200 DOUGLAS WILSON JOHNSON 



the Cretaceous period, at least, the drainage relations in this region 

 have been essentially as they now are; that the present valleys were 

 carved by the streams which now occupy them ; and that, so far as the 

 time element is concerned, all of these valleys are of practically the 

 same age, no recent capture having taken place. 



Previously to the appearance of Mr. White's paper, above referred 

 to, and before I was aware that he was interested in the Tennessee 

 problem, I became convinced that the evidence presented by Messrs. 

 Hayes and Campbell, and by Mr. Simpson, while very suggestive, 

 was not conclusive. Being at the time interested in the study of river- 

 capture in general, I was in hopes that an examination of the Chat- 

 tanooga district with this particular drainage problem in mind might 

 result in securing certain evidence which would throw additional 

 light on the question. Accordingly, in April, 1904, the region was 

 visited, and a brief study made of the winding gorge ; the river above 

 and below the point of supposed capture; the divide between the 

 Tennessee and Coosa drainage south of Chattanooga, and the small 

 streams flowing north and south from this divide; the Sequatchie 

 River in the valley west of the mountain, a branch of which is sup- 

 posed to have effected the capture ; and the valley southwest of Scotts- 

 boro, Ala., which has been contrasted with the gorge of the Tennes- 

 see. Certain facts were noted which seemed to indicate that the Ten- 

 nessee River has occupied its present course since the Cretaceous 

 period of baseleveling, instead of having been diverted westward by 

 a comparatively recent capture; and which seemed to explain satis- 

 factorily the peculiar features of the gorge on the basis of this hypothe- 

 sis. Since this evidence would lead to a conclusion so radically dif- 

 ferent from that reached by former students of the problem, it is 

 desirable carefully to consider both lines of evidence — that in favor 

 of the theory of capture, as well as that in favor of the alternative 

 theory. 



EVIDENCE IN FAVOR OF THE THEORY OF CAPTURE 



Hayes and Campbell base their conclusions, that the southward- 

 flowing Appalachian River was captured near the site of Chattanooga 

 by a branch of the Sequatchie River, upon the three following lines 

 of evidence: (1) the character of the divide between the Tennessee 



