Magnetic fabrics indicating Late Quaternary seismicity in the Himalayan foothills

Jayangondaperumal, R and Dubey, Ashok Kumar and Kumar, Senthil B and Wesnousky, SG and Sangode, SJ (2010) Magnetic fabrics indicating Late Quaternary seismicity in the Himalayan foothills. In: International Journal of Earth Sciences (Geologische Rundschau), 99 (Sp. Is). S265-S278.

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Abstract

The anisotropy of magnetic susceptibility (AMS) study was performed on soft sediment samples from a trenched fault zone across the Himalayan frontal thrust (HFT), western Himalaya. AMS orientation of K-min axes in the trench sediments is consistent with lateral shortening revealed by geometry of deformed regional structures and recent earthquakes. Well-defined vertical magnetic foliation parallel to the flexure cleavage in which a vertical magnetic lineation is developed, high anisotropy, and triaxial ellipsoids suggest large overprinting of earth-quake- related fabrics. The AMS data suggest a gradual variation from layer parallel shortening (LPS) at a distance from the fault trace to a simple shear fabric close to the fault trace. An abrupt change in the shortening direction (K-min) from NE-SW to E-W suggests a juxtaposition of pre-existing layer parallel shortening fabric, and bending-related flexure associated with an earthquake. Hence the orientation pattern of magnetic susceptibility axes helps in identifying co-seismic structures in Late Holocene surface sediments.

Item Type:	Journal Article
Additional Information:	Copyright of this article belongs to Springer .
Keywords:	Anisotropy of magnetic susceptibility (AMS); Earthquake fabric; Himalaya; Paleoseismicity
Department/Centre:	Others
Date Deposited:	08 Nov 2010 08:54
Last Modified:	08 Nov 2010 08:54
URI:	http://eprints.iisc.ernet.in/id/eprint/33560

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