The Glacial Origin of Cliffs — Davis. 
17 
climate transportation is so active that the talus is reduced to a 
minimum of volume and coarsest texture; in a dry climate, 
transportation is reduced to its lowest terms, and the waste from 
the mountain slopes accumulates in maximum of volume and 
finest texture as is seen in our arid western regions, or in Persia 
where Blanford has described it as a controlling feature of the 
Piedmont country. But between New England and New Jersey, 
we cannot look for existing differences of climate of value suf¬ 
ficient to account for the differences of topography here dis¬ 
cussed. Let us turn instead to secular variations of climate, 
ssuch as brought a sheet of ice over the northern ridges. 
Heavy glaciation, long enduring, would scrape away the 
loose material of a talus and undercut the soft beds beneath the 
hard layer. When the ice melts away, the profile would be 
like d d, fig. 3, in which the cliff is very strong and the talus is 
practically wanting; then for a time the wasting of the cliff- 
face would be at its highest rate, both from its s eepness and 
from the great hight of the face exposed; and the supply of 
material for a new talus would be rapid. A new adjustment to 
sub-aerial conditions of supply and loss would be approached at 
a quick rate at first, but slower and slower as it is neared; the 
glaciated trap-ridges seem to be about half way advanced in 
this progress. The lower Connecticut valley affords excellent 
examples of these uncompleted taluses, surmounted with cliffs 
of a strength that most New Englanders do not expect to find 
so near at home. The notch in the Hanging Hills, in which the 
Meriden reservoir has been constructed, between West Peak 
and Notch Mountain, fig. 4, is enclosed by superb cliffs, c c, over 
N‘* c 
\L-Jb 
