Dear all,

I have been working on petrogenetic modeling of fractionation and partial melting processes for a while, but it appears that none of the current modeling program/software is able to successfully predict the hydrous phases behavior (e.g., amphibole and mica). There is no doubt that amphibole plays an important role at the late stage of magma evolution (e.g., on Si and Fe), and field evidence and thin section show that magma does fractionate amphibole, sometimes even to a large portion (e.g., hornblendite dike/vein). However, modeling programs (mostly MELTS, and some others such as Petrolog, etc.) I used predict nearly no amphibole (and/or mica) at the latest stage of magma fractionation even under water-saturated conditions. Also amphibole is generally absent during modeling of melting even an amphibolite. Many people have realized this problem, but I am wondering could any one provide a "better" modeling program or alternative methods to model these hydrous minerals, instead of empirically "assigning" a value to these minerals based on estimation of mineral modal proportions in cumulate assemblages (e.g., gabbro and hornblendite)? The purpose is to predict both major and trace element variations of magmas/melts evolving from intermediate (~56 wt.% SiO2) to highly felsic (>75 wt.% SiO2) composition.

Thank you.

Weiyao