Variation in Upper Plate Crustal and Lithospheric Mantle Structure in the Greater and Lesser Antilles from Ambient Noise Tomography

Schlaphorst, D.; Harmon, N.; Kendall, J.M.; Rychert, C.A.; Collier, J.; Rietbrock, A.; Goes, S.; Allen, R.W.; Bie, L.; Blundy, J.D.; Chichester, B.; Cooper, G.F.; Davidson, J.P.; Davy, R.G.; Henstock, T.J.; Hicks, S.P.; Macpherson, C.G.; Maunder, B.; Prytulak, J.; Hunen, J.; Wilkinson, J.J.; Wilson, M.

doi:10.1029/2021gc009800

Variation in Upper Plate Crustal and Lithospheric Mantle Structure in the Greater and Lesser Antilles from Ambient Noise Tomography

Schlaphorst, D.; Harmon, N.; Kendall, J.M.; Rychert, C.A.; Collier, J.; Rietbrock, A.; Goes, S.; Allen, R.W.; Bie, L.; Blundy, J.D.; Chichester, B.; Cooper, G.F.; Davidson, J.P.; Davy, R.G.; Henstock, T.J.; Hicks, S.P.; Macpherson, C.G.; Maunder, B.; Prytulak, J.; Hunen, J.; Wilkinson, J.J.; Wilson, M.

Authors

D. Schlaphorst

N. Harmon

J.M. Kendall

C.A. Rychert

J. Collier

A. Rietbrock

S. Goes

R.W. Allen

L. Bie

J.D. Blundy

B. Chichester

G.F. Cooper

J.P. Davidson

R.G. Davy

T.J. Henstock

S.P. Hicks

Professor Colin Macpherson colin.macpherson@durham.ac.uk
Professor

B. Maunder

J. Prytulak

J. Hunen

J.J. Wilkinson

M. Wilson

Abstract

The crust and upper mantle structure of the Greater and Lesser Antilles Arc provides insights into key subduction zone processes in a unique region of slow convergence of old slow-spreading oceanic lithosphere. We use ambient noise tomography gathered from island broadband seismic stations and the temporary ocean bottom seismometer network installed as part of the Volatile Recycling in the Lesser Antilles experiment to map crustal and upper mantle shear-wave velocity of the eastern Greater Antilles and the Lesser Antilles Arc. Taking the depth to the 2.0 km/s contour as a proxy, we find sediment thickness up to 15 km in the south in the Grenada and Tobago basins and thinner sediments near the arc and to the north. We observe thicker crust, based on the depth to the 4.0 km/s velocity contour, beneath the arc platforms with the greatest crustal thickness of around 30 km, likely related to crustal addition from arc volcanism through time. There are distinct low velocity zones (4.2–4.4 km/s) in the mantle wedge (30–50 km depth), beneath the Mona Passage, Guadeloupe-Martinique, and the Grenadines. The Mona passage mantle anomaly may be related to ongoing extension there, while the Guadeloupe-Martinique and Grenadine anomalies are likely related to fluid flux, upwelling, and/or partial melt related to nearby slab features. The location of the Guadeloupe-Martinique anomaly is slightly to the south of the obliquely subducted fracture zones. This feature could be explained by either three-dimensional mantle flow, a gap in the slab, variable slab hydration, and/or melt dynamics including ponding and interactions with the upper plate.

Citation

Schlaphorst, D., Harmon, N., Kendall, J., Rychert, C., Collier, J., Rietbrock, A., …Wilson, M. (2021). Variation in Upper Plate Crustal and Lithospheric Mantle Structure in the Greater and Lesser Antilles from Ambient Noise Tomography. Geochemistry, Geophysics, Geosystems, 22(7), Article e2021GC009800. https://doi.org/10.1029/2021gc009800

Journal Article Type	Article
Acceptance Date	Jun 21, 2021
Online Publication Date	Jun 25, 2021
Publication Date	Jul 12, 2021
Deposit Date	Jun 30, 2021
Publicly Available Date	Jul 8, 2021
Journal	Geochemistry, Geophysics, Geosystems
Electronic ISSN	1525-2027
Publisher	American Geophysical Union
Peer Reviewed	Peer Reviewed
Volume	22
Issue	7
Article Number	e2021GC009800
DOI	https://doi.org/10.1029/2021gc009800

Files

Accepted Journal Article (7.2 Mb)
PDF

Copyright Statement
Accepted for publication in Geochemistry, Geophysics, Geosystems. Copyright 2021, American Geophysical Union. Further reproduction or electronic distribution is not permitted