6 



NEW YORK STATE MUSEUM 



s. 



OU o 

 GO 



w. 



Mooers ; faint striae, on sandstone, % niile s. e. from Wood 









Falls on wood road 



s. 



31° 



w. 



Altona; on Potsdam about 1 mile w. of "Rattlesnake den" 



s. 





w. 



Altona; s. of bend in public road, 1% miles e. of Alder Bend 



S. 



no 



y 



w. 



Altona ; s. of e.-w. road, 1% miles n. by e. from Purdy Mill on 









sandstone 



s. 



1U 



e. 



Altona ; on red sandstone in road gutter s. of Purdy Mill 



s. 



61 



w. 



Altona ; n. slope of Pine ridge 1.1 m. n. n. e. of Dead Sea 



s. 



26° 



w. 



Altona; on Potsdam sandstone by sclioolbouse 3% miles due e. 









from Altona 



s. 



on 

 oO 



w. 



Altona ; in road gutter on grit, near brook just s. w. of Robinson 



s, 



1 



w. 



Beekmantown ; on summit of Rand hill by n.— s. road 



s. 



00 



w. 



Altona; on old military road, 1% miles s. e. of Robinson on red 









sandstone ; also s. 61° w. 



s. 



1 



w. 



Altona; on military road lVi*. miles n. w. from West Beekman- 









town Comers 



s. 



2° 



e. 



Altona; in road gutter of flat rock area e. of Corbeau creek, 









2y 2 miles s. by w. from Sciota 



s. 



4° 



e. 



Chazy; 1% miles 11. of West Chiazy, on road to Scioita 



Interpretation of the striae 



The localities named in the above table are grouped as nearly 

 as possible as they would be traversed in going from northwest 

 to southeast so as to give readings along a line normal to the 

 direction of ice flow, beginning on the northwest at a locality 

 in Canada about 4 miles beyond the limits of the map, where 

 the striation of the upper St Lawrence valley is well marked. 



For the proper understanding of the divergence of the glacial 

 striae toward the south and west in this part of Clinton county, 

 it is necessary to consider the relation of the Adirondack moun- 

 tain mass and the valleys which surround it to the ice sheet 

 moving southwestward against it from the center of movement 

 in Ungava. The fact that the ice sheet moved in the direction 

 stated approximately along the lines of striation indicated on 

 the accompanying map is attested by several phenomena: first, 

 by the occurrence within this field of erratics derived from the 

 basic eruptive rocks of the chain of paleozoic volcanic stocks 

 which extend from the northern termination of the Green moun- 

 tains north and westward to and beyond Mt Royal; second, 

 by the character of the ice-worn surfaces southward in the Cham- 

 plain valley; and third, by the position of moraines and deposits 

 of gravel and sand laid down in temporary lakes held in on the 

 northern slopes of the Adirondack® by a now vanished wall, 



