84 IOWA ACADEMY OF SCIENCE 



writer found specimens of Anomphalus rotulus in the shale bed 

 number 9. The dominant fauna of this horizon is Ambocoelia 

 planocanvexa, both valves, and Pugnax uta. 



One mile north of Stennett on the west side of the river, about 

 one hundred yards above the old mill site, road grading has ex- 

 posed twelve feet of Nishnabotna sandstone, the base of which 

 must reach nearly down to the Platte shales. For a distance of 

 one-half mile south of the mill site in the bluffs on the west side of 

 the river, is the location of the old extensive quarries of the past ; 

 at present they are so obscured by slumping no section can be 

 obtained. 



Directly west of Stennett recent road grading has uncovered 

 the contact of the Platte and Forbes formations at the foot of the 

 bluffs. 



SECTION ONE-HALF MILE WEST OF STENNETT. 



FEET INCHES 



7. Limestone, in thin layers badly shat- 

 tered 5 



6. Limestone, gray, cherty 1 6 



5. Limestone, shaly 2 



4. Shale, gray 1 



3. Shale, black, carbonaceous 1 6 



2. Shale, gray, calcareous 2 



1. Shale, blue 4 



Total 17 



Several thin bands in the shale number 2 are almost entirely 

 composed of specimens of Chmietes granulifer and Squamularia 

 perplexa. The strata dip at the rate of twenty-five feet to the 

 mile, north of east from the outcrops west of the river to Pilot 

 creek. A number of the gray limestone layers carry many nodu- 

 lar masses of black chert, and in places are oolitic in texture. 

 Of all the limestones in the Carboniferous of southwestern Iowa 

 the Stennett limestones deserve the name of Fusulina limestone. 

 In past years when the quarries were in active operation, in 

 the debris, at the foot of the limestone ledges Fusulina could be 

 found in millions. There seems to be a varietal or even a specific 

 difference in the Fusulina at Stennett and those at McKissicks 

 Grove; the former are large and globular, the latter long and 

 curved forms. 



