Topography of Hozvard Co., la. — Calvin. 379 
moraine ( Fig. 2, PI. XXVII) . From the summit of the marginal 
ridges the observer looks in one direction upon a tumultuous 
series of erosionally developed and well rounded hills and 
ridges (Fig. i, PI. XXVII) ; in the other direction the land- 
scape is an uneroded plain stretching away to an uninterrupted 
horizon, as level as a sea (Fig. 3, PI. XXVII). 
The typical characteristics of the lowan plain are best il- 
lustrated on the broad, fiat divides between the drainage cour- 
ses. The region having its center at the southeast corner of 
Saratoga township, may be cited as a concrete example of the 
ideal lowan plain. But all portions of the county lying south- 
west of the lowan-Loess boundary, and not immediately ad- 
jacent to streams, present the type of topography illustrated in 
figure 3. The surface is everywhere a plain slightly modified 
by elevations and depressions. As intimated above, such ine- 
qualities and irregularities as are present are due to the man- 
ner in which the drift material was arranged by the action of 
the lowan glaciers, and not to any subsequent shaping or carv- 
ing by drainage waters. Drainage is as yet imperfectly devel- 
oped. There are in fact no drainage channels in the inter- 
stream areas. The storm waters simply flow ofif along broad, 
shallow, concave sags or so-called sloughs, the surfaces of 
which gradually blend into the low, broadly rounded swells 
which constitute the higher and better drained portions of the 
surface. 
The permanent streams of the lowan area, in the south- 
western three-fourths of the county, flow in shallow depres- 
sions broadly concave from side to side, the margins of the 
depressions blending imperceptibly into the general lowan 
plain. This is the condition presented by the Wapsipinicon 
and Little Wapsipinicon in Wayne township and by Crane 
creek' in Saratoga, Howard and Paris townships. These ill 
defined valleys, however, are all in a sense remnants of a pre- 
lowan, even of a pre-Kansan, topography which has been 
modified by deposits of drift. The streams are simply follow- 
ing ancient valleys which are almost completely filled. Along 
all these streams there are beds of ferruginous, oxidized Bu- 
chanan gravels which show that here were drainage courses 
when the Kansan ice was melting. The gravels rest on Kan- 
san drift with which the old valleys, probably preglacial, were 
