166 THE CLAYS OF ARKANSAS. 
Those who may seek for clay in the Fourche Mountain district 
should bear in mind that it is not likely to be found on the hilltops, 
but rather in the lower grounds, where the rocks are kept constantly 
saturated with the acid waters by which decomposition is produced. 
It is surmised that places favorable to the formation of clay beds may 
be found in the northern part of sec. 3, T. 1 S., R. 12 W. 
It should be added that at several places the lower portions of the 
bauxite beds of Pulaski County grade into clays. 
MABELVALE DISTRICT. 
The Mabelvale district lies about halfway between the Fourche 
Mountain district, south of Little Rock, and the Saline County dis- 
trict. No feldspathic rocks have been observed in the immediate 
neighborhood of Mabelvale, but a band connecting the Fourche 
Mountain and the Saline County areas would embrace Mabelvale. 
This fact and the existence of bauxite seem to suggest the probability 
that syenites exist not far beneath the surface in the vicinity of 
Mabelvale. The clays in this district are all more or less pisolitic, 
and are believed to be simply the kaolin varieties of bauxite. Their 
chemical composition, however, seems to suggest the possibility that 
some of them may be available as china clays. 
On the middle of the east side of the NW. \ sec. 10, T. 1 S., R. 13 
W., about 150 yards south of the west end of the railway siding at 
Mabelvale station, on the St. Louis, Iron Mountain and Southern 
Railway, there is a deposit of bauxite which merges into pisolitic clay, 
the two covering about 25 acres. The material outcrops at many 
points, but it is concealed for the most part by a thin covering of sand 
and pebbles and nodules of sandy limonite. The covering becomes 
• gradually more abundant toward the higher ground and thins out on 
the margins of the knolls. But little is known of the actual area 
covered by the clay. A well said to have been dug 92 feet deep at 
the house of J. W. Hopkins, within 300 feet of the western outcrop, 
is reported to have penetrated 8 feet of soil and then "soapstone," 
or gray clay, all the rest of the way. 
The following analysis shows the character of the clay from the 
Mabelvale locality: 
Analysis of 'pisolitic clay from SE. \ NW. \ sec. 10, T. 1 S., R. 13 W. 
[Brackett & Smith, analysts.] 
Silica (SiOo) 45. 20 
Alumina (A1 2 3 ) 37. 60 
Iron (ferric) oxide (Fe 2 3 ) ". 3. 00 
Lime (CaO) , , 89 
Magnesia (Mg() ) *.-..., , , Trace. 
