56 J. D. Dana on the origin of some of the 



(2.) If Mill River ouce flowed tlirougli the Beaver Ponds and thence 

 through West Creek to the bay, the force of its waters would have 

 continued to keep this channel open, and West Creek would not have 

 been disjoined from the part above. 



(3.) If, during the Glacial era. Mill River had had no channel through 

 the Whitneyville gap, it could hardly have afterward gained a foot- 

 hold there where the alluvium has a height of 60 feet or more above 

 mean tide level. 



There is hence not only no proof of a former connection between 

 Pine-Marsh valley and the Beaver Pond depression, but strong rea- 

 son against it in the condition and character of Mill river and Its 

 present channel. 



Secondly — The Elevations, or Hills and Ridges made by the Glacier. 

 Besides extensive excavations, there are also elevations which were 

 due to the glacier. They were a consequence mainly of the interrupt- 

 ed series of trap ridges in its way. The hard trap-rock dikes. Mill Rock 

 and East Rock, were fenders both to the sandstone lying on their north- 

 ern side, and also that on the southern, and especially to the latter. 

 The glacier, moving from the north and approaching Pine Rock, would 

 have had its under surface forced up into an arch by the resisting mass, 

 and the ice thus shaped would have been made firm and solid by the 

 pressure ; and as such an arching of the ice below is an arching of the 

 abrading surface of the glacier, an elevation of sandstone correspond- 

 ing to it should have been left by the glacier on its southward mai'ch. 

 An elevation vms tJms left south of Pine Rock — that of the Beaver 

 Hills {Bh.) The Hills are now disjoined from the Rock because of 

 erosion (a) by the waters and ice that descended the slope during the 

 declining Glacial era ; {h) by the waves and marine currents of the 

 subsequent period of submergence in the sea ; (c) by streamlets down 

 the declivities due to the rains and melting snows of later time when 

 the land was elevated to its present level — an era of greater elevation 

 or emergence. It was the eastern abutment of this great Pine-Rock 

 arch that scooped out the Beaver Pond basin. 



In the same manner the narrow north-and-south Sachem's ridge 

 {Sm^ a mile and a half in length, was evidently made through the 

 lifting action of Mill Rock. Similarly also, the small Cedar Hill, south 

 of East Rock, owes its existence, apparently, to the arch made by the 

 East Rock range ; it is sntall because the East Rock range has a north- 

 and-south direction, or lies with its end toward the moving glacier; 

 and also because the ice of the wide Quinnipiac valley would have 

 pressed westward as it escaped the limits of the valley and passed 



