Lawson.] 



Coast of Northern California. 



253 



relatively younger condition of the lower stretches of the canons 

 is clearly ascribable to the progressive emergence of the block. 

 The uplift affects the profile of the stream first at its mouth, and 

 the gradient which was established in the upper stretches for an 

 older stage of the uplift may persist far into a succeeding stage. 

 Degradation is thus less intense in the middle than in the lower 

 stretches of the canon, and the topography appears somewhat more 

 mature. In reality, for the new baselevel, it lags behind that of 

 the lower part of the stream, and is less mature. 



Making just allowance for this apparent anomaly, due to the 

 fact that the uplift, although for convenience considered as a 

 single event, is really a series of movements, the writer has endeav- 

 ored to estimate the degree of advancement of the region in the 

 geomorphic cycle, using the terminology introduced by Davis. 

 The features of the region as a whole seem to be those of a 

 geomorphy which may fairly be classed as in late adolescence or 

 early maturity. This statement, of course, breaks down entirely if 

 consideration be given only to the seaward, terraced edge of the 

 plateau; for, with reference to the broad, lower terraces, the topog- 

 raphy is in its infancy. Indeed, when the tide is out on man)' 

 parts of the coast, plateaux in embryo are visible, which await only 

 another throe, similar to the many which have constituted the gen- 

 eral uplift, to appear on the scene of the present cycle as the veriest 

 squalling topographic sucklings. It also breaks down if considera- 

 tion be confined to the head-waters of the streams, where the topog- 

 raphy is much less advanced than in the middle stretches. It 

 would be well if we could express the state of degradation of a 

 block, or its position in the geomorphic cycle, in terms distinct 

 from those used to express the degree of topographic advancement 

 in the various portions of a stream valley. The general constancy 

 of the character of the canons, for analogous parts of the stream, 

 under geological conditions which would favor uniform degrada- 

 tion, affords evidence indicative of a general uniformity of uplift. 



EEL RIVER. 



In traveling northward along the coast from Bodega Bay to 

 Cape Mendocino the streams which are crossed all descend rapidly 



