Impact-related microspherules in Late Pleistocene Alaskan and Yukon “muck” deposits signify recurrent episodes of catastrophic emplacement

Scientific Reports
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Abstract

Large quantities of impact-related microspherules have been found in fine-grained sediments retained within seven out of nine, radiocarbon-dated, Late Pleistocene mammoth (Mammuthus primigenius) and bison (Bison priscus) skull fragments. The well-preserved fossils were recovered from frozen “muck” deposits (organic-rich silt) exposed within the Fairbanks and Klondike mining districts of Alaska, USA, and the Yukon Territory, Canada. In addition, elevated platinum abundances were found in sediment analysed from three out of four fossil skulls. In view of this new evidence, the mucks and their well-preserved but highly disrupted and damaged vertebrate and botanical remains are reinterpreted in part as blast deposits that resulted from several episodes of airbursts and ground/ice impacts within the northern hemisphere during Late Pleistocene time (~46–11 ka B.P.). Such a scenario might be explained by encounters with cometary debris in Earth-crossing orbits (Taurid Complex) that was generated by fragmentation of a large short-period comet within the inner Solar System.

Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Impact-related microspherules in Late Pleistocene Alaskan and Yukon “muck” deposits signify recurrent episodes of catastrophic emplacement
Series title Scientific Reports
DOI 10.1038/s41598-017-16958-2
Volume 7
Year Published 2017
Language English
Publisher Springer Nature
Contributing office(s) Geology, Minerals, Energy, and Geophysics Science Center
Description Article 16620; 15 p.
Country Canada, United States
State Alaska, Yukon Territoriy