California Tertiary Formations.—Hershey. 355 
and well characterized and widespread division of the Es- 
condido series. 
East of the main Escondido canyon, the lava spreads out 
to a width in places of several miles and continues east to a 
valley trending north from Acton. But in this belt of mainly 
dark reddish brown lava hills, there are irregular areas of 
granite. Apparently the region abounds in faults, and by 
them the lava (which here lies at a comparatively low angle, ) 
-has been in places carried up high, removed by erosion and 
the underlying granitic rock laid bare. Conglomerate and 
sandstone appear with the lava as far as a prominent eleva- 
tion south of the South Escondido canyon, but eastward there 
is apparently little of it present in the series which is mainly 
lava and tuff. 
The lava bends south to the railway at Acton and one 
small area of it lies south of that village, on the south side of 
Soledad canyon. <A narrow belt of lava crosses the summit 
about two miles north of the railroad, but just north of the 
summit it bends around to the southeast, spreads out to quite 
a belt and reaches the railroad about one and one-half miles 
northeast of Vincent station. Here on both sides of the rail- 
road are low hills of dark red and purple color, composed 
of a massive bed of coarse tuff, much like that in Tick 
canyon, but containing a greater variety of lava fragments. 
A rugged purple mountain just west of this, near the summit 
is probably also of this tuff. 
Farther down the slope toward Antelope valley, certain 
dark red conglomerates, dipping northerly at a rather high 
angle and appearing in very limited patches from under the 
Quaternary detrital slope, and composed of granitic debris, 
seem to represent the Escondido series. West of the rail- 
road near Palmdale, the bright colors of a low range of hills 
indicate the same. Here also it contains a gypsum bed which 
is extensively mined. Apparently a belt of the same series 
runs westerly a long distance on the south border of An- 
telope valley. Out in the broad desert plain eastward from 
Vincent are low hills whose rugged crests and dark reddish 
color suggest that they are an eastward extension of the lava 
belt of the Soledad country. 
