TY - JOUR

T1 - Grain fabric measured using magnetic susceptibility anisotropy in deformed sediments of the Barbados accretionary prism

T2 - Leg 110

AU - Hounslow, M. W.

N1 - Copyright: Copyright 2020 Elsevier B.V., All rights reserved.

PY - 1990

Y1 - 1990

N2 - The fabric observed in initial accretion is largely produced by overprinting of the original sedimentary susceptibility anisotropy by an E-W horizontal tectonic shortening and vertical extension. The response of the sediments to stress during initial accretion is variable and appears to reflect the inhomogeneous distribution of strain rate in the overthrust sequence. The slope sediments deposited on the accreted sequence are also affected by tectonic shortening. The accreted sequences at Sites 673 and 674 show a complex history of fabric modification, with previous tectonic fabrics overprinted by later fabric modifications, pointing to continued tectonic shortening during the accretion process. The form of the susceptibility anisotropy axes at Sites 673 and 674 is consistent with NE-SW shortening, probably reflected in the NW-SE surface expression of the out-of-sequence thrusts. The susceptibility anisotropy appears to document a downhole change in the trend of shortening from E to W at the surface to more NE-SW at depth, probably as a result of the obliquely trending basement ridge, the Tiburon Rise. -from Author

AB - The fabric observed in initial accretion is largely produced by overprinting of the original sedimentary susceptibility anisotropy by an E-W horizontal tectonic shortening and vertical extension. The response of the sediments to stress during initial accretion is variable and appears to reflect the inhomogeneous distribution of strain rate in the overthrust sequence. The slope sediments deposited on the accreted sequence are also affected by tectonic shortening. The accreted sequences at Sites 673 and 674 show a complex history of fabric modification, with previous tectonic fabrics overprinted by later fabric modifications, pointing to continued tectonic shortening during the accretion process. The form of the susceptibility anisotropy axes at Sites 673 and 674 is consistent with NE-SW shortening, probably reflected in the NW-SE surface expression of the out-of-sequence thrusts. The susceptibility anisotropy appears to document a downhole change in the trend of shortening from E to W at the surface to more NE-SW at depth, probably as a result of the obliquely trending basement ridge, the Tiburon Rise. -from Author

U2 - 10.2973/odp.proc.sr.110.156.1990

DO - 10.2973/odp.proc.sr.110.156.1990

M3 - Journal article

AN - SCOPUS:0025588212

SP - 257

EP - 275

JO - Proceedings of the Ocean Drilling Program, Scientific Results

JF - Proceedings of the Ocean Drilling Program, Scientific Results

ER -