Sample 27MW2134 is a pink-orange granite composed
of K-feldspar (38%), plagioclase (30%), quartz (25%), sericite (4%),
muscovite (1%), and trace chlorite, oxides, and possibly zircon. Nearly
equigranular K-feldspar (~0.6 mm) shows tartan twinning and some
exsolution. Plagioclase, of similar grain size to K-feldspar, shows
albite twins and is severely altered to sericite/muscovite. Some quartz
exhibits 120º grain boundaries, suggesting recrystallization has
occurred. This granite is unlike most of the other granites due to the
lack of biotite. Chlorite, occurring in trace amounts, may have replaced
biotite, but may also have replaced other mafics like hornblende. |