SECTIONS AT KEDROCK AND DUNKEATH. 



279 



feet. 



///. Bedrock Exposures {Plate 10). 



12. Drift and loss, with characteristic fossils . . .20 



11. Drab and yellow clayey shales .... 25 

 10. Coal (small basin only) . . . . 3 to 6 



9. Fire-clay, enclosing rounded water-worn pebbles, up to one 

 foot in diameter, of " Redrock " sandstone, most abun- 

 dantly on the sloping sides of an ancient ravine . 1 



8. " Redrock " sandstone ; a fine-grained, massive, yellow and 

 red sandrock, concretionary in places, the upper surface 

 more or less weathered and channeled ; maximum thick- 

 ness more than 150 feet (exposed) 



7. Shale, laminated and highly bituminous . 



6. Yellow sandstone, soft, fine-grained and thinly bedded 



5. White sandrock, compact . . . • . 



4. Yellow sandstone (like number 6) ... 



3. Highly bituminous shales, laminated and coaly above and 



becoming more and more coal-like westward . . 5 " 



2. White sandstone, fine-grained, everywhere penetrated ver- 

 tically by rootlets of lepidodendrids . . 2 to 4 " 



1. Shales, ash-colored and yellow (exposed to water's edge) . 20 "' 



Numbers 12 to 8 are shown in a quarry at Redrock bluff, in N. W. qr. N. 

 E. qr. Sec. 35, T. 77 N., R. 20 W., and are represented in figure 1, plate 10. 

 The rest of the section is exposed on the opposite side of the Des Moines 

 river, in S. W. qr. Sec. 1, T. 76 N., R. 20 W. 



55 

 l\ 

 3 

 1 



2 



IV. Dunreath Exposures.— N. E. qr. Sec. 28, T. 77 -^Y., E. 20 W. 



15. Quaternary deposits .... 



14. Clayey and sandy shales (exposed) 



13. Dark clayey slate, with abundant ferns at base 



12. Coal 



11. Fire-clay ...... 



10. Clayey and sandy shales .... 



9. Sandstone, massive and compact, in two layers, separated 

 by a soft, sandy seam and a thin bituminous bed, witl 

 abundant calamites and a few lepidodendrids 



8. Dark shales, clayey and sandy 



7. Bituminous shales .... 



6. Coal, impure in places 



5. White fire-clay .... 



4. Dark clayey shales .... 



3. Thinly bedded clayey sandstone, with numerous lens-shaped 

 septarial concretions up to four feet in diameter 



2. Bituminous shales .... 



1. Dark-colored sandy and clayey shales (exposed) 



. 20 feet 



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