IOWA ACADEMY OF SCIENCES. 
277 
Kansan drift. This bed is not cut up into irregular blocks 
by the presence of such numerous joints and cracks as 
appear in the clay found in Number 3 above. At the top 
of this number, just below the soil band, the calcareous 
matter has been entirely leached out for a depth of eigh- 
teen to twenty-four inches. At a depth of thirty inches 
from the top there is in some places a slight action in 
response to hydrochloric acid, and in the other places at 
Fig. 16. Drift exposure along the C. & N. W. Ry. , near Toledo, Iowa. 
the same depth the acid produces no action whatever. 
At a depth of three feet the acid usually produces slight 
effervescence. At four feet in depth the action with 
acid is still stronger than at three, while at a depth of six 
feet from the top, and so on down to the base of the expos- 
ure, the acid never fails to produce a prompt and vigorous 
action. 
CONCLUSION. 
In the above exposure the following conditions seem to 
indicate the presence of two different drift sheets. 
