78 



Adventures in Scenery 



ushered in the period of deposition of the Monterey group of 

 formations. The formations of the group have a wider distri- 

 bution south of San Francisco Bay than those of Eocene age, 

 and in some places they rest upon Cretaceous or older rocks, 

 showing a widespread extent of the sea during Monterey time. 

 The interval between the Tejon (Eocene) and Monterey 

 (Miocene) epochs was a notable one in the geologic history of 

 the region. Large areas were raised above the sea and the forma- 



Photo by G. W. Stose, U. S. Geol. Sitney 



FIG. 22. Terrace deposits (Quaternary) resting unconformably upon 

 eroded edges of Monterey shale (Miocene) , on coast of San Luis Obispo Bay. 

 The contact is a wave-cut plain. Rain sculpture is shown in the soft terrace 

 gravels. 



tions that had been deposited were bent, folded, and faulted by 

 earth disturbance and uplift. The new land surface was ex- 

 tensively eroded before the subsidence which brought in the 

 Monterey, so that Monterey rocks lie unconformably upon the 

 Tejon and older formations. 



A fact of much interest is the record of crustal oscillation 

 shown in the rocks. Four movements of depression and four of 



