THE ADIRONDACK GRAPHITE DEPOSITS 83 



its typical development. Consulting the geological map of the North 

 Creek quadrangle we find that Miller has indicated a fault extend- 

 ing from a point a mile northeast of Holcombville northeast to the 

 edge of the sheet. He says : x it extends " along the western base of 

 the Henderson mountain mass. Its position is plainly marked by 

 the topography, and though the scarp is not as steep as usual, it is 

 nevertheless very prominent and straight and cuts across the folia- 

 tion of the rocks at a high angle. ... As judged by the height 

 of the scarp at the south end and also at the base of Henderson 

 mountain, the displacement is fully 700 feet. . . . No tilting 

 of this fault block is noticeable. This fault certainly continues for 

 some 3 miles northward into the Schroon Lake quadrangle along 

 the western bases of Green and Pine Hills." The writer's observa- 

 tions are in perfect accord with this interpretation. This fault, 

 which brings in the granite, delimits the graphite ore on the west. 

 Several prospect pits to the east of the mine show graphite, but the 

 rock actually exposed is the micaceous schist — the upper transition 

 beds of the ore. How far the graphitic schist can be traced east- 

 ward along the strike is not known, but it is quite reasonable to 

 expect that it can be done for some distance. 



Mining and milling methods. The main inclined shaft is com- 

 pletely housed and leads directly from the floor of the hoisting shed 

 downward for 150 feet with a steep angle, at which level a little 

 drifting has been done. From the hoisting house the ore was 

 trammed in small cars through a covered passageway to the ore 

 bin and drying house. Crushing, stamping, huddling and screening- 

 were the essential features of the process. 



Economic conditions at this property are not very favorable for 

 production. Mining operations are down to creek level, forcing 

 the employment of pumps every inch of the way. The ore, although 

 exceedingly rich in spots is very variable, due to the igneous (mag- 

 matic) agencies of the Algoman granite. The latter rock exists 

 near the surface beneath the ore which probably limits the schist 

 as to depth. The high biotite-phlogopite content and toughness are 

 factors also to be considered. 



The Rowland Graphite Company 

 Situation. The property is in the township of Johnsburg, Warren 

 county, about a mile south-southwest of the village of Johnsburg 

 and 6 miles bv an excellent state road southwest of Riverside station 



Loc. cit., p. 56. 



