100 H.W. FAIKBANKS — GEOLOGY OF THE COAST RAI^GES. 



Ventura county along the Sespe, in the valley of the Sisquoc, canyon of 

 the Cuyamas river, south of the old mission of Santa Ynez, in the upper 

 valley of the Salinas, and many other places. The nonconformity is so 

 pronounced that it is surprising it should have escaped the observa- 

 tions of the older geologists. Dr Lawson has recently called attention 

 to a nonconformity between the Miocene and the supposed Tejon at 

 Carmel bay. 



The Santa Ynez is the greatest single range formed wholly of Miocene 

 strata. Lithologically, the Miocene is strongly marked, the bituminous 

 slate series of Whitney being the most widespread and characteristic 

 portion of the formation. These rocks have been studied recently by 

 Dr Lawson, with the development of some interesting features. Gypsum- 

 bearing clays are also very widely distributed. 



A great elevation of the Coast ranges took place at the close of the 

 Miocene, a fact noted by all geologists. There is no portion of the state 

 where this has been so great as in the San Emidio range, where the 

 Tertiary is found flanking mounts Frazer and Pinos at elevations vary- 

 ing from 5,000 to nearly 7,000 feet. Kocks of Miocene age cap the sum- 

 mit of the Monte Diablo range, in southwestern Fresno county, at an 

 elevation of 4,000 feet. In various places in Santa Barbara county the 

 Miocene has an elevation of from 3,000 to 4,000 feet. 



Formation of new Axes with each succeeding Elevation. 



A feature of peculiar interest in this region is the fact that the Coast 

 ranges do not consist of one main axis with a dominating range, but of 

 a number of wholly independent ranges formed at different geologic 

 periods. The northern portion of the Santa Lucia range, and the almost 

 buried granite ridge connecting it with the San Jose range, belongs to 

 one of the two or three earliest elevations in this region. At the pre- 

 Cretaceous upheaval a divergent range was formed which constitutes the 

 southern continuation of the rugged granite ranges of Monterey county. 

 Additional movements took place along this line, while the granite ridge 

 extending a little more easterly remained comparatively undisturbed. 

 The Santa Ynez range seems not to have existed until post-Miocene 

 times. 



A little south of Santa Margarita, along a line from the valle}^ to the 

 summit of the Santa Lucia, there is crossed successively the pre-Creta- 

 ceous, the Cretaceous and the Miocene. The presence of the older rocks 

 in the valleys or on the slopes of the range and the younger on the 

 summit is a condition very striking in many places. Over much of what 

 might be termed the Coast Range plateau the compressive and elevating 



