54 NEW YORK STATE MUSEUM 



property along Miirder creek just south of Akron showed the 

 presence there of but a small amount of gypsum. These would 

 seem to define the limits of the western end of the basin. The 

 boundaries of the eastern end under the ledge south of the Ameri- 

 can Gypsum Go's shaft have received but little attention, and nothing 

 could be learned concerning them. The bed of gypsum as mined 

 consists of a 4 to 5-foot bed of light colored crystalline or granular 

 gypsum. It is overlain by from 25 to 50 feet of thinly bedded 

 impure limestones, and these in turn are rather heavily covered by 

 a mantle O'f glacial clay varying from a few feet up to 25 feet in 

 thickness. The section at the new (no. 2) shaft of the American 

 Gypsum Go. is as follows : 



MATERIAL THICKNESS 



Feet Inches 



Drift clay 18 



Rock (waterlime) 3 4 



Clay 3 • 



Rock (waterlime) 3 8 



Clay, water-bearing 4 



Rock (waterlime) 21 



"Ashes " ; 4 



Gypsum i 



Rock (waterlime) •. . . 2 



Rock, roof (vv^aterlime) 2 



"Ashes " 8 



Gypsum . 4 



Other sections in the vicinity "are very similar, so that the above 

 might be taken as typical. The clay beds below the drift are evi- 

 dently a series of soft weathered shales and are frequently a seri- 

 ous source of annoyance to mining operations on account of the 

 large amount of water they contain. They are often so thoroughly 

 saturated with water as to be veritable " miUd seams " of soft fluid 

 clay. Above the main gypsum bed so called " ashes " (an impure 

 shaly gypsum or a mixtuire of selenite and shale) and even more 

 massive gypsum rock is found in small la^^ers. 



The acreage known to be underlain with gypsum is controlled 

 mainly by three companies, the American Gypsum Go., the Akron 

 Gypsum Go. and the United vStates Gypsum Go., of which the two 

 companies first mentioned are engaged in the mining and milling 

 industry, while the United States Gypsum Go. does not at present 

 work its property. The whole field is comparatively new, the first' 

 development work having been done in 1903. 



American Gypsum Co. This company operates a large crushing ^| 

 plant and mines 2^/^ miles northeast of Akron on the boundary 

 line between Genesee and Erie counties, the lands on whicli it 

 owns mineral rights being situated on both sides of the line. En- i 



