Dear geo-metamorphism members,
I am working in a project to understand the geology of a undersaturated
syenite complex of Paleoproterozoic age. The syenite contains a huge amount
of pelite xenoliths, some are from the host rocks and some are brough from
elsewhere in the continental crust, what is deduced from the great
diversity of xenoliths parageneses, ranging from UHT conditions (with
sapphirine + quartz) until amphibolite facies (Crd + Qtz + Sill +
phogopite); paragenesis with two micas, Qtz and oligoclase are common. One
paragenesis is the main subject of this e-mail. Some rocks or bands are
constituted just by green spinel + biotite. I have already looked for
references about the coexistence of these two minerals but I have found
nothing.
Could anybody help me with this subject?
Best regards
Renato
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