Big ammonite heaven on the Volga river

[RuMert]

Hi all!

This time I'll show you a very special site, located on the Volga river near the city of Rybinsk, 250 km north of Moscow.

The site is famous for its huge Volgian ammonites, the biggest in our Jurassic (big Cretaceous ones are no surprise). The largest ammonites here reach 70 cm, they are inflated and surprisingly common. If you find an ammonite in concretion, it will most likely be big and whole (but often broken inside).

The main outcrops are situated by the village of Glebovo, they occupy about 6 km of the shore.

Glebovo:

 

 

 

 

 

Edited October 4, 2021 by RuMert

[tombk]

6 km of shoreline with giant ammonites! That is truly a special place. 

[RuMert]

The shore in autumn. Low water level

 

 

 

 

 

 

 

Edited October 3, 2021 by RuMert

[Paleorunner]

Will we have photos of ammonites?   

[RuMert]

The shore is made up of "Jurassic sand" (never thought I'd say that as we're used to "Jurassic clay"). Small stones are washed out of 2 conglomerate layers but more peculiar is the presence of big glacial erratics which sank down to the Cretaceous boundary and formed a sort of "erratics layer", clearly visible in some locations. Those boulders are scattered all over the shore. The biggest is above human height and is a local landmark.

 

 

 

Edited October 4, 2021 by RuMert

[Paleorunner]

Good views, and bun reporting ... As always. 
Thanks for sharing.

[RuMert]

The water level is regulated by the "Volga-Kama cascade" of hydroelectric power stations authorities in such a way that the highest river level is observed in summer, during which the water penetrates deep into the cliff sands and greatly accelerates their erosion. The cliffs are always weathered and do not get covered by vegetation (which is good for fossil hunting).

On a typical cliff we see a reddish Quaternary layer, followed by pale Valanginian deposits and a thick Volgian layer, marked by 2 conglomerate belts - one at the bottom of the Valanginian and one at the bottom of the mid-Volgian nikitini zone. Here is the unique place where nikitini layer (also present in Moscow, Syzran, etc) dominates, reaching 10+m in thickness.

The big ammonites are situated between the belts in big solitary concretions. On the latest pic you see holes where the ammonite concretions were - they are situated at 3-5m above ground

 

 

 

 

Edited October 4, 2021 by RuMert

[RuMert]

The preservation is not that good with calcite dissolved and ammonite phragmocones hollow. There are lots of concretions with itty-bitty fauna and lots of wood. All fossils are located in either small fauna concretions or big ammonit ones, with some concretions being empty.

 

 

 

Thought it was a tooth lol

 

 

Edited October 4, 2021 by RuMert

[RuMert]

And now to the ammonites. You'll need to locate concretions in the sand layer by tapping on suspicious "growths" and try to uncover what they contain. Note that the concretions are pretty high up the cliffs so getting to them is not that easy and somewhat dangerous.

If you see that the concretion contains a big ammonite, you extract it from the layer which usually takes 30-40 minutes. Then the ammonite gets extracted from the concretion itself. The good thing is that the matrix is comfortable: hard enough to hold ammonites in place but soft enough to get removed with minimal effort

 

 

 

 

 

 

Unfortunately many finds are already broken or break up on extraction.

 

 

Edited October 4, 2021 by RuMert

[RuMert]

Some of the finds. Unfortunately there are almost nothing besides those ammonites: reptile remains and such are very scarce. It's a pity as the nikitini layer is famous for vertebrate remains, but not in this site

 

30 cm ammonite

 

Smaller, but better preserved (different genus)

 

40 cm ammonite. There are signs of an outer whorl which did not fit in the concretion (which contained another big ammonite). So it was initially that 70 cm specimen

 

The weight of the latter (not that much)

Edited October 4, 2021 by RuMert

[Castle Rock]

BEAUTIFUL scenery and WONDERFUL finds!  THANK YOU for the report!   Dave 

[Ludwigia]

Nice finds. Saved the best one for last, eh?

[RuMert]

Thanks for reading!

[RuMert]

2 minutes ago, Ludwigia said:

Nice finds. Saved the best one for last, eh?

As usual

[Tidgy's Dad]

1 hour ago, RuMert said:

As usual

I've said it before and I'll say it again; your threads are a wealth of information and fantastic finds. 

Have you considered playing Secret Santa this year, old chap? 

[RuMert]

Thank you! Maybe Started already?

[Tidgy's Dad]

1 hour ago, RuMert said:

Thank you! Maybe Started already?

Signing up started yesterday. 

Here's a link to the thread : 

 2021 Secret Santa Spectacular! - Page 2 - Member Fossil Trades Bulletin Board - The Fossil Forum

 

Hope to see you there! 

[connorp]

Lovely finds and great report. Thanks for sharing.

[minnbuckeye]

Even I could find ammonites with signs like this and a white stripe leading the way. We need to start doing this in the USA too!!!!  Thanks again for a stunning report.

 

  

 

[pachy-pleuro-whatnot-odon]

Great trip report again, Yury! Quite spectacular to be able to find ammonites like that! One of those odd locations I've seen in the Baltics as well, where sediments haven't quite received enough pressure to solidify into rock...!

 

Any idea why only ammonites - moreover, only big specimens - are preserved at the location, and there are no marine reptile finds? Is that just soil acidity, you think, or could there be other factors at play? It's interesting that you observe that calcite is affected, as this should not automatically apply to bone as well, as I understand it... Very peculiar, with apparently similar symptoms as the British Chalk:

 

 

[RuMert]

3 hours ago, pachy-pleuro-whatnot-odon said:

Any idea why only ammonites - moreover, only big specimens - are preserved at the location

I'm not sure, maybe vertebrae form the same concretions, but these are exceptional. On the other hand big ammonites did live in this period unlike for example, Kimmeridgian and Upper Volgian

[Everhardus]

Wow, spectacular !!

 

[Fossildude19]

Amazing report, and finds!

Thanks for posting it.