The extent of continental material in oceans: C-Blocks and the Laxmi Basin example

Werner, P.; Foulger, G.R.; Gernigon, L.; Guan, H.; Geoffroy, L.

doi:10.1093/gji/ggaa215

The extent of continental material in oceans: C-Blocks and the Laxmi Basin example

Werner, P.; Foulger, G.R.; Gernigon, L.; Guan, H.; Geoffroy, L.

Authors

P. Werner

G.R. Foulger

L. Gernigon

H. Guan

L. Geoffroy

Abstract

We propose a tectonic interpretation for the outer-SDRs (SDRs: Seaward-Dipping Reflectors) and Pannikar central ridge in the aborted Laxmi Basin west of India from wide-angle seismic reflection data. The outer-SDRs comprise syn-tectonic extrusives (lavas and/or volcaniclastics) emplaced above passively exhumed mid-to-lower mafic crust of continental origin. They erupted following sudden lithosphere weakening associated with isolation of a continental block (a ‘C-Block’). Continuous magmatic addition during crustal extension allowed stretching of the lower crust whilst maintaining constant or even increasing thickness. A similar process occurred at both conjugate margins allowing bulk, pure-shear plate separation and formation of linear magnetic anomalies. The Laxmi example can explain enigmatic features observed in mature oceans such as presence of distal buoyant plateaus of thick continental crust away from the margins.

Citation

Werner, P., Foulger, G., Gernigon, L., Guan, H., & Geoffroy, L. (2020). The extent of continental material in oceans: C-Blocks and the Laxmi Basin example. Geophysical Journal International, 222(3), 1471-1479. https://doi.org/10.1093/gji/ggaa215

Journal Article Type	Article
Acceptance Date	Apr 30, 2020
Online Publication Date	May 5, 2020
Publication Date	2020-09
Deposit Date	Oct 7, 2020
Publicly Available Date	Oct 7, 2020
Journal	Geophysical Journal International
Print ISSN	0956-540X
Electronic ISSN	1365-246X
Publisher	Oxford University Press
Peer Reviewed	Peer Reviewed
Volume	222
Issue	3
Pages	1471-1479
DOI	https://doi.org/10.1093/gji/ggaa215

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This article has been accepted for publication in Geophysical journal international ©: 2020 Published by Oxford University Press on behalf of The Royal Astronomical Society. All rights reserved.