論文

査読有り
2018年7月27日

Direct ascent to the surface of asthenospheric magma in a region of convex lithospheric flexure

International Geology Review
  • Yuki Sato
  • ,
  • Naoto Hirano
  • ,
  • Shiki Machida
  • ,
  • Junji Yamamoto
  • ,
  • Masao Nakanishi
  • ,
  • Teruaki Ishii
  • ,
  • Arashi Taki
  • ,
  • Kazutaka Yasukawa
  • ,
  • Yasuhiro Kato

60
10
開始ページ
1231
終了ページ
1243
記述言語
英語
掲載種別
研究論文(学術雑誌)
DOI
10.1080/00206814.2017.1379912
出版者・発行元
Taylor and Francis Inc.

The stress field of oceanic lithosphere controls the distribution of submarine petit-spot volcanoes. However, the eruption sites of these petit-spot volcanoes are considered to be limited to concavely flexed regions of lithosphere off the outer rise. Here, we present new data for a recently identified petit-spot lava field on a convexly flexed section of the lithosphere adjacent to the subduction zone offshore of northeast Japan in an area containing more than 80 volcanoes. This area is marked by strongly alkaline lavas that were erupted on the convexly flexed region. As for the concavely flexed region where the petit-spots previously reported, the base of the lithosphere beneath the eruption sites is under extension, whereas the upper part of the lithosphere is under compression. This change in the stress field, from the lower to upper lithosphere, causes ascending dikes to stall in the mid-lithosphere, leading to metasomatic interaction with the surrounding peridotite. The new geochemical data of rocks and xenocrysts presented in this study indicate that strongly alkaline magmas erupted on the convexly flexed region would have ascended more rapidly through the mid-depth of lithosphere because of the extensional regime of the upper lithosphere and decreasing the degree of metasomatic reaction with the surrounding mantle peridotite. The results indicate that the degree of metasomatism and the compositional variations of petit-spot magmas are controlled mainly by the stress field of the lithosphere.

Web of Science ® 被引用回数 : 5

リンク情報
DOI
https://doi.org/10.1080/00206814.2017.1379912
Web of Science
https://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=JSTA_CEL&SrcApp=J_Gate_JST&DestLinkType=FullRecord&KeyUT=WOS:000435009900003&DestApp=WOS_CPL

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