Drift in Minneapolis, Minn. — Uphain. 285 
deposit: but here it also often displays much contortion. The 
whole hill, indeed, through which the street is cut, was evi- 
dently subjected to much compression, crumpling , and over- 
thrusting, when its materials were amassed. 
In the central part of section i, beneath the western end 
of the superficial yellow till, at depths of 5 to 15 feet below the 
surface, the red till incloses two shreds of yellow till, i to 2 
feet thick and 10 to 15 feet long, running crookedly in an al- 
most vertical general direction. A few feet from these and a 
little lower, within a fold of the red till, is inclosed a prolonged 
pocket of red sand and gravel, extending about 20 feet with a 
maximum thickness of 4 feet, changing downward gradually 
into till. 
The west half of these sections is nearly all red till, but it 
incloses. 5 to 20 feet below the surface, a contorted and faulted 
layer of yellow till, or in part of yellow gravel, sand, and fine 
silt, from lYz to 5 feet thick and extending about 250 feet. In 
one place, insfead of continuing as a layer, this yellow till 
forms a definitely bounded nearly round mass, 10 or 12 feet in 
diameter. Again, near the bottom of this west part, about 20 
feet below the surface and 5 to 10 feet under the layer already 
described, is another and thinner layer of such yellow till, 6 to 
15 inches thick, extending 125 feet or more, very clayey and 
clearly laminated, but containing stones up to six inches in 
diameter. This layer also is contorted and cut by faults, one of 
which has a downthrow of 3 feet to the west. 
How we should account for the intercalation of the thin 
yellow till layers in the red till, which there reaches up quite to 
the surface, is a most dif^cult problem. It seems to me prob- 
able that wavering of the belt of confluence between the ice 
flowing from the northeast and that from the northwest, one 
side repeatedly pushing back the other in alternation with be- 
ing itself similarly displaced, may best supply the clue for the 
interpretation of the history of these sections. The whole de- 
posit, in all its complications, I believe to have existed as en- 
glacial and finally superglacial drift, being amassed somewhat 
as I would explain the accumulation of drunilins, and falling 
together and settling to the subglacial ground while the ice- 
sheet at this i)lace was being melted above and beneath its in- 
closed drift. 
