432 GLACIAL GEAVELS OF MAINE. 



to distinguish them. The application of this test is not so simple as it is 

 in the West. Onlj^ in eastern Maine are the outcrops such that the test 

 can be applied without considerable study of the local rocks. In Enfield 

 and Prospect, granite bowlderets and some bowlders appear in osars 

 within much less than a mile from the north edge of a granite area — 

 in fact, it may be only a few rods. On the other hand, in Aurora and 

 eastward toward Deblois the water transportation has been so great that 

 almost all the gravel has traveled several to many miles. This Avas in the 

 course of the Katahdin osar river, one of the largest glacial rivers of the 

 State. The law seems to be that the local matter appears in osars of mod- 

 erate or small size. 



But these ridges at Enfield and Prospect are stratified; hence, on the 

 superglacial hypothesis, the bottom of the superficial canyon had probably 

 reached the ground at the time of deposition; and if so, would contain 

 basal and local matter. The most noticeable thing about these granite 

 bowlderets and bowlders is that they appear on the tops of ridges 30 to 50 

 feet in height. I do not see how superficial streams can elevate bowlderets 

 and bowlders, whereas the subglacial streams of the Malespina glacier do 

 raise such coarse matter. If the osars were deposited by superficial streams, 

 the bowlderets and bowlders in question must have been raised by ice 

 movements, and when released from the grasp of the ice by the melting, 

 they tumbled into the canyon. If so, they must have risen in the ice 30 

 to 50 feet within a fraction of a mile, and that, too, on level ground or on 

 a gentle northern slope, as in Enfield, not from the brows of crags or hills. 

 This is only one of numerous instances where the superglacial hypothesis 

 demands that the englacial debris should arise very rapidly in the ice and 

 to considerable height. 



After making allowance for local difiiculties, it appears to me that on 

 the whole the sudden appearance of local matter in the smaller osars and 

 to such a height in the ridges distinctly favors the hypothesis tliat the osars 

 were formed by subglacial streams. At one time it seemed to me incredible 

 that the subglacial sti'eams could raise bowlderets, and especially bowlders, 

 against the force of gravity. Anyone who has doubts on this subject can 

 have them all removed by inspection of the device for ]3lacer mining termed 

 the hydi-aulic elevator. 



