389 



the right in a high cliff a fault appears in which buff -colored 

 Monterey sandstones and shales (Miocene) rest with marked 

 unconformity upon black Eocene shales. East of Vallejo Junc- 

 tion is Carquinez Strait, through which the waters of the Sacra- 

 mento and San Joaquin rivers pass to San Francisco Bay and 

 through the Golden Gate to the ocean. Along the south shore 

 of Carquinez Strait the steep bluffs show many good exposures 

 of folded sedimentary rocks (Chico formation, of Upper Cre- 

 taceous age) . From an elevated point Mount Diablo may be 

 seen, about 15 miles south and east. If the route via Walnut 

 Creek is followed, turn east to reach the mountain, then con- 

 tinue north. It will be necessary to ferry across the strait from 

 Martinez or Port Costa to Benicia. 



State Agricultural College on Plain 



but Little above Sea Level 



North and east of Benicia rocky headlands crowd in upon 

 Carquinez Strait, and fine exposures of Cretaceous and Tertiary 

 sandstones and shale occur in the cliffs and road cuts. Suisun 

 Bay lies close at the right and Suisun Flats, a swampy district 

 but little above tidewater, extends for 16 miles to the towns 

 of Suisun and Fairchild. The foothills of the Coast Range are 

 passed through to Elmira. Then a broad alluvial plain ensues 

 to Davis, where is located the State Agricultural College and 

 U. S. Experiment Station. The land about Davis is a smooth 

 plain but little above tide-level, but high enough to be drained 

 and used for agricultural purposes. Between Davis and Sacra- 

 mento marshy tule-lands extend for many miles. Sacramento 

 River is crossed just below the mouth of American River to 

 the city of Sacramento. 



Levees Protect Flood plain of Lower 



Sacramento River 



The lower courses of the main streams in the Sacramento 

 Valley have built their floodplains above the level of the ad- 

 jacent land, and levees have been built to protect the farm 



