Formation conditions of hydrothermal uranium deposits associated with organic matter, with special reference to the unconformity-related and sandstone-type deposits.

DOI Open Access
  • KOJIMA Shoji
    Institute of Mineralogy, Petrology and Economic Geology, Faculty of Science, Tohoku University
  • YAMADA Yasuo
    PNC Exploration (Australia) Pty. Ltd.
  • KOGITA Shuzo
    Information and Mathematical Science Laboratory

Bibliographic Information

Other Title
  • 有機物の関与する熱水性ウラン鉱床の生成条件　とくに不整合関連型及び砂岩型鉱床について
  • with special reference to the unconformity-related and sandstone-type deposits
  • とくに不整合関連型及び砂岩型鉱床について

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Description

This study summarizes geologic and geochemical features of the “unconformity-related type” (Athabasca and Alligator Rivers districts), “Oklo-Mounana type” (Franceville district) and “sandstone-type” (Grants district) uranium deposits, in order to compare mechanisms of ore-formation and the role of organic matters in uranium mineralizations.<br> The unconformity-related type and Oklo-Mounana type uranium deposits occur mostly in Early Proterozoic sedimentary rocks, and are controlled frequently by basal unconformity of the overlying unmetamorphosed sediments and/or steeply dipping faults. Principal mineralization in these types of deposits is considered to have been caused by reactions of uraniferous oxidizing solution with hydrocarbon-bearing reducing fluid derived from carbonaceous materials (graphite and bitumen). The uranium deposits in the Grants district are located in felsic sandstone members within the Upper Jurassic Morrison Formation, and uranium enrichment can be regarded as a result of interactions of diagenetic uraniferous solution with amorphous organic matter (humic substance). These phenomena clearly indicate that all of the three types of deposits are "epigenetic", although these deposits passed through distinct thermal histories in the diagenetic-hydrothermal metallogenic processes. In the processes of uranium fixation, such carbonaceous and humic materials are inferred to have played an important role as actual reductants.

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Details 詳細情報について

  • CRID
    1390282681192004992
  • NII Article ID
    130003884766
  • DOI
    10.2465/ganko.88.49
  • ISSN
    18813275
    09149783
  • Text Lang
    ja
  • Data Source
    • JaLC
    • Crossref
    • CiNii Articles
    • OpenAIRE
  • Abstract License Flag
    Disallowed

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