Below is a recent paper about the evaluation of extraterrestrial impacts in mass extinctions, which I found both thoughtful and an interesting read.
Racki, G., 2011, The Alvarez impact theory of mass extinction; limits to its applicability and the “great expectations syndrome” Acta Palaeontologica Polonica, vol. 57, no. 4, pp. 681–702. http://www.app.pan.pl/article/item/app20110058.html http://www.bioone.org/doi/abs/10.4202/app.2011.0058 PDF file at: http://www.app.pan.pl/archive/published/app57/app20110058.pdf Yours, Paul H. ______________________________________________ Visit the Archives at http://www.meteorite-list-archives.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list