Transition of accretionary wedge structures around the up-dip limit of the seismogenic subduction zone

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doi: 10.1016/j.epsl.2007.01.005
Author(s): Kimura, Gaku; Kitamura, Yujin; Hashimoto, Yoshitaka; Yamaguchi, Asuka; Shibata, Tadahiro; Ujiie, Kohtaro; Okamoto, Shin'ya
Author Affiliation(s): Primary:
University of Tokyo, Department of Earth and Planetary Science, Tokyo, Japan
Other:
Japan Agency for Marine-Earth Science and Technology, Japan
Kochi University, Japan
Volume Title: Earth and Planetary Science Letters
Source: Earth and Planetary Science Letters, 255(3-4), p.471-484. Publisher: Elsevier, Amsterdam, Netherlands. ISSN: 0012-821X CODEN: EPSLA2
Note: In English. 78 refs.; charts, sects., geol. sketch maps
Summary: The Nankai accretionary prism is divided into three segments: outer and inner wedges and their transition zone. These wedges reflect different aspects of wedge taper, internal deformation, and basal plate boundary fault. The outer wedge is characterized by narrow critical taper, internal deformation by in-sequence-fold-and-thrust and aseismic decollement. The inner wedge represents a stable narrow taper, weakly deformed internal structure and seismogenic plate boundary fault along its base. The transition zone between the two wedges shows large critical taper with steep surface slope, internal structure of out-of-sequence thrust, and step-down of decollement onto the sediment-oceanic basement interface. The trench slope break and oceanward margin of forearc basin is located around the landward edge of this transition zone. These common aspects might be related to the lithification of both accreted and underthrust sediments and the resultant switch of the plate boundary fault. Deformation and lithification process recorded in exhumed on-land melange of accretionary complexes suggest that the step-down of the plate boundary decollement occurs around the up-dip limit of seismogenic subduction zone. Abstract Copyright (2007) Elsevier, B.V.
Year of Publication: 2007
Research Program: IODP Integrated Ocean Drilling Program
Key Words: 18 Geophysics, Solid-Earth; Accretionary wedges; Compaction; Decollement; Deformation; Expedition 314; Expedition 315; Expedition 316; Faults; Friction; Integrated Ocean Drilling Program; Lithification; Melange; NanTroSEIZE; Nankai Trough; North Pacific; Northwest Pacific; Pacific Ocean; Plate boundaries; Plate tectonics; Porosity; Pressure solution; Subduction zones; Underplating; West Pacific
Coordinates: N310000 N340000 E1370000 E1330000
Record ID: 2008013123
Copyright Information: GeoRef, Copyright 2019 American Geosciences Institute. Reference includes data from CAPCAS, Elsevier Scientific Publishers, Amsterdam, Netherlands