Biotite occurs in the matrix as well as inclusions in staurolite and
garnet. The well-oriented biotite in the matrix has an XMg that ranges
from 0.52 to 0.58 and a TiO2 content that varies from 1.50 wt.% to 2.00
wt.%. The biotite inclusions in garnet and staurolite have XMg and TiO2
contents (0.55–0.57 and 1.95–2.00, respectively) similar to those of
the matrix biotite