'250 21ie American Geoloyist. October, 1895 
several miles, beyond which they are sometimes represented by delta 
remnants farther down the valley from which the terrace remains have 
been removed by erosion. The terrace gravel and sand often extend 
across the country from one valley to another. 
Subject to certain corrections, the succession of terraces and flats 
.marks the repeated lowering of the base planes of erosion, or, in other 
words, an intermittent elevation of the land, which has been raised ap- 
proximately as much as the sum of the vertical intervals between the 
terrace planes. These are commonly situated close together, with only 
a few feet or tens of feet of elevation between them: but in inany local- 
ities several of the steps are so comVjined that the great terraces may be 
from 50 to 250 feet above the rivers. In the course of a few miles scores 
of terraces may be ascended or descended and counted with certainty. 
At any one locality there are seldom more than four or five lateral ter- 
races distinguishable; but these are not identical with the four or five 
observed several miles up or down the valley wherever the slope of the 
stream is considerable. 
Distinct terrace steps occur up to an elevation of 2,700 feet at the 
base of Mt. Washington: and similar gravel and sand continue much 
higher, but without the preservation of the terrace structure upon the 
steep mountain slopes. Such relationship of gravel terraces has been 
observed under so many conditions and over so wide extent of territory 
that it appears to be the prevailing condition, and not the exception. It 
is nearly everywhere well preserved within the region of the drift, which 
has been the source of supply for the gravel and sand. 
If these deposits, lying as terraces in the valleys and here and there 
expanding into plains even two or three miles or more in width, were 
observed only on the northern and western sides of the high lands, they 
might appear to favor the theory of their formation in glacial lakes. 
But they also occur on the southern and eastern sides of so many moun- 
tain masses as to preclude the idea of their accumvxlation in glacial 
lakes. Moreover, the author has oVjserved the same structure within a 
few degrees of the equator, occvu-ring there at both low and high alti- 
tudes. He concludes that the jnountainous part of New England has 
been recently uplifted at least 2,700 feet. As the valleys had been re- 
excavated out of till, he thinks that the glacial submergence of the re- 
gion equaled this elevation. The magnitude of the movements in the 
coastal regions appears to have been less, but this question is still one 
for future investigations. 
Profs. G. F. Wright, H. L. Fairchild, and C. H. Hitchcock, in the 
ensuing discussion, distrusted this interpretation of the valley terraces, 
and cited reasons for doubting any greater uplift than the 300 to 560 
■feet above the sea which measure the hight of Champlain marine fos- 
sils in Maine and in the St. Lawrence and Lake Champlain valleys. 
Vieiv of the Ice Age as ttco Epochs., the Glacial and Champlain. 
Warren Upham, Cleveland, Ohio. The Glacial period or Ice age, is 
found divisible in two parts or epochs, the first or Glacial epoch being 
marked V)y high elevation of the drift-bearing areas and their enveloj)- 
