NON-REPRODUCIBILITY OF YOUNGER DRYAS EXTRATERRESTRIAL IMPACT RESULTS

Based on elevated concentrations of a series of impact markers at the onset of the Younger Dryas stadial from sedimentary contexts across North America, Firestone, Kennett, West, and others have argued that 12,900 years ago, the Earth experienced an impact by an extraterrestrial body, an event that had devastating ecological consequences for humans, plants, and animals in the New World. In this paper, we report the results of an independent analysis of two of their markers, magnetic minerals and microspherules, from seven sites of similar age including two examined by Firestone et al. We were unable to reproduce any results of the original Firestone et al. study and find no support for Younger Dryas extraterrestrial impact.