SOME PLEISTOCENE EXPOSURES IN DES MOINES ^ 
JAMES H. EEES 
In the early spring of 1921 as the writer was examining the 
face of the bluff bounding the north side of the Des Moines val- 
ley just below the Capitol grounds he noticed, on the west side of 
the entrance to a ravine between Southeast 13th and 14th streets, 
where the State operated a small drift coal mine for some time, a 
section of Pleistocene material above the Coal Measures sand- 
stone, which seemed to present features of some interest. Closer 
inspection showed the probable presence of two drift sheets and 
since the superposed evidence of successive invasions of the con- 
tinental glaciers always excites curiosity it may be worth while 
to record this bit of evidence here. 
Overlying the sandstone and shale of the Coal Measures, which 
rise twelve feet above the railway tracks, is a four foot layer of 
pebbly till, which is red below and partly gray and calcareous in 
the upper foot. Over this till, which probably is Kansan in age, 
is loess, which is gray and hard in the lower foot or two, but yel- 
lowish and softer above. A small gully which has been cut 
through the loess shows fossil shells. Lime concretions are abund- 
ant throughout the loess and a few sand grains, some of them as 
large as one-eighth of an inch in diameter, were seen in the basal 
portion. The loess must be seven feet thick as exposed here at the 
point of the bluff. The overlying material is not well exposed but 
it is pebbly and probably is Wisconsin till since this is known to 
be present over Capitol Hill, as at the exposure next to be de- 
scribed. 
In the fall and winter of 1915 a rather deep cut was made 
along East Court Avenue between 10th and 12th streets for the 
purpose of giving an easier grade to and through the enlarged 
Capitol grounds. The exposures made at that time were closely 
watched by the writer and were reported in detail in volume 
XXIII of these Proceedings. However, it seems well to discuss 
them here in connection with other exposures in the general re- 
gion. It chanced that this cut included two of the spots described 
by McGee and Call in their classic paper published in 1882 in 
1 Published with permission of the Director of the Iowa Geological Survey. 
