PLEISTOCENE GEOLOGY OF MOOERS QUADRANGLE 



37 



480 to at least the 560 foot line, but I am not certain that it is 

 wave-made. 



When one compares the rather marked shore lines between 

 590 feet and 680 feet on the south, and between 620 feet and 

 720 feet on the north of this area, with this indistinctly marked 

 zone between, extending down to about 500 feet on the south 

 and to 540 feet on the north, it is evident that the sinking of 

 the water level or the rise of the land in relation to the wave 

 zone was rapidly accomplished. The greater number of the 

 wave marks in this interval on the south, both as regards the 

 cases mapped and their broader distribution in the vertical 

 space, is taken to indicate that water action lasted there longer 

 than on the north of the Cor beau. It is to be noted also that 

 the large streams which traverse the northern part of this field 

 have no deltas between 500 feet and 600 feet. They apparently 

 extended their mouths from the deltas above the 600 foot line 

 to those below the 500 foot line suddenly. The English river 

 has no delta immediately below the 500 foot line, as the Big 

 Chazy has just south of it, unless we 'regard that delta as partly 

 formed also by the English river. The English river has how- 

 ever a delta at about 450 feet. 



From a comparison of these shores lines and deltas southward 

 throughout the Champlain valley with certain spillways and 

 outlets between Fort Edward and Stillwater it appears that a 

 glacial lake must have existed for a long time over the region, 

 held in on the north by the retreating ice front and thus over- 

 flowing southward. The earliest stage of this lake is appar- 

 ently marked by a spillway over the west bank of the Hudson 

 gorge between Schuylerville and Quaker Springs. This stage of 

 the lake is probably not represented on the Mooers quadrangle by 

 lacustrine deposits or shore lines. The ice appears still to have 

 covered the district. 



Later the excurrent stream cleared out a drift-filled side chan- 

 nel of the Hudson west of Schuylerville and joined the Hudson 

 gorge at Coveville. By this time the glacial lake appears to 

 have extended into the Mooers district. The upper line of wave 

 action on Cobblestone hill, and the signs of wave action rising 



