224 R. S. TARE — MORAINES OF SENECA AND CAYUGA LAKE VALLEYS 



in the valley bottoms, while on the opposite side of the valley the mo- 

 raines are usually either very faint or else absent. The records of these 

 active ice tongues from opposite directions are often very clear. The 

 distance to which they extended into the valleys of the plateau depended 

 on the direction, slope, and width of the valley and the height and direc- 

 tion of approach of the main ice mass at the valley entrance. 



Terminal moraine Loops 



In valleys, into which the active ice lobes extended and stood in one 

 position for awhile pronounced terminal moraine loops were built. 

 These loops vary greatly in composition, but usually contain a large 

 percentage of assorted drift. In form they vary from terrace fronts faced 

 by lake beds, where built in marginal lakes, to a complex of kames, ridges, 

 and hummocks and, in some instances, single ridges 50 to 100 feet high 

 extending part way across the valley. They are usually concave in the 

 direction from which the ice came. Several typical instances of these 

 loops are described in the Watkins Glen Folio. 



Morainic Fans 



On several valley slopes, below broadly open divides, extensive accumu- 

 lations of morainic drift occur. In such cases a morainic band extends 

 from both directions toward the divide, on the opposite side of which is 

 a thickened drift deposit, mainly of till, deeply dissected by valleys, 

 many of which could not have been formed by post-Glacial erosion. 

 The thickened deposits assume a more distinctly morainic topography 

 farther down the slope, and at the same time the percentage of stratified 

 materials increases. Near the base of the valley slope the moraine 

 topography is very perfect, and the material is prevailingly stratified 

 drift. 



The morainic deposits in such situations are believed to be due to the 

 presence of hanging glacier tongues which passed over the divides when 

 the edge of the main ice mass rested at a level just above the divides, 

 and from which debris-laden waters escaped, both eroding and deposit- 

 ing. The name " morainic fan " for these deposits was suggested by 

 Mr M. L. Fuller, who crossed one of these localities with the author. 



Nunatak Moraines 



During the several ice stands it frequently happened that isolated 

 hills or groups of hills projected through the ice as nunataks, on which 

 moraines were often accumulated. These nunatak deposits vary from 

 till ridges to hummocky kame moraines, and they vary greatly in posi- 



