研究者業績

宇野 康司

ウノ コウジ  (Koji Uno)

基本情報

所属
兵庫県立大学 環境人間学部 教授
学位
博士(理学)(神戸大学)

研究者番号
10510745
J-GLOBAL ID
201801009422849969
researchmap会員ID
7000024521

論文

 43
  • Koji Uno, Hayao Morinaga
    Journal of the Geological Society of Japan 129 663-671 2023年12月  査読有り
  • Koji Uno, Honoka Ohara, Kuniyuki Furukawa, Tatsuo Kanamaru
    Geoscience Letters 10 21 2023年4月  査読有り
    Abstract To test the hypothesis that a Cretaceous hairpin turn is absent in the apparent polar wander path (APWP) of the inner arc of southwestern Japanese island (southwest Japan), we refined a mid-Cretaceous (100 Ma) paleomagnetic pole from southwest Japan. Red mudstone samples from the 100 Ma Hayama Formation were collected for paleomagnetic analysis from eight sites in the Hayama area in the central part of southwest Japan. A high-temperature remanent magnetization component carried by hematite was isolated from these sites and was found to be of primary mid-Cretaceous origin. The primary nature of the magnetization is supported by the detrital character of the magnetic carrier. The primary directions provided a paleomagnetic pole (35.0°N, 209.6°E, A95 = 6.1°, N = 8), which represented southwest Japan at 100 Ma. This pole falls into a cluster of Cretaceous poles in southwest Japan. An APWP for southwest Japan between 110 and 70 Ma was updated to ascertain the stationarity of the pole positions for this region. Therefore, it is unlikely that the APWP for southwest Japan experienced a hairpin turn during the Cretaceous.
  • Yoshihiro Sawada, Koji Uno, Tetsuya Sakai, Hironobu Hyodo
    Bulletin of Volcanology 85 26 2023年4月  査読有り
  • Kuniyuki Furukawa, Koji Uno, Yu Horiuchi, Shintaro Murohashi, Motohiro Tsuboi
    Volcanica 4 107-134 2021年7月  査読有り
    This study presents a description of a rhyolite lava-forming eruption, including the conduit system, degassing history during the lava flow dynamics. We examined the Pleistocene Shiroyama rhyolite lava on Himeshima Island, Japan. The lava is mainly characterized by locally developed obsidian. Based on the structural variation, the obsidian lithofacies correspond to the shallow conduit. The geological investigation and FTIR analyses showed that gas removal from the conduit magma proceeded via vesiculation, fracturing, and brecciation, allowing formation of the dense obsidian. Since the lava originally maintained some extent of water, the lava effervesced just after the effusion. This vesiculation resulted in pervasive bubble coalescence and the formation of abundant permeable pathways. The volcanic gasses escaped via those pathways, allowing collapse of the bubbles and deflation of the lava. AMS (anisotropy of magnetic susceptibility) results indicate that the lava spread concentrically.
  • Koji Uno, Yuta Idehara, Daichi Morita, Kuniyuki Furukawa
    Earth, Planets and Space 73 132 2021年6月  査読有り

講演・口頭発表等

 6

共同研究・競争的資金等の研究課題

 10

メディア報道

 2