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old red sandstone fossils


patrick plesiosaurus

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patrick plesiosaurus

Are these just bivalves. 

 

is the old red sandstone not quite a high energy environment with big clasts for preserving fossils. 

 

Orroland member Dumfriesshire southern Scotland. 

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Fossildude19

Yes, these look like bivalves in cross section. 

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FranzBernhard
55 minutes ago, patrick plesiosaurus said:

Are these just bivalves. 

Highly interesting, thanks for sharing!

 

55 minutes ago, patrick plesiosaurus said:

is the old red sandstone not quite a high energy environment with big clasts for preserving fossils. 

It has various facies, but most (all??) of that ORS group is non-marine, so I find the bivalves highly interesting.

 

Concerning high energy environment, I am finding at the moment often fossils in conglomerates, which I find also quite surprising. Here is one example, just one snail in conglomerate:

Konglomerat_AN4476_kompr.thumb.jpg.1237b1e2222f2c45f71832862868d9f3.jpg

Franz Bernhard

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patrick plesiosaurus

Thankyou,

 

Yes, that makes sense, what are the bivalves doing in an Australia like desert. 

 

I also found this coral. 

 

Thats an amazing gastropod fossil, could it have already been a fossil when it was put in the conglomerate, therefore it would be hardier. 

 

There were also some interesting sedimentary layers of sand, pebbles, congolmerates. DB8F77E2-5D21-4FE2-B8BA-AEF67B86B00A.thumb.jpeg.3f4b09e6a013b897db1b92b354a71860.jpeg

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FranzBernhard

Those colonial corals are amazing! I find it most interesting and indicative, that the matrix between the corallites is only partially red. They surely have been transported into its red surroundings from another type of environment. There could be some age difference (a few millions of years, but also even less) between the age of the corals and the deposition of the corals in the red matrix (sea level is always fluctuating). The same could hold true for the bivalves you have found.

Is there any literature about marine fossils in the ORS? How far away are the next marine strata of the same age as this ORS unit?

 

1 hour ago, patrick plesiosaurus said:

Thats an amazing gastropod fossil, could it have already been a fossil when it was put in the conglomerate, therefore it would be hardier. 

Usually these gastros are in a somewhat more sandy matrix, and the infill of the gastros is the same as the surrounding matrix. I don´t think it was a fossil when it set to rest in this conglomerate. And these gastros are rather thick-shelled and somewhat sturdy. Here you can find a summary:

Trochactaeon - Gosau Group of Kainach, Styria, Austria

Franz Bernhard

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FranzBernhard

I would like to revive this thread. I am very interested in this kind of fossil occurrences in the ORS, but can not find literature.

@TqB, @Tidgy's Dad, are you able to help me ;)? Many thanks!
Franz Bernhard

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Posted (edited)

The coral (appears to be Syringopora) is Carboniferous.

The Orroland Member of the Lyne Formation is Chadian I think, well into the Carboniferous - the formation includes fluvial and peritidal units.

The only corals in the Lyne Formation that I can find a mention of occur (rarely) towards the top in the Arundian age Cambeck Member.

 

@FranzBernhard Search "Lyne Formation" for this - it's well after the ORS which has no marine fauna in Scotland.  :)

Edited by TqB
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FranzBernhard

Thanks so much, @TqB!

Franz Bernhard

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Tidgy's Dad

I was taught that the Old Red Sandstone covered the terrestrial deposits that outcropped in parts of South West England, Wales and Scotland and covered an age from Late Silurian though to the lowest Carboniferouss times. The term Old was used to differentiate these rocks from the otherwise often similar looking New Red Sandstone formations of the Permo-Trias.  They do not include the thick grey marine limestones of Devon,but do include lots of thinner layers that are not red and maybe conglomerates or marine or fresh water sediments of varying colours. Most of the archetypal ORS is not fossiliferous, but some of the other bands are. I found a couple of fish scale fragments in the red ORS at Lydney on the shores of the Severn Estuary, but mostly didn't bother with these beds due to a lack of fossils and them often being ridiculously hard. 

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Posted (edited)
1 hour ago, Tidgy's Dad said:

I was taught that the Old Red Sandstone covered the terrestrial deposits that outcropped in parts of South West England, Wales and Scotland and covered an age from Late Silurian though to the lowest Carboniferouss times. The term Old was used to differentiate these rocks from the otherwise often similar looking New Red Sandstone formations of the Permo-Trias.  They do not include the thick grey marine limestones of Devon,but do include lots of thinner layers that are not red and maybe conglomerates or marine or fresh water sediments of varying colours. Most of the archetypal ORS is not fossiliferous, but some of the other bands are. I found a couple of fish scale fragments in the red ORS at Lydney on the shores of the Severn Estuary, but mostly didn't bother with these beds due to a lack of fossils and them often being ridiculously hard. 

 I didn't realise or had forgotten that ORS just extends into the Lower Carboniferous. :)  I did once see (on an undergraduate field trip) brackish water bivalves in the Pembrokeshire Skrinkle Sandstone right on the Devonian/Carboniferous boundary.

 

Search for "Lyne" in this document for a fairly up to date account of the Lyne Formation's modern status. There's no mention of ORS though it may have been included in it in older works.

Lithostratigraphical framework for Carboniferous successions of Great Britain (Onshore)

Edited by TqB
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Tidgy's Dad
1 hour ago, TqB said:

 I didn't realise or had forgotten that ORS just extends into the Lower Carboniferous. :)  I did once see (on an undergraduate field trip) brackish water bivalves in the Pembrokeshire Skrinkle Sandstone right on the Devonian/Carboniferous boundary.

 

Search for "Lyne" in this document for a fairly up to date account of the Lyne Formation's modern status. There's no mention of ORS though it may have been included in it in older works.

Lithostratigraphical framework for Carboniferous successions of Great Britain (Onshore)

I used to love the old British names for stratigraphy, vague and inaccurate they may have been.

The Crag: (Split into Red Crag and Coralline Crag) -  Red Crag described back then as Miocene, but now as being Late Pliocene - Early Pleistocene. Coralline Crag also said to have been Miocene, now Pliocene. 

 I won't go into all the myriad names used for the Eocene, lots of 'em as they were in South East England in and around London, so extensively studied.) London Clay was my favourite. 

Chalk  (Late Cretaceous.) 

Gault, Lower Greensand, Upper Greensand (Early Crataceous)

Purbeck Beds (Top of the Upper Jurassic.) 

Portland Stone. (Middle bit of the Late Jurassic.)

Coral Rag (Coralline, Late Jurassic ) 

Inferior Oolite underneath the Great Oolite (M. Jurassic)  

Lias - Lower Jurassic. 

Magnesian Limestone - Permian. 

Coal Measures - Upper Carboniferous. 

Millstone Grit. - all the bits between the Mountain Limestone and the Coal Measures.  

Mountain Limestone - the Early Carboniferous, most amusing as England doesn't really have any mountains to speak of and the ones in Wales and Scotland aren't very big.

I've already talked about the Devonian. (Devonian Formation) 

 

Some of these terms are still in use in one way or another, of course, but I still like to use a lot of them when thinking to myself. :D

Cambrian and Silurian, Ordovician often not used in the oldest papers. And these would be called the Cambrian Formation, Ordovician Formation, etc. 

   

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