204 
THE ('LAVS OF ARKANSAS. 
By the month of November, 1889, W. A. Doyle was using the 
Nigger Hill clay shales at Fort Smith in the manufacture of paving 
bricks. The business succeeded from the outset, and there was soon 
built up at that place a large and prosperous business in the manu- 
facture of paving and building bricks from the shales. 
Two analyses are here given of the Fort Smith clay shales, and for 
purposes of comparison analyses of the well-known Carboniferous 
shales of Akron. Ohio, and of Cheltenham, Mo., are added. 
Analyses of clay shales. 
[Specimens dried at 110°-115° C. Brackett & Smith, analysts.] 
Silica (Si0 2 ) 
Alumina (A1 2 3 ) 
Iron (Fe 2 3 ) 
Lime (CaO) 
Magnesia (MgO) 
Potash (K 2 Oj . . . 
Soda (NaoO) 
Sulphur (S) 
Loss on ignition . 
Sand 
Water at 110°-115 c 
Fort Smith. 
Harding & 
Boucher's 
quarry. 
57. 10 
23.74 
8.18 
.53 
1.04 
1.53 
.87 
7.21 
100.20 
.12 
4.24 
W. A. 
Doyle's 
paving- 
brick kiln. 
58. 43 
22. 50 
8.3(5 
.32 
1.14 
2.18 
1.03 
.16 
6.87 
100. 99 
25.72 
3.37 
Akron, 
Ohio. 
60.05 
20.00 
6.82 
.52 
.45 
1.79 
1.60 
1.95 
6.96 
100. 14 
29.12 
1.25 
Chel- 
tenham, 
Mo. 
54.92 
22.71 
9.81 
.52 
2.59 
3.16 
.62 
5.88 
100. 21 
2.04 
These Carboniferous shales outcrop at many places in the vicinity 
of Fort Smith and, indeed, in all parts of Sebastian County . a They 
are exposed at W. A. Doyle's paving-brick factory between Towson 
and Wheeler avenues, Fort Smith; at Harding & Boucher's quarry 
in the northeast corner of the SW. i sec. 28, T. 8 N., R. 32 W.; and 
immediately across the Texas road from Harding & Boucher's quarry, 
on the railway track running through the SE. J sec. 20 and the NE. J 
SE. I sec. 29 of the same township and range. They are also seen 
in a railway cut on the lands of the Oak Park Company in the SE. \ 
NE. J sec. 35, T. 9 N., R. 32 W. At all these places the shales have 
disintegrated and formed a clay. A well on the Adams lot, in the 
NE. \ SW. \ sec. 15, T. 8 N., R. 32 W., shows a section of this clay 
10 feet thick. At Harding & Boucher's quarry the clay formed 
from the disintegrated shale has a thickness of 6 feet, and in the rail- 
way cut through sees. 20 and 29 a thickness of 3 feet is visible. 
The analysis of the Harding & Boucher shales is given above. 
There are exposures also in the banks of a small stream near Now- 
land's spring, in the NE. \ NE. \ sec. 34, T. 9 N., R. 32 W. In the 
SW. i NE. J sec. 9, T. 8 N., R. 31 W., near the center of the section, 
and in the SW. \ SW. i sec. 7, T. 7 N., R. 31 W., and in a cutting on 
the Little Rock road in the SW. \ SE. i sec. 15, T. 8 N., R. 32 W., 
similar shales are exposed. In these sections the shales are overlain 
a The notes on the occurrence of shales about Fort Smith are by William Kennedy. 
