CLASSIFICATION BY THE BUREAU OF SOILS 109 



rolling to hilly. Much is too rough for the use of farm machinery. 



Maracopa Series. The soils range from dark gray through 

 the darker shades of brown and chocolate to black. They are loose, 

 porous, ordinarily well drained and free from alkali. The soils 

 represent assorted, colluvial material, largely derived from granite 

 rocks. When water is sifpplied they are well adapted to fruits, 

 vines and general farm crops. 



Lynden Series. The soils are light brown to reddish brown 

 and in the lighter textured sandy types often light gray on the 

 .surface. The subsoil is sandy or gravelly. Drainage is usually ex- 

 cessive. The soils are derived principally from stratified deposits 

 of sand and gravel formed by glacial outwash. They occupy gently 

 rolling upland terraces and plains formerly glacial flood plains, 

 now dissected and eroded. All types are suited to agriculture. 



Olympic Series. These soils are light brown and brown with 

 a reddish cast. The subsoils are generally of compact structure and 

 somewhat lighter in color than the soils. They are derived mainly 

 from basaltic rock. The topography is rough to mountainous. 

 Rainfall is abundant and the soils are heavily forested. When not 

 too rough they may be used for general farming and dairying. 



Oxnard Series. The soils are generally of dark color and 

 compact structure, and though sometimes underlain by porous 

 subsoils of light texture, are generally underlain by heavier sub- 

 soils. The subsoils lack the red color and adobe structure of the sub- 

 soils of the Placentia series. They represent alluvial delta plain 

 deposits. These are particularly adapted to the production of lima 

 beans. Sugar beets, barley, and vegetables do well. 



Placentia Series. The soils are reddish brown or brown and 

 underlain by heavy, compact, red loams or clay loams of tough, 

 impervious adobe structure. The soil material consists of alluvial 

 outwash, deposits of intermittent or torrential mountain streams. 

 They are derived from granitic rocks. They are tilled with diffi- 

 culty but retain moisture well and produce grains, citrous fruits, 

 and beans. 



San Joaquin Series. The soils are prevailingly red and fre- 

 quently gravelly. Both (he finer soil particles and gravel are 

 rounded. The soils are underlain at depths ranging from 2 to 

 3 feet by red or mottled indurated clay or sandy layers and some- 

 times by gravel and cobbles cemented by iron salts into a dense, 

 impenetrable hardpan. Some of the members are used in the 



