360 



University of California. 



[Vol. 1. 



founded with the normal disintegration of the sandstone in the 

 superficial zone of weathering. In the latter case the sandstone is 

 broken up into angular pieces by the intersection of divisional 

 planes along which no movement has taken place. The disinte- 

 grated zone extends down for several feet below the surface, and the 

 angular fragments become rapidly smaller towards the surface, and 

 eventually pass into the soil. In this disintegration of the surface 

 zone of rock under the influence of alternate saturation and desicca- 

 tion and of other meteoric agencies, we have an excellent illustra- 

 tion of the general process of the conversion of rock into seden- 

 tary soil. 



These sandstones, with their subordinate beds of shale, occur in 

 large stratigraphic volume on both sides of Strawberry Canon. On 

 the north side they are found extending to the top of Serene Hill 

 and across Wolsey Canon; and on the south side, as before stated, 

 to the summit of Skyline Ridge. They also form the bed-rock 

 over which fun the waters of Strawberry Creek and Hamilton 

 Gulch. They are also well exposed in Telegraph Canon and 

 abundantly along the range to the southeast, but to the northwest 

 the formation thins out rapidly and we see little of it beyond North 

 Berkeley. The general strike of the rocks is coincident with the 

 trend of the range, and the general dip is easterly, or rather north- 

 easterly, but at variable angles, and no section in the vicinity of 

 Berkeley reveals the attitude of the rocks sufficiently well to afford 

 data for a satisfactory estimate of the thickness of the series. It is 

 probably, however, not less than 2,000 feet. 



The only fossils which these sandstones have yielded in the 

 vicinity of Berkeley are fragments of a large inoceramus and a 

 small pecten. A few miles along the range to the southeast, how- 

 ever, at Shepherd's Canon, a number of cchinoderms and other 

 fossils have been found which indicate the Chico age of the rocks, 

 and the sandstones are of the same petrographical character as 

 those of the established Chico in not distant parts of the Coast 

 Ranges. They are, therefore, regarded as a part of the Chico 

 formation. The highest part of the formation on Skyline Ridge is 

 a thickness of perhaps fifty feet of a soft ocherous-yellow, friable 



