220 H. L. FAIRCHILD PLEISTOCENE MARINE SUBMERGENCE 



Introduction 



Some postglacial submergence of New England has long been recog- 

 nized, but the amount has not been determined. Eecently it has been 

 shown that the marine plane in the Hudson-Champlain Valley rises from 

 zero at New York Bay to about 750 feet on the Canadian boundary.^ It 

 is evident that the territory adjacent to the Hudson Valley must have 

 participated in the depression and uplift of the land, and it seems quite 

 certain that the Connecticut Valley, lying parallel with the Hudson- 

 Champlain A^alley and only 60 miles distant, should exhibit similar evi- 

 dences of submergence in oceanic waters. 



After reviewing the literature on the Connecticut Valley terraces an 

 examination was made of the valley from Long Island Sound northward 

 to Wells River, Vermont. The uplifted plane of the static waters as 

 determined by Professor Emerson for Massachusetts was taken as the 

 provisional datum, and it was found that this plane when projected 

 north and south throughout the valley coincided, with unexpected pre- 

 cision, with the highest shoreline features. The plane is shown in the 

 diagram, plate 10. 



The tilted marine plane in the Connecticut Valley has nearly the same 

 gradient as the corresponding plane in the Hudson Valley, but lies 50 

 feet higher for the same latitudes. The isobases consequently lie about 

 20 degrees north of west by 20 degrees south of east. 



The elevated terraces on the slopes of the Connecticut and neighboring 

 valleys, which have been attributed to enormous river floods, are really 

 shore deposits, spread out in sealevel waters as the land was slowly lifted 

 out of these waters. The summit plane of these waters, as indicated by 

 scattered beaches and deltas, has not been previously recognized south of 

 Massachusetts, because the phenomena lie higher than the broad terraces, 

 often far back on the valley slopes, and are inconspicuous. 



The physical history of the Connecticut Valley, and of all New Eng- 

 land, is so radically different from the prevailing river theory that it 

 seems desirable to review the entire problem. 



Historical 



views of edward hitchcock and c. h. hitchcock 



In the Geology of Massachusetts, 1841, Edward Hitchcock speaks of 

 only the lower terraces of the Connecticut Valley, which he attributed to 



2 New York State Museum, Bull. 164, 1913, pp. 23-25. Bull. Geol. Soc. Am., vol. 24, 

 1913, pp. 157-160. 



