The suggested mechanism is that sedimentary rocks form over ice. That puzzles me in itself, because it implies a river with ice at the bottom. But anyway, then some heat source arrives and melts the ice, causing a sort of rug pull that means the rock layer drops down and breaks up. Kaboom.
replyAt first I thought perhaps it was a non-h20 liquid, since that would explain the frozen bits on the bottom.
replyBit apparently it’s more banal, and sediment doesn’t need a river or a liquid at all. It’s any kind of deposit. So wind can deposit sedimen, volcanic ash is sediment glaciers deposit it etc.
I think the most likely case for sedimentary deposition over ice would be something like volcanic eruption or an impact event redepositing material onto pre-existing ice.
replyWe almost certainly did at one point, but life and tides can fill-in the gaps. We also truly do not know what terrain is underneath Antarctica, Greenland, etc.
replyI didn't understand, how is that dissimilar to mountains? Large tilted blocks, hundreds of meters high, hills and depressions...
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