70 



GEOLOGICAL KECONNOISSANCE 



half feet in thickness, which, as the fossils show white, against a black 

 ground, will' when polished, produce a beautiful marble. 



On section 12, township 13, range 15 west, the subcarboniferous lime- 

 stone extends to the height of 15 to 20 feet above the bed of Lesley's 

 creek, covered by the afore-mentioned shales. This is on the immediate 

 confines of the western boundary of Van Buren county ; the line passes 

 through the orchard of Hatchet, who resides on the banks of Lesley's 

 creek, at the foot of the mountain. 



SEARCY COUNTY. 



No 8.— KNOB OF SEARCY COUNTY, TAKEN FROM THE DAWSON FARM, ON FORREST CREEK. 



Proceeding towards "Wiley's cove, in this county, from Lesley's fork of 

 Little Eed river, the Archimedes and encrinital beds of the upper sub- 

 carboniferous group gradually ascend to a higher level above the water- 

 courses ; so that there appears, beneath these, in Wiley's cove, a consider- 

 able thickness of hard, sheety, black, bituminous shale, which has all the 

 lithological aspect of the black bituminous shale at the foot of the foils of 

 the Ohio. But that shale belongs to the devonian period, whereas subse- 

 quent observation showed this black shale of Searcy county to be a mem- 

 ber of the subcarboniferous period. 



