Topographical Features of the Neto Haven region. 83 



ing period itself; and the decrease of rate would have been quite 

 gradual. On the west side of the bay near Halleck's place (where the 

 present railroad grounds abut against it), a section of the terrace for- 

 mation 25 feet in height (the upper twenty-five) is exposed to view, 

 and throughout it, the beds have pi'ecisely the structure exhibited in 

 fig. 1 (p. 73), and difier only in the paucity of pebbles ; they evince the 

 same free supply of material and rapid deposition under the action of 

 the waves. Moreover, the slope of the oblique lamination is toward 

 the south (as in the lower part of fig. 1), showing that the deposition 

 was accomplished mainly during the inflowing tides. 



The result of all this transportation and deposition was an exten- 

 sion southward of the sand beds, as well as an increase in their height ; 

 and the terrace formation was thus completed to its outer limit. The 

 plain stretching south to Oyster Point and over West Haven gives us 

 some idea of its extension in that dii'ection ; but not necessarily its 

 original extent, since the sea may have washed away much from its 

 borders as well as from its upper surface. 



Over the region toward Oyster Point, the beds are sandy through- 

 out, and free from any upper layer of fine river or bay detritus, such 

 as is deposited about existing mud-flats and sand-banks. On Grape 

 Vine Point, between the mouths of Mill River and the Quinnipiac, 

 there is the same absence of any thing like a layer of harbor mud 

 over the sandy beds of the drift formation. The proof appears hence 

 to be quite positive that these sandy beds did not lie for a long period 

 beneath the water, after the material was deposited. 



2. Sand-formations on the borders of the Quinnipiac valley, — The 

 Quinnipiac valley was the site of the inner harbor of the bay, during 

 the Champlain era — and a harbor of great extent and depth, as already 

 stated. While the sand-formation was in progress down the bay, 

 changes should have been going forward within its area. On its bor- 

 ders we naturally look for sand beds distinguishable from those that 

 were made during the hurrying time of the melting by unconforma- 

 bility, and also by freedom from layers of coarse pebbles and cobble 

 stones. One locality of such sand beds of considerable extent occurs 

 on what was the southwestern border of the old harbor, at the north- 

 eastern end of the cut made through the terrace formation for the Air- 

 line railroad, south of the East Rock range. The character of the 

 terrace formation along this cut has been described on pages 73, 74. The 

 position and general character of these whitish sand beds are shown 

 in the following cut. The part A B C is the terrace formation, con- 

 sisting of beds of sand, some quite coarse pebbly, and below including 



