Sample 03MW2152 is a porphyritic chlorite
orthogneiss with an estimated composition of plagioclase (30%),
K-feldspar (25%), quartz (20%), chlorite (15%), muscovite/sericite (6%),
epidote (3%), sphene (1%) and trace oxides. Porphyroclasts of feldspar
are wrapped by muscovite and chlorite (which probably replaced biotite)
resulting in an augen texture. Alteration of plagioclase has resulted in
the growth of secondary sericite. Quartz shows interlocking grains and
some aggregates aligned in the foliation. |