LAWSON ~| 



palacheJ 



The Berkeley Hills. 



401 



so that even where there is 110 distinct outcrop of the strata, the 

 nature of the underlying formation is in this case revealed. 



This line of contact between the base of the Campan series and 

 the older rocks is interrupted by a fault in the line of the north fork 

 of Strawberry Creek, and it finally abuts squarely upon a more 

 important fault in the line of the south fork, and beyond this latter 

 fault the Campan formation does not extend. This fault has a 

 downthrow to the north of not less than 600 feet as measured by 

 the fact that the Campan beds, which must originally have had a 

 position above the level of the crest of Skyline Ridge, are let down 

 so as to abut upon the base of its north flank. This fault, thus 

 chopping off the extension of the Campan formation, serves as its 

 southern boundary for a distance along Strawberry Creek of about 

 1,1 50 feet, to a point where it intersects the Canon fault. From 

 this point the Canon fault serves as the eastern limit of the basal 

 formation of the Campan series. The Campan beds have been let 

 down by this fault against the cherts and shales of the Monterey 

 series and against the various members of the Berkeleyan series 

 which enter into the structure of Frowning Ridge. It is the rela- 

 tionship of the Campan beds to the Monterey and Berkeleyan 

 formations which proves the direction of the downthrow for this 

 fault, a question which could not be conclusively settled by the 

 facts observed on Skyline Ridge alone. 



The Canon fault may be traced very definitely to a point in the 

 upper part of Wildcat Canon, about 1,100 feet north of the summit 

 of Little Grizzly. At this point the base of the fault plane appears 

 to pass beneath the overlying Campan beds, but emerges from 

 beneath them again two-thirds of a mile distant, in the same 

 general direction, again faulting the lower Campan beds down 

 against the Berkeleyan rocks. 



Diastrophic Trough. — Thus far, in speaking of the Campan 

 series, we have referred to it as a basin, but as regards the basal 

 formation it will be evident from what has been stated above, that 

 it in reality occupies a disastrophic trough. One side of the 

 trough is the steeply-inclined plane of the Canon fault; the other 

 side is the gently-inclined pre-Campan surface, sloping north- 

 easterly till it intersects this fault. The general dip of the forma- 



