GEOLOGY OF SOUTHWESTERN IOWA 



Whether the break south of the Wilson section is a fault or 

 an abrupt monocline to the south cannot be definitely decided, 

 at the present time, owing to the heavy covering of loess in the 

 bluffs; at any rate there is no considerable dip in strata less 

 than a mile apart. 



Twenty years ago the quarrying industry was in a flourishing 

 condition at Stennett. Many large quarries were in operation, 

 affording excellent exposures of the different strata. In recent 

 years this industry is practically abandoned, and owing to over- 

 wash and slumping a connected section can not be found. Many 

 of the old quarries are completely covered, and not a single un- 

 disturbed ledge is visible. 



On Pilot creek, one-fourth mile north of Stennett, at the site 

 of the abandoned Wayne Stennett quarry, is the best and most 

 extensive section seen in this vicinity. 



SECTION AT THE OLD WAYNE STENNETT QUARRY. 



FEET 



15. Limestone, gray, two layers 2 



14. Shale, black 3 



13. Shale, gray, calcareous 5 



12. Limestone, gray, one layer 2 



11. Shale, gray, calcareous 2 



10. Limestone, gray, one layer iy 2 



9. Shale, buff and gray 3% 



8. Limestone, brown, cherty, impure 1 



7. Limestone, gray, cherty 2*4 



6. Limestone, blue 1 



5. Limestone, buff 1 



4. Limestone, blue 1 



3. Limestone, buff, cherty 2 



2. Limestone, blue 3 



1. Limestone, gray 4 



Total 34i ; 



,-j 



The limestones below the shale member number 9 are the upper 

 layers of the Forbes limestone. In the bed of the creek are several 

 additional feet of limestone belonging to this formation. The 

 upper part of the section is the base portion of the Braddyville 

 beds. 



On the Millner farm, about one hundred rods above the bridges 

 on the creek, thirty feet of Nishnabotna sandstone rests upon the 

 black shale number 14. In tho year 1900 Doctor Calvin and the 



