76 GEOLOGICAL RECONNOISSANCE 
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 
creel, 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 Healey s 8 
creek, at the foot of the mountain. 
SEARCY COUNTY. 
ee 
No 8.—KNOB OF SEARCY COUNTY, ti FROM TIE DAWSON FARM, ON FORREST CREEK. 
Proceeding towards Wiley’s cove, in this county, from Lesley’s fork of 
Little Red 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 falls 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. | 
