A Blind Test of the Younger Dryas Impact Hypothesis

Vance T Holliday, Todd Surovell, Eileen Johnson

Research output: Contribution to journalArticle

3 Citations (Scopus)

Abstract

The Younger Dryas Impact Hypothesis (YDIH) states that North America was devastated by some sort of extraterrestrial event ~12,800 calendar years before present. Two fundamental questions persist in the debate over the YDIH: Can the results of analyses for purported impact indicators be reproduced? And are the indicators unique to the lower YD boundary (YDB), i.e., ~12.8k cal yrs BP? A test reported here presents the results of analyses that address these questions. Two different labs analyzed identical splits of samples collected at, above, and below the ~12.8ka zone at the Lubbock Lake archaeological site (LL) in northwest Texas. Both labs reported similar variation in levels of magnetic micrograins (>300 mg/kg >12.8ka and <11.5ka, but <150 mg/kg 12.8ka to 11.5ka). Analysis for magnetic microspheres in one split, reported elsewhere, produced very low to nonexistent levels throughout the section. In the other split, reported here, the levels of magnetic microspherules and nanodiamonds are low or nonexistent at, below, and above the YDB with the notable exception of a sample <11,500 cal years old. In that sample the claimed impact proxies were recovered at abundances two to four orders of magnitude above that from the other samples. Reproducibility of at least some analyses are problematic. In particular, no standard criteria exist for identification of magnetic spheres. Moreover, the purported impact proxies are not unique to the YDB.

Original languageEnglish (US)
Pages (from-to)e0155470
JournalPLoS One
Volume11
Issue number7
DOIs
StatePublished - 2016

Fingerprint

Nanodiamonds
Proxy
Microspheres
Lakes
North America
nanodiamonds
testing
sampling
reproducibility
lakes

ASJC Scopus subject areas

  • Medicine(all)
  • Biochemistry, Genetics and Molecular Biology(all)
  • Agricultural and Biological Sciences(all)

Cite this

A Blind Test of the Younger Dryas Impact Hypothesis. / Holliday, Vance T; Surovell, Todd; Johnson, Eileen.

In: PLoS One, Vol. 11, No. 7, 2016, p. e0155470.

Research output: Contribution to journalArticle

Holliday, Vance T ; Surovell, Todd ; Johnson, Eileen. / A Blind Test of the Younger Dryas Impact Hypothesis. In: PLoS One. 2016 ; Vol. 11, No. 7. pp. e0155470.
@article{cab60dfe7b1c419986e3fe565eaa25e4,
title = "A Blind Test of the Younger Dryas Impact Hypothesis",
abstract = "The Younger Dryas Impact Hypothesis (YDIH) states that North America was devastated by some sort of extraterrestrial event ~12,800 calendar years before present. Two fundamental questions persist in the debate over the YDIH: Can the results of analyses for purported impact indicators be reproduced? And are the indicators unique to the lower YD boundary (YDB), i.e., ~12.8k cal yrs BP? A test reported here presents the results of analyses that address these questions. Two different labs analyzed identical splits of samples collected at, above, and below the ~12.8ka zone at the Lubbock Lake archaeological site (LL) in northwest Texas. Both labs reported similar variation in levels of magnetic micrograins (>300 mg/kg >12.8ka and <11.5ka, but <150 mg/kg 12.8ka to 11.5ka). Analysis for magnetic microspheres in one split, reported elsewhere, produced very low to nonexistent levels throughout the section. In the other split, reported here, the levels of magnetic microspherules and nanodiamonds are low or nonexistent at, below, and above the YDB with the notable exception of a sample <11,500 cal years old. In that sample the claimed impact proxies were recovered at abundances two to four orders of magnitude above that from the other samples. Reproducibility of at least some analyses are problematic. In particular, no standard criteria exist for identification of magnetic spheres. Moreover, the purported impact proxies are not unique to the YDB.",
author = "Holliday, {Vance T} and Todd Surovell and Eileen Johnson",
year = "2016",
doi = "10.1371/journal.pone.0155470",
language = "English (US)",
volume = "11",
pages = "e0155470",
journal = "PLoS One",
issn = "1932-6203",
publisher = "Public Library of Science",
number = "7",

}

TY - JOUR

T1 - A Blind Test of the Younger Dryas Impact Hypothesis

AU - Holliday, Vance T

AU - Surovell, Todd

AU - Johnson, Eileen

PY - 2016

Y1 - 2016

N2 - The Younger Dryas Impact Hypothesis (YDIH) states that North America was devastated by some sort of extraterrestrial event ~12,800 calendar years before present. Two fundamental questions persist in the debate over the YDIH: Can the results of analyses for purported impact indicators be reproduced? And are the indicators unique to the lower YD boundary (YDB), i.e., ~12.8k cal yrs BP? A test reported here presents the results of analyses that address these questions. Two different labs analyzed identical splits of samples collected at, above, and below the ~12.8ka zone at the Lubbock Lake archaeological site (LL) in northwest Texas. Both labs reported similar variation in levels of magnetic micrograins (>300 mg/kg >12.8ka and <11.5ka, but <150 mg/kg 12.8ka to 11.5ka). Analysis for magnetic microspheres in one split, reported elsewhere, produced very low to nonexistent levels throughout the section. In the other split, reported here, the levels of magnetic microspherules and nanodiamonds are low or nonexistent at, below, and above the YDB with the notable exception of a sample <11,500 cal years old. In that sample the claimed impact proxies were recovered at abundances two to four orders of magnitude above that from the other samples. Reproducibility of at least some analyses are problematic. In particular, no standard criteria exist for identification of magnetic spheres. Moreover, the purported impact proxies are not unique to the YDB.

AB - The Younger Dryas Impact Hypothesis (YDIH) states that North America was devastated by some sort of extraterrestrial event ~12,800 calendar years before present. Two fundamental questions persist in the debate over the YDIH: Can the results of analyses for purported impact indicators be reproduced? And are the indicators unique to the lower YD boundary (YDB), i.e., ~12.8k cal yrs BP? A test reported here presents the results of analyses that address these questions. Two different labs analyzed identical splits of samples collected at, above, and below the ~12.8ka zone at the Lubbock Lake archaeological site (LL) in northwest Texas. Both labs reported similar variation in levels of magnetic micrograins (>300 mg/kg >12.8ka and <11.5ka, but <150 mg/kg 12.8ka to 11.5ka). Analysis for magnetic microspheres in one split, reported elsewhere, produced very low to nonexistent levels throughout the section. In the other split, reported here, the levels of magnetic microspherules and nanodiamonds are low or nonexistent at, below, and above the YDB with the notable exception of a sample <11,500 cal years old. In that sample the claimed impact proxies were recovered at abundances two to four orders of magnitude above that from the other samples. Reproducibility of at least some analyses are problematic. In particular, no standard criteria exist for identification of magnetic spheres. Moreover, the purported impact proxies are not unique to the YDB.

UR - http://www.scopus.com/inward/record.url?scp=85008429307&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=85008429307&partnerID=8YFLogxK

U2 - 10.1371/journal.pone.0155470

DO - 10.1371/journal.pone.0155470

M3 - Article

C2 - 27391147

AN - SCOPUS:85008429307

VL - 11

SP - e0155470

JO - PLoS One

JF - PLoS One

SN - 1932-6203

IS - 7

ER -