THE MINING AND QUARRY INDUSTRY I909 4I 



are not well stratified but form pockets and larger masses of lenr 

 ticular and irregular shape of perhaps a few hundreds of feet in 

 area. In exposure the clear gypsum, freed from the admixed clay, 

 lends a semblance of purity to the deposits which is very decep- 

 tive; the actual gypsum content is usually less than 75 per cent. 

 The deposits are worked only as a source of material for land 

 plaster. 



The deposits that are worked in Onondaga county and in the 

 counties to the west, belong to the usual stratified type and are 

 more homogeneous than those first described. They are made up 

 of finely divided gypsum fibers or minute crystals forming a felted 

 mass in which the impurities are evenly distributed. The color 

 of the gypsum varies from gray or drab to nearly white. 



The maximum development of the gypsum is reached in Onon^ 

 daga county where there is a single bed 60 feet thick consisting of 

 a number of individual layers which vary somewhat in appearance 

 and color, though they are quite uniform in regard to gypsum 

 content. This bed is exposed in the townships of Dewitt and 

 Manlius, east of Syracuse, where it is quarried for land plaster, 

 for admixture with portland cement, etc. In western Onondaga 

 county, the gypsum as seen in outcrop has a thickness of 15 or 

 20 feet. 



Near Union Springs, Cayuga co., a deposit from 20 to 30 feet 

 thick is worked. 



The Salina belt crosses Seneca, Wayne and Ontario counties 

 and deposits of workable dimensions are found at frequent inter- 

 vals. No production has been made from this section in recent 

 years, though some of the gyipsum, notably in Ontario county, is 

 of very good quality. In the town of Victor, two beds, 8 feet 

 and 6 feet thick, have been found by drilling and the drill icores 

 indicated a close resemblance to the gypsum at Garbutt, Oakfield 

 and Akron farther west. 



The deposits are encountered in the town of Wheatland, Mon- 

 roe CO. and are there mined on an extensive scale for the manu- 

 facture of calcined plasters and for other purposes. Twoi beds are 

 generally present, separated by 6 feet or more of limestone. The 

 upper bed measuring from 5 to 8 feet thick is mainly worked 

 though the lower bed is of equal size and purity. The area at 

 present developed covers about 3 square miles. 



Another important locality is in the town of Oakfield, Genesee 

 CO., where a light-colored rock 4 feet or more thick is extensively 

 mined and employed in calcined plaster manufacture. The plaster 

 works near Oakfield Station are the largest in the State. 



In Erie county, the whole middle of which is crossed by the 

 Salina belt, mines have been recently opened near Akron, 20 miles 

 east of Bufifalo. The bed is 4-5 feet thick, light-colored and well 

 adapted for calcination. It is probable that gypsum occurs also 

 in the interval between Akron and Buflfalo, though no records of 

 its discovery have been made known. A series of test wells put 



