IOWA ACADEMY OF SCIENCE 
223 
These are the characteristics’ of loess. The writer accepts the aeolian 
theory as to the origin of the loess. But to prove a deposit aeolion is 
not equivalent to proving that it is loess. Unless it has the texture and 
physical characteristics of loess, it is not loess! Sand, whatever its 
origin, is not loess. Joint clay is not loess. Heavy, “sad” soils are 
not loess. Soils whose materials are distinctly granular are not loess. 
We are not justified in calling any material by that term unless it 
possesses the requisite physical characteristics. 
THE PROBLEM IN ADAIR COUNTY. 
Adair county lies within the Kansan drift area of Iowa. The crest 
of the grand divide between the Mississippi and Missouri rivers passes 
through the county. Erosion has cut deeply into the drift, the county 
is greatly dissected by streams, anekits drainage system is complete. It 
contains no lakes, except an occasional ox-bow in the flood-plain of one 
of the larger streams. As is to be expected in an area of this sort there 
is a very considerable variation in the elevation of different points 
within the county limits. This can best be appreciated by a few ex- 
amples. The elevation at the town of Greenfield is 1,368 feet. Eight 
miles northeast, at the village of Howe, the elevation is 1,098. Half a 
mile east of Howe, on the banks of Middle River, it is 1,047. At the in- 
tersection of Middle River with the county line the elevation is 940 feet. 
At the town of Adair it is 1,442 feet. 
The material of the Kansan drift in Adair is not unlike that found 
in the other counties of southern Iowa where this drift forms the; sur- 
face soil. When not leached out, the till is a dark blue or blue-brown 
varying to purple brown or sometimes nearly black when moist. Near 
the surface it leaches to light yellow-brown or grey-brown. Small 
bowlders of granitic rock, and more particularly of Sioux Quartzite, 
are common in the drift, but are not evenly distributed 1 , being very 
abundant in places, and in other places scarce or lacking. This uneven 
distribution is to be attributed to the accidental irregularity of glacial 
deposition. It is not to be expected that the glacial agencies would 
distribute the bowlders in a mass of till with absolute uniformity. One 
might reasonably expect a priori that there would be more at some 
points than at others. Gravels also are occasionally present. These 
are always more or less intermixed with till, except where post-Kansan 
erosion has been at work re-assorting 'the materials. Where the gravel 
and till occur in their original position, no trace of stratification can 
be detected. Like the bowlders, gravel is occasionally lacking at many 
points in the till, and this again is to be attributed to the accidental 
