32 Cuptain Bayfield on the 
The following rough eye sketch, from memory, will pro- 
bably serve to make us understood, and explain the nature of 
the constantly increasing alluvial deposits of the St. Louis. See 
Fig. 
This sketch is merely explanatory ; it is not pretended 
that the number or shapes of the islands are correct. 
At Mauvaise Riviere, near the islands of the Twelve Ap- 
ostles, the Michipicoten River, and the Kamanistiqui-4, the 
alluvial depositions are extensive ; and of course constantly 
encroachingon the lake. The last, (on the north bank of 
which is Fort William,) has formed two Deltas, through 
which it enters the lake by three mouths. In excavating a 
few feet through the sand, we always came to clay, similar to 
that deposited immediately without the bar of sand. In this 
clay, clam and other fresh water shells were abundant; and 
in the superstratum of sand, small angular fragments of the 
flinty slate which is found in place at the rapids of the river 
above. These last have been brought down and deposited by 
the stream. 
The river has evidently elevated its bed ; for on either side, 
its immediate banks are not only much higher than the land 
a little back ; but this last is, in many parts, lower than the 
level of the river when the waters are high. 
' It appears that the lighter argillaceous matter is carried out 
by the strenm, and deposited without the bar; and that the 
sand which is continually coming down also, is thrown out 
further and further, covering this clay by degrees as it is de- 
posited—an operation which meets with little interruption, 
from without, as the place is well sheltered from the prevailing 
winds, 
As the nature of these alluvial depositions has, we trust, been 
explained by the instances which we have related; and as this 
paper has extended to a much greater length than we at first 
anticipated, we shall pass over the other rivers, and proceed 
to give a synopsis of the mincrals which we observe in the 
various orders of rocks. 23, 
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