Visiting a mini Konzentrat-Lagerstätten

[DeepTimeIsotopes]

 Sorry I haven’t been around the forum as much for a couple months now but I’m starting to get some more free time recently.

Here’s a quick trip @Earth Chemistry and I did a little bit ago. 

 

Let’s start out with what stratigraphy we’re looking at here.

I’ve been visiting multiple locations of what is locally known as the Gardison Limestone.

 

Source: http://utahgeology.com/utah-stratigraphic-columns/?var=strat_27

 

 

It is from the early Mississippian or Early Carboniferous for our international members.

[DeepTimeIsotopes]

Much of the formation is micrite that is devoid of fossils but every so often is a small layer that is absolutely chock-full of fossils. I like to call it my mini Konzentrat-Lagerstätten. Here’s a look at the outcrop

[DeepTimeIsotopes]

Some places are so full there’s almost no matrix between the shells. But this formation is not without some nuances. In some places, there has been a major amount of metamorphism. The outcrop below shows where hot groundwater with dissolved silica flowed through. The water would dissolve out some of the calcium carbonate and drop the silica. This forms as small nodules at first but overtime can build up into essentially layers of chert.

[DeepTimeIsotopes]

Some of that chert infiltration has occurred on the fossils as well. They’ve been replaced with silica here so that when they weather the softer matrix gets removed and you can see the internal structures such as in this horn coral

 

What else can we see in this picture?

 

I can see the different depositional events creating the layers perhaps from stronger than usual out-flowing currents or storms pulling debris downslope a reef or even reoccurring underwater landslides.

[DeepTimeIsotopes]

How about we look at some brachiopods? We’ve got a little of everything in this rock. Perhaps @Tidgy's Dad could provide us with some ID’s 

[DeepTimeIsotopes]

Worm burrows or tabulate coral? You decide!

[DeepTimeIsotopes]

The entire layer is only 4-5 feet (~1.5 meters) thick.

[DeepTimeIsotopes]

Above or below this particular member there are basically no fossils.

Empty Late-Devonian cliff-forming sandstones that sit stratigraphically below the Gardison Limestone. Maybe they show the effects of the Late Devonian mass extinction.

[DeepTimeIsotopes]

Some crazy faulting patterns mirroring the direction of a nearby fault

[DeepTimeIsotopes]

A beautiful cross section through a rugose coral. 

If you zoom in you can see the remnants of its septa. It’s crazy to think this thing was alive 350+ million years ago.

[DeepTimeIsotopes]

Look at this crazy facies shift

To me this either shows an underwater landslide or a dramatic change in sea level.

[DeepTimeIsotopes]

My favorite find of this trip.

 

 

 

There’s a little bit of metamorphic geology (chert), a little bit of sedimentary geology (facies changes), a lot of paleontology (a whole lot of diverse fossils), and a little bit of structural geology (the small joints on the top left) all rolled into one specimen.

[DeepTimeIsotopes]

I’ll end with this shot of the Great Salt Lake from the ridge line.

thanks for reading!

[Kasia]

17 hours ago, UtahFossilHunter said:

I’ll end with this shot of the Great Salt Lake from the ridge line.

thanks for reading!

Thanks for sharing - very nice finds and the last picture of the lake 

[DeepTimeIsotopes]

54 minutes ago, Kasia said:

Thanks for sharing - very nice finds and the last picture of the lake 

You’re welcome! It’s a very pretty area.

[Coco]

4 hours ago, UtahFossilHunter said:

It is from the early Mississippian or Early Carboniferous for our international members.

 

Coco

[Monica]

What beautiful scenery!  And the fact that you get to find some fossils is a bonus!  Congrats, and thanks for sharing!

[Ludwigia]

Great report! Thanks also for all of the educational comments about the outcrop.

[DeepTimeIsotopes]

13 hours ago, Coco said:

 

Coco

2 hours ago, Monica said:

What beautiful scenery!  And the fact that you get to find some fossils is a bonus!  Congrats, and thanks for sharing!

I really love this particular area. It’s great that it has such a rich geologic history. It always blows my mind!

16 minutes ago, Ludwigia said:

Great report! Thanks also for all of the educational comments about the outcrop.

Thanks! I just want to share all the cool things with you guys!

[FranzBernhard]

5 hours ago, UtahFossilHunter said:

I just want to share all the cool things with you guys!

Can´t wait for your next trip!! Thanks for sharing your super-trips and thanks for all the information you are providing, together with superb scenery and superb fossils!
Many thanks!
Franz Bernhard

[DeepTimeIsotopes]

2 hours ago, FranzBernhard said:

Can´t wait for you next trip!! Thanks for sharing your super-trips and thanks for all the information you are providing, together with superb scenery and superb fossils!
Many thanks!
Franz Bernhard

As long as you keep enjoying them, I’ll keep posting them!

[doushantuo]

Nice one,UFH

[DeepTimeIsotopes]

4 minutes ago, doushantuo said:

Nice one,UFH

It was a short trip but fun. Thanks!

[Tidgy's Dad]

Excellent and informative trip report as always.

Great photos too. 

There are productid and spiriferid brachiopods there, but i can't be sure of the genera, i'm afraid. 

[DeepTimeIsotopes]

33 minutes ago, Tidgy's Dad said:

Excellent and informative trip report as always.

Great photos too. 

There are productid and spiriferid brachiopods there, but i can't be sure of the genera, i'm afraid. 

Thanks!

That’s alright. If I look into it, I’m sure I’ll find them. It’s a pretty well known layer here.