A granite, sample 27MW0105 contains plagioclase
(40%), K-feldspar (36%), quartz (20%), biotite (3%), and trace
muscovite, sphene, oxides, chlorite, and epidote. Plagioclase grains are
equigranular and fine-grained, showing some recrystallization and
myrmekite. K-feldspar occurs as tartan twinned matrix grains and as
perthitic porphyries with plagioclase inclusions and overgrowths. Quartz
grains show a wide size variation and occur in the matrix. Biotite is
partially overgrown by chlorite, and is aligned in a weak foliation.
Sphene is visible in hand sample as mm-sized rhombohedral grains. |