is Sil + Grt + Bt + Kfs + Pl + Qtz.
This sample comes from the contact aureole around
one of the younger granites, rather than from the
regional sillimanite zone, but it adequately
represents a typical assemblage in the upper part
of the amphibolite facies. Sillimanite is mostly of
the fibrolitic variety, forming sheaves draped
around the grain boundaries. Garnet forms rather
small rounded crystals. Biotite occurs in
red-brown, poorly-aligned flakes. Matrix quartz and
plagioclase are granoblastic.
Field of view
is 7 mm wide.