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      Permanent link:
      https://www.ias.ac.in/article/fulltext/jess/122/01/0137-0147

    • Keywords

       

      Northeast Japan arc; volcanism; tectonic shortening; Quaternary.

    • Abstract

       

      The Northeast Japan arc, a mature volcanic arc with a back-arc marginal basin (Japan Sea), is located on a convergent plate boundary along the subducting Pacific plate and the overriding North American plate. From a compilation and analysis of stratigraphy, radiometric age and data on erupted magma volumes, 176 eruptive episodes identified from 69 volcanoes so far, indicate that notable changes in eruption style, magma discharge rates and distribution of eruptive centres occurred around 1.0 Ma. Before ca.1.0 Ma, large-volume felsic eruptions were dominant, forming large calderas in the frontal arc, a region of low crustal strain rate. After ca. 1.0 Ma to the present, the calc-alkaline andesite magma eruptions in the frontal and rear arcs, synchronous with crustal shortening characterized by reverse faulting, resulted in stratovolcano development along narrow uplifted zones. Although, it is widely assumed that magma cannot rise easily in a compressional setting, some of the magma stored within basal sills could be extruded where N–S-trending uplifted mountains bounded by reverse faults formed since about ca.1.0 Ma.

    • Author Affiliations

       

      Koji Umeda1 Masao Ban2 Shintaro Hayashi3 Tomohiro Kusano1

      1. Tono Geoscientific Research Unit, Geological Isolation Research and Development Directorate, Japan Atomic Energy Agency, 959-31, Jorinji, Izumi, Toki, 509-5102, Japan.
      2. Department of Earth and Environmental Sciences, Yamagata University, 1-4-12 Kojirakawa-machi, Yamagata, 990-8560, Japan.
      3. Department of Natural and Environmental Sciences, Akita University, 1-1, Gakuen-machi, Tegata, Akita, 010-8502, Japan.
    • Dates

       
  • Journal of Earth System Science | News

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