At http://cosmictusk.com/a-personal-essay-from-vance-holliday-on-the-clovis… is another nail in the coffin of the comet impace theory at the beginning of the Younger Dryas. It looks more and more like they rushed into press without fully weighing up alternative ideas. Claim and counter claim has become a problem and the theory has one glaring problem that it can't get around – the Younger Dryas event was a carbon copy of the Older and Oldest Dryas events and half a dozen Heinrich events that took place over the last 70,000 years (conventional dating). Vance Holliday highlights what he says are some basic errors in the Firestone et al book, The Cycle of Cosmic Catastrophe. The article is worth reading solely for that. However, the comments on Tusk are awful – not worth a light.
The YD impact hypothesis is a theme at a 27th July conference in Berne – Switzerland (see http://cosmictusk.com/upcoming-bern-inqua-conference-packed-with-younger… and sounds like a worthwhile experience for those able to attend.