22 



NEW YORK STATE MUSEUM 

 Size of the Graphite Flakes in the Concentrates 



No. i 



No. 2 



No. 3 



Average diameter . . 

 Maximum diameter 

 Minimum diameter. 



48 x .33 mm 

 .90 mm 

 .20 mm 



. 143 x .074 mm 

 .310 mm 

 .015 mm 



no x .070 mm 

 . 1 50 mm 

 .030 mm 



Geology. The geology in detail is most complicated, while the 

 structure is comparatively simple. Starting to the north of the 

 mine openings and proceeding southward, 15 feet of quartzite (ap- 

 proaching the vitreous type) is found dipping at a high angle 

 under a sill-like mass of white granite of a similar thickness. A 

 second bed of quartzite follows, heavily injected with granite, finally 

 becoming sandy as it nears the limestone ore. The total thickness 

 of the rocks here shown is about 70 feet. The ore is limestone 

 carrying, besides the graphite, small amounts of dark green silicates 

 that are today altered to serpentine, producing a verde antique 

 marble. Farther south the white granite occurs in a huge mass that 

 eventually becomes pink, deepening into red. . 



Such a succession of beds could hardly be repeated in another 

 parallel section because the granite and the pegmatites penetrate 

 and cut to pieces the sedimentary layers in a most complicated way. 

 In one of the pits, where a coarsely crystalline pegmatite is shown, 

 beautiful crystals of brown tourmaline can be secured, as well as 

 pyroxene, scapolite and other pegmatite-contact minerals. 



Usually the line of contact between the pegmatite and the lime- 

 stone is marked by the development of the characteristic green 

 contact rocks, rich in pyroxene crystals and graphite flakes, the latter 

 frequently three-eighths of an inch in diameter. This rock con- 

 stituted a portion of the ore formerly utilized. 



Structure. At the pits the rocks dip about 6o° south 68° west 

 (magnetic), while farther west the strike changes to north io° east 

 and the dip decreases to 42 east. Here we are probably dealing 

 with a syncline which seems to pitch eastward. Thus the mine 

 pits are located on the northern edge of a trough of sedimentary 

 rocks highly injected and cut to pieces by pegmatite dikes. 



Economic future. The mine was worked during 1903 and 1904 

 but the company moved to Rock Pond in 1905. It is not a difficult 

 matter to comprehend the cause of the failure of the company. 



