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Radiocarbon simulation fails to support the temporal synchroneity requirement of the Younger Dryas impact hypothesis

Part of: 50th Anniversary issue

Published online by Cambridge University Press:  13 February 2020

Ian A. Jorgeson Open the ORCID record for Ian A. Jorgeson [Opens in a new window] ,
Ryan P. Breslawski Open the ORCID record for Ryan P. Breslawski [Opens in a new window]  and
Abigail E. Fisher Open the ORCID record for Abigail E. Fisher [Opens in a new window]
Ian A. Jorgeson
Affiliation:
Department of Anthropology, Southern Methodist University, P.O. Box 750235, Dallas, Texas75275, USA
Ryan P. Breslawski*
Affiliation:
Department of Anthropology, Southern Methodist University, P.O. Box 750235, Dallas, Texas75275, USA
Abigail E. Fisher
Affiliation:
Department of Anthropology, Southern Methodist University, P.O. Box 750235, Dallas, Texas75275, USA
*
*Corresponding author e-mail address: rbreslawski@smu.edu (R.P. Breslawski).
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Abstract

Fine-scale temporal processes, such as the synchronous deposition of organic materials, can be challenging to identify using 14C datasets. While some events, such as volcanic eruptions, leave clear evidence for synchronous deposition, synchroneity is more difficult to establish for other types of events. This has been a source of controversy regarding 14C dates associated with a hypothesized extraterrestrial impact at the Younger Dryas Boundary (YDB). To address this controversy, we first aggregate 14C measurements from Northern Hemisphere YDB sites. We also aggregate 14C measurements associated with a known synchronous event, the Laacher See volcanic eruption. We then use a Monte Carlo simulation to evaluate the magnitude of variability expected in a 14C dataset associated with a synchronous event. The simulation accounts for measurement error, calibration uncertainty, “old wood” effects, and laboratory measurement biases. The Laacher See 14C dataset is consistent with expectations of synchroneity generated by the simulation. However, the YDB 14C dataset is inconsistent with the simulated expectations for synchroneity. These results suggest that a central requirement of the Younger Dryas Impact Hypothesis, synchronous global deposition of a YDB layer, is extremely unlikely, calling into question the Younger Dryas Impact Hypothesis more generally.

Keywords

Radiocarbon datingMonte Carlo simulationYounger Dryas Impact HypothesisLaacher See Tephralate QuaternaryTerminal Pleistocene

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Type
Research Article
Information
Quaternary Research , Volume 96: 50th Anniversary Issue , July 2020 , pp. 123 - 139
Copyright
Copyright © University of Washington. Published by Cambridge University Press, 2020

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