[andix]

St. Stephens cathedral in Vienna was built with sandstone that contains seashells. It's hundreds of kilometers away from the shore, but ~15 million years ago the area where it stands now was a seabed.

The stones are not from the exact location where it was built, but from close by. The quarry where the stones came from hundreds of years ago is still active, and you can find tons of fossils there. It's practically impossible to get a piece of rock from there without visible seashells.

[kakacik]

Almost any surface on earth was once under the water. You can find sea shells and various sea deposits high on some 8000m peaks or 1000kms inland.

Everybody who cares at least slightly knows this, and I am pretty sure author knows this too, he could have spared us the initial hyperbole. Analysis itself is good but not everything needs to read like dramatic novel.

[PaulDavisThe1st]

Not Vienna or Europe, but N. America: https://en.wikipedia.org/wiki/Western_Interior_Seaway

[andix]

It’s a very common occurrence. It’s fascination to find maritime fossils far away from the shore, but also very common.

[thrownthatway]

Was the land lower, the seas higher, or some combination, way back when?

[mkl]

Land lower - Alps and Carpathians hadn't formed yet: https://en.wikipedia.org/wiki/Paratethys and its predecessor https://en.wikipedia.org/wiki/Tethys_Ocean

[Crunchified]

I would wager that the land was lower than the sea back then.

[thrownthatway]

Ha! Indeed.

If all the ice melted it would raise the oceans by something like 230 feet, so modern Vienna would still be above water at 495 – 1778 ft elevation.

Although some estimates suggest Earth loses 20 - 30 cubic kilometres of water to space annually. Plus whatever water is bound up in mineralisation annually.

450 million cubic kilometres of water lost over a 15 million year period would lower ocean by something like … a bit?

The total volume of water on Earth is presently estimated to be around the 1.386 billion cubic kilometre mark.

The volume of a sphere increases to the cube of its radius … carry the 1 … nup, that’s to hard for me.

Beach front property in Vienna, at a guess?

https://www.usgs.gov/faqs/how-would-sea-level-change-if-all-...

https://www.ewash.org/how-much-water-disappears-from-earth-e...

https://science.nasa.gov/earth/earth-observatory/the-water-c...

[andix]

I'm not sure, I would guess both.