I've got a quartz bearing-epidote-chlorite-amphibole schist, from which I've couldn't get a trustworthy thermo-barometry data.

By microscopic analysis combined with the mineral chemistry of the amphiboles, I allocate my sample in the transition of Greenschist to Amphibolite Facies. The amphiboles chemistry show an edenite, pargasite and less common Mg Honrblende composition, all compossitions in apparent equlibrium state.

Can anybody suggest me any other way to approach this sort of problem?

Do you think wether the plagioclase-free metabasite is a protolite inherited feature or it's maybe related to the plagioclase use up during the metamorphic reactions to produce chlorite, epidote and calcic-amphiboles?