Valley Loess of Lansing, Kan. — Uphain. 27 
Report of the L^nited States Geological Survey, 1885, leaves 
no g-roimd for doubt that the loess of the Mississippi and 
Missouri valleys was derived mainly from the North American 
ice-sheet, being a deposit of the flooded rivers during a stage 
of very abundant ice-melting, with considerable redistribution 
over the interfluvial upland areas by winds. Several 
years later, an equally important work by McGee, "The 
Pleistocene History of Northeastern Iowa," appeared in 
the Eleventh Annual Report of the same survey, presenting 
most satisfactory and conclusive evidence that the chief stage 
of plentiful and rapid deposition of the loess was when the 
ice-sheet still covered a large part of Iowa and stretched 
thence very far northward, but after it had relinquishd the 
outer area of its drift which extends south to central Missouri 
and northeastern Kansas. 
Paha, or eskers of loess, described by McGee, and broad 
swells and embanked ridges of loess, also described by him and 
by Calvin, amassed along the border of the ice-sheet at its 
lowan stage, rising 20 to 5o_feet or more above the adjoin- 
ing almost perfectly level expanse of till on which the ice lay 
at the time of these loess accumulations, give me a complete 
assurance that the loess there was supplied principally from 
englacial drift which at last became superglacial by ablation 
or surface melting. As with the more common types of eskers 
and kames, composed of coarse and fine gravel and sand, I am 
obliged to refer these loess formations to streams flowing down 
from the dissolving ice surface, not upward from subglacial 
tunnels. They go with the numerous arguments of Profs. 
N. H. Winchell and W. O. Crosby, and of the present writer, 
to prove that the departing North American ice-sheet, when 
its thickness near the margin was greatly reduced, became cov- 
ered there by the drift which had previously been enveloped 
within the slowly flowing ice, nearly as the Malaspina ice- 
slieet or piedmont glacier in Alaska, between Mt. St. Elias and 
the ocean, is covered by its formerly englacial drift, on which 
are now growing forest trees of large size and luxuriant 
thickets. Similarly the Greenland ice-sheet, if it were melt- 
ing away instead of increasing or remaining nearly unchanged, 
would become covered at its border by the drift of its basal 
l^art, then becoming superglacial. 
