THE MINING AND QUARRY INDUSTRY I913 39 



only a thin bed, too small to be workable. A hole put down on 

 the farm of W. K. Flint, 2 miles southwest of Akron and near the 

 crossing of the West Shore and New York Central (Batavia 

 branch) railroads, encountered the following strata: 



Feet Inche 



Soil and earth 25 



Broken limestone 20 



Shale, water-soaked 2 6 



Broken limestone 14 6 



Water seam i 



Limestone (flinty) 7 



Light brown limestone 7 



Blue shale and gypsum 5 



Hard " ashes " (shaly gypsum) 4 



Rock 2 



Soft " ashes " .... 6 



White gypsum 3 6 



The results of mining and exploration in the gypsum belt have 

 tended to confirm the view that the deposits are in general lenticular 

 and that the workable bodies are separated into more or less dis- 

 tinct areas.^ Between such areas in which the gypsum attains a 

 thickness of 4 feet and upward may intervene considerable stretches 

 in which the beds are very thin or else so interleaved with shale 

 that they have -no commercial value. In some parts of the belt two 

 or more workable seams occur, separated by shale. 



So far the surficial portion of the gypsum belt alone has been 

 explored and that in a very incomplete way. There are still possi- 

 bilities of uncovering profitable rock in the unexplored sections 

 lying between the developed areas. In the western sections where 

 the gypsum is rarely more than 5 or 6 feet thick it is seldom found 

 exposed at the surface. This is ascribable to the fact that the 

 gypsum weathers very rapidly, much more quickly than the over- 

 lying limestones, and it has been largely removed near the surface. 

 As a rule, the full thickness of the gypsum bed does not appear 

 until it is covered by 40 or 50 feet of rock, which with the average 

 rate of inclination means a mile back from the projected line of 

 outcrop. Consequently, the lack of gypsum at the surface is no 

 indication that beds may not be found further south under cover. 



Under the conditions the work of prospecting has to be carried 

 on entirely by drilling. A core drill, armed with either diamonds 

 or hardened steel shot, is employed so as to secure accurate records 

 of the rocks penetrated and samples of the gypsum for testing. 

 The results obtained with a churn drill have little value beyond 

 proving the possible presence of gypsum. 



' For details of 'the 'distribution of 'the gypsum deposits, see N. Y. State 

 Museum Bui. 143. 



