For those in the US you can watch this documentary with some interesting ideas

[www.smithsonianchannel.com]

I havent seen it so cannot comment on its production value, but Patrick McCafferty has some great ideas. I wouldnt put much stock in the segments with Dallas Abbott though as i dont find her work on the ice core chronology convincing.

Jonny

The path to good scholarship is paved with imagined patterns. - David M Raup