三瓶火山溶岩ドームの形成過程  [in Japanese] Formation Process of Lava Domes in Sanbe Volcano  [in Japanese]

Access this Article

Search this Article

Author(s)

Abstract

<p>Four peaks (Osanbe, Mesanbe, Kosanbe, and Magosanbe) form the major body of Sanbe Volcano. A possible scenario of formation of such discrete peaks could be creation of a single lava dome followed by eruption and erosion, as an explosion-center-like depression is located in the center of four peaks. However, the following lines of evidence may suggest that four lava domes formed individually. Firstly, rocks constituting each peak exhibit distinctive petrographic features in terms of the amount of quartz phenocrysts and compositions of plagioclase phenocrysts. Secondly, Mesanbe rocks tend to possess SiO<sub>2</sub> contents lower than other rocks and show unique chemical trends. Lastly, rocks from Osanbe and Mesanbe exhibit systematically higher, K, Rb, Sr, Ba, and Zr concentrations than those from Kosanbe and Magosanbe. This geochemical characteristics together with rather constant concentration of Y for Sanbe lavas may lead to the conclusion that four types of magmas are produced by anatexis of the lower crust in the presence of garnet, plagioclase, and amphibole by different degrees of melting.</p>

Journal

  • BULLETIN OF THE VOLCANOLOGICAL SOCIETY OF JAPAN

    BULLETIN OF THE VOLCANOLOGICAL SOCIETY OF JAPAN 63(2), 19-32, 2018

    The Volcanological Society of Japan

Codes

  • NII Article ID (NAID)
    130007403445
  • NII NACSIS-CAT ID (NCID)
    AN10512786
  • Text Lang
    JPN
  • ISSN
    0453-4360
  • NDL Article ID
    029133745
  • NDL Call No.
    Z15-101
  • Data Source
    NDL  J-STAGE 
Page Top