EDITORIAL 77 



the granites are much older than the Chico formation resting on them 

 as they had suffered much erosion prior to the Chico epoch. 



It is finally concluded that the weight of evidence places the 

 granitic intrusion just about at the close of the Jurassic period. The 

 effect of the argument is to show that there is a sound basis for the 

 inference heretofore entertained that the Klamath Mountains belong 

 rather to the Sierra Nevada system than to the Coast Ranges and may be 

 considered a sort of outlier to the former. 



The Drainage Features of California. By Andrew C. Lawson, 

 Berkeley, Cal. 

 A comparative study of the geomorphy of the Sierra Nevada and 

 the Coast Ranges. There is a remarkable contrast in the character of 

 the river valleys in the two mountain systems, those of the Sierra 

 Nevada being consequent and the geomorphy immature, while those 

 of the Coast Ranges are subsequent and the geomorphy mature. In 

 the Coast Ranges the geomorphic profiles of the river valleys, leaving 

 out of consideration the head-water streams, are not so steep as in the 

 Sierra Nevada, and the valleys are much wider as a general rule. The 

 divides are rounded or ridge like, with but small remnants of the 

 earlier geomorphic cycle identifiable, in the Coast Ranges, while in a 

 large part of the Sierra Nevada the divides have a marked table or 

 plateau form. The drainage of the Coast Ranges is clearly controlled 

 by the structure of the country while the streams of the Sierra Nevada 

 cut across the strike of the rocks, and have made but little headway in 

 the working out of canyons along the strike of the softer formations. 

 The Klamath River is regarded by the author as partly having the 

 consequent character of the Sierra Nevada drainage and partly the 

 character of the Coast Range drainage. The Trinity River and its 

 prolongation in the lower Klamath belongs to the Coast Range system 

 being parallel to the strike of the country and in part mature in its 

 development, while the upper Klamath is consequent and young. 

 This affords us a basis for the separation of the Klamath Mountains 

 from the Coast Ranges, and supports the orogenic correlation of the 

 Klamath Mountains with the Sierra Nevada. The comparison thus made 

 points clearly to the conclusion that the Sierra Nevada and probably 

 also the Klamath Mountains are of later date than the emergence of 

 the Coast Ranges which inaugurated the present cycle of geomorphic 

 evolution. But the subsequent valleys of the Coast Ranges are in 



