The Journal of the Geological Society of Japan
Online ISSN : 1349-9963
Print ISSN : 0016-7630
ISSN-L : 0016-7630
Volume 55 , Issue 647
Showing 1-4 articles out of 4 articles from the selected issue
  • Setsuji Ota
    1949 Volume 55 Issue 647 Pages 85-89
    Published: November 20, 1949
    Released: April 11, 2008
    JOURNALS FREE ACCESS
    1., "Oya-ishi" is an important building stone from Oya, Shiroyama-mura, Kawachi-gun, Tochigi Prefecture, Japan., 2., The writer has made studies on its geological and mineralogical properties and their effect on use as building stone., In this preliminary report, the writer describes the geological occurence and properties of "Oya-ishi"., 3., "Oya-ishi" is a Tertiary green tuff containing volcanic rock fragments which are commonly altered to clay minerals and are called "miso"., The thickness is about 3O0m., 4., The writer has classified "Oya-ishi", from the view point of building stone, into three parts: Upper, middle and lower., The upper part is classified into two zones: Upper and lower., The middle part is classified into three zones: Upper, middle and lower., 5., The lower part is easily decomposed by weathering, so it has no value as building stone., Toe middle and upper zones in the middle part are used mainly for building stone., The lower zone in the upper part has the properties required for best-quality building stone., The upper one in the upper part has no value for building stone, because of theinclusion of many large "miso".,
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  • Katsuhiko Sakakura
    1949 Volume 55 Issue 647 Pages 90-94
    Published: November 20, 1949
    Released: April 11, 2008
    JOURNALS FREE ACCESS
    1., An aggregation of foraminifera considered in two previfus showed many differences from recent aggregations which are being studied by ecologists., 2., The author discussed the characteristic nature of "fossil aggregations", the relation betweent tne fossil aggregation itself and the amount of sample to be used in its statistical study, and the influence of size of foraminifera, etc., ., 3., This paper is a supplement to the two former papers on statistical studies of foraminifera aggregations.,
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  • Akira Morishita, Chuzo Nakagawa
    1949 Volume 55 Issue 647 Pages 95-98
    Published: November 20, 1949
    Released: April 11, 2008
    JOURNALS FREE ACCESS
    1., Tertiary formations in this district may be divided into the following five members: Shinzyo alternations, Zitogata alternations, Sagara mudstone, Egenoya sandstone-rich alternations and Yamadanoya alternations., As a result of our latest survey, it was clarified that an outlier of the Kakegawa group occurs in a basin-shaped Hikimura syncline, and that the underlying Oigawa rocks are exposed in the core of the Sinzyo anticline., These Tertiary formations are covered by Quaternary formations: Ogasa gravels, Kaizawa sandy-muds, Makinohara gravels and Shiroha gravels., 2., The Shiroha gravels are marine, occuring in a marine terrace which is a step lower than the Makinohara fluviatile terrace.,
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  • Tadao Arita
    1949 Volume 55 Issue 647 Pages 99-104
    Published: November 20, 1949
    Released: April 11, 2008
    JOURNALS FREE ACCESS
    1., The Kasagi granitic intrusives may be divided into the following two types: a., The older granitic rocks which represent deeper facies (Koya)., b., The younger granitic rocks wlnich represent shallower facies (Yagyu)., 2., The associated metamorphic rocks of the Koya granites are usually characterised by addition of potassium and those of Yagyu by silicification., Complex polymetamorphic rocks are often in the found area between the two types of granites., There is no conclusive evidence as to geologicalt age of thehegranites in this district.,
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