論文

査読有り
2017年9月

A high-T metamorphic complex derived from the high-P Suo metamorphic complex in the Omuta district, northern Kyushu, southwest Japan

ISLAND ARC
  • Kazuhiro Miyazaki
  • ,
  • Takeshi Ikeda
  • ,
  • Hirohisa Matsuura
  • ,
  • Tohru Danhara
  • ,
  • Hideki Iwano
  • ,
  • Takafumi Hirata

26
5
記述言語
英語
掲載種別
研究論文(学術雑誌)
DOI
10.1111/iar.12208
出版者・発行元
WILEY

New U-Pb ages of zircons from migmatitic pelitic gneisses in the Omuta district, northern Kyushu, southwest Japan are presented. Metamorphic zonation from the Suo metamorphic complex to the gneisses suggests that the protolith of the gneisses was the Suo metamorphic complex. The zircon ages reveal the following: (i) a transformation took place from the high-P Suo metamorphic complex to a high-T metamorphic complex that includes the migmatitic pelitic gneisses; (ii) the detrital zircon cores in the Suo pelitic rocks have two main age components (ca 1900-1800 Ma and 250Ma), with some of the detrital zircon cores being supplied (being reworked) from a high-grade metamorphic source; and (iii) one metamorphic zircon rim yields 105.15.3Ma concordant age that represents the age of the high-T metamorphism. The high-P to high-T transformation of metamorphic complexes implies the seaward shift of a volcanic arc or a landward shift of the metamorphic complex from a trench to the sides of a volcanic arc in an arc-trench system during the Early Cretaceous. The Omuta district is located on the same geographical trend as the Ryoke plutono-metamorphic complex, and our estimated age of the high-T metamorphism is similar to that of the Ryoke plutono-metamorphism in the Yanai district of western Chugoku. Therefore, the high-T metamorphic complex possibly represents the western extension of the Ryoke plutono-metamorphic complex. The protolith of the metamorphic rocks of the Ryoke plutono-metamorphic complex was the Jurassic accretionary complex of the inner zone of southwest Japan. The high-P to high-T transformation in the Omuta district also suggests that the geographic trend of the Jurassic accretionary complex was oblique to that of the mid-Cretaceous high-T metamorphic field.

リンク情報
DOI
https://doi.org/10.1111/iar.12208
Web of Science
https://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=JSTA_CEL&SrcApp=J_Gate_JST&DestLinkType=FullRecord&KeyUT=WOS:000408947100010&DestApp=WOS_CPL
URL
http://orcid.org/0000-0002-7159-2010
ID情報
  • DOI : 10.1111/iar.12208
  • ISSN : 1038-4871
  • eISSN : 1440-1738
  • ORCIDのPut Code : 45377586
  • Web of Science ID : WOS:000408947100010

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