COAST LINE LOS ANGELES TO SAN FKANCISCO. 119 



crust with 



vest edge, under the valley. The surface 

 with the Paso Robles formation, throu<?h w 



stronger streams have cut into the midcrlymg Santa Margarita 

 formation. 



The Paso Robles formation forms the near hiUs on both sides of the 

 river between San Miguel and Bradley. Just north of the mouth 

 of Indian Valley, at Chanslor (205.5 miles from San Francisco) there 

 is an excellent example of one of the landslides which frequently 

 occur in the soft Paso Robles formation when it has been under- 

 mined by stream erosion. 



From McKay a branch raihoad runs to the Stone Canyon coal 

 mine (24 miles), now worked only in a small way to supply local 

 demand* The coal of Stone Canyon occurs in the lower part of the 

 Vaqueros sandstone and is the best in Cahfornia. In places the bed 

 is 16 feet thick, and if it were not for the abundant supply of oil in 

 the State the coal would probably again be mined for shipment. 



Near the mouth of Sierra River (on the left) the raihoad bears to 

 the right and crosses Sahnas River on a steel bridge that was partly 

 washed away in 1913. Two of the old steel spans may be seen 

 ^yi^g 11^ the river to the left. Very Httle water flows over the sandy 

 river bed in summer, but there is a large flow beneath the sm-face. 



Bradley, though a small town, is the center of a considerable 

 cattle industry. The alluvial flat and terrace of Salmas River in this 



vicinity are shown in Plate XXIX, A. Beginning 

 Bradley, about 2J miles northwest of Bradley there are indi- 



Eievation 538 feet. catious of a line of disturbance, apparently a great 



L^!SSs^279 miles, f^^*, aloug the wcst side of Sahnas Valley. A little 



farther on, at 192.5 miles from San Francisco, the 

 prominent bluffs on the right (east) are of the Paso Robles formation 

 and the hills on the left, across the river, are composed largely of the 

 Monterey shale. Inasmuch as the Paso Robles normally overhcs the 

 Monterey, their occurrence so close together at nearly the same level 

 suggests that there is an extensive fault between them, along the 

 river. That a largo fault occurs along the west border of the Sahnas 

 Valley is indicated also by the presence of a line of springs in that 

 region. Many of these springs are hot, and some of them, as at 

 Paso Robles andParaiso (pa-ra-ee'so, Spanish for paradise), have been - 

 unproved as health resorts. Along this fault hne the gi^eat earth 

 block previously referred to as sloping up toward the crest of the 

 Gabilan Range on the northeast side of the Salinas Valley must have 

 dropped down, bringing the Paso Robles gravels into Juxtaposition 

 with the Monterey and Santa Margarita (Miocene) beds and pro- 

 viding the structural conditions for the subsequent erosion of the 

 long, straight valley. 



