POST-GLACIAL COURSE OF THE RIVER 179 



attempted by these authors. During pre-Glacial time the principal 

 streams of the region had become thoroughly adjusted to the geologic 

 structure and topography, and even a casual examination of the maps 

 shows that the two distinct embayments of Paleozoic . rocks, which pro- 

 duce valleys extending northward into the Adirondack mass, must have 

 contained important streams which drained normally southward out of 

 the mountains. The post-Glacial course of the Hudson Eiver across the 

 Luzerne range between Corinth and Glens Falls has been touched on in a 

 paper by G. F. Wright.^ 



The Hudson River 

 post-glacial course 



Between North Creek and Warrensburg, as will be shown below, the 

 Hudson River follows essentially the same general course as during pre- 

 Glacial time. From Warrensburg to Glens Falls, however, the course of 

 the Hudson is wholly post-Glacial. That the pre-Glacial Hudson did not 

 cross the Luzerne quadrangle is clearly shown by the existence of a pre- 

 Glacial divide where the great gorge of the Hudson is now located, just 

 above Stony Creek station on the Delaware and Hudson River Railroad. 

 This gorge, well shown on the topographic map, has a length of about 3 

 miles and a maximum depth of about 1,200 feet, the river here being at 

 an altitude of 600 feet, while the highest points immediately on either 

 side rise to nearly 1,800 feet. This is the most striking example of a 

 gorge in the whole region under discussion and is quite certainly of post- 

 Glacial origin. It affords a fine illustration of a "through valley," to use 

 the term of Professor Davis. 



Some of the stronger evidences favoring the existence of a pre-Glacial 

 divide near Stony Creek are as follows : The deep narrow gorge of recent 

 origin; the flaring of the channel both northward and southward from 

 the deepest part of the gorge, which is just what would be expected in 

 the case of a divide with drainage in both these directions ; the anomalous 

 turns of both the Hudson and Schroon rivers towards the southwest in 

 the vicinity of Warrensburg, which is scarcely to be expected, because, 

 instead of swinging southwestward to cut a channel through the highland 

 country in the northern portion of the Luzerne quadrangle, an easier and 

 more natural course might have been found towards the southeast, across 

 the much lower land between Warrensburg and Lake George; the ten- 

 dency of the tributaries between Warrensburg and the gorge to double 

 back on their courses; the existence in the gorge of hard gneisses rather 



Science, November 2^, 1895, p. 675. 



