The Journal of the Geological Society of Japan
Online ISSN : 1349-9963
Print ISSN : 0016-7630
ISSN-L : 0016-7630
Volume 61 , Issue 716
Showing 1-6 articles out of 6 articles from the selected issue
  • Shohei KOKAWA
    1955 Volume 61 Issue 716 Pages 189-194
    Published: May 25, 1955
    Released: April 11, 2008
    JOURNALS FREE ACCESS
    The Eruptive-tectonics of the Hozanji Andesite Knoll was worked out., Joint-prisms of the knoll are radiating from the center., Hypersthenes and plagioclases generally tend to be oriented to the vertical direction., From these facts the andesite mass may be presumed to be a volcanic neck in the real sense of the term.,
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  • Hideo ISHIKAWA
    1955 Volume 61 Issue 716 Pages 195-199
    Published: May 25, 1955
    Released: April 11, 2008
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    Around the quartz-diorite mass of the Tanzawa Mountainland, Central Japan, there are developed various contact metamorphic rocks., Of these metamorphic rocks, those distributed in the southern vicinity of the quartz-diorite include various schistose rocks which range from chlorite-green schists to amphibolites., The problem of heat-trandition in the formation of these contact metamorphic rocks is discussed from a view point of heat-conduction and the results are compared with the actual metamorphic facies in these rocks., Lastly the relations between the model cases and the geological condition are discussed.,
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  • Toshio SUDO
    1955 Volume 61 Issue 716 Pages 200-207
    Published: May 25, 1955
    Released: April 11, 2008
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    Long spacings as 29., 6 Å and 26., 6 Å are confirmed from certain clays from Japan, which have very complicated clay mineral compositions including kaolin minerals, chlorite, sepiolite and montmorillonite., Each long can be explained by a regular interstratification between two kinds of lattices selected from the following ones: montmorillonite lattice with the cell height of 15., 4 Å, a magnesian chlorite of 14., 5 Å, sepiolite with 12., 7 Å, and a new lattice of 14., 0 Å; the last is a regular interstratification of gibbsite and silicate (pyrophyllite unit) layers., This new lattice is proposed to explain the spacing and all other mineralogical properties of the clay., Thus the 29., 6 Å spacing agrees well with that of a regular mixed-layer lattice configurated by the 15., 4 Å and 14., 0 Å cells, and the 26., 6 Å spacing with a regular mixed-layer lattice by 12., 7 Å and 14., 5 Å cells., These long spacings are liable to be found in a clay in which several kinds of clay minerals co-exist, and such a complex clay tends to be found in special conditions, such as a boundary area between two different kinds of altered zones, and or an area affected by successive hydrothermal alteration.,
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  • S. HASHIMOT0, S. KUMAN0
    1955 Volume 61 Issue 716 Pages 208-217
    Published: May 25, 1955
    Released: April 11, 2008
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    Schon vor Jahren war es den japanischen Geologen nichts Neues mehr, dass die Kartopographie im Hidaka-Gebirge, Hokkaido, sicher vorhanden sei., Aber erst vor kurzem haben M., MINATO und einer der Verfasser (HASHIMOTO) mit Bestimmheit festgestellt, dass dort eine zweimalige Karbildung stattgefunden hat., Bei anderen Gelegenheit haben MINAT0 und HASHIMOTO den Vorschlag gemacht, die altere Eiszeit im Hidaka-Gebirge als die "Poroshiri-Eiszeit" und die neuere Eiszeit als die "Tottabetsu-Eiszeit" zu bezeichnen., Erst kurzlich haben HASHIMOTO und KUMANO entlang des Flusses Tottabetsu im Tokachi Bezirke, Hokkaido, geologische Untersuchungen angestellt, um die stratigraphischen Verhaltnisse zwischen den Moranen im hoheren Gebirge und den Schotterablagerungen der Terrassen bzw., der Facherablagerungen im Tale zu bestimmen., Es gibt nun mehrere Terrassen in verschiedenen Hohen bzw., Facherablagerungen entlang des Tottabetsu Flusses., Geologisch uncl stratigraphisch sind diese Terrassen in drei Gruppen teilbar: Hohen, Mittel-und Niederterrassen., Auch die Facherablagerungen sind in zwei teilbar., Dabei liegt die altere Facherablagerung auf der Mittelterrasse, und gleichzeitig kann man die Beobachtung machen, dass die sogenannten alteren Moranen (Poroshiri-Eiszeit) die Mittelterrassen decken., Deshalb nehmen wir die Gleichzeitigkeit der Poroshiri-Eiszeit und der Mittelterrassenbildung an., Die Tottabetsu-Eiszeit ist jetzt schwer mit der Zeit der Terrassenbildung zu vergleichen, aber aus topographischen Grunden vermuten wir", dass die neueren Moranen (Tottabetsu-Eiszeit) mit den Schotterablagerungen der Niederterrassen beinahe vergleichbar sind., In Hokkaido kommen die Molaren von Mammontens primigenius in einigen Lokalitaten der sogenannten Schotterablagerungen der Niederterrassen vor., Deshalb ist jetzt ein Vergleich der Tottabetsu-Eiszeit mit der Wurm-Eiszeit moglich, und folglich kann geschlossen werden, dass die Poroshiri-Eiszeit der Riss-Eiszeit annahernd entspricht., Zum Schlusse mochten wir kurz berichten, dass die sogenannte Tottabetsu-Eiszeit in zwei Stufen teilbar ist, wofur wir die Bezeichnung Tottabetsu I und II wahlen., Die Spuren von Kargletschern in einigen Karen des Hidaka-Gebirges zeigen, dass diese nicht auf einmal schrumpfig geworden sind, sondern ncah der Tottabetsu I-Eiszeit zeitweilig vergrossert waren.,
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  • Ikuro SHIMADA
    1955 Volume 61 Issue 716 Pages 218-226
    Published: May 25, 1955
    Released: April 11, 2008
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    From field observations of the Cenozoic strata in the Onikobe basin, Miyagi prefecture, the writer recognized lake deposits (Pleistocene ?), which be named the Onikobe formation., These are well developed along the upper course of the Arao River., The purpose of this paper is to describe the mode of sedimentation and environmental conditions under which the formation was deposited., Sedimentological problems of the Uppermost Miocene lake basins formed by the crustal deformation in the backborn ranges of Northern Honshu, Japan was described in the preceding Paper (I., KATO and I., SHIMADA, 1953)., The results are summarized as follows., (1) On the basis of lithogical characteristics the strata are classified into two parts, namely, the marginal part which is characterized by loose conglomerate and sandstone beds, and the central part by tuffaceous sandstone and mudstone beds; both parts are contemporaneous with each other., (2) The marginal part is considered to be of deltaic deposition from the distinct structural features and litho-facies., The central part from the mudstone with thin lamina which form a rhythmical facies seems to hove been deposited in a fresh water lake., (3) During almost the whole period of accumulation of the strata, dacitic volcanic activity prevailed., This may have relation with the development of the sedimentary lake basin., (4) Although the origin of this sedimentary lake basin is obscure, the writer considers it to have been formed by subsidence in the inner zone and relative upheaval in the outer zone of this area after deposition of the Uppermost Miocene lake deposits., Although there remain interesting and important problems concerning the sedimentation and tectonics of the sedimentary lake basin, further geological data is necessary to settle the problem.,
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  • Takao YAMAGUCHI
    1955 Volume 61 Issue 716 Pages 227-228
    Published: May 25, 1955
    Released: April 11, 2008
    JOURNALS FREE ACCESS
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