1052 Surface Geology of Burlington. 
with numerous small, rounded erratic boulders up to four feet in 
diameter, is well exposed in all its characteristic details. It is over- 
laid by six to eight feet of typical loess, containing numerous small 
leesskindchen. The deposits here presented have an exposed 
thickness of sixty feet, and are seen to lean against the steep sides, 
the rather narrow gorge preglacially eroded by the waters of Flint 
creek to a depth of more than one hundred and thirty feet. North 
of Flint creek, and beyond the area represented in the annexed 
map, the topography in its general aspect is similar to that of the 
insulated plateau south. On the upper brow of the north slope of 
“ North hill,” a road cutting discloses the following arrangement :— 
SECTION II. 
i Brownish-yellow clay, free from gravel, and for the r pant 
homogeneous; gradating into No. 2 t. 
2. Typical ashen compact loess *aining numerous small en 
kindchen and the following fossils :— 
Pupa muscorum Linn. ` Succinea obliqua Say. 
Patula striatella Anth. Limnophysa desidiosa Bay. 
Patula perspectwa Say. Helicina occulta Say.......8 feet. 
3. Till with an abundance of gravel, and pebbles up to three feet 
in diameter, exposed 20 feet. 
Over the entire central portions of the nokiaa ‘platens the dis- 
tribution of quaternary deposits is essentially the same, except the 
lower member suffers a considerable attenuation over the more ele- 
vated parts, sometimes being reduced to a few feet in thickness. 
Upon removal of the drift materials glacial scorings and strie on 
the subjacent paleozoic stratum have been disclosed in various 
laces, 
South of the Hawkeye creek rises a broad elevated plain so level 
in many places as to be almost devoid of natural drainage. North- 
eastward it is scalloped by short, deep ravines, but eastward it 
abruptly terminates with a perpendicular declivity, washed at its 
base by the Mississippi river, which has evidently separated the 
plateau from the highland of Henderson county, Illinois. To the 
southward and westward this level elevated plain gradually becomes 
gently undulatory and finally more broken by the small tributaries 
of Be ie creek. Northwestward it merges into the general elevated 
