THE MAPS 615 



Figure 3 shows in a generalized way the drowned areas at the maxi- 

 mum submergence; but the flooding here shown did not prevail at any 

 one period of time. The progressive land uplift had probably raised 

 some of the southeastern territory out of water while the ice-sheet was 

 yet resting on the northern part of the area. 



As most of the large area is hilly, and some with high relief and with 

 many interlacing valleys, it is impossible in a sketch map to indicate 

 the submergence w4th accuracy. In the w^idely flooded areas there are 

 many hills w^hich stood as islands. For the depth of submergence com- 

 parison should be made with the map of isobases, figure 2. 



Areal Description 

 in general 



The submergence phenomena of a few districts deserve brief descrip- 

 tion, even if involving some repetition of facts already stated. One area 

 not strictly covered by the title of the paper requires notice — that of 

 Mount Desert, Maine. 



CONXEGTICUT VALLEY 



Flooding. — This valley was flooded by estuarine waters to South 

 Lunenburg, Vermont. The lower silt plains are a conspicuous topo- 

 graphic feature. The higher and more sandy stretches are less promi- 

 nent, but evident as standing-water products when their nature and rela- 

 tionship are recognized. All streams pouring into the estuary built 

 deltas at the highest level ; and these, with some shore phenomena, record 

 the full amount of the submergence. The heaviest gravel bars "seen by 

 the writer are at Portland, Connecticut, with altitude 220 feet, and at 

 Bradford, Vermont, w4th altitude 660 feet. 



hi Massachusetts. — The Connecticut A^alley is the only ground -in the 

 western part of the State which stood low enough to be immersed in the 

 sealevel waters. The evidence of the high-level waters was shown and 

 the deposits mapped by Professor Emerson long before the writer began 

 this study of continental movement. The writer has examined a suffi- 

 cient number of localities to prove the fact that on every stream which 

 poured from higher ground into the valley estuary a delta was built at 

 tlie summit marine plane. 



Professor Emerson made the summit w^ater plane 400 feet at the north 

 line of the State and 288 feet at the south line. Eecent study by the 

 writer requires that these figures be raised about 10 feet. 



A good example of stream delta built in the Connecticut estuary is 

 found on Millers River, at Millers Falls, on the Warwick and Greenfield 



XLII— Bull. Geol. Soc. A.m., Vol. 30, 1918 



