32 NEW YORK STATE MUSEUM 



these clays were deposited on the east and south." It is true that 

 Lake Albany deposits occur north of Ballston lake (crossed by the 

 northern edge of the sheet). These deposits, however, represent 

 deltas made by currents flowing from the north. They are thickest at 

 the edge of the sheet and thin out toward the south, indicating that 

 the currents dropped their loads not much south of the present 

 boundary lines of these deposits. 



There was, therefore, little to obstruct the northward flow of 

 strong currents through the Ballston channel. The Lake Albany 

 deposits in the southern end offered at least no more resistance than 



Fig. 5 Sketch map showing the distribution of land and water on the area of the Schenectady 

 quadrangle when Lake Albany had subsided to the level of about 320 feet 



