342 DRIFT ICE AS AN ERODING 
for many days the upturned edges of the ice floes as they were 
driven on shore, I saw very few with debris thus frozen in. The 
deposits seen by me were often very unequally laid on, and 
frequently absent near the bottom, where they naturally should 
be. Sometimes an overturned ice pan showed sand, but for the 
old idea that field ice obtained most of its debris from overhang- 
ing precipices I could find no evidence. 
Conclusions. 
After having spent two months surrounded by ice fields, and 
often beset on all sides with its difficulties, I have concluded 
that very little of all the debris seen on the ice in polar regions 
ever reaches the latitude of the Straits of Belle Isle, and also 
that the Grand Banks are only receiving a fraction of the amount 
of material formerly supposed. Consequently the Banks from 
Newfoundland westward aie almost solely the products of the 
period of the greatest extension of ice erosion when the source 
of the debris was our own provinces. It appears, therefore, 
that those submerged banks are but the marine representatives 
of the sand dunes and flats of New Jersey, Long Island, Cape 
Cod and other places, and are principally the natural result of 
greatly prolonged wave action on true glacial moraines ; with, 
however, this difference, that while the western deposits were 
formed almost solely from the detritus from Apalachian and 
local glaciers, the eastern have been added to in the later Pleis- 
tocene by an Arctic current. The paucity of transported material 
on the ice in the latitude of the Straits of Belle Isle convinces 
me that it takes but a short time for storm and surf to clean 
thoroughly all the ice brought down by the Greeniand current. 
Therefore, we cannot look farther north than Eastern Labrador 
and Newfoundland for the source of any debris that may have 
been added to the Grand and Sable Island Banks. In regard to 
Sable Island, a recent paper by Dr. A. H. MacKay, on a fresh 
water sponge found there, may furnish food for speculation as. 
to its origin. This, however, I do not think would affect my 
conclusions. The sponge, if not an evolution from a marine 
