Origin of Spherule Samples Recovered from Antarctic Ice Sheet—Terrestrial or Extraterrestrial?

Thirty-eight spherules from the Antarctic ice sheet were analyzed using neutron activation analysis under two different conditions to investigate their origin. In almost all of these spherules, the contents of iron, cobalt, and manganese were determined to be 31% to 88%, 17 mg/kg to 810 mg/kg, and 0...

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Bibliographic Details
Published in:Nuclear Engineering and Technology
Main Authors: Shun Sekimoto, Takayuki Kobayashi, Koichi Takamiya, Mitsuru Ebihara, Seiichi Shibata
Format: Article in Journal/Newspaper
Language:English
Published: Elsevier 2016
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Online Access:https://doi.org/10.1016/j.net.2016.02.004
https://doaj.org/article/f4291d41fb9140889b0f1b11236f50a6
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Summary:Thirty-eight spherules from the Antarctic ice sheet were analyzed using neutron activation analysis under two different conditions to investigate their origin. In almost all of these spherules, the contents of iron, cobalt, and manganese were determined to be 31% to 88%, 17 mg/kg to 810 mg/kg, and 0.017% to 7%, respectively. A detectable iridium content of 0.84 mg/kg was found in only one spherule, which was judged to be extraterrestrial in origin. A comparison of elemental compositions of the Antarctic spherules analyzed in this study with those of deep-sea sediment spherules and those of terrestrial materials revealed that most of the Antarctic spherules except for the sample in which iridium was detected could not be identified as extraterrestrial in origin.