306 K. A. DALY OSCILLATIONS OF LEVEL 



writer has been specially impressed by the comparative feebleness of the 

 waves which worked on this coast before and during the recent uplift. 

 At the higher levels the bedrock was locally fretted and roughened, largely 

 by frozen spray, but notable clifhng is exceedingly rare. Even the till of 

 drumlins, which when submerged directly faced the sea on the east and 

 south, has been little affected by erosion.' An example is seen in Pigeon 

 Hill, Cape Ann. At the existing sealevel many cliffs cut in granite and 

 other hard rocks, to say nothing of the visible destruction of drumlins, 

 show the power of the open Atlantic. Sea-chasms eroded along trap- 

 dikes are well widened out at present sealevel, but rapidly narrow upward. 

 Grood illustrations are seen at Cape Neddick, Maine, and at Magnolia, 

 about 500 yards southwest of Normans Woe Eock. At the latter locality 

 the glaciated surfaces of the dikes are almost intact at and near the 

 highest strand-level; the same dikes are the loci of notable sea-chasms at 

 present sealevel. 



Constructional forms in the emerged belt give similar testimony. The 

 raised beaches, bars, and spits are small, poorly developed in many in- 

 stances, and usually not composed of well assorted materials. In all 

 these respects the contrast with corresponding embankments at present 

 sealevel is striking. Moreover, the pebbles of the higher embankments 

 are usually not well rounded, having preserved much of their original 

 angularity. 



A detailed account of the foregoing observations is hardly necessary, 

 since several authors have already stressed the same facts regarding the 

 emerged belt, from Boston to Eastport, Maine. ^ On the other hand, the 

 facts are subject to different interpretations. 



The prevailing explanation has been well expressed by Stone : 



''When we compare the ragged and uneven cliff of erosion at the present 

 beach with the still moutonneed ledges at higher levels, it becomes evident that 

 the sea has stood at or near its present position many times as long as at any 

 higher level. At the higher elevations the surf had time to erode the till from 

 the more exposed shores, but it had not time to form a cliff of erosion in the 

 solid rock before a change of level transferred the wave-action to higher or 

 lower rock. In other words, the changes of level of the sea were relatively 

 rapid." ® 



A similar view is taken by Bastin for the areas covered by the Eock- 

 land, Penobscot Bay, and Eastport folios of the United States Geological 

 Survey. 



5 G. H. stone : Monograph 34, TJ. S. Geol. Survey, 1889, pp. 44-52 ; Penobscot Bay 

 Folio, U. S. Geol. Survey, 1907, p. 12; Rockland Folio, 1908, p. 10; Eastport Folio, 

 1914, p. 11. 



8 G. H. Stone : Monograph 34, U. S. Geol. Survey, 1899, p. 44. 



