42 NEW YORK STATE MUSEUM 



of the channel. As the ice front retreated.northward it permitted 

 the escape of at least part of the waters through another channel 

 half of a mile north of the Railway channel. Later part of the 

 waters passed north of east through a shallower channel crossing 

 the southeastern part of the city of Syracuse, and still later the 

 waters passed eastward through the central part of the site of the 

 city, through the depression now followed by the Erie canal and 

 the New York Central Railroad. 



While the channels mentioned were being formed through the 

 divide separating the Onondaga and Butternut creeks, other con- 

 temporaneous channels were in process of formation west of Onon- 

 daga creek and east of Butternut creek, in the southwest and south- 

 east portions of the area of the Syracuse quadrangle, 1 



TERRACES 



During the period that the channels were being cut by the east- 

 flowing waters, the north-south valleys, such as the Onondaga and 

 the Butternut, would be partly filled by the impounded waters form- 

 ing temporary lakes in which the water would stand at successively 

 lower levels as the lower cross-channels were opened one after the 

 other. Where such lakes remained at the same level for a consider- 

 able period of time, more or less well-defined shore features would 

 be developed, especially sand and gravel terraces. Besides their 

 interest as topographic features, these terraces are important com- 

 mercially as from them are obtained the large quantities of sand and 

 gravel required in structural work in and around the city. 



The terraces occur at several different levels, at least five fairly 

 distinct ones appearing on the higher hills south of the city. On 

 the area of the Syracuse quadrangle the most prominent terrace 

 is near the level of the 500 foot contour above sea level. It shows 

 on both sides of the Onondaga valley but is more prominent on the 

 east side. It marks the west margin of the Syracuse University 

 campus. Eastward from the campus through the city it has been 

 largely obliterated by building operations, but southward it is nearly 

 continuous as far as the Indian reservation. Large quantities of 

 sand and gravel have been removed from this terrace at the Calthrop 

 residence on South Salina street, at Kelley's coal yard on the Dela- 

 ware, Lackawanna and Western Railroad and other points. On 

 the west side of the Onondaga valley this terrace is quite promi- 



1 For further details of the surface geology of this region, see the various 

 papers by H. L. Fairchild published as bulletins of the N. Y. State Museum. 



