WORK OF GLACIAL WATERS 149 



along the slopes northwest of Plattsburg, on the Dannemora and Mooers 

 quadrangles. 



STREAMS: CONSTRUCTIONAL 



Sub glacial: eskers. — The singular ridges of gravel, the laggard ma- 

 terial 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 

 northwestern section of the State have been studied, but the results are 

 not published. Tarr describes in Folio 169 (pages 22-23) several which 

 lie in the Susquehanna drainage 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 gra- 

 dient and free flow, but in. localities where the ice-margin was compara- 

 tively stagnant and the drainage was sluggish. 



The argument for subglacial origin of eskers finds some support in 

 the New York examples. Tarr regarded some of those in the Susque- 

 hanna District as certainly made by subglacial streams. An esker four 

 miles east of Clayton was deposited about 350 feet beneath the level of 

 Lake Iroquois, which was laving the ice-front, and it is difficult to ex- 

 plain how it could have been constructed and its definite ridge form 

 preserved unless it was built directly on the ground. The same argu- 

 ment applies to the Ingraham esker, north of Plattsburg. 



Extraglacial: harries. — Isolated mounds of sand or gravel are usually 

 embryo deltas of glacial streams, and are commonly associated with 

 eskers. By linear multiplication 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 mo- 

 raines, and indeed constitute a large part of the New York moraines. 

 The glacial debris which was not spread as the till sheet or nibbed 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 con- 

 nected or clearly associated with any conspicuous moraine belt, hut. 

 nevertheless, must represent recessional moraine. It is possible that 

 sonic smaller kames might have been built by land drainage into lateral 

 glacial lakelets, but detritus from land erosion must commonly have pro- 

 duced deltas or sand plains and he easily recognized by form and associa- 

 tion. The great development of kames, at least in western New York, is 

 north of the divide and tlicv were built in (lie waters of the glacial lakes. 

 This association will] standing waters is so pronounced that it gi\es force 



