TopograpMcal Features of the New JSauen region. 97 



tion to the north,) then the interval between the level of the terrace 

 plain and that of the present flood-plain of the river (47 feet at Augui- 

 ville) would just equal that of the amount of elevation. But in fact 

 the river's bed at Augurville is 3 or 4 feet above what is required for 

 a restoration of the earlier slope (p. 101), and not more than one foot 

 of this 6 or 7 can be attributed to tlie rise of the land being greatest 

 to the north ; and hence 50 feet lor the amount of elevation in the lat- 

 itudes of Whitneyville and north to Augurville cannot be too great. 



(2.) Slope made during the pkogress of the Elevatiox. — 

 Since the sand-flats of a bay have their height determined by the 

 tides and waves, and are thus kept, for the most part, below mean 

 tide level, a rise of the region exceedingly slow in progress might re- 

 sult in a wearing away of the surface at the same rate of progress ; 

 and thus the height of the sand-flats would be lowered, as the rise 

 went on. But the material washed ofi" from the flats would be carried 

 to the shore to extend the beach seaward. The relation of the beach 

 to the sand-flats may be seen along the shores near Savin Rock. As 

 the rise went forward, the beach would keep extending ; and as the 

 beach attains a height by the accumulations, of only a few feet (three 

 or four at Savin Rock) above high tide (the height of wave action), 

 the final result would be a gradual seaward sloj^e in the surface of the 

 land, and one made during the progress of the elevation. But in such 

 a case beach accumulations would have been laid down over the land 

 to a depth of six feet or more ; which would evince their origin by a 

 dip in the layers of the lower part corresponding with the slope of the 

 original beach, and an irregular arrangement of layers in the upper ; 

 if not. also, in the presence of beach relics. 



Now, over the New Haven plain, all the way to Oyster Point, the 

 drift formation in the numerous sections has a uniform horizontal 

 stratification to the very top. The sands of the upper foot or less are 

 discolored by the growth of vegetation, yet they are in fact a part of 

 the upper layer. An overlying beach formation is nowhere distin- 

 guishable. There is therefore no certain evidence that any of the sea- 

 ward slope of the plain was jiroduced by the method here explained. 



The facts tend to show that the elevation that placed Oyster Point 

 and the land farther north above the sea was not slow in progress. 



(3.) Slope resulting from a later sinking of the sea-margin. — 

 The evidences of a later sinking of the sea-margin to be looked for 

 are the following: (1) Old stumps, in the position of growth im- 

 bedded in the flats or the shallow waters off" the coast ; (2) sub- 

 merged remains of human structures; (3) submerged shell heaps 



Trans. Connecticut Acad., Vol. II. 7 January, 1870. 



