224 H. L. FAIRCHILD PLEISTOCENE MARINE SUBMERGENCE 



upper, narrow valley, while recognizing in the lower valley a river of 

 such enormous volume as to account for the high "tributary deltas/' 

 Certainly he left the deltas hung up in the air and without sufficient ex- 

 planation. 



While Upham could not admit any depression of the land in glacial 

 time, yet he thought that after the departure of the ice-sheet the sea 

 stood below its present level, which implies a rise of the land ; and he ap- 

 peals to this to explain the disappearance of the enormous volume of 

 detritus that under the river theory must have been swept into the sea 

 at the river mouth. 



Conceding that the invasion of ocean waters in the Hudson and Saint 

 Lawrence valleys was due to the attraction of the glacier, then as the 

 ice-body waned and the gravitational force decreased, the water surface 

 should have fallen. Consequently the marine plane should decline 

 toward the north, instead of rising. 



WORK OF B. K. EMERSON 



In the State of Massachusetts the Pleistocene features of the Con- 

 necticut Valley were carefully studied for many years by Professor 

 Emerson, and his results are found in two admirable publications by the 

 IT. S. Geological Survey, '^Geology of Old Hampshire County, Massachu- 

 setts,'' Monograph XXIX, 1898, and the Holyoke Folio, Number 50, 

 1898. 



Professor Emerson recognized that the terraces and all the plains ex- 

 cept the very lowest in the valley were the product of static waters, and 

 that the highest deltas or sand plains on the borders of the open valley 

 indicated the summit level of those waters. He credited to the river 

 only the lowest terraces, as floodplains. The level of the standing water 

 in the open valley he accurately differentiated from the higher and varied 

 levels of "the deposits made by streams and by glacial lakes. He was non- 

 committal as to the nature or control of the static waters and simply 

 called them the "Connecticut lakes." He did not attempt to show their 

 extent north and south of his State, nor to determine the barrier or outlet. 



The name "lakes" as used by Emerson is not inappropriate, in his de- 

 scription of the local features, even if it be understood that the waters 

 were an extension of or confluent with the sea, since the connection with 

 the sea was by two narrow straits, the gorge of the Connecticut below 

 Middletown and the Quinnipiac Valley at ISTew Haven, and the water was 

 kept fresh by the southward current. 



Professor Emerson did not publish any diagrams or profiles of the ter- 



