38 NEW YORK STATE MUSEUM 



most part in the form of ridges with axes parallel to the direction] 

 of the prevailing wind that is, northwest-southeast. These dunej 

 features are brought out strikingly by the contour lines of the sheet 

 in the portion of the plain crossed by the New York Central 

 Hudson River Railroad tracks, southeast of Schenectady. 



The extent to which sands have been shifted by wind agency ij 

 clearly indicated on this plain. The western portion is nearly level] 

 and its soil has some clay mixed with the sand. It bears the appear-* 

 ance of a wind-denuded plain, from which the surface sands have 

 been partially stripped leaving the underlying clays. To the east 

 of this level area lies the highly irregular surface, marked by ridges 

 and hillocks of sand. The highest dunes attain an elevation of 400 

 feet or 60 feet above the level of the denuded portion of the plain. 

 This does not represent, however, the full extent to which the sands 

 have been lifted, as farther to the east where the hills of till rise 

 to the height of 500 feet, the country is more or less overspread 

 with wind-laid sands. 



In the sand region of the eastern portion of the sheet lying 

 between the Mohawk valley and the Round lake depression there 

 are extensive areas marked by the effects of wind agency. The 

 country around Clifton Park is especially characterized by hills and 

 hollows of sand. There is no evident regularity to the forms of the 

 dunes, indicating that winds blowing from different directions have 

 had part in their formation. Recent effects of the wind in modify- 

 ing existing surface features are noticeable. 



