Ron and list... > Double meteorite strike 'caused dinosaur extinction' > By Howard Falcon-Lang > BBC News > August 27, 2010 > > The dinosaurs were wiped out 65 million years ago by at least two > meteorite impacts, rather than a single strike, a new study suggests.
with all due respect to my British science-writing colleagues, this is a misleading and not very good write-up. Boltysh has been recognized as an impact since at least the 1970s, and its age has been pegged at 65.2 +/- 0.64 MY since 2002 (Chicxulub is 65.5 MY). the whole "double-whammy" debate played out almost a decade ago, because the craters' respective age uncertainties left the impact order unclear. in any case, Earth gets a new 20-km crater every million years or so, and while damage from Boltysh would have been significant regionally it wouldn't have had long-lasting global consequences, if at all. in fact, the real news is that ferns and flowering plants took hold in the sediments on the floor of Boltysh *quickly* - 2000 to 5000 years after the impact (based in part on comparable recoveries from volcanic events) - before being snuffed out during the K-Pg extinction. there's no hint in the actual research paper whatsoever that Boltysh somehow contributed to the K-Pg extinction. rather, the discussion focuses on where these two impactors might have originated. it wasn't a binary asteroid (not simultaneous) nor was it likely two random but closely spaced asteroid strikes (0.01% chance). I hesitate to suggest where you might go for more details, but you can probably guess. ;-) clear skies, Kelly **************** J. Kelly Beatty Senior Contributing Editor SKY & TELESCOPE 617-416-9991 SkyandTelescope.com ______________________________________________ Visit the Archives at http://www.meteoritecentral.com/mailing-list-archives.html Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
