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dc.date.accessioned2018-08-18T09:46:57Z
dc.date.available2019-06-07T22:47:23Z
dc.date.created2017-12-27T17:51:46Z
dc.date.issued2017
dc.identifier.citationBaron, Marzena Anna Lord, Oliver T. Myhill, Robert Thomson, Andrew R. Wang, Weiwei Trønnes, Reidar G Walter, Michael J. . Experimental constraints on melting temperatures in the MgO–SiO2 system at lower mantle pressures. Earth and Planetary Science Letters. 2017, 472, 186-196
dc.identifier.urihttp://hdl.handle.net/10852/63169
dc.description.abstractEutectic melting curves in the system MgO–SiO2 have been experimentally determined at lower mantle pressures using laser-heated diamond anvil cell (LH-DAC) techniques. We investigated eutectic melting of bridgmanite plus periclase in the MgO–MgSiO3 binary, and melting of bridgmanite plus stishovite in the MgSiO3–SiO2 binary, as analogues for natural peridotite and basalt, respectively. The melting curve of model basalt occurs at lower temperatures, has a shallower slope and slightly less curvature than the model peridotitic melting curve. Overall, melting temperatures detected in this study are in good agreement with previous experiments and ab initio simulations at ∼25 GPa (Liebske and Frost, 2012; de Koker et al., 2013). However, at higher pressures the measured eutectic melting curves are systematically lower in temperature than curves extrapolated on the basis of thermodynamic modelling of low-pressure experimental data, and those calculated from atomistic simulations. We find that our data are inconsistent with previously computed melting temperatures and melt thermodynamic properties of the SiO2 endmember, and indicate a maximum in short-range ordering in MgO–SiO2 melts close to Mg2SiO4 composition. The curvature of the model peridotite eutectic relative to an MgSiO3 melt adiabat indicates that crystallization in a global magma ocean would begin at ∼100 GPa rather than at the bottom of the mantle, allowing for an early basal melt layer. The model peridotite melting curve lies above the mantle geotherm at the core–mantle boundary, indicating that it will not be molten unless the addition of other components reduces the solidus sufficiently. The model basalt melting curve intersects the geotherm at the base of the mantle, and partial melting of subducted oceanic crust is expected.en_US
dc.languageEN
dc.publisherElsevier Science
dc.rightsAttribution-NonCommercial-NoDerivatives 4.0 International
dc.rights.urihttps://creativecommons.org/licenses/by-nc-nd/4.0/
dc.titleExperimental constraints on melting temperatures in the MgO–SiO2 system at lower mantle pressuresen_US
dc.typeJournal articleen_US
dc.creator.authorBaron, Marzena Anna
dc.creator.authorLord, Oliver T.
dc.creator.authorMyhill, Robert
dc.creator.authorThomson, Andrew R.
dc.creator.authorWang, Weiwei
dc.creator.authorTrønnes, Reidar G
dc.creator.authorWalter, Michael J.
cristin.unitcode185,15,22,40
cristin.unitnameSenter for Jordens utvikling og dynamikk
cristin.ispublishedtrue
cristin.fulltextpostprint
cristin.qualitycode2
dc.identifier.cristin1532228
dc.identifier.bibliographiccitationinfo:ofi/fmt:kev:mtx:ctx&ctx_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:journal&rft.jtitle=Earth and Planetary Science Letters&rft.volume=472&rft.spage=186&rft.date=2017
dc.identifier.jtitleEarth and Planetary Science Letters
dc.identifier.volume472
dc.identifier.startpage186
dc.identifier.endpage196
dc.identifier.doihttp://dx.doi.org/10.1016/j.epsl.2017.05.020
dc.identifier.urnURN:NBN:no-65731
dc.type.documentTidsskriftartikkelen_US
dc.type.peerreviewedPeer reviewed
dc.source.issn0012-821X
dc.identifier.fulltextFulltext https://www.duo.uio.no/bitstream/handle/10852/63169/1/EPSL-2017-Baron-accepted%2Bmanuscript.pdf
dc.type.versionAcceptedVersion
dc.relation.projectNFR/223272


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