286 The American Geologist. May, 1902. 
complementary series. They are bound together by a common 
feldspar, andesine. 
This plutonic series is unique for southern California, if 
not for the state at large, judging from its appearance in the 
field. Its relation to the granite on the north was not de- 
termined and remains one of the interesting problems of Cal- 
ifornia historical geology. I predict that it will be 
found to be Mesozoic in age and just a little older than 
the granitic series. 
THE GNEISS NEAR BARSTOW. 
From near Barstow a broad low range of hills (in places 
truncated as if a dissected terrace) extends toward the west- 
northwest about four miles. The colors are black and dull 
light green with some spots of ‘white and yellow. Upon close 
inspection at three miles from Barstow, I was surprised to 
find the black color due to a very basic, dark greenish dioryte, 
generally massive, but in many places schistose from shearing. 
The dioryte is intruded by light pink granite, coarse pegmatitic 
in narrow dikes, seemingly apophyses of the great mass on the 
west. There are other masses of a light gray rock having the 
general appearance of dacyte porphyry of the Klamath region. 
Bands of schists among dioryte layers are mineralized and 
prospected for ores. 
A great black mountain several miles farther northwest is 
probably also of dioryte. This is a more ancient dioryte than 
any known in the Klamath and Sierra Nevada regions. 
About one mile west of Barstow, the same north bluff 
shows a series of dark and light greenish gneisses and schists. 
This is evidently an old complex intruded by the light colored 
granite. In particulars it is somewhat different from any- 
thing which I have seen in any other part of California, but 
while it is not exactly like any particular stratum in the “Kla- 
math and Pelona schist series, it has a general resemblance to 
them in the matter of character of metamorphism and appear- 
ance of age. I shall tentatively correlate this schist-gneiss 
series near Barstow, with the Pelona schists and neighboring 
gneisses and with the Abrams schist of the Klamath region 
ina general way, considering them all pre-Paleozoic and per- 
haps in part Archean and in part Algonkian. The schists and 
gneisses near Barstow, east of the great Sierra Nevada-Mo- 
