248 



SCIENCE 



[N. S. Vol. XXXVII. No. 946 



Helderberg scarp, west of Albany, the 

 waters of the Ontario and Mohawk basins 

 escaped southward into the Hudson marine 

 inlet. (4) In the district about Rome, at 

 the east end of the Ontario basin, the waters 

 from both the north and the west flowed 

 along the sides of the ice lobe to reach the 

 Mohawk Valley. (5) On the north and 

 west sides of the Lowville highland the 

 waters of the southwestern Adirondacks 

 and the Black Valley forced their passage 

 into Lake Iroquois. 



The channels leading east through cen- 

 tral New York, more conspicuously de- 

 veloped in the Syracuse district, were the 

 predecessors of Niagara River in their 

 function, the equal of Niagara in volume, 

 and the rival of Niagara in cataract phe- 

 nomena. 



The successor of the Iromohawk and the 

 immediate predecessor of the St. Lawrence 

 was the outlet river of the second Lake Iro- 

 quois. This flowed across the north point 

 of the Adirondack highland, at Covey Gulf, 

 on the international boundary, with further 

 flow in ice border channels along the slopes 

 northwest of Plattsburg, on the Dannemora 

 and Moors quadrangles. 



CONSTRUCTIONAL WORK OP STREAMS. 



Subglacial: Eskers. — The singular ridges 

 of gravel, the laggard material in the beds 

 of glacial streams, are well represented in 

 the western part of the state and occur in 

 the eastern part. Those lying in the north- 

 western section of the state have been 

 studied, but the results are not published. 

 Tarr describes in Folio 169 (pp. 22-23) 

 several which lie in the Susquehanna drain- 

 age territory, and of large dimensions, and 

 Carney recognizes nine on the Moravia 

 quadrangle. Eskers may not occur on 

 southward slopes where the glacial streams 

 had steeper gradient and free flow, but in 

 localities where the ice margin was com- 



paratively stagnant and the drainage was 

 sluggish. 



The argument for subglacial origin of 

 eskers finds some support in the New York 

 examples. Tarr regards some of those in 

 the Susquelianna district as certainly made 

 by subglacial streams. An esker four miles 

 east of Clayton was deposited about 350 

 feet beneatli the level of Lake Iroquois, 

 which was laving the ice front, and it is diffi- 

 cult to explain how it could have been con- 

 structed and its definite ridge-form pre- 

 served unless it was built directly on the 

 ground. The same argument applies to the 

 Ingoraham esker, north of Plattsburg. 



Extraglacial: Karnes. — Isolated mounds 

 of sand or gravel are usually embryo deltas 

 of glacial streams, and are commonly as- 

 sociated with eskers. By linear multipli- 

 cation they not infrequently grade into 

 esker ridges. 



As kames are built at the debouchure of 

 glacial streams, they indicate positions of 

 the ice edge. Areas of kames lie in belts of 

 recessional moraines, and indeed constitute 

 a large part of the New York moraines. 

 The glacial debris which was not spread as 

 the till sheet or rubbed into drumlins was 

 largely gathered up by the drainage and 

 dropped as some form of water-laid drift. 



In western New York a few large kame 

 areas are not closely connected or clearly 

 associated with any conspicuous moraine 

 belt, but nevertheless must represent re- 

 cessional moraine. It is possible that some 

 smaller kames might have been built by 

 land drainage into lateral glacial lakelets, 

 but detritus from land erosion must com- 

 monly have produced deltas or sandplains 

 and be easily recognized by form and as- 

 sociation. The great development of 

 kames, at least in western New York, is 

 north of the divide, and they were built in 

 the waters of glacial lakes. This associa- 

 tion with standing waters is so pronounced 



