Dear All,
I'm working on calc-silicates bearing the assemblage carbonate scapolite +
plag (An92)+ calcite. The scapolite is mizzonitic (EqAn=0.68). a-X models
assuming complete disordering (Baker and Newton, 1995, Oterdoom and
Gunter, 1983) yield unreasonably low temperatures (approx 450-500oC) for
mizzonite and an ideal Al/Si model yields temperatures I believe are too
high for the rocks (710oC or so). Does anyone know of a-X models that work
well for more sodic carbonate scapolite compositions approaching mizzonite?
Cheers,
Nick Bulloss
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* Nick Bulloss *
* Department of Geology and Geophysics *
* University of Minnesota *
* 108 Pillsbury Hall *
* 310 Pillsbury Drive SE *
* Minneapolis MN 55455-0219 *
* *
* Phone: (612) 624-8557 *
* Fax: (612) 625-3819 *
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