REPORT OF THE DIRECTOR AND STATE GEOLOGIST 1903 147 



a little west of Alabama, and the rock is shipped to the company^s 

 mill at Black Bock. 



About 6 feet of good gypsum are mined, while overlying this 

 are about 8 feet of an impure gj-psum, which is too 

 hard for use.^ Above this upper bed of gypsum is a 

 crumpled deposit of impure limestone, w^hich is much broken 

 up. The gypsum rock is found outcropping along the creek for 

 more than half a mile and is about 30 feet above the creek, so 

 that it is mined by tunnels, and the rock is loaded directly from 

 the mine cars onto the railroad cars for shipment. Intermittent 

 mining has been carried on at this place for years, but no work 

 of any importance was undertaken till the summer of 1901, when 

 the Standard PlasteT Co. secured the mining right for the entire 

 reservation and opened its first tunnel. 



The only great difficulty encountered in mining the gypsum is 

 caused by the mud pockets described in a former chapter [p. 110] ; 

 but this difficulty is likely to grow less as the overburden becomes 

 greater, and the chance of surface water reaching the deposit 

 becomes less. How^lFs twast drills are used in drilling the rock, 

 and both hand and power dr'ills are employed. The power is 

 furnished by an automatic air compresser for the air drills, and 

 black powder is used in blasting. The rock is loaded on small 

 flat cars, holding about a quart eT of a ton, which are pushed to 

 the entrance of the mine, whei^ the rock is sorted, the good rock 

 being thrown into the railroad car and the waste being thrown 

 over the bank of the creek. 



The mill of this comipany is located on Dart street and 

 Sicajaquada creek, Black Bock. The equipment consists of a 

 gyratory crusher and screen, one Cummer calciner, one cooling 

 bin and five Sturtevant emery mills. 



The power is furnished by two electric motors of 100 horse powef 

 and 250 horse power respectively, which are run by electricity 



^It is probable that this upper layer is anhydrite as after this report 

 was prepared the deposit in the Lehigh shaft at Leroy which was supposed 

 to be gypsum was reported by Mr Charles Root of Caledonia to be anhy- 

 drite. The greater hardness and the higher percentage of Ca SO4 would 

 indicate this mineral. 



