• Search Research Projects
  • Search Researchers
  • How to Use
  1. Back to project page

1990 Fiscal Year Final Research Report Summary

Study on the Extension Tectonics of Northeast Honshu Arc Just Before 15 Ma.

Research Project

Project/Area Number 01540622
Research Category

Grant-in-Aid for General Scientific Research (C)

Allocation TypeSingle-year Grants
Research Field 地質学一般
Research InstitutionTohoku University

Principal Investigator

OTSUKI Kenshiro  東北大学, 理学部, 助手 (70004497)

Project Period (FY) 1989 – 1990
KeywordsJapan Sea opening / half-grabens / asymmetry of half-grabens / strain gradient / laws of convergence rate of plates / Philippine Sea Plate
Research Abstract

1) Half-grabens were active in Northeast Japan in the period from 23 Ma to 14 Ma. They trend NNW to NNE, and have a width of about 10 km. The grabens were filled by thick and coarse clastic sediments.
2) Newly investigated grabens in the Oguni area Yamagata Prefecture and the Ani area of Akita Prefecture have nearly same characteristics as others in Northeast Japan.
3) The analysis of the metalliferous veins suggests that one of the middle to Late Miocene Principal stress trendeds ENE-WSW and was weakly compressional and another was NNW-SSE in trend and tensional. This stress field suggests that not only Southwest Japan but also Northeast Japan were suffered by the subduction of the Philippine Sea Plate.
4) The early Miocene half-grabens in Northeast Japan are west side down in the Pacific side and east side down in Japan Sea side. Our new sand box experiments testified that the normal faults with fault plane dipping toward the high strain region are selectively grown, and that the degree of the asymmetry depends positively on the magnitude of the strain gradient. These results suggest that there was a zone of maximum tensional strain along the Ou backbone region during the early Miocene.
5) The laws of convergence rate of plates (Otsuki, 1989) and the Paleomagnetic data from the Philippine Sea Plate suggest that not only Southwest Japan but also Northeast Japan suffered the subduction of the Philippine Sea Plate, and that the development of the early Miocene half-grabens and the Japan Sea opening were due to the slow northward motion of the Philippine Sea Plate during the period from ca. 24 Ma to ca. 12 Ma.

  • Research Products

    (10 results)

All Other

All Publications (10 results)

  • [Publications] Kenshiro Otsuki: "Westward migration of the IzuーBonin Trench,northward motion of the Philippine Sea Plate,and their relationships to the Conozoic tectonics of Japanese island arcs." Tectonophysics. 180. 351-367 (1990)

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] 大槻 憲四郎: "フィリッピン海プレ-トの運動と日本海の拡大" 上田誠也教授退官記念論文集ー活動的縁辺域ー 月刊地球号外. 号外3号. 27-31 (1991)

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] 幡各 竜太・大槻 憲四郎: "山形県小国町付近の地質ー東北本州弧前期中新世ハ-フ・グラ-ベンの一例ー" 地質学雑誌.

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] Kenshiro Otsuki: "Neogen tectonic stress fields of northeast Honshu Arc and implications for plate boundary conditions." Tectonophysics. 181. 151-164 (1990)

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] Masahiro Ishikawa and Kenshiro Otsuki: "Sand box experiments for asymmetrical development of conjugate normal faults." Journal of Structural Geology.

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] Kenshiro Otuski: "Westward migration of the Izu Bonin Trench, northward motion of the Philippine Sea Plate, and their relationships to the Cenozoic tectonics of Japanese island arcs." Tectonophysics. V. 180. 351-367 (1990)

    • Description
      「研究成果報告書概要(欧文)」より
  • [Publications] Kenshiro Otsuki: "Neogene tectonic stress fields of northeast Honshu Arc and implications for plate boundary conditions." Tectonophysics. V. 181. 151-164 (1990)

    • Description
      「研究成果報告書概要(欧文)」より
  • [Publications] Kenshiro Otsuki: "The motion of the Philippine Sea Plate and the Japan Sea opening. (in Japanese)" Chikyu (Prof. Seiya Uyeda Memorial volume). 27-31 (1991)

    • Description
      「研究成果報告書概要(欧文)」より
  • [Publications] Ryuta Hataya and Kenshiro Otsuki: "Geology of Oguni machi area. An example of Early Miocene half grabens in Northeast Honshu Arc. (in Japanese)" Journal of Geological Society of Japan. (1991)

    • Description
      「研究成果報告書概要(欧文)」より
  • [Publications] Masahiro Ishikawa and Kenshiro Otsuki: "Sand box experiments for asymmetrical development of conjugate normal faults." Journal of Structural Geology. (1991)

    • Description
      「研究成果報告書概要(欧文)」より

URL: 

Published: 1993-08-12  

Information User Guide FAQ News Terms of Use Attribution of KAKENHI

Powered by NII kakenhi