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Corals (10 + 11) from the Campanian St. Bartholomä formation, Styria, Austria (Gosau group, Eastern Alps)


FranzBernhard

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FranzBernhard

My hunting at point 25 east of Kalchberg at 05/16/2019 did not yield any good rudist. However, two coral colonies were found. Now I have a total of about 20 from this formation.

This one is very small, poorly preserved and has a very, very low contrast (already strongly enhanced). It has some similarities to that one, but only remotely:

http://www.thefossilforum.com/index.php?/topic/87677-coral-3-from-the-campanian-st-bartholomä-formation-styria-austria-gosau-group-eastern-alps/

Corallites seems to have a diameter of about 1.2 mm. I do not expect any definitive answer ;), just showing it off :). Thanks for your interest!

Franz Bernhard

AN_Koralle_AN4196_AN4197_kompr.thumb.jpg.a2dcf674dc6ba4af03c17763e50ba8f5.jpg

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FranzBernhard

The other one is probably an Actinastrea. It has a rather good contrast, but not much else to say about it, just showing it off :).

Franz Bernhard

AN_Koralle_AN4195_kompr.thumb.jpg.5e16e0fda72745dc14ccc36d6475fa0b.jpg

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very nice! Believe I've mentioned before that we have no coral like this in our Campanian. Just Micrabacia and a tiny encruster that I can think of.

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HansTheLoser

Both specimens look interesting to me, but much closer views are necessary to say anything more detailed.

 

4195

Coenosteum is absent, no isolated trabeculae, so this could be an early member of the Stylophoridae (= Astrocoeniidae, but not Actinastraeidae) family.

 

4196/97 (same block?)

Actinacis or Paractinacis. Difficult to tell from each other in this view. The genera belong to different families, and were always mixed up in the Gosau area.

 

corals " that we have"

 

I guess Plax refers to the United States of America. Micrabacia is from a deeper water facies, but there is shallow marine Campanian  in Texas (Travis County, Pilot Knob; Austin Fm) that has also colonial corals. There is not much published but I have seen specimens at the TMM in Austin.

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I'm certain that Plax was referring to the Cretaceous formations in his area, the eastern US coastal plain.  The United States is huge, and it would make no sense to refer to the whole country as "local".

I have collected a variety of colonial coral species from the Cretaceous (Turonian) Mural Formation in southern Arizona.  

 

Don

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FranzBernhard

@HansTheLoser, many thanks for your continued expert input! As usual, I was wrong... :).

Franz Bernhard

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On 6/23/2019 at 9:05 AM, FossilDAWG said:

I'm certain that Plax was referring to the Cretaceous formations in his area, the eastern US coastal plain.  The United States is huge, and it would make no sense to refer to the whole country as "local".

I have collected a variety of colonial coral species from the Cretaceous (Turonian) Mural Formation in southern Arizona.  

 

Don

Yes, sorry. I am thinking that folks look at the poster's info. I was too vague. Should have said "Our Campanian from New Jersey to North Carolina".

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53 minutes ago, Plax said:

Yes, sorry. I am thinking that folks look at the poster's info. I was too vague. Should have said "Our Campanian from New Jersey to North Carolina".

No criticism of your comment was intended.  I'm often simultaneously amused and annoyed when people refer to the "United States" or "Canada" (as examples) for the locality info for a specimen, as if the whole vast country only contains one geological formation.

 

Interestingly, your comment on coral diversity (or lack thereof) also holds for Georgia, Alabama, Mississippi, and Tennessee.  In all these areas Cretaceous formations are almost entirely clastics (clay, glauconite, and other sediments) as opposed to carbonates such as limestones (although a few thin limestone formations or members may occur).  Such clastics do not lend themselves to coral reef development, as corals prefer clear warm water with a low sedimentation rate.  The Mural Formation that I mentioned before is a thick series of limestone beds, and even there diverse coral faunas are restricted to certain horizons.

 

Don

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HansTheLoser

@FossilDAWG The Mural Fm does not reach the Turonian. Upwardly the series starts to become continental and/or lacustric in the Middle Albian. I think the upper part of the Bisbee Group has another name (?Cintura Fm). Corals in the Mural Fm have a Late Aptian (clastic Lower Mural) or Early Albian (transitional part just below the massive carbonate rocks, including these rocks) age.

 

"as we have"

It is always good to be as specific as possible. Even more when treating science stuff. 

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