Name:   Quartz Monzonite Porphyry

Geologic Name:  None

Reference: Crawfored, R.D., Geology and ore deposits of the Monarch
and Tomichi districts, Colorado: Colorado Geol. Survey Bull., No. 4, 
pp. 80, 84, 155, 159, 170, 182.  1913.

Microscopic characters:   Hypautomorphic-granular texture.  The rock
consists of phenocrysts of albite-oligoclase, quartz, biotite and 
hornblende in a granular groundmass composed of quartz, orthoclase, 
and plagioclase.  Magnetite, apatite and titanite are abundant
accessory constituents while zircon is less common.  The biotite and
hornblende are somewhat altered to chlorite and the feldspar to
sericite.  Some secondary epidote is present.