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Posted on 06/03/2006 3:23:27 PM PDT by NormsRevenge
They don't but oceanic magnetic stripes do (a recording by the solidifying rock at midocean ridges that records the magnetic field at time of extruding magma solifiying--since the magnetic field flips occasionally, they can be used to tell time). If this crater hit 250 million years ago along the plate boundary, there should be remnants 250 million years along the direction that the plates have moved, in both directions. This means that if you take a measurement of oceanic magnetic stripes you should be 250 million years to the plate boundary from the location of the current crater near Antarctica and another 250 million years to the plate boundary from other debris near Australia.
I agree. It was probably a "doublet" impact, that is, multiple, nearly simultaneous impacts from a large body torn apart by an earlier encounter, or by reaching its Roche point during terminal descent, or even more likely, by never having been a single body in the first place, a la TVF. :')
An Asteroid, Cobbled Together
ScienceNOW Daily News | 2 June 2006 | Phil Berardelli
Posted on 06/03/2006 3:34:15 AM EDT by neverdem
http://www.freerepublic.com/focus/f-news/1642717/posts
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