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The meteorites we find fell “recently”? The iron is in a stable oxide?
by nraynaud 6y ago
The meteorites we find fell “recently”? The iron is in a stable oxide?
- ChuckMcM 6y agoI don't think so, meteoric iron (according to the wonderful blog series[1]) is early Egyptian. Iron (and steel) is stable outside the presence of oxygen and water. It doesn't just dissolve. And certainly if it were part of the steel reinforcement inside concrete in a building where special measures had been taken to insure that neither oxygen nor water would come in contact with it (as modern skyscrapers do) would persist for an exceptionally long time. But I'm just guessing ;-) [1] https://acoup.blog/2020/09/18/collections-iron-how-did-they-make-it-part-i-mining/ https://acoup.blog/2020/09/18/collections-iron-how-did-they-...
- analyte123 6y agoWhat about when the skyscraper’s pieces are submerged under saltwater for a million years? Or are covered up by a mile of river sediment and then plunged another 5 miles under the earth for several million years?
- mcguire 6y agoOr the concrete develops cracks, allowing water into the steel reinforcement, which expands, further cracking the concrete until it collapses. Like modern bridges.
- yxhuvud 6y agoIf there are two things the glaciers you mentioned a few posts back would accomplish it would be creating cracks that would expose things to water and oxygen, and also expose the resulting heaps to loads and loads of water. This is how stones found in glacial deposits look like: https://sv.wikipedia.org/wiki/Rullstens%C3%A5s#/media/Fil:Rullstens%C3%A5s_i_genomsk%C3%A4rning.JPG https://sv.wikipedia.org/wiki/Rullstens%C3%A5s#/media/Fil:Ru... Note how rounded all the stones are. And the stones that are there are generally speaking a LOT more resilient than any variant of limestone will ever be (including concrete).