THE ADIRONDACK GRAPHITE DEPOSITS 113 



to the long north and south depression that is traceable from Trout 

 pond to Elizabethtown. The origin of this side valley is directly 

 due to the easily eroded Grenville strata which here arc composed 

 in large measure of limestone. The valley walls and inclosing 

 hills are of igneous rocks that are much more resistant to destructive 

 forces. 



The continental ice sheet widened the north and south valley 

 as well as scraped off the decomposed rock decay which had 

 formed during the interglacial periods. During the retreat of the 

 glacier, heavy glacial streams flowed through the main valley along- 

 side of the ice tongue which occupied the valley bottom. Extensive 

 boulder trains and deltas were deposited, which can be traced for 

 a long distance southward. The ice tongue deposited crescent- 

 shaped moraines north of Lewis and one in the side valley in which 

 the graphite schist is exposed. This moraine is convex up stream 

 showing that it is the work of the continental ice rather than that 

 of a local glacier. Although it is somewhat dissected yet it has 

 forced the present brook to seek a course to one side of the valley 

 forcing it out of its normal course. Morainal ridges and glacial 

 silts obscure much in this side valley and greatly interfere with 

 detail mapping. 



The pits. Graphite was discovered years ago by marble men 

 seeking a supply of serpentinized limestone (verd antique). In 

 their original search they were disappointed. The property is now 

 owned by George W. Smith of Keeseville, N. Y. A large number 

 of pits and small diggings have been made to determine the extent 

 and quality of the graphite rock. Two of them are situated on 

 the east side of the valley where the schist is exposed, dipping from 

 55 to 40 to the east. From north to south these pits will be called 

 No. 1 and No. 2 respectively. Seven hundred feet to the southwest 

 of these pits are a number of diggings and pits situated near a 

 wood road. The rocks exposed here are nearly horizontal. To the 

 east of the road they dip to the northeast at a low angle, while to 

 the west of the road the strata dip in the opposite direction. 



Geology and structure. It is evident from the behavior of the 

 graphite schist and associated Grenville rocks that they have been 

 folded into a anticline, which is slightly tilted to the west and 

 pitches to the north (see figure 25). The present surface of the 

 region has so truncated the graphite schist that the line of outcrop 

 forms a U-shaped pattern on the map. While the stratigraphy of 

 the Grenville series in this locality is in many respects similar to 



