78 



NEW YORK STATE MUSEUM 



The International Acheson Graphite Co. of Niagara Falls re- 

 ported a production in 1905 of 4,591,550 pounds of artificial graphite 

 manufactured by the electric furnace. The value of the output 

 was $313,980. The quantity reported for the preceding year was 

 3,248,000 pounds, valued at $217,790. 



GYPSUM 



The gypsum quarried in New York is the rock or massive variety. 

 It occurs as interbedded deposits in shales and limestones of Salina 

 age. Seams of selenite, the crystallized variety, sometimes accom- 

 pany the deposits, but they are so limited as to have little economic 

 value. The rock gypsum usually contains clay, carbonates, silica 

 and other impurities, the presence of which in appreciable quan- 

 tities is injurious to its use for some purposes. Till recently most 

 of the gypsum obtained in the State was ground and sold as land 

 plaster. It has been found, however, that the better quality of rock 

 can be utilized in manufacturing wall plaster, and several com- 

 panies have engaged in this industry which now consumes the 

 greater part of the output. 



The main gypsum beds outcrop near the southern edge of the 

 area occupied by the Salina strata. The latter extend as a belt, 5 

 to 25 miles broad, from the Niagara river east to Madison county, 

 and thence with diminishing width to Albany county. They dip 

 generally to the south. The gypsum occurs below the Bertie water - 

 lime which marks the top of the Salina, and above the Syracuse salt 

 beds. The following divisions of the Salina group have been estab- 

 lished for New York State, beginning with the highest. 



1 Bertie waterlime : argillaceous magnesian limestone, used for 

 the manufacture of natural cement in Erie county 



2 Camillus shale : workable gypsum deposits, shale and dolomite 



3 Syracuse salt beds : horizon of the rock salt 



4 Vernon shale : red. gray and green shales and thin dolomites ; 

 carries local small seams of gypsum of no economic value 



5 Pittsford shale, with interbedded dolomite 



There is little doubt that the workable gypsum beds all occur 

 within the horizon of the Camillus shale. Their eastern limit so 

 far as known is in Madison county, but from here they have been 

 traced by outcrop and borings across the central and western parts 

 of the State almost to Buffalo. They have been encountered in 

 many of the deep salt wells which have been sunk south of the 

 Salina outcrop. In sinking the salt shaft at Livonia, Livingston 



