IOWA ACADEMY OF SCIENCE 
235 
One mile east and also one mile west of National a thin stratum 
of drift underlies the loess. 
On the road from Garnavillo to Clayton Center, at one mile west 
of Garnavillo on southwest of section 7, in the ditch on the south 
side of the road ; about 80 rods farther west on the northeast quarter 
of section 12, in ditch on north side of road ; near center of section 12 
in ditches on both sides of road, and near center of section 11 in 
ditches on both sides of road, under from five to ten feet of loess, 
are exposed, from a trace to two or three feet of red sandy clay 
containing an abundance of small pebbles up to a half-inch in 
diameter, and a good number of larger ones up to occasional small 
boulders six to eight inches in diameter. About 75 per cent by 
actual count of those from one to four inches in diameter are 
greenstone, while of the larger ones, about 10 per cent are granite. 
On the road from Elkport to Elkader, about one mile east of 
Communia, on sections 17 and 18, are thin exposures, and about 
one-half mile west of this place, about ten feet can be seen on same 
road. 
Two miles from Elkader, where this road descends a steep hill 
into the valley of a ravine opening into the valley of the Turkey 
river about half a mile away, fifteen feet of stratified material is 
exposed. 
Three miles west of McGregor on the Monona road, near the 
top of the John Orr hill, in the ditch on the south side of the road, 
is an exposure of apparently unmodified drift. July, *06, a section 
about 20 feet long and 1 foot deep could be seen. While the bot- 
tom could not be seen, it probably rests on the Trenton which 
crops out a short distance down the road towards McGregor. 
Over it was the blue pipe clay, — about a foot, — and over this the 
loess. Twenty rods west the road reaches the top of the divide 
between Sny Magill and Bloody Run, which it follows to Monona. 
The elevation is probably about 800 feet above the river. 
This deposit is composed of small quartz and other pebbles and 
coarse sand cemented by a red tenacious clay. Pebbles of other 
material than quartz were often so rotten that they could be 
crushed in the hand. No granite or syenite was noticed. The 
largest piece of rock seen was oval, about 6 inches fin its longest 
diameter and four in its shortest, of a tough, well preserved mate- 
rial resembling quartz. 
Only the most noticeable exposures noted are given here. Traces 
of till or modified drift and scattering pebbles and small boulders 
are found wherever the bottom of the loess is exposed, over the 
entire area observed. 
