Publication Date:
2014-07-10
Description:
The High Atlas and the Anti Atlas are fold-belts linked to former and still ongoing continent–continent collisions. Despite their high elevation, studies indicate a lack of a deep crustal root (〈40 km) while the lithosphere underneath is thinned (〈100 km). Previous explanations for this thinning include asthenospheric upwelling due to small-scale convection or a small plume. We use data recorded at stations in SW Morocco to analyse teleseismic P - and S -wave receiver functions. Our study yields a crustal thickness ranging from 24 km near the Atlantic coast to 44 km beneath the High Atlas with an average crustal V p / V s ratio of 1.77 in the entire region. A crustal thickness of 40 km cannot entirely support the topography in this region. Furthermore, we find the lithosphere–asthenosphere boundary at ~80 km depth. The lithosphere beneath SW Morocco is thinner than beneath northern Morocco (〉150 km). This lithospheric thinning supports the theory of thermal compensation of the mountain ranges. The mantle transition zone thickness amounts to 240 ± 10 km. The transition zone seems to be slightly thinned which might indicate a higher mantle temperature in this region.
Keywords:
Seismology
Print ISSN:
0956-540X
Electronic ISSN:
1365-246X
Topics:
Geosciences
Published by
Oxford University Press
on behalf of
The Deutsche Geophysikalische Gesellschaft (DGG) and the Royal Astronomical Society (RAS).
