230 National Geogra/phic Magazme. 



have had but moderate northwestward declivity. The depres- 

 sion and submergence of the broad Newark belt may at this time 

 have broken the continuity of the streams that once flowed 

 across it. The headwater streams from the ancient Archean 

 country maintained their courses to the depression ; the lower 

 portions of the rivers may also have gone on as before ; but the 

 middle courses were perhaps turned from the central part of the 

 state back of the Newark belt. No change of attitude gives so 

 fitting a cause of the southeastward flow of our rivers as this. 

 The only test that I have been able to devise for the suggestion is 

 one that is derived from the relation that exists between the loca- 

 tion of the Newark belt along the Atlantic slope and the course of 

 the neighboring transverse rivers. In Pennsylvania, where the 

 belt reaches somewhat beyond the northwestern margin of the 

 crystalline rocks in South mountain, the streams are reversed, as 

 above stated ; but in the Garolinas where the Newark belt lies far 

 to the east of the boun'dary between the Cambrian and crystal- 

 line rocks, the Tennessee streams persevere in what we suppose 

 to have been their original direction of flow. This may be 

 interpreted as meaning that in the latter region, the Newark 

 depression was not felt distinctly enough, if at all, within the 

 Alleghany belt to reverse the flow of the streams ; while in the 

 former region, it was nearer to these streams and determined a 

 change in their courses. The original Anthracite river ran to the 

 northwest, but its middle course was afterwards turned to the 

 southeast. 



I am free to allow that this has the appearance of heaping 

 hypothesis on hypothesis ; but in no other way does the analysis 

 of the history of our streams seem possible, and the success of 

 the experiment can be judged only after making it. At the 

 same time, I am constrained to admit that this is to my own view 

 the least satisfactory of the suggestions here presented. It may 

 be correct, but there seems to be no sufficient exclusion of other 

 possibilities. For example, it must not be overlooked that, if 

 the Anthracite river ran southeast during Newark deposition, the 

 formation of the Newark northwestward monocline by the 

 Jurassic tilting would have had a tendency to turn the river 

 back again to its northwest flow. But as the drainage of the 

 region is still southeastward, I am tempted to think that the 

 Jurassic tilting was not here strong enough to reverse the flow of 

 so strong and mature a river as the Anthracite had by that time 



