326 F 



REPORT OF PROGRESS. E. W. OLAYPOLE. 



The Hamilton lower shale, ( VIII. ) 



This shale occupies a considerable area in the township 

 in its southern, western, and central portions. Its southern 

 outcrop is a nearly straight line running along the south 

 tlank of Buffalo hills. Its western outcrop is a series of 

 short low undulations caused by the flattening out of as 

 many folds involving the Lower Helderberg limestone and 

 Oriskany sandstone in Madison township. These undula- 

 tions largely increase the area of the outcrop. Its northern 

 exposure runs along the north slope of Raccoon ridge, but 

 is complicated by a small fold near the west and several 

 others near the east side of the township. 



A necessary result of this geological structure is the ex- 

 posure of a very large area of this shale at the surface, and 

 the production of much poor land. The greater part of it 

 is still covered with wood. 



Conducing to the same result is another cause. In this 

 part of the county the Lower Hamilton shale shows an un- 

 usual composition. A great part of its middle mass becomes 

 sandy far beyond its usual proportion, and shows a close 

 approach in this respect to the Hamilton sandstone. But 

 instead of being, as that is, a solid, hard, white or greenish 

 mass thickbedded and fracturing irregularly, it is a set of 

 even-bedded, hard, dark green sandstones, varying from 

 half an inch to six inches in thickness, and splitting with 

 great regularity into flag-like or slate-like sheets. This 

 structure is best seen at Mr. Shope's quarry, about a mile 

 from Bixler's mills, where the stone has been quarried for 

 several years. About 25 feet are here exhibited, some of 

 it affording a tolerable but unshapely paving stone which 

 would !>♦> valuable were it capable of being dressed square. 

 This is. however, impracticable. Two parallel edges can be 

 obtained, but the cross edges resist the tool, and the slab 

 usually breaks under the hammer. This structure causes, 

 of coins.', a !<>\v ridge over the country which can sometimes 

 be, with difficulty, distinguished from the adjoining ridge 

 of the genuine 1 Camilton sandstone. 



The peculiar deep green color and smooth texture of the 



