Cape Verde hotspot from the upper crust to the top of the lower mantle

Details Cape Verde hotspot from the upper crust to the top of the lower mantle Cape Verde hotspot from the upper crust to the top of the lower mantle

Feb 2012

adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2012e%26psl.319..259v&link_type=abstract

Earth and Planetary Science Letters, Volume 319, p. 259-268.

Other

Scientific paper

We investigate the crust, upper mantle and mantle transition zone of the Cape Verde hotspot by using seismic P and S receiver functions from several tens of local seismograph stations. We find a strong discontinuity at a depth of ~ 10 km underlain by a ~ 15-km thick layer with a high (~ 1.9) Vp/Vs velocity ratio. We interpret this discontinuity and the underlying layer as the fossil Moho, inherited from the pre-hotspot era, and the plume-related magmatic underplate. Our uppermost-mantle models are very different from those previously obtained for this region: our S velocity is much lower and there are no indications of low densities. Contrary to previously published arguments for the standard transition zone thickness our data indicate that this thickness under the Cape Verde islands is up to ~ 30 km less than in the ambient mantle. This reduction is a combined effect of a depression of the 410-km discontinuity and an uplift of the 660-km discontinuity. The uplift is in contrast to laboratory data and some seismic data on a negligible dependence of depth of the 660-km discontinuity on temperature in hotspots. A large negative pressure-temperature slope which is suggested by our data implies that the 660-km discontinuity may resist passage of the plume.Our data reveal beneath the islands a reduction of S velocity of a few percent between 470-km and 510-km depths. The low velocity layer in the upper transition zone under the Cape Verde archipelago is very similar to that previously found under the Azores and a few other hotspots. In the literature there are reports on a regional 520-km discontinuity, the impedance of which is too large to be explained by the known phase transitions. Our observations suggest that the 520-km discontinuity may present the base of the low-velocity layer in the transition zone.

Affiliated with

Also associated with

No associations

Rating

Cape Verde hotspot from the upper crust to the top of the lower mantle does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Cape Verde hotspot from the upper crust to the top of the lower mantle, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Cape Verde hotspot from the upper crust to the top of the lower mantle will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-1838227