ISOLATED OSAR-MOUNDS OR MASSIVBS. 369 



find no other gravel deposit for 10 miles south of it, and the nearest on the 

 north is in the northern part of Litchfield, nearly 5 miles away. The great 

 thickness of the marine clay in the vicinity and its somewhat sandy or silty 

 character testify that one and perhaps two glacial streams here flowed into 

 the sea at a time when the ice front had retreated to this point. To the 

 northwest of the plain is a rather steep terrace in the till, which may be 

 due to the erosion of the ground moraine. If so, this would be more 

 probably performed by a subglacial than by a superficial stream. The 

 rapid slowing of the water after entering the sea proves that the streams 

 were not large. The great swiftness of a small stream required in order to 

 transport so large bowlderets would be more probably attained by a sub- 

 glacial stream under pressure in its tunnel by the water behind it. 



Elsewhere are described two short eskers or kames in Amherst (see 

 pp. 117-118) which at the south converge into a small plain of horizontally 

 stratified matter showing clearly a horizontal transition of the gravel into 

 They are at the foot of a hill sloping south, and were in places favorable 

 for crevasses. They are, in fact, hillside kames situated below 230 feet. 



The class of kames or eskers under discussion are here termed isolated 

 because no other gravels can be proved to have been deposited by the same 

 glacial streams to which these are due. The field evidence rather favors 

 the hypothesis that they were deposited by subglacial streams. Besides, 

 we have the general consideration that near the ice front crevasses could 

 sand and finally into marine clay, all within about one-fourth of a mile- 

 freely form and conditions would be favorable to the formation of sub- 

 glacial channels. 



ISOLATED OSAR-MOUNDS OR MASSIVES KOT ENBING IN MARIISTE 

 DELTAS PROPER. 



These deposits, being very broad, are massives or mesas rather than 

 ridges. They belong to the region below former sea level. One of these 

 plains is found about 2 miles northwest of Freeport Village. It is solid 

 and rather level on the top, somewhat uneven of surface, but with no reticu- 

 lated ridges or kettleholes proper. The smoothness of surface may be in 

 part due to the waves of the sea sweeping over it, since it occupies a posi- 

 tion where it would be much exposed to the waves of the broad bay which 

 then covered the valley of Royal River to the south of it. Judging from 



MON XXXIV 24 



