Petroleum Resources and Industries 

 rels. The oil comes from the sands of the Fer- 

 nando horizon (upper Miocene), which are here 

 slightly domed on the flank of a great monocline. 

 From 200 to 400 feet of productive sands are en- 

 countered in the wells. 



Santa Maria District. — The Santa Maria district 

 lies in northern Santa Barbara County, in the region 

 of rolling hills and sinuous anticlines between the 

 Santa Ynez and San Rafael mountains. The dis- 

 trict comprises the Santa Maria or Orcutt field, 

 Lompoc field, and Cat Canon field, which include, 

 respectively, 6000, 4390 and 7505 acres of proven 

 ground, a total of 17,895 acres. The wells, of which 

 there are now 220 producing, range from 1000 to 

 5200 feet in depth, the great bulk of the production 

 coming from wells over 2500 feet deep. The in- 

 dividual wells vield from 60 to 2500 barrels daily: 

 the gravity of the oil being from 18" to 31° Beaume 

 (0.9459 to 0.8695 sp. gr.) in the Orcutt field; 16" 

 to 37" Beaume (0.9589 to 0.8383 sp. gr.) in the 

 Lompoc field; and 11" to 19" Beaume (0.9929 to 

 0.9395 sp. gr.) in the Cat Canon field. The oil from 

 the first two fields is largely used for refining; that 

 from the last for the manufacture of asphalt and 

 for fuel. The oil from the Orcutt and Lompoc 

 fields comes from the Vaqueros and basal Monterey 

 (lower and middle Miocene) formations; that from 

 the Cat Canon field from the Fernando or upper 

 Miocene. The fields are all situated on well-defined 

 anticlines, the maximum production coming from 

 nodes or domes on the main folds. 



Summerland District. — ^The Summerland district 

 owes its importance largely to the fact that its 

 oil is obtained from wells which penetrate sands 

 lying below the Pacific Ocean, and one of the 

 most novel and interesting sights along the coast 

 of California is that of the wharves carrying the 

 derricks which mark the location of these unique 

 wells. The field lies in southern Santa Barbara 

 County and the productive area covers about 125 

 acres. The wells, of which there are now 125 pro- 

 ducing, range in der)th from 100- to over 600 feet 

 and originally produced as high as 100 barrels 

 daily; the average daily production is now 1.3 

 barrels per well. The oil varies from 10" to 18" 

 Beaume (1.000 to 0.9459 sp. gr.), and because of 

 its high asphalt content, is used largely for asphalt 

 manufacture and road dressing. The oil comes 

 from sands of Fernando age, lying as a seaward- 

 dipping monocline, complicated by a transverse 

 anticline. (See PI. VIII.) 



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