Sample 28MW0035 is an amphibolite with a
composition of hornblende (40%), plagioclase (35%), chlorite (9%),
quartz (8%), sericite (3%), epidote (2%), biotite (1%), oxides (1%), and
trace alkali-feldspar. Hornblende defines the foliation and shows
irregular grain boundaries, oxide inclusions, carlsbad twins and strong
pleochroism. A matrix of fine plagioclase is partially altered to
sericite. Coarse quartz grains occur in 0.4 mm-thick aggregates.
Epidote, showing subgrains and undulose extinction, occurs throughout.
Biotite defines a foliation and has been almost entirely altered to