Geol.— Vol. II.] ANDERSON— CRETACEOUS DEPOSITS. 1 7 



was not uniform throughout the whole area. * * * 

 and it appears that the subsidence was greater in the 

 Sacramento Valley than in the region of the Coast Range 

 and Sierra Nevada." And continuing the same topic he 

 adds: "If the subsidence was uniform throughout the 

 whole region it follows that what is now the western foot of 

 the Sierra Nevada, as well as the corresponding portion 

 of the Coast Range, where in both cases the Chico rests 

 directly upon the folded pre-Cretaceous rocks, must have 

 been at an elevation of twenty-five thousand feet above the 

 sea when the basal portion of the Knoxville was deposited 

 in the Sacramento Valley. This hardly seems possible, for 

 we know of no such mountains in the country to-day. It 

 seems much more probable that the subsidence was not 

 uniform." 



It is probable that at no time during the subsidence was 

 the whole of either the Sierra Nevada or Klamath Mount- 

 ains below the sea. Scattered areas of Cretaceous deposits 

 occur among the Klamath Mountains west of the Sacra- 

 mento Valley; but it is not necessary to suppose that the 

 sea reached these localities across mountain summits. 

 More likely it found its way into earlier basins through inlets 

 from the open ocean at the west. This was undoubtedly 

 the case in Southern Oregon, where portions of the same 

 series are represented in different places. 



3. The Oregon Basin. 



In Rogue River Valley, beds of Upper Cretaceous age 

 occur, following generally the western side of the valley, 

 and resting tipon the older metamorphic slates and crystal- 

 line rocks, with a fairly uniform dip toward the east. The 

 strata consist for the most part of sandstones and conglom- 

 erates, with a subordinate amount of shales. The con- 

 glomerates predominate in the upper part of the section, 

 while shales are common at and near the bottom. These 

 beds are apparently equivalent to those of the Upper 



