• Search Research Projects
  • Search Researchers
  • How to Use
  1. Back to previous page

Chronological application of Re-Os system to sulfide ores

Research Project

Project/Area Number 62430009
Research Category

Grant-in-Aid for General Scientific Research (A)

Allocation TypeSingle-year Grants
Research Field 分析・地球化学
Research InstitutionUniversity of Tokyo

Principal Investigator

MASUDA Akimasa  Univ. Tokyo, Fac. Sci., Professor, 理学部, 教授 (40030788)

Co-Investigator(Kenkyū-buntansha) NAKAI Shun-ichi  Univ. Tokyo, Fac. Sci., Res. Associate, 理学部, 助手 (50188869)
SHIMIZU Hiroshi  Univ. Tokyo, Fac. Sci., Associate Prof., 理学部, 助教授 (60090544)
Project Period (FY) 1987 – 1989
Project Status Completed (Fiscal Year 1989)
Budget Amount *help
¥25,100,000 (Direct Cost: ¥25,100,000)
Fiscal Year 1989: ¥1,500,000 (Direct Cost: ¥1,500,000)
Fiscal Year 1988: ¥3,600,000 (Direct Cost: ¥3,600,000)
Fiscal Year 1987: ¥20,000,000 (Direct Cost: ¥20,000,000)
KeywordsRe-Os geochronometer / sulfide ore minerals / ICP mass spectrometer / isotopic equilibrium / mass discrimination / gas-mist merging introduction / molybdenite / ReーOs法 / 年代測定 / ^<187>Reの壊変定数 / 安定同位体 / ICP質量分析 / SmーNd法 / 安低同位体
Research Abstract

For the studies of sulfide ore deposits, chronological studies of them are of much significance. However, such studies of formation ages of sulfides have been retarded, since there remain some problems concerning Re-Os dating which has been expected to be a promising geochronometer. In the present work, we tried to examine the problems underlying the practical and wide application of Re-Os clock to the sulfide ore minerals, from basic points of view involving the technical improvement, where the mass spectrometer with inductively coupled plasma (ICP) ion source was employed. Our results are summarized below:
(1) A new method has been developed to make a correction about the effect of mass discrimination which takes place in ICP mass spectrometer. By combination of this correction method with isotope dilution employing highly enriched Os-192, we succeeded in simultaneous determination of (Os-187)/(Os-186) ratio and Os abundance. In this connection, an apparatus was devise to treat Os as … More tetroxide which has very high volatility.
(2) Also we succeeded in enhancing the sensitivities of Os and Re. In this method, the vapor of OsO_4"or Re_2O_7 generated from a specially designed small furnace merges into the "pure" mist produced by a conventional nebulizer. Thus, Os or Re is introduced into the plasma torch without substantial loss or discard. In use of the customary introduction employing the simple nebulization of aqueous solution of element(s), 50-100 ng Os was required, whereas -10 ng Os is sufficient amount according to our system.
(3) We recognized that the Re content in molybdenite is different from portion to portion. This problem is solved by careful pulverization. Besides, it was found out that it is difficult for us to attain the isotopic equilibrium between the radiogenic Os and the Os spike added. This isotopic problem can be solved by distillation for 5 hours, in which the distillate is collected separately for each hour and isotopic measurement of Os distilled is made for each fraction. As a result, we could obtain the correct age. Less

Report

(4 results)
  • 1989 Annual Research Report   Final Research Report Summary
  • 1988 Annual Research Report
  • 1987 Annual Research Report
  • Research Products

    (14 results)

All Other

All Publications (14 results)

  • [Publications] Takafumi Hirata: "Simultaneous determination of isotopic ratio and abundances and abundances of osmium by ICP-MS: fundamental studies for the application to rhenium-osmium systematics" ICP Inf.Newslett.13. 731-735 (1988)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      1989 Final Research Report Summary
  • [Publications] Takafumi Hirata: "Determination of osmium and osmium isotope ratios by microelectrothermal vaporization by inductively coupled plasma mass spectrometry" Analytical Chemistry. 61. 2263-2266 (1989)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      1989 Final Research Report Summary
  • [Publications] Takafumi Hirata: "Direct introduction of powder samples into inductively coupled plasma mass spectrometry with spark dispersion/merging introduction technique" Analyst(submitted).

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      1989 Final Research Report Summary
  • [Publications] Takafumi Hirata: "Determination of rhenium with enhanced sensitivity by inductively coupled plasma mass spectrometry" Journal of Analytical Atomic Spectrometry(submitted).

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      1989 Final Research Report Summary
  • [Publications] Takafumi Hirata: "Simultaneous determination of isotopic ratio and abundances and abundances of osmium by ICP-MS: fundamental studies for the application to rhenium-osmium systematics" ICP Inf. Newslett.13. 731-735 (1988)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      1989 Final Research Report Summary
  • [Publications] Takafumi Hirata: "Determination of osmium and osmium isotope ratios by microelectrothermal vaporization by inductively coupled plasma mass spectrometry" Anal. Chemistry, 61 2263-2266, 1989.

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      1989 Final Research Report Summary
  • [Publications] Takafumi Hirata: "Direct introduction of powder samples into inductively coupled plasma mass spectrometry with spark dispersion/merging introduction technique" Analyst.

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      1989 Final Research Report Summary
  • [Publications] Takafumi Hirata: "Determination of rhenium with enhanced sensitivity by inductively coupled plasma mass spectrometry" J. Anal. Atomic Spectrometry.

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      1989 Final Research Report Summary
  • [Publications] Takafumi Hirata: "Determination of osmium and osmium isotope ratios by microelectrothermal vaporization by inductively coupled plasma mass spectrometry" Analytical Chemistry. 61. 2263-2266 (1989)

    • Related Report
      1989 Annual Research Report
  • [Publications] Takafumi Hirata: "Direct introduction of power samples into inductively coupled plasma mass spectrometry with spark dispersion/merging introduction technique" Analyst.

    • Related Report
      1989 Annual Research Report
  • [Publications] Takafumi Hirata: "Determination of rhenium with enhanced sensitivity by inductively coupled plasma mass spectrometry" Journal of Analytical Atomic Spectrometry.

    • Related Report
      1989 Annual Research Report
  • [Publications] T.Hirata;H.Shimizu;T.Akagi;A.Masuda: ICP Information Newsletter. 13. 722-726 (1988)

    • Related Report
      1988 Annual Research Report
  • [Publications] T.Hirata;T.Akagi;H.Shimizu;A.Masuda: Anal.Chem.

    • Related Report
      1988 Annual Research Report
  • [Publications] T. Hirata; H. Shimizu; T. Akagi; A. Masuda: ICP Infomation Newsletter. (1988)

    • Related Report
      1987 Annual Research Report

URL: 

Published: 1987-04-01   Modified: 2016-04-21  

Information User Guide FAQ News Terms of Use Attribution of KAKENHI

Powered by NII kakenhi