LOGAN COUNTY. 129 
Analysis of relay from sec. 84, T. 8 N., R. 26 W. 
[Brackott & Smith, analysts.] 
Silica (SiO,) 88. 66 
Alumina (A1 2 3 ) 5. 73 
Ferric oxide (Fe 2 3 ) 2. 55 
Lime (CaO) Trace. 
Magnesia (MgO) Trace. 
Potash and soda (K 2 0, Na 2 0) 81 
Loss on ignition 2. 25 
100. 00 
Water at 110°-115° C 1. 33 
Sand in clay dried at 110°-115°C 17. 94 
Clays of this class are widely distributed over Logan County, and 
these examples do not fairly represent them either in thickness or 
importance. The Carboniferous clay shales are so abundant, so 
thick, and so widespread in Logan County that only a few typical 
areas will be mentioned. 
In the southwest corner of the county the line between Logan 
and Scott counties crosses Jennings Hill. The alternate series of 
' sandstones and shales forming this hill is described under the head- 
ing "Scott County." The same beds extend from Jennings Hill 
toward Booneville, a distance of 5 miles. The most important 
shale of this group underlies the town of Belva, in Scott County, 
but it crosses into Logan County in the NW. \ sec. 30, T. 5 N., 
R. 28 W., runs northeastward for 5 miles, and swings westward 
along the valley of Petit Jean Creek. This shale is 200 to 400 feet 
thick at Belva. Below this shale are two beds of sandstone and 
a thinner bed of shale, followed below by a thicker bed of shale. 
A thick deposit of shale near the top of the Atoka formation 
covers a large area in Logan County and extends also into the adja- 
cent counties both east and west. It ranges in thickness from 400 
to nearly or quite 2,000 feet. It is generally of dark color, and 
although it is usually a clay shale it is. at some places sandy. Start- 
ing in the southwest corner of the county near Golden City, this 
shale and its accompanying beds of coal form the surface rock along 
the upper parts of the valley of Brashy Branch and extend down 
Fletcher Creek toward the town of Booneville, and thence down 
the valley of Petit Jean Creek to Magazine. West of Booneville 
the same shale runs through the northern tier of sections in T. 5 N. ; 
R. 28 W., to Barber post-office. East of the town of Magazine 
the outcrop of this shale divides, one arm of it passing south of 
Magazine Mountain and underlying the northern part of the north- 
ern tier of sections across T. 5 N., R. 25 W., and the southern tier 
of the tpwnship just north of it. The same shale lies along the 
48136— B all. 351—08—9 
