Topographical Features of the JVeio Hacen region. 81 



minal moraine " in tlie ordinary slow way would never have stopped 

 the course of a Niagara. But before a sudden down-throw of sand 

 and gravel from a freighted glacier, no stream is too large or rapid 

 to hold its jDlace. 



Although the accumulation of freight by the old glacier must have 

 required a very long period, even that of the whole Glacial era, the 

 deposition of a large part of the older " alluvium," if the above view 

 is right, was a rapid work — much more rapid than has hitherto been 

 suspected. Any attempt to measure the interval of time between the 

 depositing of the top and bottom layers by comparing the thickness 

 of the formation at New Haven with the accumulations now going for- 

 ward along the shores would lead only to great error. This conclu- 

 sion holds not merely with reference to all similar formations made by 

 direct deposition from the glacier, but also to others accumulated by 

 the action of moving or running 'waters immediately afterward, inas- 

 . . t 



in the Champlain era, and states that its present course along the falls or rapids near 

 Loiiisville was thus determined. Other cases also are referred to. 



It is possible that in Mill River we find an example of such a change of course, as I 

 have stated above. But the facts with regard to the Mill River gravel-course (p. 71) 

 are another argument against it. It wiU be understood that this gravel is not that of 

 the bed of the stream, but the material of the terrace or drift formation standing high 

 along the border of the river ; and that it is similar in character above and below the 

 WhitneyvUle dam. It seems to be good evidence that the river occupied its present 

 channel throughout the period of the deposition of the drift. 



A change of course in the Quinnipiac through the cause alluded to is quite probable. 

 The river at the bridge flows in a sandstone trough, the rock rising above the river 

 10 feet on the western side and over 20 on the eastern. Along the road running 

 thence eastward to the depot (50 to 60 rods distant) which rises from 15 to 25 feet in 

 level, there is no sandstone, and instead a deep bed of the sand of the stratified drift. 

 The wells at three of the houses west of the depot go down 2 to 4 feet below high- 

 water mark in the river, without reaching the " red rock." Moreover the low flats of 

 the river north of the bridge spread eastward and sweep around to within 40 yards of 

 the depot ; and ia consequence, a brick house recently buUt opposite the depot (across 

 the street), while it stands in front on the firm sands, rests its northern or back walls 

 on piles which were driven down in the meadows 20 feet without finding for all of 

 them a firm footmg. That the river's bed was once here is the supposition of those on 

 the spot who know the facts. But we may suspect further, that the river from this 

 point flowed southward to join the present channel half a mile below, the low level of 

 the bottom of sandstone over this region determining it; and that the sands and gravel 

 derived directly from the glacier or indirectly through the river floods, during the sub- 

 mergence (45 to 50 feet in amovmt, as shown beyond) of the Champlain era, filled up 

 the earlier channel, so that the stream, when the land was afterward elevated was 

 forced to open a new channel, in doing which it took a course over the rocks because 

 compelled to it by the existing slope of the surface. 



Trans. Connecticut Acad. Vol. II. 6 January, 1869. 



