Localized rifting at Chagos Bank in the India-Capricorn plate boundary zone
Localized rifting at Chagos Bank in the India-Capricorn plate boundary zone
Chagos Bank is a region of thick crust in the central Indian Ocean where a concentration of seismicity indicates that extension is ongoing. We have modeled bathymetry and gravity data to show that the crust-mantle boundary shallows near a seabed trough, consistent with a total extension of ~15 km over a zone ;50 km broad. This estimate is consistent with 5–10 m.y. of deformation at the present rate of relative India-Capricorn motion; the ~15 km of extension is toward the lower limit of the total extension expected from magnetic anomaly reconstructions, but would be accumulated in 1–3 m.y. in a regime having the present-day seismicity. We attribute the localization of seismicity beneath Chagos Bank to a weak rheology caused by its thick crust.
extensional tectonics, indian ocean, plate boundaries, intraplate tectonics, seismicity
237-240
Henstock, Timothy J.
27c450a4-3e6b-41f8-97f9-4e0e181400bb
Minshull, Timothy A.
bf413fb5-849e-4389-acd7-0cb0d644e6b8
2004
Henstock, Timothy J.
27c450a4-3e6b-41f8-97f9-4e0e181400bb
Minshull, Timothy A.
bf413fb5-849e-4389-acd7-0cb0d644e6b8
Henstock, Timothy J. and Minshull, Timothy A.
(2004)
Localized rifting at Chagos Bank in the India-Capricorn plate boundary zone.
Geology, 32 (3), .
(doi:10.1130/G19850.1).
Abstract
Chagos Bank is a region of thick crust in the central Indian Ocean where a concentration of seismicity indicates that extension is ongoing. We have modeled bathymetry and gravity data to show that the crust-mantle boundary shallows near a seabed trough, consistent with a total extension of ~15 km over a zone ;50 km broad. This estimate is consistent with 5–10 m.y. of deformation at the present rate of relative India-Capricorn motion; the ~15 km of extension is toward the lower limit of the total extension expected from magnetic anomaly reconstructions, but would be accumulated in 1–3 m.y. in a regime having the present-day seismicity. We attribute the localization of seismicity beneath Chagos Bank to a weak rheology caused by its thick crust.
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Published date: 2004
Keywords:
extensional tectonics, indian ocean, plate boundaries, intraplate tectonics, seismicity
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Local EPrints ID: 9818
URI: http://eprints.soton.ac.uk/id/eprint/9818
ISSN: 0091-7613
PURE UUID: f558120e-7c74-4e07-ad9e-56b6cce8ce33
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Date deposited: 13 Oct 2004
Last modified: 16 Mar 2024 03:13
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