A Significantly High He Isotopic Signature from the End-Paleozoic (250 Ma) Extinction-related Interval: For Detecting Ancient Extraterrestrial Fluxes through the Earth's History since the Hadean

• TAKAHATA Naoto

  Atmosphere and Ocean Research Institute, The University of Tokyo

• ONOUE Tetsuji

  Faculty of Advanced Science and Technology, Kumamoto University

• SANO Yuji

  Atmosphere and Ocean Research Institute, The University of Tokyo

• ISOZAKI Yukio

  Department of Earth Science and Astronomy, The University of Tokyo

Bibliographic Information

Other Title

• 古生代末（2.5億年前）大量絶滅層準の高いヘリウム同位体記録
• 古生代末(2.5億年前)大量絶滅層準の高いヘリウム同位体記録 : 冥王代以来の地球史を通した地球外物質流入同定方法の探索
• コセイダイマツ(2.5オクネンマエ)タイリョウ ゼツメツソウ ジュン ノ タカイ ヘリウム ドウイタイ キロク : メイオウダイ イライ ノ チキュウシ オ トオシタ チキュウ ガイブツシツ リュウニュウ ドウテイ ホウホウ ノ タンサク
• ─冥王代以来の地球史を通した地球外物質流入同定方法の探索─

Abstract

 It is important to know the influx of extraterrestrial material on old Earth in order to understand global environmental changes. Helium is suitable for detecting extraterrestrial material in marine sediments, as well as platinum group elements, because there is more helium in extraterrestrial matter than on the Earth's surface. Extraterrestrial material is detected in old sedimentary rocks collected from a Permian/Triassic (P/T) boundary section in the Mino Belt, central Japan, which accumulated in a deep seafloor environment in the ancient Pacific Ocean. Much higher ³He/⁴He ratios (up to 150 Ra; 1 Ra = the atmospheric ratio) are observed in the samples. These high ³He/⁴He ratios may infer the existence of extraterrestrial helium carried in fullerenes or interplanetary dust particles. Moreover, the distribution of ³He concentrations indicates a significant increase in the influx of extraterrestrial material before the P/T boundary, which is equivalent to the influx at the Cretaceous/Paleogene boundary, because of the long duration. This increase may have caused global cooling leading to mass extinction.

Journal

• Journal of Geography (Chigaku Zasshi)

  Journal of Geography (Chigaku Zasshi) 128 (4), 667-679, 2019-08-25

  Tokyo Geographical Society

Keywords

• P/T boundary
• mass extinction
• extraterrestrial material
• helium isotope
• Mino Belt

Details

• CRID: 1390001277350983680
• NII Article ID: 130007709689
• NII Book ID: AN00322536
• DOI: 10.5026/jgeography.128.667
• ISSN: 18840884
• ISSN: 0022135X
• NDL BIB ID: 029957150
• Web Site: https://ndlsearch.ndl.go.jp/books/R000000004-I029957150
• Web Site: https://www.jstage.jst.go.jp/article/jgeography/128/4/128_128.667/_pdf
• Text Lang: ja
• Data Source:
  • JaLC
  • NDL
  • Crossref
  • CiNii Articles
  • KAKEN
• Abstract License Flag: Disallowed