[Robert A Cook PE]

Wonder what 250 million years of 5 mile deep ice moving around on top of the original sediments and gravel does to fossils in those rocks...

But actually, it'd probably be irrelevant: Inside the original crater, and around it, there are no fossils. Nothing but melted rock and shatter cones.

[kinghorse]

Put Macready on it. He'll get to the bottom of this crater.

[WoofDog123]

i am just trying to imagine the blast area (i.e. beyond the crater, 300 mi diameter there already) from such an impact. could be an area thousand+ miles diameter of tunguska-type devastation.

I wonder if that impact noise would have covered the world? been defeaning at the opposite end of the world? surely would have been felt all over the world.

maybe some math models on the possible meteor impact area/effect will be put together later.

[Mike Darancette]

Wonder what 250 million years of 5 mile deep ice moving around on top of the original sediments and gravel does to fossils in those rocks..

Antarctica did not have year around ice untill it separated from Austrailia about 100mya.

[Renfield]

Antarctica wasn't ice-covered for most of the last 250 million years. In fact, for much of that time it wasn't even in a polar region. Remember, the continents drift around on the surface of the earth like corks (albeit slowly).

Somewhere I have a link to a good web site that explains this nicely (probably on my work computer). If I can find it, I'll post it for you.