THE MINING AND QUARRY INDUSTRY 93 1 



effort has been made to carry on exploitation at any considerable 

 depth, and in most cases ordinary quarrying methods are employed 

 for extracting the rock. The edges of low hills are considered 

 favorable points for opening new deposits. After the beds have 

 been followed back into the hill for some distance, if the overlying 

 strata are heavy, the work may be continued under cover as in 

 mining. 



The gypsum when first extracted is gray or drab in color, becom- 

 ing lighteB on exposure. Organic matter seems to be the principal 

 coloring agent. The presence of iron oxids gives a brownish tint to 

 the rock which can not be removed by calcination. 



Quarries have been opened at frequent intervals along the out- 

 crop of the Salina formation. The most easterly points w^here 

 gypsum is produced are in Madison coimty , near Cotton and Hoboken- 

 ville. The output in this region is small and is used locally for land 

 plaster. In Onondaga county there are quarries at Fayetteville, 

 Manlius Centre, Marcellus and Half Way, those at Fayetteville 

 being most important. At the latter locality the gypsum attains 

 a maxim.um thickness of 60 feet, made up of several beds ranging 

 from 18 inches to 30 feet each. The output is used in part for land 

 plaster; the greater quantity, however, is calcined either by the 

 local cement plants or by the wall plaster manufacturers that have 

 works in Syracuse. At Union Springs, Cayuga co., a large quarry 

 has been operated for a number of years, the first opening having 

 been made in 1828. The deposits in Ontario cotmty near Port 

 Gibson and Victor are not worked at present. They have pro- 

 duced mostly land plaster. In Monroe county the town of Wheat- 

 land is an important center of the industry. The product goes to 

 mills located at Garb utts ville and Wheatland which make land 

 plaster, plaster of paris and wall plaster. Still farther west in 

 Genesee county, gypsum is quarried extensively at Oakfield w^here 

 large plaster works have been built. The deposit is not so thick 

 here as in the eastern localities, but owing to its lighter color it is 

 better adapted for calcination. In Erie coimty, the quarries at 

 Akron have been intermittently active, supplying agricultural 

 plaster to the local markets. 



The development of the gypsum industry in New York, both 

 present and future, depends altogether on the demand for the 

 different products, since the crude rock exists in almost unlimited 

 quantities. Its progress recently has been promoted by the estab- 

 lishment of plants for making stucco and wall plaster. The latter 

 is perhaps the most important application, and the one that has 



