Sample 28MW0031 is an orthogneiss with a
composition of quartz (33%), plagioclase (29%), K-feldspar (29%),
muscovite/sericite (4%), chlorite (2%), oxides (1%), and trace biotite,
sphene, epidote and garnet. Fine (0.1-0.4 mm) anhedral quartz grains
showing relict igneous textures dominate the matrix. Feldspars in this
sample have been considerably altered to sericite and epidote. Garnet is
believed to be of igneous origin.