132 



Adventures in Scenery 



diatoms, microscopically minute animals encased in siliceous 

 shells. It is from this shale, the Monterey group of formations, 

 that the greater part of the wealth of California oil has been 

 obtained. 



Formations Disturbed by Earth Movements 



During Tertiary time violent and widespread disturbances 

 occurred. Sediments that had been deposited in the bay or arm 

 of the ocean that during this time filled the great basin have 



Courtesy Fresno County Chamber of Commerce 

 FIG. 37. Part of a 10,000-acre fig orchard in Fresno County. 



been broken by faulting, upheaved, bent, and folded. Out- 

 cropping on the flanks of the bounding mountain ranges, both 

 on the east and west sides of the great basin, Tertiary rocks form 

 the foothills of the ranges. The foothills are the outcropping 

 edges of the uplifted Tertiary formations. The strata dip or 

 incline toward the axis of the basin, those on the Sierra side 

 dipping toward the west-by-south and those on the Coast 



