2IPGP - Institut de Physique du Globe de Paris (IPGP, 1 rue Jussieu, 75238 Paris cedex 05 ; Université Paris Diderot, Bât. Lamarck A case postale 7011, 75205 Paris CEDEX 13 - France)
Abstract : 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 T 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.
https://hal.archives-ouvertes.fr/hal-00613178
Contributor : Danielle Thomas <>
Submitted on : Wednesday, August 3, 2011 - 11:28:31 AM Last modification on : Thursday, October 15, 2020 - 3:25:30 AM
G. Fiquet, A. L. Auzende, J. Siebert, A. Corgne, H. Bureau, et al.. Melting of Peridotite to 140 Gigapascals. Science, American Association for the Advancement of Science, 2010, 329, pp.1516. ⟨10.1126/science.1192448⟩. ⟨hal-00613178⟩