Amongst all these high glens there is a remarkable absence of lakes and waterfalls; nor are there down in the lower valleys at the foot of the mountains, as one would naturally expect in a region so extensively glaciated, any sheets of water corresponding to the Swiss lakes.
The maturely dissected and recently glaciated uplands of New England are now somewhat depressed with respect to sea-level, so that the sea enters the valleys, forming bays and estuaries, while the interfiuve uplands and hills stand forth in headlands and islands.
Thus local sheets or aprons of gravel and sand are spread more or less abundantly along the outer side of the morainic belts; and long trains of gravel and sands clog the valleys that lead southward from the glaciated to the non-glaciated area.
In this central region, however, it is only by way of exception that the cirques were so far enlarged by retrogressive glacial erosion as to sharpen the preglacial dome-like summits into acute peaks; and in no case did glacial action here extend down to the plains at the eastern base of the mountains; but the widened, trough-like glaciated valleys frequently descend to the level of the elevated intermont basins, where moraines were deployed forward on the basin floor.
C. Russell, have yielded evidence of past climatic changes second in importance only to those of the Pleistocene glaciated areas.