LOESS AND THE IOWAN DRIFT. 367 



on the latter ten feet of yellow loess, the lower five or six feet 

 being fossiliferons. Other exposures along the same road show 

 the Iowan drift capped with loess. 



An exposure east of Greenwood Park, Des Moines, Iowa, 

 shows fossiliferons loess between the Kansan and Wisconsin 

 drifts, and several similar examples were reported by McGee 

 and Call.* 



In the first Chicago Great Western Railway cut northeast 

 of Carroll, Iowa, the following succession of strata is clearly 

 shown: Kansan-drift at the base, overlaid by a foot of gumbo 

 the upper part of which grades into a layer of black mucky 

 soil (the Yarmouth), also about a foot in thickness; next a pale 

 bluish fossiliferous loess (post-Kansan), six feet in thickness, 

 separated from the yellow (post-Iowan) fossiliferous loess above 

 by an oxidized band, the whole being capped with one to five 

 feet of Wisconsin drift. In several cuts along the Chicago 

 Great Western Railway between Carroll and L,anesboro a thin 

 loess-like veneer appears on the Wisconsin, the latter often 

 showing a distinct band of pebbles and boulders along its upper 

 line. The first Chicago Great Western cut south of Carroll, 

 represented in PL XI, fig. 2, shows Kansan drift below, a 

 sharply defined layer of bluish fossiliferous loess above this, 

 and over it a deposit of yellow loess. This is outside of the 

 Wisconsin drift border, and no Wisconsin appears in the sec- 

 tion. Of the more than twenty cuts between Carroll and 

 Manning fully half the number show essentially the same re- 

 lative arrangement of drift and loesses. 



All the foregoing exposures in which the two loesses occur 

 together, lie outside the Iowan drift-border, and the loesses 

 are uniformly separated by a more or less distinct oxidized 

 band. 



The cut at Loveland, showing two loesses which are not so 

 clearly differentiated, has already received attention. It is 

 more remote from the Iowan border. The foregoing, and 

 other similar sections indicate the following succession of de- 



* Am. Jour. Sci., vol. xxiv, pp. 202, et seq., 1882. 



