Crustal structure of the Murray Ridge, northwest Indian Ocean, from wide-angle seismic data

Minshull, T.A.; Edwards, R.A.; Flueh, E.R.. 2015 Crustal structure of the Murray Ridge, northwest Indian Ocean, from wide-angle seismic data. Geophysical Journal International, 202 (1). 454-463. https://doi.org/10.1093/gji/ggv162

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This article has been accepted for publication in Geophysical Journal International ©: 2015 Royal Astronomical Society. Published by Oxford University Press on behalf of the Royal Astronomical Society. All rights reserved. doi: 10.1093/gji/ggv162
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Official URL: http://dx.doi.org/10.1093/gji/ggv162

Abstract/Summary

The Murray Ridge/Dalrymple Trough system forms the boundary between the Indian and Arabian plates in the northern Arabian Sea. Geodetic constraints from the surrounding continents suggest that this plate boundary is undergoing oblique extension at a rate of a few millimetres per year. We present wide-angle seismic data that constrains the composition of the Ridge and of adjacent lithosphere beneath the Indus Fan. We infer that Murray Ridge, like the adjacent Dalrymple Trough, is underlain by continental crust, while a thin crustal section beneath the Indus Fan represents thinned continental crust or exhumed serpentinized mantle that forms part of a magma-poor rifted margin. Changes in crustal structure across the Murray Ridge and Dalrymple Trough can explain short-wavelength gravity anomalies, but a long-wavelength anomaly must be attributed to deeper density contrasts that may result from a large age contrast across the plate boundary. The origin of this fragment of continental crust remains enigmatic, but the presence of basement fabrics to the south that are roughly parallel to Murray Ridge suggests that it separated from the India/Seychelles/Madagascar block by extension during early breakup of Gondwana.

Item Type:	Publication - Article
Digital Object Identifier (DOI):	https://doi.org/10.1093/gji/ggv162
ISSN:	0956-540X
Additional Keywords:	Controlled source seismology, Continental margins: transform, Indian Ocean
Date made live:	11 Nov 2015 15:55 +0 (UTC)
URI:	https://nora.nerc.ac.uk/id/eprint/512195

Item Type:

Publication - Article

Digital Object Identifier (DOI):

https://doi.org/10.1093/gji/ggv162

ISSN:

0956-540X

Additional Keywords:

Controlled source seismology, Continental margins: transform, Indian Ocean

Date made live:

11 Nov 2015 15:55 +0 (UTC)

URI:

https://nora.nerc.ac.uk/id/eprint/512195