I. 



PHYSIOGRAPHY. 



Prof. W. M. Davis. 



UPLANDS OF SOUTHERN NEW ENGLAND. 



The view from any of the hills near Boston, preferably from 

 Arlington Heights (reached by electric cars, passing through Cam- 

 bridge) , discloses the moderate relief of the skyline, little in ac- 

 cord with the great disorder of the rock structures. This has given 

 rise to the opinion that the skyline represents the general level to 

 which denudation reduced the deformed structures, when the whole 

 region stood lower than now ; and that the valleys by which the 

 uplands now are so freely dissected result from a later cycle of 

 denudation, which was introduced by the uplift of the region to an 

 altitude somewhat greater than that of to-day. A slight depression 

 after the valleys had been eroded was the chief cause of the existing 

 irregularity of the shore line, subject to modification by slight 

 oscillations of level, and by plentiful deposits of drift in connec- 

 tion with the glacial period. 



In the neighborhood of Boston, the area occupied by rocks of 

 moderate resistance is so great that an extensive lowland has been 

 worn down, known as the "Boston Basin" in its topographical (not 

 strictly in its geological) sense. Here the overlapping sea enters 

 farthest into the coast line by reason of the lowland, and this has 

 given Boston an advantage over the neighboring early settlements 

 of Plymouth and Salem. The harbor would enter still farther into 

 the land, but for the drift that floors much of the basin. 



The uplands in eastern Massachusetts are so extensively inter- 

 rupted by valleys that it would be difficult to convince anyone 

 of the reality and continuity of the ancient peneplain which the 

 uplands are thought to represent. An excursion farther into the 



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