Question for the floor

[andrewducker]

So, how long in the past would a previous civilisation of, say, Mesopotamian levels have had to be for their to be no remaining sign of it? i.e. for any bronze tools to corrode away to nothing, pottery to do likewise.

How long will it take until Stonehenge is worn down to nothing by the wind and rain?

Comments

[sigmonster.livejournal.com]

Pottery would take fossilisation much better than, say, a dinosaur egg, so the answer has to be in the hundreds of millions of years. Most of the objects wouldn't fossilise, of course, but I do wonder about some of the North Sea sites (unless we fuck them all up with repeated dredging).

[andrewducker]

How long would pottery last without fossilisation?

[sigmonster.livejournal.com]

Well, we have physical remains from every civilisation we know of, and right back beyond civilisation to stone age tools preserved alongside human fossils. So there's a continuous spectrum with no well-defined upper limit. Stuff gets covered over by rubbish and soil in a very predictable way - ground levels change all the time - so even if I left a pot in the middle of a grassy field, compelely exposed, it'd get incorporated into the soil and could last indefinitely.

Having said which, if I left it near a cat, about 3 minutes.

[alitheapipkin.livejournal.com]

Assuming the civilisation had the technical know-how to fire the pottery at high (1000 degrees C+) temperatures, and access to the right sort of clay, pottery would basically last as long as stone. They would need charcoal for this and a properly built kiln though. Most, if not all early pottery is earthernware fired at a lower temperature though so I don't think that is at all likely for an interglacial society.

As for how long eartherware ceramics would last, I guess a soft sandstone would be comparable in terms of erosion-resistance. If it was buried, strong temperature variations would be the main culprit for breaking it down (cracking from expanding and contracting, especially in damp conditions when water could seep into cracks) so it would depend where in the world the remains were.

/pottery and soil science geekery