114 KANSAS ACADEMY OF SCIENCE. 
been found over the county. One east of Arrington measures 715x6 feet, and 
formerly protruded three feet above the ground. The Agassiz Science Club is 
keeping a record of the location and dimensions of these boulders, on a map pre- 
pared for that purpose. One of the most interesting studies in this section is the 
glacial drift, which constitutes most of the surface of Atchison county. I have 
found it varying from a few feet in thickness to over 100 feet. During the past 
two years arrangements have been made with well borers to collect, in boxes pre- 
pared for the purpose, specimens of clay passed through, together with the thick- 
ness of the clay beds. This work has not progressed far enough to reach any 
definite conclusions. The clay lies in sharply separated beds, some of which are 
very thick. In 1868, Prof. Louis Agassiz, accompanied by Roscoe Conkling and 
others, visited northeast Kansas. Agassiz recognized in the red, gray, and green 
boulders on our hills a verification of the glacial theory he had worked out in his 
native Switzerland, viz., that these boulders were brought here by the ice sheet 
which about 10,000 years ago covered all the northern part of the northern con- 
tinents. The ice sheet grated over the surface of the country, scraping up huge 
boulders and smaller particles from the limestones, granites, and greenstones of 
Canada and from the red quartzites of Minnesota and Dakota. These boulders 
were dropped by the melting ice on the prairies. 
I have carefully observed this glacial deposit covering northeast Kansas from 
Kansas City to Junction City and Washington county. I have seen it at West 
Point and other places up and down the Hudson river; in Central Park, New 
York city; in the Sierra Nevada mountains, and along the Pacific coast. In 
fact, the ice sheet sprinkled its boulders and mud on top of the older deposits 
over all the northern continents as far south as the 39th parallel of latitude. 
NOTES ON KANSAS PHYSIOGRAPHY. 
By J. W. BeepE. Read before the Academy January 2, 1897. 
GENERAL OUTLINE. 
Kansas erosion is from plain to plain rather than from ridge to plain. In 
other words, the elements have an elevated plain to break up and reduce to a 
plain of lower elevation, instead of a high ridge to reduce toa base level, as is the 
case in mountainous regions. At present, the parts under consideration are in- 
termediate forms, varying according to the nature of the rocks of which they 
are composed and the climatic conditions to which they have been subjected. 
In various parts of the state good examples of these intermediate forms of 
reduction may be seen, modified by climate and structure. The youngest is in 
the Red Beds, in the more highly developed part, and illustrates an early stage 
of reduction. The original plain is represented roughly by the more elevated 
summits, while the valleys and cafions represent the amount of material re- 
moved. A more advanced stage of erosion is represented in the eastern ex- 
tremity of the Dakota formation. Here a slightly different climatic condition 
has obtained, and there is also a difference of rock structure. It has been sub- 
jected to other conditions which are as yet but very little understood. Near the 
Smoky Hill valley, the Permian shales on which the Dakota rests sink to a lower 
level than to the eastward or westward, which seems to be due to erosion, produc 
ing a marked unconformity. It may indicate a pre-Dakotan drainage channel. 
Section 3 is in the Carboniferous of eastern Kansas. This is the oldest of the 
