The Journal of the Geological Society of Japan
Online ISSN : 1349-9963
Print ISSN : 0016-7630
ISSN-L : 0016-7630
Volume 60 , Issue 709
Showing 1-10 articles out of 10 articles from the selected issue
  • Koji FUJII
    1954 Volume 60 Issue 709 Pages 413-427
    Published: October 25, 1954
    Released: April 11, 2008
    JOURNALS FREE ACCESS
    1) The Usuki area in eastern Kyushu belongs to the so-called Chichibu Terrain of the Outer Zone of Southwest Japan., This mountainous area comprises rocks of the Chichibu supergroup, largely of the Permian period and less so of the late Mesozoic., They are arranged in a number of parallel or nearly parallel belts of NEE-SWW trend and separated by tectonic lines., 2) From paleontological and other evidences, the respective ages of the formations are as follows., (Fossils listed in Japanese text) Mesozoic formations: Shinkai formation., ., ., ., ., ., ., ., ., ., ., ., ? ., ., ., ., ., ., ., ., ., ., ., ., Upper Jurassic Yamabu formation., ., ., ., ., ., ., ., ., ., ., ., ., ., ., ., ., ., ., ., ., ., ., ., ., ., ., Kochian (Kl., Lowest Cretaceous) Haidateyama formation., ., ., ., ., ., ., ., ., ., ., ., ., ., ., ., ., ., ., ., ., Miyakoan (K3., Upper part of Lower Cretaceous) Tano formation ., ., ., ., ., ., ., ., ., ., ., ., ., ., ., ., ., ., ., ., ., ., ., ., ., ., ., Gyliakian (K4., Lower part of Upper Cretaceous) Palaeozoic formations: Those in the Chinnanzan tectonic belt., ., ., ., ., ., ., ., ., ., ., ., Partly Lower Permian Those in the Tsukumi tectonic belt., ., ., ., ., ., ., ., ., ., ., ., ., ., ., Lower-Middle Permian Those in the Meiji tectonic belt., ., ., ., ., ., ., ., ., ., ., ., ., ., ., ., ., ., ., ., ., Lower-Middle Permian Katauchi formation., ., ., ., ., ., ., ., ., ., ., ., ., ., ., ., ., ., ., ., ., ., ., ., ., ., ., ., ., ., ., ., ., ., ., ., ., ., ., ., ., ., Visean (Lower Carboniferous) ? Those in the Usuki, Nakano and Kashimine tectonic belts., ., ., ., ., ., ., ., ., undetermined 3) Each of the tectonic lines which separates the formations into the tectonic belts is not a simple fault but a narrow zone containing several faults accompanied with a sheared zone., Peculiar igneous and metamorphic rocks squeezed out along these tectonic lines are found frequently., They are leucocratic granite, schistose diorite-gabbro, quartz-porphyry, porphy-rites, hornblende-bearing biotite granite, gneiss and serpentinite., The structural features are similar to those in the Yatsushiro-Kuma area., (See T., MATSUMOTO and K., KANMERA, 1949)., 4) The Paleozoic rocks are generally intensely folded and locally metamorphosed, while the Mesozoic rocks are moderately folded., 5) It is noteworthy that an important tectonic epoch towards the mid-Cretaceous is indicated by the unconformity between the Haidateyama (K3) and the Yamabu (K7) and the Paleozoic formations., The post-Cretaceous (or at least post-Gyliakian) crustal movements also play an important role in the development of the geological structure of the Usuki Area.,
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  • Jun TESHIMA
    1954 Volume 60 Issue 709 Pages 428-435
    Published: October 25, 1954
    Released: April 11, 2008
    JOURNALS FREE ACCESS
    The Yubari, which is an important coal-bearing formation extensively developed in the Ishikari coal-field, has been hitherto regarded as comprising one continuous sequence of sediments from base to top., Detailed observations in the field as well as by careful examinations of the correlated boring logs from the Heiwa Area, shows that it is not a single, continuous deposit, but that it is composed of six successive subformations, each separated by diastems., The six subformations are represented by six cyclothems, each of which commences with conglomeratic beds, thus indicating a pause in sedimentation and erosion of the sediments of the preceding cyclothems.,
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  • Hidekata SHIBATA, Kikuo HARA
    1954 Volume 60 Issue 709 Pages 436-444
    Published: October 25, 1954
    Released: April 11, 2008
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    There are five types of granitic rocks in the North Alps of Japan, viz., The Hida System type, Shimonomoto type, Funazu type, Takase type, and the Nishina type., The Hida System type is a member of the Hida metamorphic complex., The Shimonomoto type intrudes gneisses of the Hida system and grades into the Funazu gtype ranite, which is assumed as a migmatite derived from the former, at the Kamioka Mine., The Funazu type granite intrudes the Palaeozoic system and is intruded by the Takase type granitic rocks and is covered by the Mesozoic Tetori series., The Takase type granitic rocks intrude the Tetori series., They are divided into two series, one of gabbro and grano-diorite, and the other of rhyolitic quartz-porphyry, quartz-porphyry and granite, which intrudes the former., The Nishina type granitic rocks are sub-alkalic and derived from those of the Takase type rocks., Soda-quartz-porphyry, adamellite-porphyry, and quartz-syenite, all characterized by alkali-amphiboles, are found as xenoliths in the pink biotite-granite of the Takase type or are intruded by it., Adamellite-porphyry very poor in quartz-phenocrysts resembles porphyrite., The large dike exposed at the ridge between Yarigatake and Hodakadake consists of andesite intruding the porphyry which is called porphyrite.,
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  • Nobuo KOZIMA
    1954 Volume 60 Issue 709 Pages 445-454
    Published: October 25, 1954
    Released: April 11, 2008
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    The stratigraphic succession of the rocks of the Oiso district is in descending order as follows : 10) Alluvium 9) Simobara beds K 8) Terrace deposits J3 7) Kanto volcanic ash, 6) Takao formation, 5) Kuroiwa conglomerate J2∼J3 4) Tutizawa group J1 3) Ninomiya group I2 2) Miura group and Asigara group H1 1) Koraizan group F1 base unknown 1) In the eastern part of Terugasaki, the Koraizan group unconformably underlies the Miura group., It may be correlated with the Hayama group in the Miura Peninsula., 2) The Nisikoiso formation is considered to be a fossil enclosure within the Oiso formation of the Miura group, as already suggested by S., IZIRI and Y., HUZITA., 3) The conglomerate at Kozu and Simosoga belongs to the Tutizawa group and not to the Ninomiya formation as formerly considered by Y., OTUKA., 4) A conformable relationship is ascertained between the Kanto volcanic ash and the Tutizawa group at several places in the area, while elsewhere the relation between the two is unconformable.,
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  • Minoru TAMURA
    1954 Volume 60 Issue 709 Pages 455-456
    Published: October 25, 1954
    Released: April 11, 2008
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  • Toshio KIHARA, Shigeo MURATA, Michiyoshi SUGAHARA
    1954 Volume 60 Issue 709 Pages 457
    Published: October 25, 1954
    Released: April 11, 2008
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  • Noriyuki NASU
    1954 Volume 60 Issue 709 Pages 458
    Published: October 25, 1954
    Released: April 11, 2008
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  • Nobuo KOZIMA
    1954 Volume 60 Issue 709 Pages 459a
    Published: October 25, 1954
    Released: April 11, 2008
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  • Masao MINATO
    1954 Volume 60 Issue 709 Pages 459b-460
    Published: October 25, 1954
    Released: April 11, 2008
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  • M. MINATO, S. HASHIMOTO
    1954 Volume 60 Issue 709 Pages 460
    Published: October 25, 1954
    Released: April 11, 2008
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