THE SANTA FE ROUTE. 161 
colemanite,! a crystalline borate of lime. These clays have been 
mined extensively for the production of borax. For many years large 
amounts of this material were treated at a refinery in Daggett, but 
the working of deposits of purer mineral in other areas has forced 
this refinery to cease operations. The ‘‘borax mines”’ are not visible 
from the railway except possibly by a very distant view to the north- 
west from Newberry. 
South of Daggett is a broad range of rounded hills which rise 
steeply from the valley. Canyons among them reveal thick deposits 
of gravel and sand, in part cemented into conglomerate. Beds of 
volcanic tuff and ash are also included in these deposits.? 
From Daggett to Barstow the train ascends the valley of Mohave 
River along its south side and in places follows the bank of that 
stream. For much of the year the water does not flow as far down 
as Daggett, but sometimes after a heavy rainfall the river bed is 
filled from bank to bank. The Mohave is one of the largest of the 
so-called lost rivers of the desert provinces. It rises on the north 
slope of the San Bernardino Range, flows northward for about 50 
miles, to Barstow, and then, east of Daggett, turns eastward into a 
stretch where it ceases to flow except at times of high flood, when it 
ultimately reaches Soda Lake, or the sink of the Mohave, just south 
of the Amargosa drainage basin. Mohave River is in sight of the 
railway all the way from a point near Newberry to a point south of 
Victorville. 
Near milepost 745, about 4 miles west of Nebo siding, the river 
valley is narrowed by high buttes of reddish lava (rhyolite) and other 
rocks, and bends considerably to the north around a ridge projecting 
1Colemanite contains 50.9 per cent of 
boric acid, 27.2 per cent of lime, and 21.9 
per cent of water. The deposits near 
Daggett are believed to have been formed 
by replacement of limy beds that were 
laid down locally during the evaporation 
of lake waters of Tertiary time, in inter- 
vals between some of the great outbursts 
of volcanic ejecta, which formed so large 
a part of the Tertiary deposits. The boric 
acid was undoubtedly derived from fresh 
voleanic materials and carried to its 
present position by underground waters. 
The deposits are in two principal beds, 
each 5 feet thick and about 50 feet apart. 
These beds dip steeply and have been 
Mined to a depth of 500 feet. 
borax produced in the United States is 
obtained alifornia mines, mainly 
from Lang, north of Los Angeles and 
Death Valley. The value of borate ores 
in 1913 is estimated at nearly $1,500,000. 
The borax is produced by heating the 
pulverized colemanite with a solution of 
m bonate, forming the soluble 
sodium borate, which crystallizes. 
2 At the base of this series is a coarse 
breccia which, in the canyon 6 miles 
south of Daggett, is underlain by granite. 
It contains large fragments of various 
igneous rocks and also of the underlying 
fneceiead rock (basalt), evidently - 
rived from Ord Mountain, a high ri 
miles southeast of Daggett. In the a 
western slope of this mountain there are 
mines of copper ore carrying gold. 
