Density profile of pyrolite under the lower mantle conditions | INSTITUT DE PHYSIQUE DU GLOBE DE PARIS

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  Density profile of pyrolite under the lower mantle conditions

Type de publication:

Journal Article

Source:

Geophysical Research Letters, Volume 36 (2009)

ISBN:

0094-8276

Numéro d'accès:

WOS:000264678500001

URL:

http://www.agu.org/pubs/crossref/2009/2008GL036759.shtml

Mots-clés:

UMR 7154 ; Minéralogie ; high-pressure experiments ; lower mantle composition

Résumé:

The pyrolite model is one of the possible compositions of the Earth's lower mantle. The lower mantle's composition is generally modelled by comparing seismic observations with mineral physics data of possible lower mantle end-member phases. Here, we report the compression behavior of a natural KLB-1 peridotite (a representative composition of the pyrolite model) in a quasi-hydrostatic environment at simultaneous high pressure (P) and temperature (T), covering the entire range of lower mantle P-T conditions up to 112 GPa. This is the first experimentally determined density profile of pyrolite under the lower mantle conditions. The results allow us to directly compare the measured density of peridotite mantle along the geotherm with the Preliminary Reference Earth Model (PREM) derived from seismic observations, without extrapolation. The comparison shows significant mismatch between the two, which calls for a re-evaluation of the PREM density model or a non-pyrolite lower mantle composition. Citation: Ricolleau, A., et al. (2009), Density profile of pyrolite under the lower mantle conditions, Geophys. Res. Lett., 36, L06302, doi:10.1029/2008GL036759.