Geology of Lake Superior. 17 
coast opposite, for at least 20 miles to the north eastward of 
the entrance of that river. We ascended the St, Louis, about 
15 miles in a direct line from its entrance. The first rapids 
are about 1! or 2 miles further and are over this rock. . 
Having now traced the extent of the sandstone from one 
extremity of the lake to the other, noticed its existence on 
both shores, and traced it across the lake by many of the islands, 
soastoleave no doubt of its being a general formation, 
throughout the whole of the basin of Lake Superior, we next 
proceed to mention some other particulars concerning it. In 
the first place, it rests immedjately on the granite.* It is in 
general horizontally stratified, or nearly so, even at its imme- 
diate contact with that rock ; asin the following sketchest 
taken on the south coast where there are many peninsulas of 
granite, joined to the main by isthmuses of sandstone, which 
are fast yielding to the incessant washing of the lake, so that, 
at no very distant period, these peninsulas will become islets, 
like many otheys near them, and which have become so in the 
same manner. 
There are many other instances of the conjunction of these 
rocks similar to those above, which serve to prove that the 
sandstone was deposited after the granite occupied its present 
position, and that it has not been disturbed since: but our 
duty is to relate that which may hear on either side of a 
question ; consequently we must say that we think that there 
are other appearances which directly contradict this inference, 
such as those represented in the following sketch,} and obser. 
vations. 
The sketch was taken on the west side of abay the next 
north westward of that in which is Soosoowagaming river, 
*Doctor Bigsby saw conglomerate resting upon and alternating 
with amygdaloid a} or near the Point Mamainse north coast 
Lake Superior. , ' 
Sce figure 2 aud 3, 
See figure 4, ¥ 
Y 49 
