226 National Geographic Magazine. 



synclinal basins, but a reason for this will be found later ; for the 

 present we look only at the location of the streams, not at their 

 direction of flow. As far as this illustration goes, it gives evidence 

 that the smaller streams at least possess certain peculiarities that 

 could not be derived from persistence in a previous accidental lo- 

 cation, but which would be necessarily derived from a process of 

 adjustment following the original establishment of strictly conse- 

 quent streams. Hence the hypothesis that these smaller streams 

 were long ago consequent on the Permian folding receives con- 

 firmation ; but this says nothing as to the origin of the larger 

 rivers, which might at the same time be antecedent. 



29. Departure of the Juniata from the Juniata- Gatawissa syii- 

 cline. — It may be next noted that the drainage of the Broad Top 

 region does not follow a single syncline to the Anthracite region, 

 as it should have in the initial stage of the consequent Permian 

 drainage, but soon turns aside from the syncline in which it 

 starts and runs across country to the Susquehanna. It is true 

 that in its upper course the Juniata departs from the Broad Top 

 region by one of the two synclines that were indicated as the 

 probable line of discharge of the ancient Broad Top lake in our 

 restoration of the constructional topography of the State ; there 

 does not appear to be any significant difference between the summit 

 altitudes of the Tuscarora-Mahanoy and the Juniata-Catawissa 

 synclinal axes and hence the choice must have been made for 

 reasons that cannot be detected ; or it may be that the syncline 

 lying more to the northwest was raised last, and for this reason 

 was taken as the line of overflow. The beginning of the river is 

 therefore not discordant with the hypothesis of consequent 

 drainage, but the southward departure from the Catawissa 

 syncline at Lewistown remains to be explained. It seems to me 

 that some reason for the departure may be found by likening it 

 to the case already given in figs. 16-18. The several synclines 

 with which the Juniata is concerned have precisely the relative 

 attitudes that are there discussed. The Juniata-Catawissa syn- 

 cline has parallel sides for many miles about its middle, and 

 hence must have long maintained the initial Juniata well above 

 baselevel over all this distance ; the progress of cutting down a 

 channel through all the hard Carboniferous standstones for so 

 great a distance along the axis must have been exceedingly slow. 

 But the synclines next south, the Tuscarora-Mahanoy and the 

 Wiconisco, plunge to the northeast more rapidly, as the rapid 



