385 



at Haywards. Eastward from Haywards is the broad alluvial 

 Livermore Valley. The route leads across the Diablo Range, 

 the easternmost range of the Coast Range system. 



Diablo Range Broken by Many Faults 



The rocks of the Diablo Range are metamorphic sedimen- 

 tary and igneous rocks of the Franciscan formation, overlain in 

 places by Cretaceous and Tertiary shales, sandstones, and con- 

 glomerates. East of Haywards is a fault or break in the crust 

 of the earth. East of the fault Chico (Upper Cretaceous) 

 rocks are exposed, and immediately west of the fault the Knox- 

 ville (Lower Cretaceous) rocks are at the surface, covered and 

 obscured by the surface soil. Southeast of Haywards other 

 faults occur, which show the stresses and strains by which the 

 Diablo Range has been shattered and uplifted. 



Axis of Great Central Valley but Little 



above Sea Level 



Rolling hills of the Diablo Range are crossed to Tracy, on 

 the flat bottom of the Great Central Valley of California. 

 From Tracy to Manteca the route is across Tom Paine Slough, 

 Paradise Cut, and San Joaquin River. Here is the low axis of 

 the Great Central Valley, through which meanders San Joaquin 

 River. The valley floor is made up of alluvium washed into 

 the valley by streams on either side. The great Valley trough 

 is a sunken basin into which in Cretaceous and Tertiary and 

 later time deposits of sand, silt, and gravel have been borne. 

 The San Joaquin River, only about 20 feet above sea level, 

 meanders sluggishly over the nearly level floor. North of 

 Tracy are old abandoned river channels or sloughs, and canals 

 have been cut to salvage the land from overflow of flood waters. 

 The soils are sands, sandy loams, and loams. The Great Valley 

 of central California is one of the world's great agricultural 

 districts. A great variety of agricultural crops grains, forage 

 crops, orchard and garden fruits, and vineyard products make 

 this a region of tremendous possibilities. 



