D. F. Lincoln — Glacial Erosion of New York. Ill 



a. To the east and west of the Seneca valley, at a distance of 

 6-12 miles, there run two upland valleys; on the east, that of 

 Cayuta Creek, 26 miles long and half a mile wide ; to the 

 west, that of Pine Creek, about half that length. They be- 

 gin opposite Watkins and run southward. In this situation 

 it is hardly conceivable that a general flexure, capable of affect- 

 ing the beds both of Seneca and Cayuga Lakes, should fail to 

 affect similarly the valley of these creeks ; especially as Cayuta 

 valley lies between the south extensions of Cayuga and Seneca 

 valleys. But in point of fact, this is what has occurred : — the 

 valley of Seneca falls northward, its probable bed descending 

 nearly 900 feet in 30 miles (Elmira 700 ± A. T., lake-bottom 

 176 below tide]. The valley of Cayuta Creek falls southward, 

 descending probably 300 feet in 26 miles (and doubtless con- 

 siderably more, if its rock-bed were uncovered at its lower 

 part). Pine Creek similarly falls 337 feet southward in 13 

 miles from Beaver Dam (1279) to Corning (942). It is of 

 course quite possible that streams should interlock in this way 

 over a divide, flowing in opposite directions for a time. But 

 it is unlikely that a large river (by supposition, the upper 

 Susquehanna) should have run from Elmira north with a de- 

 scent of 30 feet to the mile for 30 miles. If such were the 

 state of things, a deep narrow gorge with vertical sides would 

 have been produced, extending back at a relatively rapid rate 

 far down into Pennsylvania. The actual outlines of the sec- 

 tion of the lake (fig. 3) are absolutely contradictory of this view. 



READING CENTRE 



10000 FEET. BURDETT. 



*SmrB®* 



Fig. 3. Combined sections of Seneca Lake and the Ohio River, on the same 

 scale (vertical 4 times the horizontal). The lake is taken near the southern end, 

 on line III of Cornell University map ; from Reading Centre east to hill at Bur- 

 dett. The river (ABBA) is an average section within 12 miles below Pitts- 

 burg obligingly furnished by Prof. F. W. Very of Allegheny, Pa. Width of 

 lake 6250 feet; width between the Ohio bluffs (B-B) 7000 feet; width, of 

 lake-valley between high points 22,000 feet. Depth of water in lake 540 feet. 

 (The greatest depth is 2 miles north of section =618 feet.) Depth of Seneca 

 valley, from level of bluffs 800 feet ; from level of plateau (Reading Centre), 

 1400 + feet. Depth of Ohio valley, from plateau at bluffs (B-B), near 500 feet. 



25. The incompatibility between the Seneca valley and 

 those of the high land appears further in this : that if they 

 had coexisted, the deeper must have " robbed " the less deep. 



