The breaks seem to be all

beautiful classic robust openings of these nodules. Did you open these

using the freeze/thaw method??

Also ... Interested in any related stories you have time to share.

PS: Love Pennsylvanian fossils from Kansas...they usually are so robust !!!

[squalicorax]

Amazing fish spine!!!!!!!!!

[Missourian]

On 12/4/2012 at 8:47 AM, Indy said:

Did you open these using the freeze/thaw method??

 

If, by "freeze/thaw", you mean "hammer/driveway", then yes. . I wasn't even aware of the freeze method when I popped them years ago. Now, will the method work as well with partially exposed fossils?

[Indy]

If, by "freeze/thaw", you mean "hammer/driveway", then yes. . I wasn't even aware of the freeze method when I popped them years ago. Now, will the method work as well with partially exposed fossils?

I've never heard of freeze/thaw for phosphatic nodules either.

So ... you cracked them open with a hammer.

Well, it appears even the nodules in Kansas are robust

The Lake Neosho nodules often break apart into 3 or so pieces ...

if not shatter all together ... regardless how careful I am using

very small hammers and just tapping till they break.

Your specimens are outstanding examples

I'm lucky to get a clean break in 1 out of 15 or so nodules

Edited December 4, 2012 by Indy

[Missourian]

The Muncie Creek nodules usually break more or less agreeably when tapped or whacked. The ones that are stubborn almost always have nothing id'able within them.

[Auspex]

...The ones that are stubborn almost always have nothing id'able within them.

Cause, or effect?

[Indy]

The Muncie Creek nodules usually break more or less agreeably when tapped or whacked. The ones that are stubborn almost always have nothing id'able within them.

When and if we meet and go into the field ... put Muncie Creek on this list

Seriously, someday we will hit the field together.

We talked before ... Put me on the Pennsylvanian and I'm a happy camper.

It's the experience and I'm not a fossil nut ... I love everything about the Pennsylvanian.

Of course, if there's fossils there ... You won't need to put X on the spot for me

I'll sniff 'em out. I do very much enjoy the shales.

[Missourian]

On 12/4/2012 at 3:14 PM, Auspex said:

Cause, or effect?

 

The calcium phosphate is really tough stuff when there is no fossil to split along.

 

To an extent, you can visually categorize the quality of the nodules:

Spherical - Usually duds. If they are too hard to crack, I give them one last whack out of spite and to verify nothing is in them, but mainly to verify that nothing is in them.

Somewhat flat - Promising. These may have something or maybe not.

Really flat - Probably duds. If nothing shows up after a couple hits, I discard them. The rare ones that do have something usually split pretty easily.

Oblong - Usually have something long and skinny like spines, etc.

With slight protrusions - Candy. It's as if the fossil is trying to get out. Sometimes a couple taps is all that's needed.

[Indy]

Interesting ...

I have some "sight recognitions" for the nodules at the Lake Neosho also.

Some day I will post some with comments ... Should make for an interesting

discussion. Several of the the "roundish" shapes are actually coprolite.

[Missourian]

On 12/4/2012 at 3:47 PM, Indy said:

Seriously, someday we will hit the field together.

We talked before ... Put me on the Pennsylvanian and I'm a happy camper.

It's the experience and I'm not a fossil nut ... I love everything about the Pennsylvanian.

Of course, if there's fossils there ... You won't need to put X on the spot for me

I'll sniff 'em out. I do very much enjoy the shales.

 

I know you've already had a taste of KC Pennsylvanian, but knowing how you've worked over the I-170 cut, you would be in heaven here.

 

Although it's not easy to come out with too many flashy specimens, the deposits here have more variety than Baskin Robbins. Take your pick of any type of deposit you can think of, and it will be there -- sometimes with many in the same exposure. Ironically, though, plant fossils are pretty scarce around here (unless you like Cordaites).

[Indy]

OK with me ...

I'm not really into plants ... and I'm really not a "trophy hunter"

I'm a fauna collector and find getting to now specific sites rewarding.

Not just for the fossils but experiencing the locality thing ...

I know you understand.

[Missourian]

I think I was reminding myself that I can enjoy the hunt without finding "trophies".

[Missourian]

I hit a couple exposures of Westerville Limestone in recent days.

 

The first is in a little creek close to home. I'd driven by this I don't know how many times, so it was time to take a look:

 

 

About six feet of brittle limestone is exposed:

 

 

Large masses of chert characterize the top of the outcrop:

 

 

Most if not all Westerville exposures from this point northward contain chert. As you go south, the chert seems to disappear. Only a mile away, the Westerville is less than half as thick as well as chert-free (see: http://www.thefossil..._20#entry283768 ).

 

In a road cut a couple miles further south, the Westerville still lacks chert, but it has thickened back up a bit:

 

 

Some Wea Shale is exposed below:

 

 

Unlike the brittle and fragmented outcrops to the north, the limestone here is comprised of three massive beds that seem to resist weathering. The top one is cross-bedded:

 

 

Cross-beds such as these are intriguing, as they characterize shoals of bioclastic and oolitic limestone that are occasionally encountered in the Westerville. One such build-up is near Raytown, Missouri:

 

 

This shoal is renowned for its diverse molluscan fauna ( http://www.thefossil..._20#entry283770 ).

[Missourian]

In case you're interested in the Westerville and wish to research it online....

 

In old publications (eg. Fauna of the Drum Limestone of Kansas and Western Missouri, 1930), the limestone in KC now called the Westerville was correlated with the Drum Limestone of southeast Kansas, which was later correlated with the overlying Cement City Limestone in KC. Recently, the Drum has been re-correlated with the Westerville, but the name 'Drum' is restricted to southern Kansas. The Cement City is now included within the Dewey Formation, which was the old name for the Cement City in southeast Kansas. Or so I think. Oy vey.... I hope they have it sorted out for good.

[Indy]

Wouldn't it be nice if all the same limestones had the same name ??!!

[Missourian]

When I spotted this park on a map, I thought there would be some good exposures of the lower Kansas City Group strata, particularly the Winterset Limestone:

 

 

The valley was beautiful, but I found no bedrock:

 

 

I didn't see one rock in the creek -- not even a pebble. The entire landscape was made of loess. Some of the steep-sided ravines were more than a hundred feet deep.

 

I've described loess deposits before in this thread, so I'll recap.

 

Loess is glacially-derived, wind-blown silt that formed large drifts along the banks of the Missouri River. As the Pleistocene ice sheets moved across the continent, they picked up chunks of rock and ground much of it into particles ranging in size from clay to boulders. This sediment choked the river channel as it was carried along. As this was still a tundra environment at the time, there was no vegetation to protect the channel deposits from the fierce winds that could whip up on the barren landscape. While the gravel and sand continued to flow down-river, much of the silt and clay were blown out of the flood plain. The clay was carried away with the wind. The silt tended to pile up along the river banks. A little further out, it partially or wholly filled the pre-existing stream valleys.

 

Just south of the park, there are large cuts into the loess along the highway:

 

 

The cliffs tend to be vertical because of the angular grains of silt. When chunks do spall off, they usually split vertically.

 

Groundwater in the loess sometimes causes strange erosional features:

 

 

Most remarkable are tunnels that work their way through the loess. These sometimes emerge at the surface where they become hazards to anyone walking by.

 

Up close, loess looks and feels like dry dirt:

 

 

At the top, a distinct, multi-layered soil horizon can be seen:

 

[Missourian]

We moved on to a second exposure of loess that I had spotted recently at a road construction site:

 

 

What immediately caught my eye were the thin, dark streaks. These are paleosols:

 

 

As you can imagine, these formed during a cessation of loess deposition. Their thinness relative to the modern soil horizon shown in the previous post probably indicates they were short lived.

 

The feldspar silt grains have broken down into a blocky clay:

 

 

In one spot, there are odd structures that resemble cross beds:

 

 

Some of the oxidized soil up close:

 

 

The lower end of the cut features yet another horizon and some oxidized material.

 

 

The colors are amazing. I'm not sure what the hood-like structures on the bottom are.

 

 

Unlike the other horizons, this one is a stream deposit made up of sand and pebbles.:

 

[Missourian]

Ok, big mounds of dirt are all fine and dandy, but where are the fossils? They do turn up at times.

 

This chunk of vegetation was exposed in the wall:

 

 

I dug out a few chips:

 

 

I'm not sure if it is a true fossil or just a root that died relatively recently.

 

More impressive are the pulmonate snails that are abundant in spots:

 

 

I found these years ago somewhere along the Missouri River bluffs.