GEOLOGY OF THE NORTH CREEK QUADRANGLE 73 



a mile, which is very close to the figure given by Woodworth fosr 

 the lower Champlain valley. 



Glacial Lake Johnsburg. This was a small irregular shaped 

 lake extending for about 2^ miles southwestward from Johnsburg; 

 as proved by a number of well-distributed sand flats or terraces 

 at, or a little above, the 1300 foot contour line which approxi« 

 mately marks the old shore line. The best terraces, practically un- 

 represented on the contour map, are : two-thirds of a mile west^ 

 three-quarters of a mile southwest, three-quarters of a mile south- 

 southwest, and at several places about 2 miles south-southwest of 

 Johnsburg. 



The cause of this static water condition appears to have beere 

 either an ice or glacial drift dam across the Mill creek channel 

 at or not far east of Johnsburg. 



Glacial Lake North Creek. The former presence of a lake in 

 the vicinity of North Creek is proved by the existence of thick 

 stratified sands, comprising terraces and flats. South of the village 

 the sands show a depth of over 100 feet where they have been 

 trenched by the small creek. Holcombville lies on a sand flat at 

 1 160 feet, and the tongue of sand just southwest of North Creek 

 rises to nearly the same altitude. Just north of the river the sands 

 were, no doubt, largely removed by postglacial stream work. From 

 13/2 to 2 miles north-northeast of North Creek (along the new 

 State road) there are stratified sands and gravels running up as- 

 high as 1 140 or possibly 1160 feet, and these seem to correlate with 

 the deposits south of the village. The precise location of the re- 

 taining dam of this lake can not be given but it was either ice or 

 drift, probably the latter, across the Hudson channel not over 2 

 miles east of North Creek. 



One-half of a mile due east of Holcombville there is a small but 

 finely developed flat-topped sand terrace at an altitude of 124a 

 feet. It extends out as a distinct apron from the mountain side 

 of syenite. The depth of sand in this terrace is fully 200 feet, and 

 it was probably formed in a small, marginal, high level lake whert 

 the ice was still present. 



The Glen glacial lake. This body of water extended from near 

 the headwater of Millington brook northwestward to the Hudsora 

 river, thence along the river channel past The Glen, and to near 

 the mouth of Mill creek. Sand flats at an altitude of 800 feet or 



