JOHN WESLEY POWELL DAVIS 



was introduced, may be otherwise explained, so that its place 

 as type will be taken by a better-proved example of antece- 

 dence, such as the Meuse in the Ardennes. This fate of a type 

 is, however, not so very rare. The uplands of southern New 

 England, described some twenty years ago as the type of an 

 uplifted and dissected lowland of erosion, for which the name 

 peneplain was then suggested, may, like Green River, have to 

 yield their place to a better-proved example. The object in here 

 pointing out the invalidity of Powell's argument is to show that 

 even when a mind as original and powerful as his works in a 

 field as inspiring as that of the Uinta Mountains, trenched by 

 the canyon of the Green River, there is danger in overlooking, 

 as Powell too often did, the work of earlier investigators on 

 similar problems. It would be no more fitting to omit men- 

 tion of this characteristic shortcoming of method from an ac- 

 count of Powell's work than to paint out a wrinkle in a true 

 picture of his rugged and kindly face. But in any case, 

 whether the Green River followed its present course ante- 

 cedent to the uplift of the Uintas or not, and whether any 

 other geologist preceded Powell in recognizing the occurrence 

 elsewhere of rivers of this origin, it is distinctly to Powell that 

 geology now owes the general acceptance of the idea of ante- 

 cedence in river development. 



GEOLOGICAL WORK. 



Powell's contribution to geology apart from the action of 

 surface processes and the explanation of surface forms re- 

 lated chiefly to large structural problems. He published many 

 carefully studied columnar sections, giving indication of thick- 

 ness, composition, and unconformities, and making provisional 

 assignment of geological datesj but on the latter point he wisely 

 held that "it would be manifestly absurd to introduce into a 

 newly studied province the nomenclature which had been 

 adopted in those provinces previously studied" (Uinta, 38). 

 This principle guided him some years later, when he pointed 

 out in his first report as Director of the United States Geo- 

 logical Survey that the introduction of local formation names 

 has taken place "in opposition to received opinions, and in spite 

 of the almost universal efforts of geologists to attain uni- 



27 



