THE THICKNESS OF THE ONONDAGA SALT GROUP 



AT BUFFALO, N. Y. 



BY JULIUS POHLMAN, M. D. 



A well drilled by the Buffalo Cement Co., at Buffalo Plains, 

 affords interesting material for a study of the thickness of the 

 Onondaga salt group, as well as of the sudden thinning out or 

 remarkable dip of the Niagara limestone. As about 500 feet of 

 this well were drilled by means of a diamond drill, and the cores 

 carefully preserved, the record gives unquestionable data, and 

 shows the development of the different formations in Erie Co. 

 in the greatest perfection. 



Beginning at a spot where the rocks of the waterlime group, 

 suitable for the manufacture of cement, had been removed, and 

 which is 70 feet above the level of Lake Erie, or 643 feet above 

 tidewater, the drill encountered the following strata : 

 1 — 25 feet, shale and cement rock in thin streaks ; 

 25 — 30 feet, tolerably pure cement rock; 

 30 — 43 feet, shale and cement rock in thin streaks; 

 43 — 47 feet, pure white gypsum; 

 47 — 49 feet, shale; 

 49 — 61 feet, white gypsum; 

 61 — 62 feet, shale; 

 62 — 66 feet, white gypsum; 

 66 — 73 feet, shale and gypsum, mottled; 



73 — 131 feet, drab colored shale with several layers ot white 

 gypsum, measuring 18 feet in all; 

 131- — 133 feet, dark colored limestone; 

 133 — 137 feet, shale and limestone; 

 137 — 140 feet, dark colored compact shale; 

 14(i — 720 feet, gypsum and shale, mottled and in streaks; 

 72(> — 725 feet, limestone; 



