Progress of illitization along an imbricate frontal thrust at shallow depths in an accretionary prism

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doi: 10.1016/j.tecto.2013.04.024
Author(s): Kameda, Jun; Yamamoto, Yuzuru; Hamada, Yohei; Fujimoto, Koichiro; Kimura, Gaku
Author Affiliation(s): Primary:
University of Tokyo, Department of Earth and Planetary Science, Tokyo, Japan
Institute for Research on Earth Evolution, Japan
Tokyo Gakugei University, Japan
Volume Title: Great earthquakes along subduction zones
Volume Author(s): Kimura, Gaku, editor; Brodsky, Emily; Di Toro, Giulio; Ide, Satoshi; Kanagawa, Kyuichi; Park, Jin-Oh; Underwood, Michael
Source: Great earthquakes along subduction zones, edited by Gaku Kimura, Emily Brodsky, Giulio Di Toro, Satoshi Ide, Kyuichi Kanagawa, Jin-Oh Park and Michael Underwood. Tectonophysics, Vol.600, p.41-51. Publisher: Elsevier, Amsterdam, Netherlands. ISSN: 0040-1951 CODEN: TCTOAM
Note: In English. 50 refs.; illus., incl. 3 tables, sketch map
Summary: Fossil imbricate thrusts, branching from a decollement in an ancient accretionary prism (the Miura-Boso accretionary prism), are exposed in the southern parts of the Miura and Boso peninsulas in central Japan. An analysis of the clay mineralogy of fault rocks along one of the imbricate thrust faults, the Shirako Fault, revealed local illitization of mixed-layer illite-smectite (I-S) and the partial breakdown of kaolinite. The shape of the I(001)-S(001) reflection in the X-ray diffraction pattern suggests that the illite fraction in I-S crystallites within the fault gouge is ≈9% more than in the surrounding rocks. These results imply that there has been a local temperature anomaly within the slip zone, attributable to frictional heating induced by high-velocity slip. A thermal model, coupled with a kinetic simulation of illitization in I-S, suggests that the reaction was probably facilitated by multiple high-velocity slips at a peak temperature of ≈450°C, suggesting repeated seismic rupture propagations to the prism toe, as also inferred from the modern accretionary prism (in the Nankai Trough). Abstract Copyright (2013) Elsevier, B.V.
Year of Publication: 2013
Key Words: 05 Petrology, Igneous and Metamorphic; Accretionary wedges; Active faults; Asia; Chiba Peninsula; Clay minerals; Decollement; Earthquakes; Far East; Faults; Friction; Gouge; Heating; Honshu; Illite; Illitization; Imbricate tectonics; Izu Peninsula; Japan; Kinetics; Metamorphic rocks; Metamorphism; Mineral composition; Miura Peninsula; Models; North Pacific; Northwest Pacific; Pacific Ocean; Shallow depth; Sheet silicates; Shirako Fault; Silicates; Simulation; Slip rates; Smectite; Subduction zones; Tectonics; Textures; Thrust faults; West Pacific; X-ray diffraction data
Coordinates: N343000 N351000 E1400500 E1384500
Record ID: 2014001325
Copyright Information: GeoRef, Copyright 2019 American Geosciences Institute. Reference includes data from CAPCAS, Elsevier Scientific Publishers, Amsterdam, Netherlands

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