Mill River into the Quinnipiac. 127 
ast Rock, where the valley terrace is seven feet higher than 
that of the Quinnipiac adjoining. It is therefore manifest that, 
on reaching the southern extremity of the ridge separating the 
two valleys, it would have made a quick turn around the pro- 
montory and plunged into the Quinnipiac basin ; and this would 
ve carried it northeastward directly over the place where the 
evidences of reversed currents occur in the drift deposits. This 
place of discharge would not have taken off all the Mill River 
waters, or the larger part; for the water level there, when the 
flood was at its height, was still thirty to thirty-five feet above 
the sea-level—height enough to have kept the tumultuous waters 
mainly on a seaward course. . 
. We hence learn from the drift deposits at this place of june- 
hon of the two streams, southeast of Hast Rock, (a mile north 
of the present head of New Haven Bay and six miles from its 
fastern cape), the following facts : 
- Until the waters of the flooded streams had reached, at 
the place mentioned, a height of fifteen feet above the then- 
rxisting sea-level, neither stream overbalanced the other; for 
the deposits of the lower stratum within the range of the Quin- 
nPlac valley show, by their structure, that they were made by 
© How of Quinnipiac waters. The pitch of the waters to the 
und was then but two or two and a half feet a mile. 
ah gay ne same water-level was riael oe: seg bia 
and plunging, as proved by the flow-and-plunge structur 
. the beds—was pate ota with what followed ; for this 
wer stratum consists mainly of sand and fine pebbles. 
». The increase in the flood on passing that level was sudden, 
48 if the dissolution of the glacier bad then received greatly 
the erated progress, For the transition in the bedding, and in 
‘he color of the sands, is abrupt, with no fine layer between to 
Cate an epoch of repose ; and, moreover, the upper stratum 1s 
* Tbid., x, 413. 
