232 THE CLAYS OF ARKANSAS. 
The following are a few localities at which the brick loam has been 
noted: On the upper Dardanelle-Danville road 3 miles from Dar- 
danelles at a place where the road crosses the stream, the loam is 6 
feet thick, with sandstone fragments at the base. It is a widespread 
deposit in the lower parts of the valley between Chickahah and 
Belleville and between Belleville and Danville. The valley soil about 
Danville is mostly the " buckshot" loam. In many of the low red- 
clay hills along Harris Creek several feet of yellow clay lies beneath 
the red clay, and waterworn pebbles beneath the yellow. At Johnsons 
Bridge, on the lower Dardanelle-Danville road 1 mile southwest of 
Dardanelle, the yellow loam is at least 12 feet thick. This exposure 
is especially interesting because it exhibits the relations of the choco- 
late clays of the river country. The following is the section: 
' Section at Johnsons Bridge. 
Feet. 
Greenish-yellow loam with some waterworn cobbles 4 
Chocolate clay with calcareous concretions and nodules 4-8 
Yellow sandy clay with calcareous matter in crevices 12 
The demarcation between the chocolate clay and the underlying 
yellow sandy clay is very clear at this locality. The lower bed is 
deeply scored by big gullies that are in places as much as 12 feet deep. 
The calcareous matter of the lower bed is derived from that of the 
chocolate clay by solution and redeposition, as is indicated by the 
fact that the concretions of the lower bed occur mainly in cracks 
and are not disseminated through the mass as they are through the 
chocolate clays. 
The following section is an analysis of the lower yellow clay of 
the Johnsons Bridge section: 
Analysis of the lower yellow clay at Johnsons Bridge, 1 mile south of Dardanelle. 
[Specimen dried nt 110 p -115° C. .1. P. Smith, analyst.] 
Silica (Si0 2 ) 74. 48 
Ferric oxide (Fe 2 .0 3 ) 7. 52 
Alumina ( A1 2 3 ) 11. 58 
Lime (CaO) (\4 
Magnesia (MgO ) 20 
Manganese oxide (Mn< )) 41 
Potash (KjjO) 1. 10 
Soda (Na 2 0) 54 
Loss on ignition 4. II 
100. 64 
Water at 1 10° 1 I5°C 1. 83 
TERRACE CLAYS ALONG ARKANSAS RIVER. 
Certain clays and silts along Arkansas River are quite different 
from any found in the Paleozoic region away from that stream. 
Such are the loams used for the manufacture of common bricks at 
