SGER: Investigations of a Likely Extraterrestrial Impact at 12.9 ka: Possible Cause of Younger Dryas Cooling, North American Mammal Mass Extinction and Demise of Clovis People

University Of California-Santa Barbara, Santa Barbara CA

Investigators

Abstract

This award, under the auspices of the Small Grants for Exploratory Research (SGER) program, funds research to test a new hypothesis that Younger Dryas climatic cooling was triggered by a comet impact on or near the Laurentide Ice Sheet. This impact may have caused destabilization, melting, and massive flooding to the northern Atlantic and Arctic oceans that in turn affected ocean circulation and climate. The research is founded on growing physical evidence for an impact at 12,900 years ago based on analyses from a discrete carbon-rich black colored sedimentary layer that is widely distributed over North America. This sedimentary layer contains iridium, cosmic spherules, carbon spherules, and fullerenes enriched in extraterrestrial noble gas concentrations. Iridium, fullerenes, cosmic spherules and glass-like carbon formed under high temperatures are being reported from the sediment rims of depressed geomorphic features called Carolina Bays. This evidence may help evaluate whether the Bays originated in an impact. The researchers will explore, chemically analyze, and date the black layer at several geographic locations. In addition to field exploration, the researchers will examine existing marine cores from the Hudson Bay region since the region is the primary location for the suspected impact event. The research could have broad impact on the wider science community and catalyze new thinking in issues surrounding climate, mass extinctions, landscape development, and human and cultural evolution in the Americas by offering a new perspective on old and knotty scientific problems.