Temporal variation of ³He/⁴He ratio recorded in deep‐sea sediment cores

• M. Takayanagi

• M. Ozima

抄録

He isotopic composition was measured for 72 deep‐sea sediments from 16 sites in the Pacific and Atlantic oceans and the Japan Sea. 3 He content ranges from less than 10 −12 cm 3 STP/g to about 6 × 10 −11 cm 3 STP/g and 3 He/ 4 He from about 10 −8 to 1.67 × 10 −4 . The He isotopic data lie fairly well on a mixing curve in a 3 He/ 4 He‐ 3 He diagram, where the end‐members of the mixing curve are extraterrestrial He in interplanetary dust particles (IDP's) and terrestrial He in ocean sediments. This confirms the view that there are significant amounts of extraterrestrial He in ocean sediments from global fallout of IDP's into deep‐sea sediments. 3 He flux estimated for two long cores gives a value of about (1.5 ± 1.0) × 10 −15 cm 3 STP/cm 2 yr over a time span of 40 m.y., which corresponds to an annual fallout rate of IDP's (size < 10 μm) of about 400 t. In one of the cores, we observe a “ 3 He‐spike” which is associated with anomalously high Ir content (1.86 ± 0.56 ppb). This may be due to meteorite debris.

収録刊行物

• Journal of Geophysical Research: Solid Earth

  Journal of Geophysical Research: Solid Earth 92 (B12), 12531-12538, 1987-11-10

  American Geophysical Union (AGU)

キーワード

• Paleontology
• Space and Planetary Science
• Earth and Planetary Sciences (miscellaneous)
• Atmospheric Science
• Earth-Surface Processes
• Geochemistry and Petrology
• Soil Science
• Water Science and Technology
• Ecology
• Aquatic Science
• Forestry
• Oceanography
• Geophysics

詳細情報

• CRID: 1360011144727108864
• NII論文ID: 30034747795
• DOI: 10.1029/jb092ib12p12531
• ISSN: 01480227
• Web Site: https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1029%2FJB092iB12p12531
• Web Site: https://agupubs.onlinelibrary.wiley.com/doi/pdf/10.1029/JB092iB12p12531
• データソース種別:
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  • CiNii Articles