GEOLOGY OF THE LUZERNE QUADRANGLE 53 



According to Fairchild/^ a long narrow branch of large Scho- 

 harie lake of the Mohawk valley extended through the Sacandaga 

 and Hudson valleys of the Luzerne quadrangle. Since the lowest 

 level Schoharie waters at the latitude of Little Falls stood at about 

 the present 88o-foot level, and allowing for postglacial uplift 

 toward the north, the branch of Schoharie lake, even at its time 

 of lowest water, must have stood fully as high as the present 900- 

 foot level in the Hudson valley of the southern part of the Luzerne 

 quadrangle, and considerably higher at the north. It is with some 

 hesitation that the writer expresses his doubt concerning the exist- 

 ence of such high-level waters in the quadrangle, but he certainly 

 was unable to locate anything like persistent well-defined delta lake 

 deposits at any such level through the Hudson valley. 



At a lower level there is, however, very good evidence for the 

 former existence of a body of water which extended all through 

 the Hudson valley of the quadrangle. The proof consists in the 

 presence of more or less perfectly preserved delta deposits and 

 sand plains or flats varying in altitude from about 700 feet on the 

 south to about 760 feet on the north at Warrensburg. Examples 

 of some of the best preserved of these high-level lake deposits are 

 the following: along the railroad west of Corinth at about 700 

 feet; lyi miles south of Luzerne at 700 feet; the fine big sand ter- 

 race just south of Lake Luzerne at 700-20 feet; i^^ miles north- 

 northeast of Luzerne at 720 feet; in the valley of Stewart brook 

 east and north of Gailey hill at 720 feet; along the road one-half 

 of a mile west of the mouth of Wolf creek at 720 feet ; a very fine 

 terrace one-fourth of a mile long (covered by dense woods) on the 

 east side of the river i mile a little east of south of Stony Creek 

 station at about 740 feet ; and in the vicinity of Warrensburg where 

 a fine sand plain 2 miles wide rises to an altitude of 760 feet. These 

 deposits were certainly formed in a body of water which occupied 

 the valley after the final retreat of the ice from the district. Their 

 steady increase in altitude northward at the rate of about 3 feet a 

 mile is the result of postglacial differential uplift of northern New 

 York as above explained. This body of postglacial water repre- 

 sents the southern extension of the lake described in 191 1 by the 

 writer^^ as Glacial Lake Warrensburg because of the fine lake 

 deposit upon which Warrensburg rests. As previously described, 

 this lake reached up the Schroon river valley about 8 miles and 



'* N. Y. State Mus. Bui. 160, 1912, p. 35. 

 "Geol. Soc. Amer. Bui. 22, 1911, p. 185-86. 



