Melting of Peridotite to 140 Gigapascals | INSTITUT DE PHYSIQUE DU GLOBE DE PARIS

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  Melting of Peridotite to 140 Gigapascals

Type de publication:

Journal Article

Source:

Science, Volume 329, Ticket 5998, p.1516-1518 (2010)

ISBN:

0036-8075

Numéro d'accès:

ISI:000281869000039

URL:

http://www.sciencemag.org/content/329/5998/1516

Mots-clés:

UMR 7154 ; Minéralogie

Résumé:

Interrogating physical processes that occur within the lowermost mantle is a key to understanding Earth's evolution and present-day inner composition. Among such processes, partial melting has been proposed to explain mantle regions with ultralow seismic velocities near the core-mantle boundary, but experimental validation at the appropriate temperature and pressure regimes remains challenging. Using laser-heated diamond anvil cells, we constructed the solidus curve of a natural fertile peridotite between 36 and 140 gigapascals. Melting at core-mantle boundary pressures occurs at 4180 +/- 150 kelvin, which is a value that matches estimated mantle geotherms. Molten regions may therefore exist at the base of the present-day mantle. Melting phase relations and element partitioning data also show that these liquids could host many incompatible elements at the base of the mantle.

Notes:

Fiquet, G. Auzende, A. L. Siebert, J. Corgne, A. Bureau, H. Ozawa, H. Garbarino, G.