402 University of California Publications in Geology [Vol. 9 



were supposed to occur iu this vicinity, according to Whitney. The 

 following notes were made incidentally. 



The rocks recognized in the area are: (1) The Basement Com- 

 plex, the bedrock series; (2) The lone Eocene of the superjacent 

 series; (3) Pleistocene (?) shore gravels (of Turner). 



The basement complex consists of slates of probable Mariposa 

 age, amphibolite schists and associated granitoid rocks. The latter 

 rocks are well exposed in Burns Creek at the county line. Schists 

 and slates are in general found in the area northeast of the old 

 Fort Miller road, along which Blake and the other geologists of the 

 Pacific Railroad expedition journeyed. Several points in their 

 description were easily recognized, particularly a small butte capped 

 by lone sandstone in the vicinity of Burns Creek, and figured in the 

 Pacific Railroad report. The slates and schists form an extensive 

 belt. 



The middle or sandstone member of the lone rests unconformably 

 on the slates and schists. It varies in thickness from 25 to 75 feet 

 in various portions of the field. Evidences of deposition along the 

 immediate shoreline were found. Distinct mud-cracks were seen 

 in the sandstone blocks on top of the butte northwest of the mouth 

 of Bear Creek Canon. The relations between the middle sandstone 

 member and the lower rhyolitic tuff member were well shown in an 

 east-west section along Burns Creek near the county line. (See 

 figure 6. An eighth-mile south of the county line the middle 



Fig. 6. Generalized section in vicinity of Burns Creek, showing relations between 

 lone members and the bedrock series. (Drawn by Chester Stock.) 



