JOHN WESLEY POWEUv DAVIS 



Himalayas. Some of the upturned conglomerates are "as thick 

 and at as high angles as those on the Righi" in the Alps (46). 

 The Sutlej in particular is instanced as having held its course 

 from a time before the outer or subhimalayan ranges were 

 raised. After issuing from deep valleys in lofty inner ranges 

 it passes through low hills of soft rocks, and then trenches a 

 ridge formed of "massive beds of coarse conglomerate of 

 boulders, such as only occur in the main river channels. These 

 beds are now raised to the vertical, and in both directions along 

 the strike these conglomerates pass gradually within a few 

 miles into the ordinary sandstones. The presumption from 

 such a coincidence seems irrestible, that the Sutlej itself had 

 deposited these banks of boulders at the spot where it still 

 flows" (47). 



Hayden's statement, based on studies in Montana, is as fol- 

 lows : "The fact that the streams seem to have cut their way"? 

 directly through mountain ranges, instead of following syn- 

 clinal depressions, indicates that they began the process of ero- \ 

 sion at the time of the commencement of the elevation of the J 

 surface. This is shown all along the valley of the Yellowstone, 

 and more conspicuously in the valleys of the Madison and 

 Gallatin, which have carved immense canyons or gorges di- 

 rectly through two of the loftiest ranges of mountains in Mon- 

 tana. We believe that the course of these streams was marked 

 out at or near the close of the Cretaceous period, and as the 

 ranges of mountains were in process of elevation to their pres- 

 ent height the erosion of the channels continued. The details 

 of the observations which contribute to form this opinion 

 would occupy a chapter or two." * Both of these authors, 

 however, treated the problem of persistent rivers in an inci- 

 dental manner, subordinating it to other larger topics; neither 

 of them gave an elaborate or an emphatic a statement to his 

 theory, and neither of them invented a handy and suggestive 

 generic name for the kind of rivers that they explained. The 

 taking term, antecedent, was a forcible supplement to the ex- 



* Report of F. V. Hayden, Sixth Ann. Kept. U. S. Geol. Survey of 

 the Territories for 1872. Washington, 1873, p. 85. The paragraph 

 above quoted was foreshadowed in an earlier article. Amer. Journ. 

 Sci., XXXIII, 1862, pp. 68-79. 



25 



