University of California Publications in Geology [Vol. 9 



ing the paper of Vance C. Osmont, who published the account of 

 the geology of that region. The locality has not been visited by 

 the writer and no additional evidence can be given. However the 

 fauna known from these beds is sufficient to warrant its correla- 

 tion with the Merced. 



Wildcat Series 



PHYSICAL FEATURES 



The Wildcat Series is typically represented in the south central 

 part of Humboldt County, California, in the form of a monocline 

 on the north slopes of Bear River Ridge, extending from the ocean 

 eastward to Bryan's Rest. The strike of the strata is more or less 

 parallel with the general course of Eel River, i. e., west or north- 

 west. The beds are inclined toward the north at angles varying 

 between fifteen and forty degrees. In a few cases the inclination 

 is as great as seventy-five degrees, but these cases are rare, and 

 dips greater than forty degrees are uncommon. A short excursion 

 into the hills four miles northeast of Fortuna revealed the occur- 

 rence of marine sediments corresponding in age to the Wildcat 

 Series. The rugged topography common throughout the region is 

 characteristic of this formation and suggests that the territory cov- 

 ered by these beds is quite extensive. Later work may prove the 

 occurrence of this series over a much greater portion of Humboldt 

 County than it is now known to cover. 



Beach Section. — As with the Merced Series, the beach section is 

 most accessible and affords the best opportunity for study. At the 

 mouth of Oil Creek, one mile north of Cape Fortunas, the basal 

 beds, composed of rusty-yellow, shaly-structured, fine-grained sand- 

 stone, overlie a massive, coarse-grained, steel-gray sandstone which 

 has been greatly fractured and folded. The latter is probably not 

 later than Cretaceous and may possibly be Jurassic. Approxi- 

 mately half a mile farther north the rusty-yellow sandstone grades 

 rather suddenly into gray and blue-gray argillaceous sandstone 

 and clay. The material is soft and not well stratified, resembling 

 very closely the lithological characters of the Merced. This gray 

 and blue-gray sandstone with some variations continues north- 

 ward to Centerville, where it dips beneath a brown beach sand and 

 gravel lying in nearly horizontal position. The strike for the whole 



