Deformation structures from the toes of active accretionary prisms

Online Access: Get full text
doi: 10.1144/gsjgs.155.4.0639
Author(s): Maltman, Alex J.
Author Affiliation(s): Primary:
University of Wales, Institute of Geography and Earth Sciences, Aberystwyth, United Kingdom
Volume Title: Journal of the Geological Society of London
Source: Journal of the Geological Society of London, Vol.155(Part 4), p.639-650. Publisher: Geological Society of London, London, United Kingdom. ISSN: 0016-7649 CODEN: JGSLAS
Note: In English. 51 refs.; illus., incl. sketch maps
Summary: Coring of sediments in active accretionary prisms (Nankai, Japan; Cascadia, W North America; Chile; Barbados; Costa Rica) has revealed a wide variety of deformation features. A synopsis is presented of these structures, the processes associated with their accretion and the drainage of water-saturated sediments during active deformation. The deformation bands are roughly planar, bedding-oblique zones of displacement that vary from resembling faults to being kink-like or ductile-shear zone-like. Narrow zones of faulting are common, and can grade into planar bands of breccia. Scaly fabric results from microscopic zones of flattening which become supplanted by shear-induced rotation and intensification into C-S bands. Hydraulic breccia is thought to be an indicator of in situ overpressuring without shear. Web structure involves cataclasis of sand under high pore P and can occur at surprisingly low depths of burial. Sediment-filled veins may indicate palaeoseismicity.
Year of Publication: 1998
Research Program: ODP Ocean Drilling Program
Key Words: 06 Petrology, Sedimentary; 16 Structural Geology; Accretionary wedges; Bedding; Breccia; Clastic rocks; Cores; Deformation; Fabric; Faults; Ocean Drilling Program; Orientation; Planar bedding structures; Plate tectonics; Sedimentary rocks; Sedimentary structures; Shear zones; Spatial distribution; Tectonic elements; Tectonics; Veins
Record ID: 1998042281
Copyright Information: GeoRef, Copyright 2019 American Geosciences Institute. Reference includes data from Mineralogical Abstracts, United Kingdom, Twickenham, United Kingdom

Similar Items