Antarctic Blast Made Australia, Room For Dinosaurs

Agent Provocateur writes "Posted on the Science Daily site is a story from Ohio State University about a massive Antarctic blast that may have contributed to the Permian-Triassic extinction." From the article: "Its size and location -- in the Wilkes Land region of East Antarctica, south of Australia -- also suggest that it could have begun the breakup of the Gondwana supercontinent by creating the tectonic rift that pushed Australia northward. Scientists believe that the Permian-Triassic extinction paved the way for the dinosaurs to rise to prominence. The Wilkes Land crater is more than twice the size of the Chicxulub crater in the Yucatan peninsula, which marks the impact that may have ultimately killed the dinosaurs 65 million years ago. The Chicxulub meteor is thought to have been 6 miles wide, while the Wilkes Land meteor could have been up to 30 miles wide -- four or five times wider."

Comments

Re:not as clear-cut as the article makes it out

[ozmanjusri]

But the situation is much murkier with the Permian extinctions. Last I'd heard, we have yet to find clear evidence of an impact in the form of iridium, a dust layer or shocked quartz.

Xu and Yang, 1993 and Yang et al. 1995 have reported Iridium spikes and Stishovite microspherules in non-marine P/T sediments in Australia and Antarctica. There's no Permian oceanic crust left since all of it has been subducted, and the Iridium and Stishovite levels are an order of magnitude smaller than C/T sediments, but it is still evidence of some type of major impact.

Notes

[hunte]

6 miles = 9.66 kilometers

http://en.wikipedia.org/wiki/Chicxulub_Crater

Problems with drilling

[Reverse Gear]

Drilling through ice is a difficult process with lot's of problems.
One of the problems is that the ice is not lying still during the time that you are drilling, the ice creeps. That is once of the reasons why all the major drillings through ice are done on the top of the ice sheets where the movements are the least there.
The problem with Ice creep is pretty big, it is for example not possible for scientist to come back to the hole's they drilled before, like you do with holes in the earth, the holes shut pretty fast, depending on the speed of the ice crawl.
So I geuss it would be possible to drill the hole, but you would have to be pretty fast to get down there after you drilled the hole and get up some material of the underlying rock.
You would get very little material up and I think that present some problems also, how would you know if the rock sample you get up is alien to the enviroment from where it came when you don't have the rock in the vicinity of the sample to compare with and look for patterns etc. on.

Link to OSU research

[KwKSilver]

The article posted above seems to be based on this from Ohio State University, which is better illustrated, etc.

If you want to "experiment" with results of various impacts, Arizona State has an online calculator.