366 The American Geologist J""*^- i^**^- 
The sand averages coarser as the depth is increased. Passing- 
northward or up the river from Ashland, the flood plain is un- 
derlain by beds belonging to the Coal Measures, Dakota, and 
Benton. Glacial clays dip beneath the river at a number of 
places. 
Todd Valley. — The following from I. S. Crawford gives 
the conditions in' the floor of this valley : "During the past 
twenty years we have put down wells throughout the whole of 
Saunders county. In this valley we go through three or four 
feet of soil, twenty feet or more of loess, and then sand. The 
sand is quite fine above and coarse below, approximating fine 
gravel in size. Fifteen to twenty feet of the tipper sand is dry. 
The lower beds are alternations of fine and coarse sand. The 
water level fluctuates no more than twelve inches between wet 
and dry seasons. Water is found at the same general level 
showing a slope to the southeast of six or seven feet to the 
mile. Depth to water line about forty feet. It is necessary at 
times to run a point down forty to sixty feet below this level 
in order to obtain a good position for the point and the best 
well. These conditions hold good throughout the length and 
breadth of the valley, except on the highest places, where the 
sand reaches to within a few inches of the surface." J. G. 
Martin has not penetrated the sand in wells 190 feet deep. 
L. J. Pospisil states the following. "Rarely do well dig- 
gers penetrate the sand which is fine above and coarse below, 
as it is along the Platte. On the place of Mr. Minas four and 
one-half miles northeast of Wahoo, a well sunk to a depth of 
120 feet did not pass through the sand." 
The Highlands. — An examination of the bordering hills 
gives additional facts from which certain conclusions may be 
reached. The region with which we are most concerned is the 
highland between Todd valley and Platte valley. Sections A 
and B, Fig. 2, represent the general arrangement and probable 
thickness of beds. A well on the place of Hon. E. J. Harmon, 
four miles east of Cedar Bluffs, in a level of 182 feet above 
the river, is 185 feet deep. Soil, loess, and glacial clay, with 
sands and a few harder beds were encountered in the well. 
Mr. Harmon's notes indicate the presence of a shaly limestone 
just above the river level. This bed may be a blue glacial clay 
associated with a chalkv laver. Otherwise, it belongs to the 
