Site provides evidence for ancient comet explosion JOEY HOLLEMAN; McClatchy Newspapers Published: October 7th, 2007 01:00 AM COLUMBIA, S.C. – For the second time in less than a decade, a South Carolina river bluff holds evidence pointing to a theory with history-rewriting potential. Microscopic soil particles from the Topper site near Allendale might hold a tiny key to a big theory: that comet-caused explosions wiped out the mammoths and mastodons, prompted the last ice age and decimated the first human culture in North America about 12,900 years ago. The comet theory first began generating a buzz at an international meeting...