THE ADIRONDACK GRAPHITE DEPOSITS 27 



ing the last five years the main drift was extended farther with the 

 hope of finding more ore, and at the same time for the purpose 

 of tapping the bottom of a large slope pit (the Young Lion pit) 

 farther up the hill to the north, but the attempt was eventually 

 abandoned. The contact rock zone, which carries spectacular 

 graphite, is likewise variable in thickness and in distribution. For 

 the most part it is a white to green pyroxene rock with accessory 

 scapolite. Frequently the pegmatite develops very coarse textures 

 and shows feldspars 8 inches long; on the other hand, certain 

 contact phases show large black-green crystals of pyroxene. Under 

 a stringer or sheet of pegmatite is a mass of coarsely crystalline 

 calcite, something like 3 feet in thickness. Between this and the 

 capping igneous rock is a 3 inch layer of quartz, the under surface 

 of which is coarsely crystalline showing the characteristic habit of 

 the mineral. The edges of all the crystals are rounded, and very 

 smooth as though corroded by solutions. This quartz, when 

 examined under the microscope, appears to be vein matter. One of 

 the hypotheses to account f-or the origin of this layer of calcite is 

 that it represents a true fissure vein. The other theory is that the 

 limestone has been recrystallized hy the action of the pegmatite. 

 In the Fryatt workings (described below) the contact is along sandy 

 quartzite and there the prevailing rock is quartz, being possibly a 

 recrystallized portion of the quartzite. 



The drifts, especially the main one, run through barren peg- 

 matitic granite which occasionally holds inclusions of sedimentary 

 amphibolite, still maintaining the original relative positions with 

 sharp outlines and without any graphitic development. Near the 

 portal of the main drift lies a small mass of limestone overlain by a 

 sheet of pegmatite, likewise without any graphite. At another point 

 the pegmatite has penetrated the limestone, which still retains its 

 crumpled and distorted foliation, by " lit-par-lit nl injection pro- 

 ducing an injection gneiss. Still again the pegmatite becomes 

 porphyritic with phenocrysts 2 inches long. 



The Young Lion pit. This lies to the north of the " Wood- 

 chuck " pits a little to the east. It consists of a large underground 

 chamber extending diagonally down the dip with an average slope 

 of 22 and for 100 feet westward. It was once timbered but the 

 pillars have long since rotted and large blocks have fallen from the 

 roof, resulting in a lofty cave. 



1 French, "bed by bed." Applied to a structure composed of alternating 

 bands composed of sedimentary and igneous rocks. 



