EL, Andrews on the Western Boulder Drift. 177 
thickness, and follows all the undulations of the surface except 
the valleys of erosion. This loam is free from boulders, and is 
very plainly stratified. It seems to have been a deposit of 
quieter water, after the violence of the previous action had ex- 
pended itself, or perhaps after the rising again of the crest of 
the Laurentian Hills above the waves had cut off the further 
progress of both water and floating ice. I am not sure 
whether this loam covers the very highest summits, but it cer- 
tainly lies like a blanket over all the lower country up to seve- 
ral hundred feet above the lake, and seems to prove that this 
region remained for a time under water after the boulders 
ceased to arrive. That it was not the product of a later 
submergence coiemporary with the loess, I infer, because I 
have never been able to discover any trace of black soil between 
it and the boulder drift, such as would have been found, had 
there intervened a period of dry land between the two. This 
loam is found both in the basin of the lakes, and outside of 
the rim of the latter on all the seaward slopes, except the 
northern, 
If we follow the western drift toward its sources in the far 
north, we are confronted with still further marks of the vio- 
lence of the action which transferred it. Rev. T. Hurlburt, 
whose paper was quoted above and who has been for forty years 
an acute observer of drift phenomena over the whole region 
from the Hudson’s Bay to the Ohio river, says there is little 
or no drift material on the north slope of the Laurentian Hills, 
The whole country is scratched and pounded by the drift ac- 
tion, but the loose material has nearly all been swept south- 
ward. Not even the boulders could keep their footing. The 
drift action, is nearly destitute of drift material, He believes 
y in the aquatic character of all our drift deposits. Ra, | 
