Name:   Granodiorite

Geologic Name:  None

Reference: Thiel, G.A., and Dutton, C.E., The architectural,
structural, and monumental stones of Minnesota:
Minnesota Geol. Survey Bull. 25, pp. 64, 86. 1933.

Microscopic characters:   Hypautomorphic-granular texture.  The essential
minerals are quartz, plagioclase, microcline, biotite and green hornblende
and a small amount of micropegmatite.  The feldspars are slightly clouded.
The accessory minerals are grains of magnetite, pyrite, apatite and zircon.
There is also a small amount of secondary calcite and sericite, the latter
largely in the feldspar.