Younger Dryas impact hypothesis

E505986

impact event hypothesis paleoclimatology hypothesis scientific hypothesis

The Younger Dryas impact hypothesis proposes that a comet or asteroid impact around 12,800 years ago triggered abrupt climate cooling, widespread wildfires, and megafaunal extinctions at the onset of the Younger Dryas period.

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Statements (56)

Predicate	Object
instanceOf	impact event hypothesis ⓘ paleoclimatology hypothesis ⓘ scientific hypothesis ⓘ
alternativeTo	changes in Atlantic Meridional Overturning Circulation as primary cause of Younger Dryas ⓘ meltwater pulse hypothesis for Younger Dryas cooling ⓘ
associatedEvent	Younger Dryas NERFINISHED ⓘ Younger Dryas stadial NERFINISHED ⓘ
boundaryAge	approximately 12,800 years before present ⓘ around 10,800 BCE ⓘ
boundaryLayer	Younger Dryas boundary ⓘ
claimsCauseOf	abrupt climate change at the Pleistocene–Holocene transition ⓘ decline of Clovis culture ⓘ late Pleistocene megafaunal extinctions in North America ⓘ onset of Younger Dryas cooling ⓘ
criticizedBy	many Quaternary geologists ⓘ many archaeologists ⓘ many paleoclimatologists ⓘ
criticizedFor	inconsistencies with regional paleoclimate records ⓘ insufficient evidence linking impact proxies to a single global event ⓘ lack of an identified impact crater of appropriate age and size ⓘ reproducibility problems with some reported impact proxies ⓘ
evidenceCited	carbon-rich layers interpreted as biomass burning ⓘ magnetic grains enriched in iridium and other platinum-group elements ⓘ nanodiamonds at the Younger Dryas boundary ⓘ peaks in microspherules at the Younger Dryas boundary ⓘ platinum anomalies in some sediment cores ⓘ
field	Quaternary science NERFINISHED ⓘ archaeology ⓘ geology ⓘ paleoclimatology ⓘ paleontology ⓘ planetary science ⓘ
geographicFocus	North America NERFINISHED ⓘ Northern Hemisphere NERFINISHED ⓘ
hasOppositionFrom	mainstream Quaternary science community ⓘ
hasSupportFrom	a small group of impact researchers ⓘ
proposedBy	Allen West NERFINISHED ⓘ James P. Kennett NERFINISHED ⓘ Richard B. Firestone NERFINISHED ⓘ
proposedMechanism	airburst or surface impact of a fragmented comet ⓘ deposition of impact-related materials over large areas ⓘ ignition of continent-scale wildfires ⓘ injection of dust and aerosols into the atmosphere ⓘ
proposes	a comet or asteroid exploded over or impacted Earth about 12,800 years ago ⓘ a cosmic impact at the onset of the Younger Dryas period ⓘ the impact caused widespread wildfires ⓘ the impact contributed to cultural disruptions among early human populations in North America ⓘ the impact contributed to megafaunal extinctions in the late Pleistocene ⓘ the impact triggered abrupt climate cooling ⓘ
publicationVenue	Proceedings of the National Academy of Sciences NERFINISHED ⓘ
relatedTo	Clovis-first model debate NERFINISHED ⓘ Pleistocene megafaunal extinction debate ⓘ research on cosmic impacts and airbursts ⓘ
status	controversial ⓘ minority view in the scientific community ⓘ
timeProposed	2007 ⓘ

Referenced by (2)

Full triples — surface form annotated when it differs from this entity's canonical label.

America Before: The Key to Earth's Lost Civilization → includesTopic → Younger Dryas impact hypothesis ⓘ

Magicians of the Gods → subject → Younger Dryas impact hypothesis ⓘ