——— 
Rocks of Southern California.—Hershey. 285 
up to 18’ and a sp. g. of 2.66. It is therefore an andesine. The feld- 
spar is partially decomposed, the alteration products being epidote and 
a colorless :vica probably paragonite, both abundant. The rock bears 
the same relation to dioryte that the anorthosytes do to gabbro, 
C. Same as B. Sp. g., constituent feldspar, 2.66. 
D. An allotriomorphic granular aggregate of plagioclase having 
symmetrical extinctions of albite lamellae ranging up to 25’ and a 
sp. g. of 2.65. This feldspar is andesine. It is rather cloudy with the 
decomposition products. With the andesine there is a little green 
hornblende but not enough to detract from its essentially feldspathic 
character. The feldspar forms two kinds of aggregates in respect of 
texture, a fine-grained granular aggregate occupying the spaces be- 
‘tween the coarser aggregate of large anhedrons. 
The rock bears the same relation to dioryte that anorthosyte does 
to gabbro. 
The first represents the commonest kind, consisting of a 
elear feldspar of a delicate bluish or black tint and green fi- 
brous horneblende; but the most remarkable variety of the ser- 
ies is a massive crystalline of medium texture, of a pure white 
color and a chalky appearance as seen from a distance. Speci- 
mens B. and C. as described above are fairly representative 
of it. It is known to the people of the vicinity as limestone. It 
begins at the small canon near Lang where it adjoins a coarse 
dioryte of medium composition, and extends eastward fo1 
miles, spreading out into a belt several miles in width and 
forming considerable mountains which from a distance hav> 
a white color strangely contrasted with the dark dioryte moun- 
tains south of them. About 3,000 feet east of Lang, Soledad 
canon issues into a Pliocene basin through a narrow gorge cut 
into this white crystalline. In the vicinity, the white massif 
contains dikes of coarse dioryte and of finer dioryte containing 
needle-shaped crystals of primary hornblende somewhat like 
the “‘dioryte-porphyryte” of the Klamath region but coarser. 
Neither the dioryte proper, the white crystalline nor the dikes 
are appreciabivy sheared. No gneiss,schists nor granite occurs 
in this area. 
Another member of the series is an aggregate of feldspar 
of the clear, lilac variety. By the appearance and increase of 
green hornblende this grades into the normal variety. By the 
continued decrease of the feldspar, the series grades into the 
most basic which has scarcely any feldspar. Bluish iron ox- 
ide (probably in part ilmenite) occurs abundantly in the more 
basic varieties as a primary constituent. All are related—a 
