38 
TACONIC PHYSIOGRAPHY. 
the first shattering of the ledges was by the mechanical action of t! 
ice sheet, and such shattered ledges may well have furnished materi 
for bowlders. When the moss- and forest-clad summits of the Taconi< 
and Green Mountain ranges are deforested they are frequently founc 
to consist of shattered ledges. Such ledges, when still covered with 
vegetation, are probably the sources of the higher ice-water brooks 
or springs which now and then surprise the summer traveler." 1 
some localities blocks of quartzite 20 by 10 by 5 feet have been move 
several feet either horizontally or up slightly inclined bedding plane 
At " The Burning," on the Green Mountain Range, near the tow 
line of Manchester and Sunderland, such blocks and a large area of 
shattered quartzite may be observed. The relative position of many 
of these blocks is such as to preclude the probability that the action 
w 
Sea level 
Um££ 
Scale 
IOOO 
?ooo feet 
Pig. 1. — Section across the western side of Stone Hill and Hemlock Brook Valley to the 
Taconic Range in Williamstown, Mass., showing the eroded fold. The lowest rock is 
quartzite, the next dolomite, then schist. 
of frost alone brought it about, although it has undoubtedly had a 
share in the work. (See PL IV. p. 24, foreground.) 
For the action of frost in the production of talus slopes see 
page 4G. 
PARTICULAR EFFECTS OF EROSION. 
The more minute sculpture of the region and the particular forms 
resulting from the action of the various erosive processes upon mate- 
rial and structure remain to be considered. 
a See Water-Sup. and Irr. Paper No. 110, U. S. Geol. Survey, 1905, p. 127. 
