The Younger Dryas Impact Event — 10,800 BCE

The Younger Dryas was a period of rapid climate cooling that began approximately 12,900 years ago and lasted approximately 1,200 years. The consensus explanation is complex and contested. The Institution’s assessment, filed in the Origins Library from the Institution’s earliest records, is considerably simpler.

Evidence for a cosmic impact event at the onset of the Younger Dryas includes: a continent-wide layer of nanodiamonds, spherules, and high-temperature melt glass across North America, Europe, and the Middle East at the relevant stratigraphic horizon; the simultaneous extinction of 35 genera of North American megafauna; a platinum anomaly at the same horizon; and the abrupt termination of the Clovis culture.

The Consensus Position

The consensus academic position continues to dispute the impact hypothesis, citing problems with the proposed mechanism and questioning the distribution of the impact markers. The Institution notes that the evidence for the markers is published in peer-reviewed literature and that the disputes concern interpretation rather than existence.

The Institution’s Assessment

The Institution’s assessment, updated in 2012 following the publication of additional marker studies, is that an impact event occurred. The assessment also notes that the timing of the event corresponds, within the margin of dating error, to the end of a period of human habitation described in documents in the restricted archive that are not from any culture currently recognised as existing at that time and place.