Geology of Lincoln Co., S. D. — Bendrat. "jy 
1. Section of cut in southern bank of Nine Mile . 
creek, zvithin T.iooN, R.49JV, 2^2 mile E. and i mile 
S. of Harrisburg. 
Feet. Inches. 
Dark brown clay graduating above into the black soil... 2j4 
Seam of flour-like gypsum, probably resulting from a layer 
of thin calcareous plates, coated with gypsum 3 
La\-er of gravel and bowlders associated, the latter dimin- 
ishing in size upward and yielding to a stratified ar- 
rangement of the gravels, the seams being tinged black 
and rust red alternately 3 
(the bowlders being derived from granite and other 
igneous rocks.) 
Bluish clay, weathering yellow, nearlj- free from pebbles 
and bowlders. (Base of this being frequented by bowl- 
ders, 3 to 4 feet in size 3 
Seam, consisting in its upper portion of coal {Yz inch) 
and in the lower one of a compact light buff colored 
clay 3 
(a hardened soil.) 
Gray sands, obliquely stratified, dipping at an angle of 20° 
to the S., streaks of rusty, iron-charged sand alter- 
nating with the gray 1-2 
The base of the exposure is about two feet above the bridge. 
2. Section I mile N. and iy2inile E. of IFortliing, in 
tite northern bank of Beaver creek. 
Cobblestones and granite bowlders, 2 to zY^ feet in size. . 2-3 
Seam of black coal in the upper and compact buff colored 
clay in the lower part 2-3 
Buff colored loam, the base of which could not readily be 
distinguished, in the upper and milk-white chalkstone, 
showing traces of fossils, down to talus 4-6 
3. Section of gravel pit, one mile S.E. of Tea. East of 
R. R. tracks. 
Dark brown pebble clay, graduating upward into black soil 2 ,7 
Light buff colored clay carrying calcareous concretions and 
a greater percentage of pebbles i 5 
Cross-bedded seams, 1Y2 to 2 inches thick, of rusty and 
gray sands and fine gravels, occasionally showing lam- 
inated and even flexed structure and at one point the 
concentration of the rusty sand into a cylinder, or 
sphere, the cross section of which is fairly brought 
out by the gray background 2 
Talus 4 
4. Section of gravel pit IV. and E. of Great North- 
ern R. R., about one mile S.E. of Lcnno.x-. 
Yellowish till i ' ; 
