Quote:
On 2002-01-27 01:48, lpetrich wrote:
That article claims that the "Big Whack" that formed the Moon also stripped the Earth of much of its original crust, making the surviving crust relatively thin, which then allows plate tectonics to take place.
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Well, at some point, the crust probably was thin, even on Venus and the early Earth.
Perhaps there never was an moon-forming impact, and the Earth just evolved, like it does today. Why didn't Venus? Maybe it did, but continental growth chewed up the thin basins somehow--ah yes, there is your original question. Maybe water is a lubricant that allows the continents to subduct the crust. I think I've seen that theory before somewhere...I'll check.