THE ADIRONDACK GRAPHITE DEPOSITS 21 



across the dip of the rocks. The second pit is 12 to 15 feet square 

 and 6 feet deep, from which starts a slope down the dip (io° south, 

 30 west magnetic). 



Geology. The conditions are very similar to those in the Betsy 

 Cook locality. The rocks involved are the biotite-hornblende schists 

 and associated members of the " Grenville " sedimentary series. 

 The granite (of " Algoman " age) has affected the schists, pro- 

 ducing contact rocks. In the vicinity of the shaft the ore consists 

 of the usual pyroxene rock carrying large flake graphite and the 

 usual pyrite. Specimens at the drift show a very different type of 

 contact rock, composed to a large degree of feldspar (andesine- 

 labradorite), partly altered to clay substances (sericite). 



The granite is frequently coarse textured and approaches a 

 pegmatitic phase at contact with the schist. 



The high biotitic nature of this contact deposit and the limited 

 amount of graphite force us to abandon hope that this will be of 

 any importance in the future. 



The Columbia Graphite Company 



Location. The Columbia Graphite Company's property is 

 situated in the township of Crown Point 1 mile east of Round 

 pond and the same distance southeast of Overshot pond, 2^ miles 

 north-northwest of Ironville within the limits of the Paradox Lake 

 quadrangle. 



The workings. The workings consist of a series of deep, open 

 cuts, all on the same line of strike, in green serpentized (verde 

 antique) limestone close to pegmatite, usually having a foot-wall of 

 fine-grained, sandy quartzite. Several shafts, inclined 62 ° south 68° 

 west (magnetic) are today filled with water. The ore was hoisted 

 and teamed to the mill a short distance away. Apparently no ex- 

 tensive operations had been carried on underground. 



The mill has been dismantled and all the valuable material 

 removed. Enough remains, however, supplemented by local in- 

 formation, for one to know that the wet method of concentration 

 was used, the ore having been reduced to proper size by crushers, 

 a 16-stamp battery, and burrstone grinders. Water was secured 

 by pumping from a brook one-half of a mile away. The concentrates 

 were sent to the finishing mill at Crown Point Center for final 

 treatment. 



