Magnetic susceptibility anisotropy in deformed sediments of ODP Leg 110


Autoria(s): Hounslow, Mark W
Cobertura

MEDIAN LATITUDE: 15.531375 * MEDIAN LONGITUDE: -58.748725 * SOUTH-BOUND LATITUDE: 15.525800 * WEST-BOUND LONGITUDE: -58.851500 * NORTH-BOUND LATITUDE: 15.538200 * EAST-BOUND LONGITUDE: -58.641500 * DATE/TIME START: 1986-06-28T12:45:00 * DATE/TIME END: 1986-08-03T07:45:00

Data(s)

27/10/1990

Resumo

The anisotropy of magnetic susceptibility documents the generation of tectonically produced fabrics in sediments that macroscopically show no evidence of this disruption. 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, particularly near the sediment surface, and appears to reflect the inhomogeneous distribution of strain rate in the overthrust sequence. The susceptibility anisotropy of sediments possessing scaly fabric is consistent with the strong orientation of Phyllosilicates seen in thin section, producing a Kmin normal to the scalyness. 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 NESW 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 NESW at depth, probably as a result of the obliquely trending basement ridge, the Tiburon Rise.

Formato

application/zip, 3 datasets

Identificador

https://doi.pangaea.de/10.1594/PANGAEA.747742

doi:10.1594/PANGAEA.747742

Idioma(s)

en

Publicador

PANGAEA

Direitos

CC-BY: Creative Commons Attribution 3.0 Unported

Access constraints: unrestricted

Fonte

Supplement to: Hounslow, Mark W (1990): Grain fabric measured using magnetic susceptibility anisotropy in deformed sediments of the Barbados Accretionary Prism: Leg 110. In: Moore, JC; Mascle, A; et al. (eds.), Proceedings of the Ocean Drilling Program, Scientific Results, College Station, TX (Ocean Drilling Program), 110, 257-275, doi:10.2973/odp.proc.sr.110.156.1990

Palavras-Chave #-; 100(K1-K3)/K1; 110-671B; 110-673A; 110-673B; 110-674A; Decl (NRM); DRILL; Drilling/drill rig; Event; Incl (NRM); Joides Resolution; k max; k max, declination, von Mises circular standard deviation; k max, inclination, arithmetic standard deviation; k max, sub-sample rotation; k max, sub-sample rotation, declination, von Mises circular standard deviation; k max, whole core rotation; k max, whole core rotation, declination, von Mises circular standard deviation; k max, whole core rotation, inclination, arithmetic standard deviation; k min; k min, declination, von Mises circular standard deviation; k min, inclination, arithmetic standard deviation; k min, sub-sample rotation; k min, sub-sample rotation, declination, von Mises circular standard deviation; k min, whole core rotation; k min, whole core rotation, declination, von Mises circular standard deviation; k min, whole core rotation, inclination, arithmetic standard deviation; Koenigsberger ratio; Label; Label 2; Leg110; Maximum degree of anisotropy; N; North Atlantic Ocean; NRM, Declination; NRM, Inclination; Ocean Drilling Program; ODP; ODP sample designation; P1 (K max/K int); P3 (K int/K min); Q-ratio; Sample amount; Sample code/label; Sample code/label 2; Standard deviation; Std dev
Tipo

Dataset