15 NEW YORK STATE MUSEUM 



A copious flow with abundant detritus passed out of the Mohawk 

 valley at an early stage of the ice removal, and long before the 

 land uplifting began in the Albany district. In the series of maps 

 prepared by the writer to show the waning of the Labradorian ice 

 sheet from New York State and the correlating waters (ii, 14), 

 the Albany district is represented as ice-free and flooded by the 

 Hudson estuary long before the flood of the Great Lakes passed out 

 through the Mohawk valley. It seems quite certain that the 

 uplifting at Albany did not begin until the outflow of the Great 

 Lakes area found escape through Lake Iroquois and the Iromohawk 

 river, and the Schenectady- Albany delta had received its main 

 deposit. At this time the head of the Iromohawk, at or near Rome, 

 had an altitude above sea of not over no feet. 



The apex or head of the delta was west of Schenectady and 

 remnants of it are now found in coarse cobble deposits above and 

 below Rotterdam Junction. 



When the wave of land uplift, subsequent to the removal of the 

 ice sheet, in its northward progress reached the Albany district, 

 the upper part of the Schenectady delta was lifted above the Hudson 

 estuary waters and the Iromohawk river was obstructed by its own 

 deposits. Previously the currents had swept southeast toward 

 Albany, but with the excessive rise of the delta the river flow was 

 diverted to the northern side of the delta, on the side of belated or 

 lesser uplift. The river channel was extended northward through 

 what is now Ballston lake toward Ballston Spa and Saratoga Springs. 

 This diversion has been recognized by Stoller (7, pages 30-31). 

 who thinks that the present channel of the Mohawk, southeast of 

 Rexford Flats and Aqueduct, carried a portion of the flow from the 

 earliest diversion. At East Line (see map) the northward coursing 

 Iromohawk was divided into three distributaries, first noted by 

 Stoller (7, page 32). One, in northward course to Ballston Spa he 

 called the Mourning Kill channel; the second, the Drummond 

 channel, led northeast toward the site of Saratoga lake, which was 

 then occupied by a huge, detached ice block. The third channel, 

 which we call the Maltaville channel, led southeast toward Mechanic- 

 ville, passing the site of Round lake, which was also occupied by a 

 mass of ice. The Round lake problem is discussed in a later chapter. 



The two distributaries first noted made contribution to the lower 

 sand plains at Saratoga Springs and west and southwest of Saratoga 

 lake. The Maltaville river swept its detritus past the Round Lake 

 ice block and dropped it in the neighborhood of Mechanic ville. The 



