Harvard scientists are now involved in the Younger Dryas Boundary Event controversy. A PNAS paper has reopened the case in a dramatic fashion and George Howard adds a touch of sarcastic humour with a spoof – see http://cosmictusk.com/petaev_platinum_harvard_younger_dryas_impact_aster… and http://cosmictusk.com/paetev_harvard_platinumyounger_dryas_comet_clovis_…
The offending paper is at www.pnas.org/cgi/dio/10.1073/pnas.1303924110 … with supporting information at www.pnas.org/lookup/suppl/doi:10.1073/pnas1303924110/-/DCSupplemental (which doesn't appear to work)
Basically, ice cores at the Younger Dryas boundary were sampled and analysed in a laboratory (at Harvard) in order to find trace elements, both major and minor. This is where the platinum was found – right on the boundary. This new discovery sits alongside sulphate spikes, ammonium and nitrate spikes, at the same point in time, and these, it is suggested, add up to an extraterrestrial catastrophe, an airburst accompanied by landscape fires.