Sample 03MW2623 is a granite with a composition of
K-feldspar (45%), plagioclase (30%), quartz (20%), biotite (2%), oxides
(1%), and trace muscovite and epidote. This sample is characterized by
large, extremely perthitic (string perthite) porphyries of untwined
K-feldspar. Plagioclase occurs as finer matrix grains and inclusions in
K-feldspar, in some places showing albite twinning. Serrated quartz
grains exhibit undulose extinction and subgrain development. "Flattened"
quartz grains near the edges of K-feldspar porphyries may represent
partial quartz annealing. Biotite is microcrystalline and does not
define a foliation.