104 GEOLOGICAL RECONNOISSANCE 
boniferous group, while this succeeds, in the descending order, the barren 
cherty limestone of the lower division. From 30 to 35 feet of this shale 
are seen in section, not only along the bluffs of White river, but also on 
Hickory creek, about a mile to the west. At both localities, the shale is 
overlaid by the barren limestone, which, on White river, forms cliffs of 80 
to 100 feet. 
I have never seen, in any of my previous surveys in the western states, 
amongst the subcarboniferous rocks, shales possessing the solidity and 
hardness of the shales of Wiley’s cove, or those of the south-east part of 
Benton county, which may be almost entitled to the appellation of slates, 
though not durable enough for roofing purposes; in this respect, these 
shales resemble, in lithological character, the hard, black, sheety shale or 
slate of the Salt river valley, in Kentucky, and at the base of the knobs 
of Floyd county, Indiana, belonging to the devonian period; which slates 
are the representatives, probably, of the “Gennessee slate” of the New 
York Reports. The superposition and association will undoubtedly place 
both the shales of Wiley’s Cove and Hickory creek, in Benton county, as 
members of the subcarboniferous group. The fossils found, as yet, in 
these shales, are too imperfect, and too few, to enable one to judge, from 
them alone, of the age of these Arkansas shales; we are, therefore, obliged 
to resort, for the present, to order of superposition for a solution of the 
preblem. 
The ascent from White river, up the ridge, on the west side is 310 feet; 
the road runs over chert, derived from the disintegration of the cherty 
limestones, overlying the aforementioned black shale. In this chert are 
found some of the disjointed disks of oval-shaped stems of platycrinus; 
and at the Osage spring, the fountain head of Osage creek, it contains 
Productus punctatus, and the same species of reticulated, fossil corallines 
which characterize the cherty limestone in the barrens of Kentucky and 
Tennessee. 
The lands between White river and Bentonville, are mostly oak bar- 
rens, interspersed with prairie. 
Samples of soil were taken from Benton county, for future chemical 
analysis, from the Hon. A. B. Greenwood’s farm, near the town of Ben- 
tonville. 
The oak and hickory timber which has now sprung up on the borders 
of the present prairie, is mostly of a growth as recent as the settlement of 
the country; since the greater portion of this part of Benton county was, 
before that time, open prairie, with, here and there, thickets of low bushes. 
West of Bentonville, there is a mulatto soil, somewhat different in its 
character from that immediately around Bentonville, and very productive, 
