THE WORK OF GLACIERS 



181 



abundant where subglacial streams emptied into bodies of water. 

 Under such conditions the outlet of the stream from the glacier would 

 be more readily closed by the delta which formed rapidly where the 

 sediment was dropped as the stream emerged from the ice into the 

 lake, and the tunnel under the ice would thus be gradually filled with 

 sand and gravel. Most eskers were probably formed, for the most 

 part, in connection with the melting of stagnant ice, since it is evi- 

 dent that had the ice been even in slight movement the winding 

 ridges would have been destroyed. 



Karnes. — In glaciated regions groups of sand and gravel hills 

 and ridges, as well as isolated, conical hills with high and steep sides, 

 are not uncommon. 

 These hills of strati- 

 fied drift are called 

 kames (Fig. 166). 

 They are often con- 

 fused with eskers and 

 indeed the two are, 

 in individual cases, so 

 closely associated and 

 shade into each other 

 so perfectly that it 

 is difficult to state 

 whether the deposit is 

 a kame or an esker. 

 Kames are composed 

 of stratified sand and 

 gravel, while drumlins 

 (p. 177) are composed 

 of till. They are often excavated for building and road material, 

 and are favored sites for cemeteries. The same origin cannot be 

 assigned to all the deposits that are classed as kames. Some were 

 formed at the margin of the ice, where the streams issuing from 

 beneath under pressure heaped up their loads against the ice front. 

 Upon the melting of the ice these deposits assumed a more or less 

 irregular surface, depending upon the character of the ice front. 

 Kames of this origin are especially common near terminal moraines, 

 and some of the conspicuous knolls and hills of moraines are often, 

 individually, kames. Isolated kames may have been formed from 

 the deposits of small lakes resting in depressions on the surface of 



Fig. 166. — Kame. North Adams, Massachusetts. 

 Kames are composed of sand and gravel, and conse- 

 quently are always characterized by rounded slopes. 



