The Journal of the Geological Society of Japan
Online ISSN : 1349-9963
Print ISSN : 0016-7630
ISSN-L : 0016-7630
Volume 61, Issue 715
Displaying 1-6 of 6 articles from this issue
  • Kei OSHITE
    1955 Volume 61 Issue 715 Pages 145-149
    Published: April 25, 1955
    Released on J-STAGE: April 11, 2008
    JOURNAL FREE ACCESS
    The reported matters in this paper are the results of qualitative and quantitative analysis of diatom-cells found in the bottom-deposits of Uranouchi-Wan in the southern part of Kochi prefecture, Shikoku., As shown in Table 3, the component of species and number of cells at each station vary with respect to the depth, character of bottom-deposits and distance from the mouth of bay.,
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  • Mitsuo NODA, Tomosuke SUJAKU
    1955 Volume 61 Issue 715 Pages 150-161
    Published: April 25, 1955
    Released on J-STAGE: April 11, 2008
    JOURNAL FREE ACCESS
    Generally the Ashiya group of the Karatsu coal-field and the equivalent Nishisonogi group of the Sakito-Matsushima coal-field are characterized by the intercalations of green glauconitic sandstone, while the Sasebo group overlying the Ashiya is characterized by the predominance of white micaceous quartzose sandstone (so-called "sugar sandstone"), and by lacking glauconite., In the north-eastern part of the Sasebo coal-field, the Sasebo group lies on the Ashiya with disconformity, or overlaps directly on the Mesozoic granite., In the vicinity of Imari, Arita and Haiki, however, the topmost part of the Ashiya, the Daito formation, about 250m., thick, consists mainly of the Ashiya-type shale with intercalations of the Sasebo-type sandstone, and the Sasebo group lies conformably over this transitional zone., The Ashiya group is subdivisible into five formations, namely the Kishima, Sari, Arita, Haiki and Daito in ascending order from a viewpoint of the cycle of sedimentation., The Nishisonogi group is also subdivisible into five formations, the Iefune, Nakaura, Okuura, Yuridake and Otao, and each formation is almost equivalent to each respective of the Ashiya group., These two groups have a general tendency, being usually rich in white tuff and tuffaceous rocks in the middle part., Furthermore, the cycle of sedimentation and rock-facies are common in the two groups on true whole., The correlation has been defined on those stratigraphic grounds., It should be noted that the Daito and Otao formations are those of the sedimentary basin, for the present distribution of strata is fairly continuous and in various localities they have much in common in rock-facies which indicates the Ashiya-Sasebo transitional zone as mentioned above.,
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  • Manzo CHIJI
    1955 Volume 61 Issue 715 Pages 162-172
    Published: April 25, 1955
    Released on J-STAGE: April 11, 2008
    JOURNAL FREE ACCESS
    The microbiostratigraphy and size distribution of the sedimentary rocks by mechanical analysis of the Yatsuo Group in the type area in Toyama Prefecture is presented., The middle Neogene Yatsuo Group consists of four formations, namely, Nirehara, Iwaine, Kurosedani and Joyama in ascending order., Some of these formations are subdivided into members., The stratigraphy of the said group has already been described elsewhere (TSUDA 1952, NAKASEKO 1952)., The fossil foraminifers were collected from three standard sections along the Jinzu, Kubusu and Yamada Rivers where are developed the Kurosedani and Joyama formations of the upper part of the Yatsuo Group., Five types of sedimentary rocks are classified by size distribution and the characteristic of each type is given in Figure 1., From the distribution of the foraminifers predominant species were recognized in each section by which the establishment of faunules was possible., By these faunules the upperpart of the Yatsuo Group was divided into four zonules, as follows: Martinottiella cf., communis-Uvigerina farinosa Zonule Buliminella cf., elegantissima-Nonion japonicum Zonule Operculina complanata japonica-Nonion japonicum Zonule Rotalia papillosa-Operculina complanata japonica-Nonion japonicum Zonule The relationship of the faunules to the above mentioned four zonules is shown in Table 3., Compared with the subdivision by IKEBE and NAKASEKO in western "Toyama Basin", the uppermost seems to belong to their Nodosaria insecta Zone and the lower three to their Miogypsina kotoi Zone.,
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  • Kiyoshi ASANO
    1955 Volume 61 Issue 715 Pages 173-179
    Published: April 25, 1955
    Released on J-STAGE: April 11, 2008
    JOURNAL FREE ACCESS
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  • Shoji IJIRI
    1955 Volume 61 Issue 715 Pages 180-182
    Published: April 25, 1955
    Released on J-STAGE: April 11, 2008
    JOURNAL FREE ACCESS
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  • Eitaro TAKAHASHI
    1955 Volume 61 Issue 715 Pages 182
    Published: April 25, 1955
    Released on J-STAGE: April 11, 2008
    JOURNAL FREE ACCESS
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