Distribution of resistive and conductive structures in Nankai accretionary wedge reveals contrasting stress paths

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doi: 10.1016/j.tecto.2013.11.025
Author(s): Conin, Marianne; Bourlange, Sylvain; Henry, Pierre; Boiselet, Aurelien; Gaillot, Philippe
Author Affiliation(s): Primary:
Universite d'Aix Marseille, Centre Européen de Recherche et d'Enseignement des Géosciences de l'Environnement, Aix en Provence, France
Other:
Universite de Lorraine, France
ExxonMobil Upstream Research, United States
Volume Title: Tectonophysics
Source: Tectonophysics, Vol.611, p.181-191. Publisher: Elsevier, Amsterdam, Netherlands. ISSN: 0040-1951 CODEN: TCTOAM
Note: In English. Includes appendices. 30 refs.; illus., incl. 1 table
Summary: In this article, we study the characteristics and spatial distribution of the deformation structures along the Kumano transect of the Nankai accretionary wedge, and use this information to interpret the stress path followed by the sediments. Deformation structures are identified from logging while drilling (LWD) resistivity images of the materials surrounding the drill hole and from 3-dimensional X-ray CT-images of cores acquired during the IODP NanTroSEIZE project. The relative resistivity of the structures identified on logs and the strike, dip, and density of structures identified on CT scan images are measured. The analysis of dip and strike of structures indicates that most of the resistive structures identified on logging data correspond to compactive shear bands. Results also indicate that conductive structures predominate at the toe of the prism and above the main out of sequence thrust, in locations where past and recent erosion occurred. We propose several mechanisms that could explain the relation between erosion and the absence of compactive shear bands. We conclude that sediments followed different stress paths depending on their location within the wedge, and that those differences explain the distribution of deformation structures within the wedge. We also show the coexistence of dilatant and compactant structures in fault zones including the frontal thrust and mega splay fault, and we interpret the coexistence of these structures as a possible consequence of a transient fluid pressure. Abstract Copyright (2014) Elsevier, B.V.
Year of Publication: 2014
Research Program: IODP Integrated Ocean Drilling Program
Key Words: 16 Structural Geology; 20 Geophysics, Applied; Accretionary wedges; Cores; Correlation; Deformation; Electrical methods; Erosion; Faults; Fluid phase; Fluid pressure; Geophysical methods; IODP Site C0002; IODP Site C0004; IODP Site C0006; Integrated Ocean Drilling Program; Kumano Basin; Marine sediments; NanTroSEIZE; Nankai Trough; North Pacific; Northwest Pacific; Pacific Ocean; Resistivity; Sediments; Splay faults; Stress; Tectonics; Thrust faults; Water-rock interaction; Well logs; Well-logging; West Pacific
Coordinates: N331300 N331300 E1364300 E1364300
Record ID: 2014028146
Copyright Information: GeoRef, Copyright 2019 American Geosciences Institute. Reference includes data from CAPCAS, Elsevier Scientific Publishers, Amsterdam, Netherlands