204 B. WILLIS AMES KNOB, NORTH HAVEN, MAINE 



facing cliff of Ames knob might thus be interpreted, but the wide bench 

 extending from the eastern end around the southern and southwestern 

 sides could not have been produced by such an action. Turning, then, 

 to consider the conditions of marine sculpture, we find that this bench 

 is on the side Avhich would be exposed, almost without protection, to the 

 full sweep of the Atlantic w-ere the islands uniformly submerged 80 feet 

 deeper than now. The heights of Vinal Haven would form a group of 

 islets, which would in some measure break the force of the advancing 

 ocean surges, but they would be too scattered and too small in area to 

 form a protecting barrier. 



CONDITIONS AND DATE OF SUBMERGENCE 



Pursuing the inference suggested by the above described relations of 

 form and direction, we may consider the land submerged to a depth of 

 80 feet below its present level, and regard Ames knob as a rocky islet, not 

 unlike the Sugar loaves which are now above water at the western end 

 of the Fox Islands thoroughfare. The islands of Vinal Haven and North 

 Haven were then to a great extent covered by water, and the group pre- 

 sented few land surfaces approaching a square mile in extent. As the 

 general topographic features of Penobscot bay, including the existing 

 submarine channels, are effects of subaerial erosion, it is recognized 

 that the coast has sunk some hundreds of feet below a former high alti- 

 tude; audit is assumed that the submergence had progressed to the 

 level marked by the bench on Ames knob, but it is possible that the land 

 was for an episode relatively rising. Whatever the relative changes of 

 altitude in reference to sealevel had been, the relation became fixed for 

 a time, during which the waves cut the wide bench which extends from 

 the present 60-foot contour to that at 80 feet above sea. Judged by the 

 features developed along the western shore of Vinal Haven, which are 

 relatively insignificant as compared with this bench, the sea stood long 

 at that position. The writer does not know of any bench of similar 

 width cut in equally hard rocks on this coast in post-Glacial time. 



Having recognized that the facts indicate a prolonged episode of sub- 

 mergence, one turns to the rock ledges for some evidence of its date. 

 The}^ bear no glacial striae, so far as observed, even though the under 

 surfaces of large loose blocks which were partially protected from the 

 weather were examined ; yet the ledges resemble in subangular charac- 

 ter of profile the glaciated form on the higher knob, and the absence of 

 striae is easily accounted for by the obvious effects of scaling and of frost 

 and sun. These evidences of ice action upon the sup[)osed wave-cut 

 bench are so general that one is convinced the surface was exposed to 

 glaciation, and it follows that the episode of marine attack preceded 



