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Grain‐scale processes during isothermal‐isobaric melting of lherzolite
Author(s) -
Lo Cascio Mauro,
Liang Yan,
Hess Paul C.
Publication year - 2004
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2004gl020602
Subject(s) - partial melting , geology , peridotite , isobaric process , olivine , geochemistry , isothermal process , mineralogy , mantle (geology) , thermodynamics , physics
The grain‐scale processes of peridotite partial melting were examined at 1340°C and 1.5 GPa using reaction couples formed by juxtaposing pre‐synthesized clinopyroxenite against pre‐synthesized harzburgite. Reaction between clinopyroxenite and harzburgite produces a melt‐enriched, orthopyroxene‐free, olivine + clinopyroxene reactive boundary layer. Clinopyroxene compositions vary systematically across the reactive boundary layer with compositional trends similar to the published clinopyroxene core‐to‐rim compositional variations in the bulk lherzolite partial melting studies conducted at similar P ‐ T conditions. The growth of the reactive boundary layer is at the expense of the harzburgite and is consistent with grain‐scale processes that involve dissolution, reprecipitation, and diffusive exchange between the interstitial melt and surrounding crystals.