110 Mile Vie INOUSINIII 
at a great number of points in the granodiorite areas of the Sierra Nevada. 
Ratio, 1.5:1. Composed of albite> anorthite > quartz> orthoclase><bio- 
tite, amphibole, etc. Calculation approximate. 
Quartz-diorite— Turner. Average of five analyses of quartz-diorite from 
the Sierra Nevada. Jour. GEOL., Vol. VII, 1899, p. 149. Ratio, 1.4: 1. 
Composed of anorthite> albite> quartz>—orthoclase. In most of the 
quartz-diorites there are biotite, hornblende, and accessory minerals present. 
Calculation approximate. 
Amphibole-gabbro.—No. 1970 Sierra Nevada. Turner. Am. Jour. Sci. 
Vol. VII, 1899, p. 297. Ratio, 1:1.5. Composed of amphibole> anor- 
thite> albite > orthoclase. There are also present magnetite, pyrite, and 
pyrrhotite. Calculation approximate. 
Taking the monozite from Monzoni as a typical mozonite 
Widn a eti@ or (Omar iNo)e 42 Ain, ie is Clears wine i Wwe 
accept the method here proposed the granodiorite No. 103, the 
Butte granite, and the Idaho Basin granite are properly quartz- 
monzonites. If we likewise place the banatites with quartz- 
monzonites, then the granitite from Barr-Andlau, and many of 
the granodiorites of the Sierra Nevada will likewise be quartz- 
monzonites. 
The use of mineralogical terms in naming granolites of 
simple composition seems to me very desirable, although it is 
not practicable with rocks of complex composition. This can 
be done with most feldspathic types as follows: 
Orthosite composed chiefly of orthoclase 
Anorthosite  ‘“ si ‘“ anorthoclase 
Albitite GE sf «« albite 
Oligosite e “ oligoclase 
Andesinite ‘<< as “ andesine 
Labradite as a “ labradorite 
Anorthitite ‘“ if ** anorthite 
By the addition of abundant and essential quartz to the 
above ingredients we have appropriate names for the quartz- 
granolites as follows: quartz-orthosite or granite in its restricted 
use, quartz-andesinite, quartz-labradite, etc. In all the above 
cases the quartz is an essential and not an accessory ingredient. 
When accessory constituents are used in naming rocks the word 
