§4 NEW YORK STATE MUSfiUM 



Mohawk valley leaving the main portion of the Adirondacks free 

 from ice. But, as the ice increased in volume, more and more of 

 the Adirondack region was covered till finally even the highest 

 points were buried. In a paper published by the writer some years 

 ago, the movement of the great ice sheet across northern New 

 York is discussed.^ During the ice retreat the higher east-central 

 Adirondack region was the first to be freed from the ice, and the 

 ice-freed portion gradually increased in size. 



Direction of Ice Movement 



The direction of ice movement across the Schroon Lake quad- 

 rangle is clearly recorded by both glacial scratches (striae) and 

 the distribution of glacial boulders. Distinct glacial striae were 

 observed in twenty localities, their bearings and locations being 

 plotted on the accompanying geologic map. They are as follows : 



1 S io° W. On Grenville gneiss i^ miles west-southwest of 

 Schroon Lake village. 



2 S io° E. On granite by the road lyi miles west-northwest of 

 Schroon Lake village. 



3 S io° E. On diabase i^ miles due west of Grove Point. 



4 N-S. On granite three-fourths of a mile northeast of Charley 

 hill. 



5 N-S. On granitic syenite near the summit of Beech hill. 



6 S io° E. On granite by the road i mile west of Charley hill. 



7 N-S. On granitic syenite by the road i mile northwest of 

 Taylors on Schroon. 



8, 9 S io° E. Two records one-fifth of a mile apart on granite 

 by the road three-fourths of a mile north-northeast of Pat pond. 



10 S iO° E. On Grenville gneiss three-fourths of a mile due 

 west of Minerva. 



11 S io° E. On granite by the road just south of Oliver pond. 



12 N-S. On granite by the road one-third of a mile west-south- 

 west of Oliver pond. 



13 S 30° W. On granite by the road one-half of a mile west- 

 southwest of Oliver pond. 



14 S 10° E. On syenite by the road one-half of a mile north- 

 east of Muller pond. 



15 S 10° E. On Whiteface anorthosite by the road i^ miles 

 west-northwest of Boreas river. 



lAmer. Jour. Sci., 27:289-98. 1909. 



