Coal Measures of Central Iowa — Keyes. 399 
Feet . Ins. 
4. Shales and clays 20 6 
3. Coal (No. a) 4 6 
2. Clays and shales, lower layers highly fossiliferous 35 
1. Coal(No.3) 4ft.6m.to6 
Section vi. Altoona Coal Mine, 8. W. N. E. 13, 79 N. 23 W. 
Feet. Ins. 
6. Drift and carboniferous clays and shales 110 
5. Shales 60 
4. Sandstone 15 
3. Coal 1 6 
2. Shales and clays 15 
I. Coal 4 
Section vii. Boring, near Mitcliellville 1, 79 N. 22 W. 
Feet. Ins, 
14, Drift and carbonaceous clays 64 
13. Yellow sandstone 4 
12. Blue shales 11 
11. Bituminous shales 1 
10. Impure limestone 6 
9. Impure shaly coal 1 2 
8. Light colored clay shales 8 
7. Bituminous shales 66 
6. Blue clayey shales 21 
5. Sandstone 3 
4. Gray clay and sand shales 21 
3. Argillaceous sandstone 16 3 
3. Light colored shales 6 4 
1. Limestone with marly partings 39 6 
Section viii. Boring near Des Moines, 13? 78 N. 2i W. 
Feet. Ins. 
15. Drift and carboniferous clays 36 
14. Sandy, blue, black and gray shales 25 
13. Sandstone and sand shales 6 
12. Bituminous clays and shales 27 3 
II. Dark colored sandstone 4 
10. Gray and blue sand shales 11 
9. Dark blue shale 13 
8. Sandstone with shaly partings 13 6 
7. Light colored clayey shale 7 
6. Limestone 1 2 
5. Gray and blue clayey shales 26 
4. Bituminous shale 12 
3. Blue limestone and sandstone 14 
3, Bituminous shale 5 6 
1. Light colored sandstone 6 
The sedimentary rocks of central Iowa in accordance with all 
of the palaeozoic strata of the state, have a general dip to the 
