ANCIENT WATER LEVELS OF CIIAMPLAIN— II I'DSON VALLEYS 155 



is a high lateral moraine terrace locally known as Sawyer hill, 

 whose surface is contoured by the 510 foot line. Buck mountain 

 rises in a steep wall to a hight of over 1000 feet above the level 

 of this deposit. An excavation made at the southern lobe of the 

 deposit showed it to be stratified with a foreset structure dipping 

 south. The materials are gravelly. In about the middle of the 

 terrace to the west of the point where the highway from Street 

 Road to Crown Point reaches the summit there is a large and well 

 defined kettle hole. Farther north evidences of deposition in the 

 presence of ice continue to appear; and in the pass between the 

 outlying tectonic block of Dibble mountain and the eastern face 

 of Buck mountain (see the Ticonderoga sheet for details of 

 topography), there is a deep depression marked with kames and 

 abundant indications of the presence of ice in the deposition of 

 the materials whether by water or ice alone. The bottom of this 

 pass according to the contours of the map is at least 80 feet lower 

 than the surface of the terrace on the south. The eastern face of 

 this terrace is a. steep slope ribbed by gentle wave lines, the high- 

 est of which is at about 500 feet elevation. The terrace appears 

 to have been built by waters discharging through the Buck moun- 

 tain pass from the depression about Crown Point north of this 

 mountain and to have been bordered by the ice sheet on its 

 eastern Hank if ice did not also lie in the depression on the north 

 of it. There was evidently a small glacial lake held in south of it 

 in the valley of the small stream which drains Buck mountain 

 and Worcester ponds. There are notable sand deltas on this 

 stream at even higher levels than the Street Road terrace. The 

 precise position of the ice front across the valley of Lake Cham- 

 plain at this time has not been determined but it presumably lay 

 to the south of Street Road. Later the front appears to have lain 

 locally on the north side of Dibble mountain, a tongue pressed 

 forward into the pass before mentioned, and east of the mountain 

 the front presumably crossed the axis of the valley somewhat 

 farther south. 



After the ice disappeared from this vicinity the open waters in 

 the Champlain valley appear not to have stood higher than the 

 wave marks on the side of the terrace, viz 500 feet, for the kame 

 kettle on the top of the terrace shows no signs of having been 



