RELATIONS OF THE CHICO. 97 



The Chico-Tejon consists to a great extent of coarse sandstone, with 

 a lesser amount of shale and conglomerate. 



RELATION OF THE CHICO TO LOWER CRETACEOUS AND PRE-CRETACEOUS. 



North of the fortieth parallel Mr Diller has found no break, ph3^sical 

 or paleontologic, in the whole series of Cretaceous sediments. While 

 he finds the lower portion of the series somewhat more crumpled, no 

 unconformity appears to exist. Whether we accept fully his conclusions 

 or reject them for other portions of the Coast ranges, it is very evident that 

 there were no great disturbances of a character to metamorphose the 

 lower portion. As to the hardening and solidification, there is very little 

 difterence between the extremes of the series. The work of the writer in 

 the Coast ranges has led him to believe that approximately similar con- 

 ditions existed during the deposition of the Cretaceous the whole length 

 of the state ; that there was a physical break, which is more or less promi- 

 nent in different localities. 



Along the trail from the Cachuma canyon across the San Rafael moun- 

 tains to the head of the Manzana a very thick section of the Cretaceous 

 is exposed. These beds rest at a steep angle against serpentine, jasper, 

 sandstone and shale of the older series. The base of the Cretaceous is a 

 black shale filled with calcareous nodules. As exposed in a canyon lead- 

 ing down to the Manzana the Cretaceous dips to the north at an average 

 angle of 45°, having a thickness of 8,000 or 10,000 feet. An ammonite 

 was found here, but in such a poor state of preservation that the species 

 could not be determined. At a distance of three miles down the canyon 

 the shales and sandstones are replaced by very extensive conglomerates, 

 with an apparent dip of 30°. The conglomerate is several thousand feet 

 thick. It is quite probable from what was observed in the northern part 

 of the county that tliis conglomerate is a part of the Chico-Tejon. It 

 would seem highly probable that future investigations will j^i'ove the 

 existence of the Lower Cretaceous in this region. The present evidence 

 favors the view of a break in the series. In the southern Coast ranges the 

 direct superposition of the Upper on the Lower Cretaceous has not been 

 observed, either one or the other of the divisions being absent. 



In the canyon of the Cuyamas the unconformity between the Creta- 

 ceous, probably the upper division, and the pre-Cretaceous series is most 

 plainly shown. The deepest portion of the canyon is cut through a series 

 of crushed sandstones and shales, containing small quartz-veins, jasj)er 

 and dark green, fine grained eruplives. On tliis series the Cretaceous 

 shale and sandstone was seen, resting at an angle of about 40°, wholly 

 unaltered and with regular bedding lines. Now, since the rocks which 

 have been referred to the ])re-Cretacei)Us series have l)een found nearly 

 continuous from the Klamath mountains south to this point, maintain- 



