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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 **************************************** * 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 * **************************************** %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%