Is This A Shocked Belmnite Or Just A Cracked And Healed One?

[Shamalama]

Hi Guys,

I picked up the Belemnite fossil below from the DMS show in Newark Delaware this weekend. It was only $6 and had a label that said "Cretaceous, Germany" on it. I couldn't help but think that it could be one of the Shocked Belemnites that come from the Reis Crater in Germany. However I see that those fossils are Jurassic in age, not Cretaceous. Well... it's kinda neat anyways for the size and naturally healed look.

Edited March 4, 2013 by Shamalama

[Auspex]

Maybe!

LINK

LINK DOS

[erose]

Way cool!

[FossilDAWG]

Well, I doubt any belemnite could have survived that much damage long enough to heal, so I'll vote "shocked". In fact I'd say it was plenty shocked when it went through that plesiosaur or whatever meat grinder did all that damage. Or maybe it was a post mortem meteor impact. How confident are you of the Cretaceous age? Anyway, cool specimen.

Don

[Mike from North Queensland]

Most of the belemnites I find are cracked in several places similar to what you have due to cell structure. I would think it very plausable for moderate tectonic groung movement to give the result you have where ground minerals would glue them back together similar to your specimen.

Mike

[Ludwigia]

I would tend to think that your belemnite is rather tectonically deformed as a shocked one from the Ries Crater, especially if it really originates from the Cretaceous. The majority of the shocked belemnites look like a jellyroll cut into slabs, which is quite different from yours. Remember this post? http://www.thefossilforum.com/index.php/topic/17249-shocked-belemnites-ries-crater-germany/

And here's another link with really typical finds: http://www.impact-structures.com/impact-germany/the-ries-impact-structure-germany/deformations/

[painshill]

I think it looks very much like the impact-shattered belemites found around the Ries crater in Germany – particularly in the 4^th pic. But such items don’t actually have to come from the Ries impact structure at Nordlingen. There is a second, smaller impact site about 25 miles away at Steinheim. In both cases, the shattered belemnites come from Upper & Middle Jurassic deposits. I have specimens from both locations which look like yours. I posted some from Nordlingen previously here:

http://www.thefossilforum.com/index.php?/topic/25818-meteorite-related-fossils

I wonder if that item was just mistakenly labelled as Cretaceous since belemnites in Europe are also common from strata of that age?

The Ries impact structure originally measured about 15 miles across, although it is now heavily eroded. The floor of the crater is anything up to 500 feet below the current remains of the rim and the town of Nordlingen sits neatly in the centre of the depression:

The nearby Steinheim impact structure is about 2.5 miles across. Both craters are believed to have been formed almost simultaneously about 14.3 – 14.5 million years ago by the impact of a binary asteroid. The two incoming asteroidal bodies have been estimated at 4,900 feet across (that’s getting on for a mile) and 490 feet across, respectively, travelling at over 12 miles a second when they impacted the Earth at an angle between 30-50 degrees. That’s the energy equivalent of 1.8 Hiroshima’s.

There’s nothing significant or recognisable left of the meteorites themselves, but at Nordlingen the larger body impacted partly onto a graphite deposit, creating over 70,000 tonnes of microscopic diamonds. The old local stone buildings in the town contain millions of them as sparkly deposits. Here’s a small cut slab of suevite (characterised by the presence of a highly shocked quartz polymorph known as coesite) from the edge of the crater. The vesicles (bubbles) are also a sure sign that this rock has been subjected to extreme heat and you can see small white speckles of diamond dotted here and there.

Some rocks on the ground were melted and flattened by the blast in situ, like this piece of limestone. The locals call these “fladel” (pancake) stones, for obvious reasons.

The shock wave from the impact reverberated through the limestone and sandstone bedrocks. As well as the shattered belemnites, limestone is particularly good at recording shockwaves and you can find pieces with what are known as “horsetail” patterns where the very fabric of the rock was violently imprinted. These structures as know as “shattercones” and they can sometimes be isolated as intact cone shapes from a few inches high up to several feet:

In addition to the well-known “moldavite” glass deposited mainly in the Czech republic, rocks in the vicinity were fragmented into various sized pieces, some partially melted, and the larger pieces rained down around the crater and reformed to create deposits of what we call “fallback breccia”. A breccia is simply a mixed rock. Here’s a small cut slab of brecciated suevite from outside the crater which shows this:

[Shamalama]

Painshill - Very good mini article about the crater and the rocks which give evidence to it's presence. I didn't know "Moldavite" came from that impact.

[Shamalama]

Most of the belemnites I find are cracked in several places similar to what you have due to cell structure. I would think it very plausable for moderate tectonic groung movement to give the result you have where ground minerals would glue them back together similar to your specimen.

Mike

I would tend to think that your belemnite is rather tectonically deformed as a shocked one from the Ries Crater, especially if it really originates from the Cretaceous. The majority of the shocked belemnites look like a jellyroll cut into slabs, which is quite different from yours. Remember this post? http://www.thefossilforum.com/index.php/topic/17249-shocked-belemnites-ries-crater-germany/

And here's another link with really typical finds: http://www.impact-structures.com/impact-germany/the-ries-impact-structure-germany/deformations/

And that is why I think it's more tectonically deformed than via an extraterrestrial body. The very tip of the piece is what makes it look "shocked" due to it's offset nature. I did look through that original post, Roger, and that is what made me suspicious. I also noted that most of the Belemnites shown are much smaller and thinner than my specimen. I wish I had a bit more provenance on the piece but it will make for a nice comparison specimen in the meantime.

[painshill]

In general, the Steinheim belemnites seem to be bigger and thicker than those from Nordlingen. Some of the Steinheim ones I have are also squashed to a flattened profile as well as being shattered.

[Nandomas]

Nice belemnite collection, Shamalana.

From the top of the Daniels tower, the center of the meteor crater in Nordlingen, Germany. The blue mountains at horizon are the crater borders .

I collected some of those shattered belemnites, and maybe ammonites. I remember they were very difficult to collect intact. I didn't photograph any of them at that time, I just remember that day was so cold and snowy. Let me see if I find something in my drawers or photo archive

Edited March 5, 2013 by Nandomas

[lordpiney]

Nice Belemnite Dave!! did you get that from Don?