THE ADIRONDACK GRAPHITE DEPOSITS 93 



The property was opened in 1906 by the Glen Falls Graphite 

 Company. In 1911 the Sacandaga Graphite Company took over 

 the mine and mill. The mill was constructed in 1906. 1 Today the 

 property is abandoned. 



Openings. There are three irregular-shaped open pits dug into 

 the southwest slope of a prominent knoll. The southernmost one 

 is a wedge-shaped pit excavated between the converging footwall 

 which forms a V in vertical section. The middle pit is verging 

 upon a drift. The third opening is a long trench, now partly filled 

 with water dug along one of the walls of the V. 



Geology and structure. The rocks found in the Sacandaga mine 

 are dipping about 30 N 20 E into the hill slope. They are 

 crushed, sheared and affected by igneous agencies to such an extent 

 that the unravelling of the geological structure is apparently a 

 difficult matter. When the stratigraphy of the beds is worked out 

 in detail, however, it is evident that we are dealing with a syncline, 

 tightly squeezed, and strongly pitching to the northwest. 



The graphite schist is very probably the familiar Dixon schist. 

 Its normal thickness has been greatly reduced so that 10 feet was 

 the maximum thickness observed, the average being about 5 feet. 

 At one spot the top layers grade into a narrow band of quartzite, 

 comparatively free from graphite, but this is immediately suc- 

 ceeded by a bed of mica schist. Stratigraphically on top is the 

 familiar limestone, referred to as the Faxon. This is never present 

 in its full thickness and is often wanting in a given section ; it has 

 been squeezed and pulled apart during the intense folding. Over- 

 lying the limestone is a quartzite, heavily injected by the Laurentian 

 granite which has developed a high percentage of feldspar (now 

 entirely altered to sericite) and biotite. This is without doubt the 

 Sw r ede Pond quartzite soaked by the old granite. The type example 

 of this is the syntectic gneiss shown on the Hooper property. The 

 rock here does not exhibit its full thickness as the upper portion 

 has been cut off and replaced by the Laurentian granite. The latter 

 rock is exposed at two places near the pits ; to the southwest of the 

 middle pit and the trench, where it has been crushed to a pulp 

 resembling the anorthosite of the east central Adirondacks. Above 

 the Laurentian is a black rock, very hard to break, containing flakes 

 of muscovite mica. It was classified in the field as a metagabbro. 

 An examination of a slide cut from a hand specimen, however, casts 

 serious doubt upon such an interpretation. This is composed almost 



1 Newland, D. H., N. Y. State Mus. Bui. 112, p. 27. 



