Open Veils · Answer
Younger dryas impact hypothesis
The Younger Dryas Impact Hypothesis remains one of the most bitterly contested questions in Quaternary science. Randall Carlson, Graham Hancock, and the Comet Research Group argue the physical evidence — platinum spikes, nanodiamonds, shocked quartz, and a continental biomass burn layer — is so geographically consistent it cannot be dismissed. A 2026 rebuttal paper (ACI, Jan 2026) accuses Holliday et al.'s 'comprehensive refutation' of systematic misrepresentations of the primary literature, suggesting the mainstream critique is itself methodologically compromised.
Evidence
- Richard Firestone and colleagues published the foundational YDIH paper in PNAS (2007), identifying impact proxies — microspherules, iridium anomalies, a platinum spike, and nanodiamonds — at the Younger Dryas Boundary (YDB) across dozens of sites on multiple continents.
- Randall Carlson has argued extensively that the biomass burning signal at the YDB represents continent-scale incineration consistent with a low-angle cometary fragmentation event, correlating with the Younger Dryas onset within decades.
- Paul LaViolette has separately proposed a galactic superwave mechanism as a trigger, while Robert Schoch has pointed to solar plasma events.
- Critics, including a University of Arizona independent evaluation, reported inability to reproduce Firestone et al.'s magnetic microspherule results at seven key sites.
- The platinum spike in the GISP2 Greenland ice core, measured by Petaev and colleagues in 2013, is independently established and cited even by critics as anomalous.