SOUTHERN PACIFIC LINES 263 
road, but the water sinks rapidly when it reaches the valley fill. In 
times of flood, however, it runs far down the Coachella Valley and has 
been known to reach Salton Sea. (Turn to sheet 28.) 
Palm Springs Station is 7 miles northwest of Palm Springs, a popu- 
lar winter resort in the valley that separates the Santa Rosa Moun- 
Palm _Sorings tains from the San Jacinto Range. The village is of 
Sta considerable size and has many luxurious homes and 
Elevation 1,130 feet. ide The springs issue from the valley fill, 
New Orleans 1,901 probably rising on a fault fissure in rocks below this 
deposit, as the tepid water indicates a deep-seated 
source. The water has a very low mineral content (243 parts per 
million), mostly sulphates and chlorides of sodium and potassium, 
silica, and a small amount of sulphureted hydrogen, which soon 
passes off. The flow, estimated by Brown at about 10 gallons a 
minute, makes a pool some 60 feet in diameter. 
These springs belong to ‘Mission’? Indians, who live on several 
small reservations in the valley. These people are of the Yuman 
family, now greatly diminished in number. Ata place about 1 mile 
north of Coachella siding the United States Government has a small 
pumping plant to supply well water for irrigation on the Cabazon 
Indian Reservation. 
The San Jacinto Mountains present steep slopes, especially to the 
northeast, Snow Creek, for example, dropping 4,000 feet in 1 mile of 
its course; end many other deep canyons head in this slope. The 
southwest . de of this range is less steep and is bounded by the San 
Jacinto f it, movement on which in 1899 and 1918 caused serious 
earthque °s in San Jacinto and Hemet. The east side of the range is 
also ver precipitous, for at Palm Springs, which is at an elevation 
of 455 _ 2t, steep slopes rise more than 10,000 feet to the summit, 
San Manindia Peak, as shown in Plate 42, A. This steep front is largely 
due to a great foal trending north, Ey is clearly exposed just west 
of Palm Springs Station. Here ie mountain face consists of granite 
and gray marble in layers that dip 75° or more to the northeast, and 
a prospector’s tunnel shows a fault breccia with slickensides. This 
long before a granite was intruded, | classed as granite gneiss, a rock exten- 
e been in late Jurassic | sively exposed on the west side of Palm 
time. The aadtaiie of their meta- | Canyon and in the region about 
morphism is indicated by the fact that | Andreas Canyon. Its thickness may 
they are crystalline far away from the | be 4,000 feet. The intrusive nature of 
granite contact. Their age may be | the granite is proved by the contact 
early Paleozoic, as they resemble rocks | relation and by the presence of included 
of that age in the region to the north. | masses of schist (xenoliths) and lime- 
Although the great central mass of | stone. The contact line is very irregu- 
granite is massive, there is a marginal | lar. (Fraz 
phase which is so schistose as to be 
