I36 NEW YORK STATE MUSEUM 



northern district was a delta lying just under or above the surface. 

 The contours, in their concentric sweeps, clearly show this. 



Outlets 



When the outlets of the Saranac glacial waters are considered, we 

 find that we deal with a bit of glacial geology that is intensely interest- 

 ing, but unfortunately the district is quite removed from this area. 

 Nevertheless, a short account is here given. 



Thirty-three miles directly east of Lake Clear, in a rather inacces- 

 sible country, in the center of the Ausable quadrangle, there exists 

 a long glacial channel running south a distance of some 9 miles with 

 a dozen side outlets to the east that were successively opened up by 

 an ice lobe that lay farther to the east. The higher spillways are to 

 the south which furnished the escape for the higher levels; but as 

 the lobe retreated northward lower and lower outlets to the north 

 were opened. In several of these side outlet channels " fossil " or 

 abandoned falls and cataracts exist today entirely void of water. 

 The channels are very impressive and furnish positive evidence of 

 the former existence and nature of these levels. 1 They are water- 

 worn by the heavy drainage that eventually found its way southward 

 in the Hudson-Champlain depression. 



Cause of the Large Amount of Material Available for the Formation 



of Terraces 



One of the striking features of the glacial geology of the Adirondack s 

 is the small amount of true morainal material 2 unmodified by water, 3 

 as contrasted with the vast quantities of sand and gravel in deltas, 

 terraces etc., when compared with other districts, such as the Catskill 

 mountains. The following hypothesis is offered to account for this. 

 It is generally conceded that with the return of a warmer climate the 

 Adirondacks were completely surrounded by a vast ring of ice that 

 isolated the Adirondack highland from the rest of the State. 4 It 

 was during this stage that the glacial lakes here described existed. 

 The great ice sheet undoubtedly destroyed all vegetable life in both 

 the Adirondacks and the Catskills. But in the latter case the ice 



1 Glacial Lakes and Other Glacial Features of the Central Adirondacks, Amer. 

 Geol. Soc. Bui., 27:658-59. 

 2 H. P. Cushing, N. Y. State Mus. Bui. 115, p. 496. 

 3 I. H. Ogilvie, Jour. Geol., 10:397-412, 1902. 

 4 H. L. Fairchild, N. Y. State Mus. Bui. 160, pi. 11. 



