SO-CALLED CRETACEOUS DEPOSITS IN MINNESOTA 689 
shaly clays of the Galena (Trenton) alt Sits ey, | Alive clay 
strata when wet would scarcely fracture under any conditions 
and the sand strata between them, being largely not compacted, 
could allow them more free movement and keep the mass from 
breaking apart, as long as the strata remained approximately 
horizontal or compressed. Moreover there is little instead of 
much gravel and till associated with it into which it might have 
been jammed by the glacier. The condition of the glacier at 
the time when this mass could have been dropped where it now 
lies, is indicated by a fine example of an esker which lies about 
one mile west of south, looking like one of the sandstone buttes 
or a dolomite swell. The esker presents an abrupt slope on its 
northwestern front, and extends indefinitely to the southeast- 
ward. At the foot of the esker is an exposure of Saint Peter 
sandstone. The brow of the hill has been excavated for a sand 
pit, and the strata of gravel may be seen in it dipping gently on 
all sides into the hill. Thin strata of nearly pure sand, unlike 
anything but Saint Peter sandstone, are conspicuous. The depth 
of the gravel is about forty feet, but the loess covering obscures 
the form of the hill and conceals the most of the esker deposit. 
A similar esker lies nearly two miles farther in the same direc- 
tion, standing west of the village of Goodhue. The eskers and 
the Cretaceous lie in line, and notably they are perched on the 
brow of sandstone hills, fronting northwesterly. Again, the 
height of these eskers contrasts with the thinness of the till, 
which is only one or two feet thick, as seen in cuttings in the 
region. The glacier which strewed débris thinly, and which 
scarcely drove the residuary clays from the rock surfaces beneath 
it, must still have been a gigantic ice mass to have built such 
eskers on the farther side of a broad valley. A clay mass such 
as the Cretaceous here, would have been comparatively slight 
when once loaded upon the ice. 
It is not my intention to urge this hypothesis of glacial trans- 
portation, but it is worthy of remark that the successive loose 
sand and tough clay strata would have been the best adapted of 
any to be easily slid upon the glacier, to be transported without 
