Dear Pulak,
We found the assemblage garnet-andalusite-staurolite-biotite-muscovite in
west-central Maine in M2. I doubt that it occurs without muscovite very
often though. The garnet is commonly high in Mn. Most of the rocks are
retrograded by M3, or prograded in some places by M3. Chuck Guidotti also
has some papers referring to this event, but again muscovite is almost
always present. Here is the reference.
Dickerson, R.P., and Holdaway, M.J., Acadian metamorphism associated with
the Lexington batholith, Bingham, Maine. American Journal of Science 289.
945-974, 1989.
I hope this helps.
Mike Holdaway
|