Open Access

P-T conditions of cataclastic deformation associated with underplating: An example from the Cretaceous Shimanto complex, Kii Peninsula, SW Japan

  • Yoshitaka Hashimoto1Email author,
  • Mamoru Enjoji2,
  • Arito Sakaguchi3 and
  • Gaku Kimura3, 4
Earth, Planets and Space201454:BF03353314

https://doi.org/10.1186/BF03353314

Received: 11 January 2002

Accepted: 27 August 2002

Published: 26 June 2014

Abstract

P-T conditions of cataclastic deformation associated with underplating in subduction zone are estimated from fluid inclusions within the post-mélange veins in the Cretaceous Shimanto Belt, Kii Peninsula, SW Japan. Both cataclasite and post-mélange veins cut the mélange fabric and are distributed along the thrusts in duplex structure. The homogenization temperatures range from 200 (±10)°C to 270 (±42)°C corresponding to entrapment pressures over a wide range from 145 (±5) MPa to 304 (−20) MPa. Our results have important implications in evaluating the relationship between underplating processes by duplexing and coseismic deformation in accretionary complexes.