LAKE WINNIPEG. 183 
small bay, near Big Swamp Point, the limestone is seen jutting out beneath heavy, 
loose masses of crystalline rocks, some of which would weigh hundreds of tons. The 
surfaces of many of the limestone slabs at this locality are crowded with well-pre- 
served specimens of the characteristic fossil, Lepteena alternata. 
Before leaving Fort Garry, I obtained a fine specimen of chain coral (Catenipora 
escharoides), which was said to have been obtained either on the shores of Lake 
Winnipeg, or in the vicinity. Thus, it appears that limestones of the age of the 
Lower and perhaps Upper Silurian rocks of England, extend as far north as the 
south shore of Lake Winnipeg, retaining not only the paleontological features which 
they possess in Wisconsin and Iowa, but much the same lithological character also. 
There is reason to believe, too, that these caleareous beds of F. 3, abut on the 
granites and syenites of this region of country, without the intervention of F. 1 and 
F. 2; since no rocks referable to these latter formations were observed there in the 
few miles between Big Swamp Point and the entrance of Winnipeg River, where 
the crystalline rocks are unequivocally in place. 
However, such might very well exist, and be easily overlooked, or hidden from 
view by the water and immense masses of erratics that line the shores, and rest 
upon the upturned edges of the sedimentary beds. 
I am led to believe, from information obtained at Fort Alexander, that the same 
limestone which we found in place at Poplar and Big Swamp Points, will be found 
extending at least as far north as Rocky Point, and Isle La Biche, or Elk Island. 
 ——————S = — =a 
DECHARGE DE LA CAVE. 
As many geological details of the country immediately bordering on the northern 
limits of the United States, have been given in the Narrative of Major Long’s Expe- 
dition, published in 1824; and, as the geology of Northern M innesota will be treated 
of more particularly in Dr. Norwood’s Report, I shall, in order to avoid unnecessarily 
increasing the bulk of this work, conclude this section with only a few general 
remarks touching one or two important features of that country along my imme- 
diate route of travel, in returning from the Lake of the Woods to Lake Superior, in 
1848. 
