Lithospheric structure of Iberia and Morocco using finite‐frequency Rayleigh wave tomography from earthquakes and seismic ambient noise

We present a new 3‐D shear velocity model of the western Mediterranean from the Pyrenees, Spain, to the Atlas Mountains, Morocco, and the estimated crustal and lithospheric thickness. The velocity model shows different crustal and lithospheric velocities for the Variscan provinces, those which have...

Full description

Saved in:
Bibliographic Details
Published in:Geochemistry, geophysics, geosystems : G3 geophysics, geosystems : G3, 2017-05, Vol.18 (5), p.1824-1840
Main Authors: Palomeras, I., Villaseñor, A., Thurner, S., Levander, A., Gallart, J., Harnafi, M.
Format: Article
Language:English
Subjects:
Ambient noise
Asthenosphere
Continental margins
Continents
Crustal thickness
Deformation
Earthquakes
Evolution
Imaging techniques
Lithosphere
Magma
Moho
Moho and LAB map
Mountains
Rayleigh wave tomography
Rayleigh waves
Seismic activity
Shear
Shear wave velocities
Sinkholes
Subduction
Tomography
Upper mantle
Velocity
Wave velocity
Westernmost Mediterranean
Online Access:Request full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:We present a new 3‐D shear velocity model of the western Mediterranean from the Pyrenees, Spain, to the Atlas Mountains, Morocco, and the estimated crustal and lithospheric thickness. The velocity model shows different crustal and lithospheric velocities for the Variscan provinces, those which have been affected by Alpine deformation, and those which are actively deforming. The Iberian Massif has detectable differences in crustal thickness that can be related to the evolution of the Variscan orogen in Iberia. Areas affected by Alpine deformation have generally lower velocities in the upper and lower crust than the Iberian Massif. Beneath the Gibraltar Strait and surrounding areas, the crustal thickness is greater than 50 km, below which a high‐velocity anomaly (>4.5 km/s) is mapped to depths greater than 200 km. We identify this as a subducted remnant of the NeoTethys plate referred to as the Alboran and western Mediterranean slab. Beneath the adjacent Betic and Rif Mountains, the Alboran slab is still attached to the base of the crust, depressing it, and ultimately delaminating the lower crust and mantle lithosphere as the slab sinks. Under the adjacent continents, the Alboran slab is surrounded by low upper mantle shear wave velocities (Vs 
ISSN:1525-2027
1525-2027
DOI:10.1002/2016GC006657