Carboniferous Limestone Fossil Death Assemblages

[ckmerlin]

Hi all Im looking for help here

In my area there are some old disused limestone quarries that have nice ,quite large death assemblages of Crinoids , some colonial corals and Brachiopods. They all seem to be in carboniferous late visean , asbian/brigantian facies. 326 Ma to 334 Ma

Most are in life position apart from some crinoid beds .

Through reading various studies it seems the death assemblages were likely caused by eustatic sea level changes caused by glaciation and/or plate tectonic activity .

My question is does any one have any similar types of death assemblages in their area during this same period ?. I would be interested to see if this was just a local event in my area or was it more widespread nationally or internationally.

The pictures show just a small bit of theses death assemblages

If anyone needs long and lat information please ask and ill be glad to provide it

Edited February 12, 2012 by ckmerlin

[Kosmoceras]

I am not sure if I can answer your question... but wow! They are good!

[ckmerlin]

Hi Kosmos if your ever up this way ( I liver near Halkyn / Holywell North Wales where theses old quarries are ) Id be happy to show you these they are quite breath taking

[ghost1066]

Love that crinoid plate. Where I hunt is older by several million years but I find the same type of thing every trip out. So common I don't even think about them anymore. It is a good question though and I hope someone has an answer.

[Kosmoceras]

Hi Kosmos if your ever up this way ( I liver near Halkyn / Holywell North Wales where theses old quarries are ) Id be happy to show you these they are quite breath taking

Sure, I would be happy to, I don't normally go to Wales, but it would be fun sometime.

[ckmerlin]

Some further information , the Brachiopod assemblages are mostly Sprifes, giant Productids , with a few other species , the beds are between 2-5m thick and there are at least 4 quarries with beds along the same or very close to the same strike. Some of the beds in the quarries have corresponding assemblages at the same levels/heights in each quarry . Sometimes the beds contain a mixture of Crinoids and Brachs , one has just Brachs, the other two have just Brachs and Colonial corals ( havnt looked up species yet)

attached photo of part of large Productid Brach assemblage

Edited February 12, 2012 by ckmerlin

[Missourian]

It's pretty cool how the shells are sitting on an irregular disconformity. Something got scoured off pretty good.

That crinoidal rock look similar to the Burlington Formation of the central US. This Mississippian limestone is early Visean.

The beds sort of remind me of some shell bands within an upper Carboniferous limestone near Kansas City: http://www.thefossil...ian-shell-beds/ . I believe these are a tidal channel fill.

[Indy]

My question is does any one have any similar types of death assemblages in their area during

this same period ?. I would be interested to see if this was just a local event in my area or was

it more widespread nationally or internationally.

Crinoid is probably the most prolific fossils found in the the Carboniferous. The ancient

sea floor, in many places, were covered with crinoid. What your looking at is a "snap shot"

of the ancient sea floor, littered with crinoid stem fragments (natural occurrence)

What you have found is extremely common in the Mississippian (Carboniferous) of Missouri.

Vertical and horizontal exposures. Solid layers of crinoid stem fragments.

I know that many of the fragments appear in what your refer to as "life position". However,

crinoid stems fall apart at death and fall to the sea floor in various positions. We are looking

at a "vertical" view (cross section) of the ancient sea floor and fragments that fell and rested

sideways appear as in the "life position. The Burlington Formation (Mississippian) in some

areas of Missouri are just solid layers of crinoid stem fragments. All a natural occurrence of

what must have been forests of crinods that lived on the ancient sea floor. So...what your

looking at is not a local occurrence but an extremely common occurrence.

The pictures you took...Looks "Identical" to many Carboniferous exposures here in Missouri.

If I didn't know better...I would have guessed you took these pictures at a Burlington Formation

exposure here in the Missouri

Edit: Found this UK website with comparable images: Link

Edited February 14, 2012 by Indy

[ckmerlin]

Thanks Barry , Missourian and kosmos for taking a look and replying There are quite a few quarries with crinoids in around here but none with the same thikness beds , what is more interesting to me is the size of the brach assemblages in these four quarries . Its very gratifying to know that we can see these snapshots of the past

Edited February 14, 2012 by ckmerlin

[Indy]

If I had to choose just 1 word to describe why I am so fascinated with the this hobby

it would be ... "Wonderment"

I wonder what this is

I wonder what this area looked like back then

I wonder why (this or that)

I wonder what matrix and fossils look like in other areas or other countries

I wonder what I might find if ...

Some of my most pleasant memories was when I would sit down in the field

and stare at what was just found...and "Wonder"

[ckmerlin]

If I had to choose just 1 word to describe why I am so fascinated with the this hobby

it would be ... "Wonderment"

I wonder what this is

I wonder what this area looked like back then

I wonder why (this or that)

I wonder what matrix and fossils look like in other areas or other countries

I wonder what I might find if ...

Some of my most pleasant memories was when I would sit down in the field

and stare at what was just found...and "Wonder"

Barry

yes I agree with you on this, I too spend a lot of time just thinking how did this happen ,why like this ,what is it ,when etc .but wonder is the main feeling I experience . The experience of just being able to look at something or the trace of something that was alive millions of years ago still fills me with awe !!

Edited February 16, 2012 by ckmerlin

[surfergirlatx]

If I had to choose just 1 word to describe why I am so fascinated with the this hobby

it would be ... "Wonderment"

I wonder what this is

I wonder what this area looked like back then

I wonder why (this or that)

I wonder what matrix and fossils look like in other areas or other countries

I wonder what I might find if ...

Some of my most pleasant memories was when I would sit down in the field

and stare at what was just found...and "Wonder"

Couldnt have said it better myself!!!! Now if my back would just comply!!!!

[ckmerlin]

Indy you pretty much summed up a fossil collector's mantra.

The only true definition of wonderment, is the experience which it ultimately creates in the sayer. Over thousands of years, many sayers have had common experiences, each person's experience is different from another's and yet on some level they are all alike.

I can view the Pennsylvanian using my mental Paleovision App and see the vast waterway with a "garden" of all the strange and beautiful Echinoderms gently swaying in the currents. Then I can picture a tumultuous storm breaking off the crinoids and ending up in the pile of remnants I would see in the encrinal limestones as a testimony to their life and death.

We feel we know what a Crinoid looks like; but do we truly understand the life style and biological forces of an animal that was living sooooo long ago. Yes, there are Crinoids in the sea we can study now; but how well do we even know them.

It is fun to see the stones from the UK, which goes on to say just how cosmopolitan these fossils are.

Fossilcrazy

Its great to imagine the past environment and ecology of fossil animals and plants. Its something I do all the time ( as do most members here I would imagine , it kinda goes with the territory ) Im sure you will agree that having some knowledge of the geology of the area the fossil was found helps in this process

Edited February 16, 2012 by ckmerlin