Agustin et al.,
Ilmenite rapidly exchanges its peak Mg/Fe/Mn in experiments and
during retrogression (Hayob et al., 1993). Thus, KD thermometry with
pyroxene and garnet generally records greenschist to low amphibolite
T. Ilmenite which is fully included in quartz or plagioclase may
preserve higher T. There is a similar problem with spinel and
magnetite although high T can be recovered by reintegration of
exsolution and ilmenite lamellae as long as the rock is not
recrystallized during retrogression. Minor elements such as Al, Fe,
Cr, V, Nb in rutile and Al, Cr, V, Nb in ilmenite and spinel are
probably slower to exchange, but phase equilibria involving these
substitutions in oxides is much more sketchy.
eric
>Hello everyone, does anyone on the list have work on the behavior of
>ilmenite and other opaques during high grade metamorphism. I am
>particularly interested on the probabbly of difussion and exsolution of
>some trace elements from the structure of this minerals.
>Thanks in advance for any comments
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