RE: Paper on Comet/Asteroid Impact Causing the Younger Dryas Cooling.
May 24, 2013 at 3:46 pm
(This post was last modified: May 24, 2013 at 4:13 pm by Anomalocaris.)
(May 24, 2013 at 2:58 pm)Minimalist Wrote:Quote:So where is the crater?
Firestone's idea is that whatever it was hit the glacier and would have made a huge crater....which subsequently melted. The glaciers got as far south as the Ohio River. Plenty of room for it.
Unlike the bible and Eden, Even such a flippant dodge as an ice crater still dignifies itself with some falsifiable predictions:
1. An impactor 400-500 meters across would fracture and generate impact brecciation 2-3 miles into hardrock and thus would leave a pretty spectacular impression even under a mile of ice. So if the theory requires the crater didn't penetrate the ice sheet, than it predicts the impactor wasn't large enough to generate 50 million tons of spheriules from its own mass.
2. Where did the spheriules come from? The theory claimed the spheriules are similar to "known impact materials derived from surficial sediments melted at temperatures 2,200 °C". That would be hard to explain if there would still be ice between the impact and the surficial sediment, which would presumable keep surface material well under 2200 degrees centigrade, and more or less rooted in place instead of being strewn over 4 continents.
It's nice to try justify a theory using an ad hoc claim that invalidates the reason why the theory was postulated in the first place.
Where it not for the falsifiable predictions that accidentally slipped in, the ice crater hypothesis would be prideworthy chutzpah of almost, but not quite, new testamental proportions.
