14 CONNECTICUT GEOL. AND NAT. HIST. SURVEY. [Bull. 



The regional depression which marked the close of the glacial 

 period slackened the speed of many rivers and caused them to 

 deposit great quantities of modified or assorted drift. Since 

 glacial time, these deposits have been dissected and formed into 

 the terraces which are characteristic of the rivers of the region. 

 A form of terrace even more common than the river-made terrace 

 is the kame terrace found along borders of the lowlands. Eskers 

 in the Danbury region have not the elongated snake-like form 

 by which they are distinguished in some parts of the country, 

 notably Maine; on the contrary, they are characteristically short 

 and broad, many having numerous branches at the southern end 

 like the distributaries of an aggrading river. The material of 

 the eskers ranges from coarse sand to pebbles four inches in 

 diameter, the average size being from one to two inches. No 

 exposures were observed which showed a regular diminution in 

 the coarseness of the material toward their southern end. The 

 clean-washed esker gravels afford little encouragement to plant 

 growth, and the rain water drains away rapidly through the porous 

 gravel. Consequently, accumulations of stratified drift are com- 

 monly barren places. A desert vegetation of coarse grasses, 

 a kind of wiry moss, and " everlastings " (Gnaphalius decurrens) 

 are the principal growth. Rattlebox (Crotolaria sagittalis), 

 steeplebush (Spiraea tomentosa), sweet fern (Comptonia 

 asplenifolia) , and on the more fertile eskers especially on the 

 lower, wetter part of the slope golden rod, ox-eyed daisy, 

 birch, and poplar are also present. All the eskers observed were 

 found to be similar: they ranged in breadth across the top from 

 loo to 150 feet and the side slopes were about 20 degrees. Only 

 a single heavily wooded esker was found, and this ran through 

 a forest region. 



The accumulations of stratified drift are distinguished from 

 other features in the landscape by their smoother and rounder 

 outlines, by their habit of lying unconformably on the bedrock 

 without reference to old erosion lines, and by a slightly different 

 tone in the color of the vegetation covering the water-laid 

 material. The difference in color, which is due to the unique 

 elements in the flora of these areas, may cause a hill of stratified 

 drift in summer to present a lighter green color than that of 

 surrounding hills of boulder clay or of the original rock slopes; 

 in winter the piles of stratified drift stand out because of the 

 uniform light tawny red of the dried grass. 



