TY - JOUR
T1 - The effect of crystal orientation on the wetting behaviour of silicate melts on the surfaces of spinel peridotite minerals
AU - Schäfer, Frank N.
AU - Foley, Stephen F.
PY - 2002/5
Y1 - 2002/5
N2 - The effect of crystal anisotropy on wetting angles of equilibrium silicate melts on crystal faces of spinel, diopside, enstatite and olivine has been determined experimentally by the sessile melt drop technique. The anisotropy, ÃγSL, of solid-liquid interfacial energies (γSL(max)-γSL(min)) can be related to the wetting angles, ψ, by ÃγSL ∝ /cos ψ (max) - cos ψ (min)/ = Pw(-maA7SL) Normalising to the smallest wetting angle gives values of Pw for diopside = 0.0728, olivine = 0.0574, orthopyroxene =0.0152, and spinel = 0.0075. Crystal anisotropy influences grain-scale morphology of small-degree partial melts, permeability and the melt connectivity threshold, ∅C. Results show that, at sufficient melt fractions, diopside should increase permeability in a peridotitic matrix, whereas enstatite should lower it. Despite its low anisotropy, spinel contributes positively to permeability and ∅C because of its high surface energies. These results suggest that harzburgitic mineral matrices typical of the subcratonic mantle should impede the movement of low-degree partial melts, whereas melts should flow more easily through spinel lherzolites.
AB - The effect of crystal anisotropy on wetting angles of equilibrium silicate melts on crystal faces of spinel, diopside, enstatite and olivine has been determined experimentally by the sessile melt drop technique. The anisotropy, ÃγSL, of solid-liquid interfacial energies (γSL(max)-γSL(min)) can be related to the wetting angles, ψ, by ÃγSL ∝ /cos ψ (max) - cos ψ (min)/ = Pw(-maA7SL) Normalising to the smallest wetting angle gives values of Pw for diopside = 0.0728, olivine = 0.0574, orthopyroxene =0.0152, and spinel = 0.0075. Crystal anisotropy influences grain-scale morphology of small-degree partial melts, permeability and the melt connectivity threshold, ∅C. Results show that, at sufficient melt fractions, diopside should increase permeability in a peridotitic matrix, whereas enstatite should lower it. Despite its low anisotropy, spinel contributes positively to permeability and ∅C because of its high surface energies. These results suggest that harzburgitic mineral matrices typical of the subcratonic mantle should impede the movement of low-degree partial melts, whereas melts should flow more easily through spinel lherzolites.
UR - http://www.scopus.com/inward/record.url?scp=0036589901&partnerID=8YFLogxK
U2 - 10.1007/s00410-001-0339-0
DO - 10.1007/s00410-001-0339-0
M3 - Article
AN - SCOPUS:0036589901
SN - 0010-7999
VL - 143
SP - 254
EP - 261
JO - Contributions to Mineralogy and Petrology
JF - Contributions to Mineralogy and Petrology
IS - 2
ER -