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IOWA ACADEMY OP SCIENCE 
4 — Yellow post-Iowan loess. 
3 — Sand. 
2 — Gray post-Kansan loess. 
1 — Kansan drift. 
In the northern part of the pahoid ridge northeast and north of North Lib- 
erty the following strata appear: 
3 — Yellow loess. 
2 — Loose sand. 
1 — Kansan drift. 
In some places 2 and 3 are interlaminated, as shown in Plate VI, fig. 1. 
This section represents the relation which would exist where post-Iowan 
loess was deposited on sand-covered Kansan areas such as have been noted in 
Dubuque and Bremer counties. 
Again the arrangement may be that shown in Bremer county along the wagon 
road on the west side of section 7, T. 91 N., R. XIII W. Norton represents* 
this cut as follows: 
4. — Loess, typical yellow 11 feet. 
3. — Loess, ashen in color, sparingly fossiliferous with small 
molluscan shells, etc 8 feet. 
2. — Red loam % foot. 
1. — Geest, red — with a few pebbles of the northern drift. . . .% foot. 
This ridge which Norton maps as a paha surrounded by Iowan drift is a part 
of a continuous Kansan area. The writer’s careful examination of this cut 
revealed the following section: 
4. — Yellow loess 7 to 14 feet deep, the depth greatest near the top of the ridge 
through which the cut is made. 
3. — Gray post-Kansas loess, 1 inch to 2 feet. 
2. — Chocolate or reddish dark compact clay which in position, texture and color 
is like the “gumbo” overlying some of the Kansan in southwestern Iowa, — from a mere 
trace to 9 inches. 
1. — Oxidized Kansan drift, 1-2 feet exposed. Northward toward the foot of the 
slope local material is mingled with the drift, which shows pebbles and small 
boulders. 
(See Plate X, figs. 1 and 2.) 
This section shows that the Iowan ice did not reach this ridge, for the post- 
Kansan loess, which certainly antedated the Iowan drift, is here in its normal 
position, and was evidently not disturbed. 
To the loess which sometimes, though not always, covers the paha and larger 
Kansan areas in the territory under discussion, McGee ascribed an origin in 
streams and lakes in ice banks** and assumed that where loess was absent it had 
been eroded.! 
Norton adopts this view of loess-origin,t but records the fact that in Linn 
county hills which are essentially paha in form have no loess, and expresses the 
well-founded opinion that upon them “there is no reason to believe that loess 
was ever deposited. ”§ 
*IbM.,p.379. 
**Ibi(i., pp. 254-5. 
tibid., p. 453. 
tiowa Geol. Sur., vol. XVI, 1906, pp. 382 and 385. 
g Iowa Geol. Sur. , vol. IV, 1895, p. 182. 
