BULLETIN OF THE GEOLOGICAL SURVEY OF JAPAN
Online ISSN : 2186-490X
Print ISSN : 1346-4272
ISSN-L : 1346-4272
Volume 65 , Issue 3-4
Bulletin of the Geological Survey of Japan
Showing 1-4 articles out of 4 articles from the selected issue
Article
  • Atsuyuki Ohta, Ran Kubota, Takashi Okai
    2014 Volume 65 Issue 3-4 Pages 23-36
    Published: July 17, 2014
    Released: January 29, 2015
    JOURNALS FREE ACCESS
    We have applied the sequential extraction procedure developed by the Community Bureau of Reference (BCR) to eight Japanese geochemical reference materials. By using this method, we attempt to extract exchangeable and carbonate phases in step 1, extract iron hydroxide and manganese oxide in step 2, and extract metal sulfide and organic material in step 3. We use X-ray diffractometry (XRD) to measure untreated samples and the residue of samples after each step of the extraction process to determine whether the target material is satisfactorily decomposed during the procedure. For JSd-1 and JSd-3, XRD patterns do not change significantly by using the BCR procedure. Actually, most of the elements in these materials are scarcely extracted by BCR scheme. The peaks of calcite in JSd-4, JMs-1 and JMs 2 disappear in the XRD patterns after the first extraction procedure. The result suggests that the target phase of step 1 process is fully decomposed. JLk-1 and JMs-2 show high concentrations of the Fe and Mn extracted in step 2. However, it is difficult to clearly confirm the full decomposition of iron hydroxide and manganese oxide in step 2 because these materials do not show distinct peaks in the XRD patterns. Pyrite in JMs-1 disappears in step 3 of the extraction, which suggests that sulfide is satisfactorily decomposed in this process. X-ray reflection intensities of some peaks for quartz and plagioclase in JSO-1 increase significantly after step 3 of the extraction. It is assumed that organic material thickly covered the mineral surfaces and reduced the X-ray reflection from the minerals prior to the third procedure. Although this evidence is indirect, we conclude that organic material is successfully decomposed and removed from the mineral surface during the third extraction procedure. On the basis of these results, it is confirmed that the BCR protocol can properly extract target materials from the geochemical reference materials.
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Report
  • Akio Cho
    2014 Volume 65 Issue 3-4 Pages 37-43
    Published: July 17, 2014
    Released: January 29, 2015
    JOURNALS FREE ACCESS
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  • Susumu Tanabe, Takeshi Ishihara, Taku Komatsubara
    2014 Volume 65 Issue 3-4 Pages 45-55
    Published: July 17, 2014
    Released: January 29, 2015
    JOURNALS FREE ACCESS
    Recently, undulating topographies have been revealed at the base of the Alluvium under the coastal lowlands of Japan. These topographies are reconstructed on the basis of spatial interpolation of the basal depth of the Alluvium interpreted from numerous numbers of borehole logs. However, the undulating topographies have been ignored in previous studies because they have been considered as a result of defective description of borehole logs. The age of the Basal Gravel of the Alluvium and the sealevel curve, which are recently reported, suggest that the undulating topographies are natural features, and they have been formed as a result of overlap of incised valleys and buried terraces of the several Marine Isotope Stages.
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  • Koki Iwao, Toshiyuki Yoshikawa
    2014 Volume 65 Issue 3-4 Pages 57-65
    Published: July 17, 2014
    Released: January 29, 2015
    JOURNALS FREE ACCESS
    The objective of this report is to disclose the technical and organization system obstacles which Geological Survey of Japan (GSJ) should take into consider under the open data policy in Japan by reviewing the French Geological Survey (BRGM) activities under the French open data policy and/or European Union activities. BRGM is carrying out technical assistance of the employment of the international project OneGeology, which distribute the world geologic map of scale 1: 1 million via the Internet and BRGM is one of the most advanced organizations in distribution of geologic maps in digital form. We clarified about the technical issues which should be work on actively when GSJ will offer geologic data to society from now on. On the other hand, from the circumstances of organization establishment, BRGM has taken the position of as both public and private institutions, and we found that the GSJ is easier than BRGM in respect of maintenance of the organization system containing a distribution rule or a copyright employment rule.
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