LENTICULAR SHAPE OF COASTAL GRAVEL MASSES. 383 



moraine was itself deposited. The moraine near the esker showed no more 

 sign of water Avash than at a distance. The lenticular eskers or short osars 

 extend about 3 miles south of the moraine and along a curved valley. We 

 can not admit that these small hummocks separated by intervals of one-fourth 

 mile or less could be formed in the open sea by a glacial stream issuing 

 from the ice front while the moraine was forming. Their materials as well 

 as their shapes testify that they were formed within ice walls by currents 

 that at no time were checked as they would have been if poured into the open 

 sea. The hummock underneath the moraine has the proper shape, size, 

 position, and composition of one of the parts of this system. If at this point 



Fig. 31.— Lenticular esker flanked with blowing marine sand ; Bowdi 



a subglacial river continued to flow during the time the moraine was being 

 formed, it ought to have more or less washed away the moraine and left, not 

 a line of discontinuous hummocks separated by intervals, but continuous 

 ridges or delta-plains of frontal gravel extending south from the moraine. 

 The same would be true of a superficial stream. This makes it probable 

 that there is no genetic connection between the hummock that underlies the 

 moraine and the moraine itself More probably the gravel system had all 

 been deposited prior to the moraine, and at the time of the moraine the 

 glacial stream had ceased to flow in this part of its former channel, or was 

 too feeble to form such deposits. 



It is possible that the Waldoboro moraine was due to an advance of 



