THE CLYDE SEEIES OF SOILS. 11 



continental glacier and the formation of large or small glacial lake 

 and glacial stream terrace areas, which in turn was succeeded by the 

 withdrawal of the lake waters and the formation of extensive swampy, 

 or at best poorly drained areas within the lake basins, and ended by 

 the accumulation of considerable amounts of partially decayed or- 

 ganic matter in the surface soils. 



The soils thus formed have been rendered capable of agricultural 

 occupation only through the installation of artificial drainage in the 

 majority of cases. Many thousands of acres of these soil materials 

 still remain poorly drained. 



TOPOGRAPHIC RELATIONSHIPS OF THE SOILS OF THE CLYDE 



SERIES. 



The greatest development of the glacial lake province in New York 

 State occurs from the vicinity of the St. Lawrence Valley westward 

 along the shore of Lake Ontario to the Niagara River. 1 In the St. 

 Lawrence River counties the area within which the glacial lake sedi- 

 ments are developed is narrow, forming a belt varying from 5 to 15 

 miles in breadth along the shore of the river. Its surface is anything 

 but smooth and the irregularities are due to the different elevations of 

 the consolidated underlying rocks, which present an uneven and slop- 

 ing surface, as well as to unequal deposition of the glacial till. Over 

 materials of diverse origin and of uneven altitude the sediments of 

 the glacial waters were deposited to greatly varying depths. 



In general, the lowest elevations occur along the shore of the St. 

 Lawrence River and around the eastern end of Lake Ontario. The 

 surface of the sedimentary lake deposits consists of large and small 

 level tracts which are interrupted by ridges of rock, by swells of 

 moraine, and by hollows within which swamps still exist. Gradually 

 this uneven surface rises toward the Adirondack border until the 

 highest distinctly glacial lake deposits are found about 750 feet above 

 sea level or about 500 feet above the waters of Lake Ontario and the 

 St. Lawrence River. 



Throughout this section of the glacial lake region there has been 

 a sufficient degree of obstruction to surface drainage to give rise 

 to the formation of swamps of large and small size, resulting in the 

 formation of soils of the Clyde series. They are always to be found 

 in locally depressed positions, which are not so poorly drained as 

 the associated swamps but which are less well provided with natural 

 drainage facilities than the surrounding upland soils. Many of the 

 areas also accumulate local seepage waters from soils or rock areas 

 lying at higher elevations. 



1 Bulletins Nos. 106, 127, and 145 of the New York State Museum. Glacial Waters iu 

 the Lake Erie Basin. Glacial Waters in Central New York. Geology of the Thousand 

 Islands Region. By H. L. Fairchild and others. 



