iQ H. W. FAIRBANKS — GEOLOGY OF THE COAST RANGES. 



eluded in the San Bernardino sierra the Santa Ynez range of Santa Bar- 

 bara count}^ This has its origin near point Conception, and, blending 

 with the San Rafael and Cuyamas mountains, extends eastward as a high 

 and rugged range to unite finally with the San Emidio mountains. 



Antisell ^ concluded, from the great elevation of the Miocene on the 

 flanks of the Cordilleras (the San Gabriel and Sierra Libre ranges, ter- 

 minating on the northwest in the San Emidio region), that the date of 

 upheaval was the same as that of the Coast ranges. It seems to the 

 writer that in the following quotation he expresses a truth the real sig- 

 nificance of which has never been appreciated. He says : 



"Nothing appears easier to trace than the relation of connection and continuity 

 between the middle of the Coast ranges (San Jose and point Pinos) and the San 

 Emidio, and between the San Emidio and the Cordilleras, a fact now for the first 

 time stated and brought to light by the exploration of this survey, by which there 

 ha^s been traced a continuous granite chain from point Pinos, at Monterey bay, to 

 the northwestern edge of the Cajon pass, terminating at the Kikel Mungo moun- 

 tain." 



This granitic chain to which he refers, although it was not found to 

 be continuous on the surface, seems to represent a single axis. There is 

 little doubt that future work will prove the unity of the whole body of 

 granitic rocks and crystalline schists along this very regular northwest 

 prolongation of the Peninsula range. 



According to all observers, no topographic distinction can be made in 

 the northern part of the state. Beginning at San Erancisco bay, there 

 is a gradual rise in the mountains northward to the Yallo Bally and 

 other ranges in Humboldt and Trinity counties. 



Rocks of the Region and their Relations. 



the wholly crystalline basement complex. 



Constitution and Distribution. — The basement rocks in the Coast ranges 

 consist of granite, crystalline schists and limestone. The exposed area 

 of these rocks, although considerable, is small in comparison with the 

 extent of this mountain region, but the part played by them in the de- 

 velopment of its geologic history is important. The known outcrops 

 were described in a former publication and illustrated by means of a 

 sketch map.f It is sufficient to add, perhaps, that they seem to be ar- 

 ranged along two axes. To the eastern one belong the granite at point 

 Reyes and vicinity, that of the Santa Cruz and Gavilan ranges, and the 

 small area near Cholame valley, in eastern Monterey county. To the 



* Pacific Railroad Survey, vol. vii, p. 90. 

 t American Geologist, vol. xi, pp. 71, 72. 



