Drift in Minneapolis, Minn. — Upham. 287 
above and below at irregular but well defined lines ; and be- 
neath this the base of the whole section is again reddish till. 
The two kinds of till are plainly distinct and unmixed, except- 
ing for an extent of about 50 feet on the upper boundary of 
the yellow till near the deepest part of the excavation. In 
theyellow till limestone fragments are frequent, but in the red 
till they are wanting or very rare. 
A few hundred feet w-estward, just after crossing Bassett 
creek, Western avenue makes a longer but lower cut, extend- 
ing 600 feet, with a depth of 8 to 12 feet, shown in section 5 as 
seen on the north side of the avenue. Yellowish gray till forms 
the greater part of the surface, and has mainly a thickness of 
5 to 8 feet. It is underlain by stratified sand and fine gravel, 
which also in part forms the surface, reaching thence down 12 
feet and continuing below the base of the section. The till 
rests conformably on the modified drift, w'hich has an inclined 
but undisturbed bedding at the east, whereas westward it is 
wrinkled and contorted, with an uneven upper line. In the 
modified drift is much limestone gravel, the largest pebbles be- 
ing two inches in diameter. 
For these sections I would give the same explanations as 
for those of Superior avenue, with which they afford a most 
instructive correlation. 
On Penn avenue {Twenty-seco)id street). A half mile 
north-northeast from the Western avenue sections, a cut 300 
feet long and 10 feet deep, on the north side of Griswold 
(Tenth) avenue, between Twenty-first and Twenty-second 
streets (Oliver and Penn avenues), was noted as in section 6, 
plate VII. Yellow till, containing plentiful limestone gravel, 
forms the surface and is 3 to 5 feet thick, succeeded, at a some- 
what irregular lower limit, by red till, wdiich extends below the 
bottom of the section. There was no intermingling of the two 
till deposits. 
The next section observed was a quarter of a mile farther 
north, at the northwest corner of Plymouth and Penn avenues, 
where a cut 300 feet long and 5 to 8 feet deep showed much in- 
terstratification, confused and contorted, of the yellowish gray 
and the red till, in layers and streaks sometimes no more than 
I to 3 inches thick, with distinctly contrasted coloration. Much 
limestone gravel was noted in the yellow till, but none in the 
red. 
