HANGING VALLEYS 



231 



in which the streams tumble precipitously down the steepened slope as 

 a series of rapids, cascades, and falls (figures 2 and 3 and plate 38). The 

 maturity of the hanging valleys proves that a long time was required for 

 their development at a baselevel not far from the 900-foot level. There 



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Figure 1. — Cross-section of Seneca Lake. 



Thr^e miles north of Watkins. Column of figures refers to elevation with reference to sealevel 

 Vertical scale exaggerated about five times. 



are two ages of gorges cut in the steepened slope, one distinctly post- 

 Glacial, the other, being both broader and deeper and partly filled with 

 deposits made by the Wisconsin ice sheet, evidently antedating the 

 advance of this ice sheet. 



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Figure 2.— Profile along Watkins Glen Creek. 

 Scale same as figure 1. 



The headwaters of the hanging valleys are far less mature than the 

 lower reaches, for from the headwaters the valleys broaden downstream, 

 while the valley walls become less steep. A gorge condition exists in 

 many of the headwater tributaries, and the valley walls are almost uni- 

 formly steep, indicating^that active erosion was in progress here when 



