GEOLOGY OF THE SALINAS VALLEY 



331 



but have not yet been identified. There is also an extensive 

 area of serpentine along the southeastern boundary of Monterey 

 county. 



Since it was cut out the Salinas Valley has been filled with 

 sediments of Tertiary and later age. If there are sediments 

 older than the Miocene and newer than the metamorphics, they 



SKETCH MAP 



SHOWING TOPOGRAPHIC FEATURES 



OF 



MONTEREY COUNTY 

 CALIFORNIA 



are not uncovered at any place visited, with the exception per- 

 haps of a small area about the headwaters of the San Lorenzo 

 River near the county line, where there are rocks resembling the 

 Franciscan cherts. The Tertiary rocks are of Pliocene and Mio- 

 cene ages, and these are separated by an unconformity. 



Southeast from the town of Salinas the valley narrows down 

 from a broad rolling plain to a sloping floor about eight miles 

 wide, bounded on each side by granite mountains. Southwest 

 of Salinas, across the river, are highlands formed of Pliocene ' 

 sands and gravels, and deeply scored by ravines. 



1 The age of these beds was determined by Mr. Ralph Arnold, of Stanford Uni- 

 versity, from fossils collected by the writer fourteen miles east of Monterey, in the 

 center of section 20, 16 south, 3 east. 



