IOWA ACADEMY OF SCIENCE 
215 
The lowest sand and gravel with the Mastodon or Elephant remains 
is referred to the Aftonian interglacial interval. 
A mile south of Hartford (see Milo Quadrangle, T. 77 N., R. 22 W., 
east half of section 29 ) a long and deep cut reveals considerable variety : 
Feet. 
6. Soil 2 
5. Loess, brownish above where weathered, gray below, laminated, 
root marks numerous, two places fossiliferous, traces of hor- 
izonal planes of oxidized iron visible 9 
4. Clay and fine sand, like a silt 1 
3. Clay, two inches of dark, then three feet of blue, changing into 
three feet of dark brownish crumbly clay, free from plant 
fibers but containing a large amount of oxide of iron; in places 
grading below into (Gumbo; Dallas) 6 
2. Clay, light brownish above, darker brown below, with pebbles and 
small cobbles; layer of Kansan pebbles seen in places; drift 
filled with characteristic pebbles and small cobbles of red 
quartzite, greenstone and granite (Kansan Drift) 10 
1. Shale, mostly clayey (Des Moines) 10 
Near the center the Des Moines shales appear above the bottom of 
the cut and rise gradually southward till they attain a height of about 
ten feet, from which the surface drops rapidly beneath the level of 
the cut. This valley side in the coal measures is rendered conspicuous 
by a thin seam of carboniferous matter that follows the side of the 
valley. The Kansan drift, wanting in a portion of the cut, is here a 
conspicuous deposit filling the old valley side in the Des Moines shale. 
Toward the south the line of pebbles and the several deposits that suc- 
ceed may be seen passing beneath the level of the cut. The weathered 
portion and the soil here become thicker. The lowest brown clay of 
No. 3, not clearly separable from the portion above, contains a fevv 
small pebbles, and rests on a layer of pebbles characteristically Kansan. 
The deposits above the distinct Kansan drift mantle the hill. The 
change toward uniformity due to weathering and to creep may be 
followed out horizontally from the more unchanged portion within the 
hill to deep black soil on the side of the hill. 
In the long cut through the high ground two and a half miles east 
of Sandyville (see Milo Quadrangle, T. 76 N., R. 22 W., Ne. % of sec- 
tion 24) the following section appears: 
Feet. 
6. Soil 2 
5. Loess, brown above, gray below, with numerous somewhat horizon- 
tal bands of oxidized material very conspicuous in places.... 8 
4. Clay, bluish where damp, gray w r here dry, extending down into 
numerous holes somewhat hemispherical in shape three to five 
feet in diameter in the deposit below T . (Gumbo; Dalis).... 1-2 
