Re:Space Is Full of Planets, and Most of Them Don't Even Hav...
by joshuahedlund on Wednesday May 30, 2018 @10:09AM
(#17187740)
> continents won't have fossils if they are under frequent bombardment.
Right, but if giant bombardments completely boil away the oceans and atmosphere to rain liquid rocks back down on the surface, there very very likely won't be life, either. So the claim is not just that "fossils only go back to X" but that X is so close to the end of the giant bombardments that there's almost no time left (geologically speaking - maybe 10-20MY) for "life but no fossils yet".
Ocean floor is continuously destroyed as it's subducted, and continents won't have fossils if they are under frequent bombardment.