The Journal of the Geological Society of Japan
Online ISSN : 1349-9963
Print ISSN : 0016-7630
ISSN-L : 0016-7630
Volume 49 , Issue 581
Showing 1-3 articles out of 3 articles from the selected issue
  • Masao MINATO
    1942 Volume 49 Issue 581 Pages 47-72
    Published: February 20, 1942
    Released: April 11, 2008
    JOURNALS FREE ACCESS
    1) In the Kitakami mountainland, Pseudoschwagerina begins to appear in the Sakamotozawa stage, together with a number of remains of Brachiopods, corals, calcareous algae, etc., of definite Permian type (including Artinskian)., This indicates that the appearance of Pseudoschwagerina means the dawn of the Permian age., 2)The Pseudoschwagerina zone lies unconformably on the inclined older formations separated by a visible erosion surface which the present writer proposes to call "The Pre-Sakamotozawa un-conformity"., The whole structural amount due to intense disturbance before the Sakamotoza stage is provisionally called "The Setamai folding"., 3) The Setamai folding is related in age to the Marathon Orogeny of North America and Kun-mingian of South China and Indo-China, and also equivalent to STILLE'S "asturische Phase"., 4) True Trlticites or Uralian fauna (s., s., ) is not yet known to occur in Japan (including Tysoen) and its adjacent lands., This fact may suggest the probable existence of hiatus of considerable amount between Carboniferous and Permian.,
    Download PDF (3109K)
  • Toshio SUGIYAMA
    1942 Volume 49 Issue 581 Pages 73-75
    Published: February 20, 1942
    Released: April 11, 2008
    JOURNALS FREE ACCESS
    Two external casts of Brachiopoda found by the writer early in this year in a trachytic tuff of the Nakazato Series developed at the south-western foot of Takainari-yama, Hikoroiti-mura, Kesen-gun, lwate-ken, are identical with Atrypa desquamata SOWERBY, the well known Middle Devonian fossil of world wide distribution., The following is the short description of this fossil : shell more or less wider than high, squarish in outline, somewhat shouldered at cardinal extremi-ties, probably widest along hinge line, ornamented with radiating ribs crossed by well marked growth lines., Ventral valve moderately convex, with slight median depression in front, dorsal valve much inflated, being more convex than ventral valve., Radiating ribs most marked near umbonal part, thence gradually weaking to frontal region, with the increase in number by successive intercalation of new ones ; flve of them counted in 5mm., Growth lines concentrical, distinct, becomming finer towards cardinal extremities, six to seven of them counted in 5mm near umbonal region., Hinge line long and straight., Area, muscular impression and brachial structure unknown., Width 27mm and height 25mm., Of the three mutations distinguished by GRABAU in the Chinese forms of Atrypa desquamata, mut., kansuensis GRABAU, particularly the figured specimen from the Miaoerhchuan bed of Kansu province approaches most closely the Japanese form, but the latter differs from the former by having better developed concentric growth lines similar to the British or west European Atrypa desquamata and by being more shouldered at cardinal extremities., To this Japanese form, a new name japonica is here proposed., Reg., No., 65468.,
    Download PDF (483K)
  • Kinji KANEHARA
    1942 Volume 49 Issue 581 Pages 76-79
    Published: February 20, 1942
    Released: April 11, 2008
    JOURNALS FREE ACCESS
    The fossill mollusca treated here are those collected by Mr., R., ENDO, geologist of the Imperial Geological Survey of Japan, from Katanisi Oil Field, Akita Prefecture., The fossil fauna is found at Tayazawa, Wakimoto-mura, Minami Akita-gori, and consists of 52 species of mollusca, as listed in the table inserted in the Japanese text, among which Pecten (Patinopecten) yessoensis JAY is most common ; no shells of the warm water type (Kurosio type) are found., Of these 52 species, 8 species are found only as fossils, while the remaining 44 are fossil as well as living., From the presence of Turritella nipponica YOKOYAMA, which is found very frequently in the Pleistocene series of our country, the writer believes the fossil fauna is later Pliocene or Plio-Pleistocene in age., Short remarks and figures are given on some interesting shells.,
    Download PDF (500K)
feedback
Top