Lawson ~| 

 palac hej 



The Berkeley Hills. 



399 



in the geological history of the Coast Ranges, does not embrace all 

 of the Pliocene formations of the Berkeley Hills. Even within the 

 small area covered by our map there is a later and scarcely less 

 important basin of rock accumulation, which is also referable to the 

 Pliocene. This basin lies to the west of the Canon fault, and on 

 the north side of Strawberry Canon, extending thence northwesterly 

 beyond our map with an expanding area. The southwestern limit 

 of the basin, as left to us by erosion, is the exposed line of contact 

 of its basal beds upon the sandstones of the Shasta-Chico. This 

 line extends from near the southeast corner of La Loma Park 

 across Wolsey Canon and Serene Hill down to the bottom of 

 Strawberry Canon near Such's ranch. This line of demarkation 

 converges upon the Canon fault, as may be seen upon the map, 

 towards the southeast, so that the area with which we have here to 

 deal is wedge-shaped, the point of the wedge being in Strawberry 

 Canon at the base of Monument Hill. 



Within the area thus defined we have a post-Berkeleyan accu- 

 mulation of fresh-water beds and volcanic lavas and tuffs to an 

 aggregate thickness of about 800 feet, and it is probable that a 

 considerable fraction of the original volume has been removed by 

 erosion. 



This series of formations is designated the Campan series 

 because of its occurrence within the limits of the University 

 Campus. Owing to the lenticular character of some of the forma- 

 tions of the Campan series and the limited extent of others, it will 

 be inexpedient to limit our inquiry to any particular line of section. 

 The different formations will be described briefly in ascending 

 sequence, and reference will be made to various sections and expos- 

 ures at which the observations here recorded may be verified. 

 The smallness of the part of the basin with which we are here 

 concerned also renders a comprehensive account of the formations 

 more appropriate than an account of individual sections. 



The lowest and most important sedimentary member of the 

 Campan series consists chiefly of a formation of lacustrine conglom- 

 erate, intercalated with which are beds of light-colored and red 

 clay-shale, sandstone, and limestone, and occasional admixtures of 

 volcanic tuff, the entire formation having a thickness of about 250 



