深海堆積物中のラジウムの挙動  [in Japanese] Behavior of radium in deep-sea sediments  [in Japanese]

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Author(s)

Abstract

Two deep-sea sediments taken from the wastern North Pacific Ocean were analyzed for <sup>232</sup>Th, <sup>230</sup>Th and <sup>226</sup>Ra. The observed vertical distributions of <sup>226</sup>Ra fit pretty well with those having diffusion coefficients of 1-3x10<sup>-9</sup> cm<sup>2</sup>/sec. The flux of <sup>226</sup>Ra out of the sediment are calculated to be 0.022 dpm/cm<sup>2</sup>/yr to 0.037 dpm/cm<sup>2</sup>/yr from the deficiency of <sup>226</sup>Ra relative to <sup>230</sup>Th in the sediments. This indicates that <sup>226</sup>Ra in sea water is mainly supplied from bottom sediments. The concentration of <sup>226</sup>Ra in the layer extremely enriched in Mn was also in large excess relative to its parent <sup>230</sup>Th. This fact may be due to its post depositional migration and adsorption on Mn oxide. The deposition rate of <sup>226</sup>Ra in the Mn rich layer is estimated to be 0.0065 dpm/cm<sup>2</sup>/yr and 0.010 dpm/cm<sup>2</sup>/yr from the excess of <sup>226</sup>Ra. The rates of migration of heavy metals (e.g. Ni and Co) in the sediments are also discussed by applying the above results on <sup>226</sup>Ra.

Journal

  • Chikyukagaku

    Chikyukagaku 15(2), 53-59, 1981

    The Geochemical Society of Japan

Cited by:  1

Codes

  • NII Article ID (NAID)
    110008679717
  • NII NACSIS-CAT ID (NCID)
    AN00141280
  • Text Lang
    JPN
  • Article Type
    Journal Article
  • ISSN
    0386-4073
  • NDL Article ID
    2427461
  • NDL Source Classification
    ME61(地質・地史)
  • NDL Source Classification
    ZM41(科学技術--地球科学)
  • NDL Call No.
    Z15-645
  • Data Source
    CJPref  NDL  NII-ELS  J-STAGE 
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