NATIONAL ACADEMY BIOGRAPHICAL MEMOIRS VOL. VIII 



planation of the profound idea involved in Powell's report; 

 and this may be fairly taken to show that, notwithstanding the 

 adverse opinion often inappropriately quoted to> the contrary 

 from the emotional pleading of a charming heroine, there is 

 really matter of much import in a name. 



But Powell's further argument in support of the antece- 

 dence of Green River through the Uinta Mountains includes, 

 curiously enough, the case of certain streams which follow val- 

 leys excavated in belts of weak strata along the flanks of the 

 range. Had the range been suddenly uplifted, these streams 

 should, according to Powell, follow the dip of the strata; as 

 they follow the strike instead of the dip, the uplift must have 

 been gradual. "The direction of the streams is indubitable 

 evidence that the elevation of the fold was so slow as not to 

 divert the streams. . . . Had the fold been uplifted more 

 rapidly, ... all the smaller streams and waterways should 

 <"~ 7 have been cataclinal" (flowing down the dip). Hence "the 

 drainage was established antecedent to the corrugation or dis- 

 placement of the beds by faulting and folding" (Colorado 

 1 River, 163). The same argument is used with respect to the 

 drainage lines of the Arizona plateaus : "All the facts concern- 

 ing the relation of the waterways of this region to the moun- 

 tains, hills, canons, and cliffs lead to the inevitable conclusion 

 that the system of drainage was determined antecedent to the 

 faulting and folding and erosion which are observed, and ante- 

 cedent, also, to the formation of the eruptive beds and cones" 

 (Ibid., 198). Yet the longitudinal valleys, here referred to as 

 so decisive in the discussion of antecedence, are apparently of 

 the kind that had been explained ten years earlier (1862) by 

 Jukes, from his studies of the Blackwater in southern Ireland, 

 as having been slowly developed by headward or retrogressive 

 erosion along the strike of weak beds ; thus interpreted, they 

 indicate slow adjustment of streams to structures and prob- 

 ably do not bear on the problems of antecedence at all. 



This is not the place for further discussion of Green River, 

 regarding which the theory of superposition suggested by Em- 

 mons merits consideration along with Powell's theory of ante- 

 cedence. It indeed seems possible that Green River, which 

 was described as the type of antecedent rivers when that term 



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