Geological Observations. — Reagan. 231 
Recent: 
1. Light colored, finely laminated clay 2 
2. Dark forest ground S 
3. Yellow sandy clay 1 
4. Fine to coarse, banded, cross-bedded, white sand 10 
6. Section at the water's edge, south side of Little White river, one 
and one~tourth mile north of Ring Thunder school house. 
Recent: 
1. Black earth 1 
2. Gravel, light colored sands and clays, resting uncon- 
formably on the next 20 
3. Partly lithified, light colored clay 10 
4. Bedded gravel interbedded with bands of light col- 
ored sand. This stratum rests unconformably on 
the next following 12 
5. Brown, clayey material, unconformable both with 
the stratum above it and the one below it 3 
6. Grayish black shales 10+ 
7. Section one mile northwest of the White Thunder day school. 
Oligocene (near base of the formation) : Feet Inches 
1. Clayey shale in which are interstratified bands, 
three to five inches in thickness, of the same 
material containing some iron ore. The bands 
are harder than the other shales and show an 
iron-rust, red ochre color when wet 7 
8. Section on Butte one mile southeast of the White Thunder day 
school. 
Arikaree: Feet Inches 
1. Greenish, shaly to thin bedded very porous sand- 
stone 6 
2. Bluish to greenish, somewhat porous sandstone.... 10 
3. Greenish sandy shale 15 
4. Clayey, thin-bedded, cream colored sandstone 14 
Oligocene: 
5. Yellowish chocolate, cream colored, and pinkish 
shales 70 
6. Greenish shales to thin-bedded, often porous, sand- 
stone 4 
7. Cream colored shales 4 
9. Scetion two and one-half miles south of the White Thunder day 
school. 
Arikaree: Feet Inches 
1. White to gray flint, in which are numerous gastro- 
