SEBASTIAN COUNTY. 205 
by grayish-brown sandstone, and retain their shaly character in a 
greater or less degree according to the protection given to them by the 
overlying sandstone. 
In the section at Nowland's spring the bluff is protected by a cover- 
ing of grayish-brown sandstone about 4 feet thick. The shales 
immediately under the sandstone are black, hard, and somewhat 
arenaceous. Thin beds of iron-stained quartz run throughout the 
upper 10 feet of the shales. Below, where they are exposed to the 
action of the waters of the stream, the shales form a soft, blue clay- 
like material. These blue shales are about 4 feet thick and overlie a 
series of soft black shales. 
In the bluff overlooking Arkansas River in the SW. J NE. \ sec. 19, 
T. 8 N., R. 31 W., near the center of the section, the covering is a 
heavy bed of brownish sandstone 7 feet thick. The shales beneath are 
light yellow for 5 feet immediately below the sandstone, and 3 feet 
of soft black shales are exposed below the yellow. 
The quantity of talus along the bluff is so great that the shales are 
almost everywhere covered up. In the section shown at the end of 
the bluff in sec. 19 the sandstone projects about 7 feet beyond the 
underlying shales. 
The following is a section at the end of the bluff in the SW. \ NW. \ 
sec. 19, T. 8 N., R. 31 W.: 
Section in bluff of Arkansas River. 
Feet. 
Brownish, heavily bedded sandstone 7 
Soft, friable, yellowish shale, with whitish streaks in the upper 
division 5 
Black shale somewhat harder than the yellow, and containing 
some red streaks 3 
Talus covering black shales to t lie level of the river 150 
A section in the SW. \ SW. \ sec. 7, T. 7 N., R. 31 W., gives the 
following: 
Section in SW. \ SW. \ sec. 7, T. 7 A'., R. .;/ IT. 
Feet. 
Sandstones 7 
Yellow shales, soft where exposed and forming dark yellow clay. ... 4 
Black shales 10 
Sandstones 5 
Blue shales 70 
Black shales. 
The black shales lying at the base of the bluffs in sec. 19, T. 8 V, 
R. 31 W., and in sees. 24, 26, 34, 35, 27, and 28, T. 8 N., R. 32 W., on 
the north side of Massard Prairie, and in sec. 6, T. 7 N., R. 31 W., on 
the southeast side of the prairie, are the same beds, and they pass 
under Massard Prairie in an almost horizontal position. These shales 
are also seen at a few places "where Massard Creek and one or two 
smaller streams have cut down through the overlying yellow 
prairie soil. 
