180 FORMATIONS OF 
were exterminated by the small-pox ; and the land remained in the possession of the 
Chippewas, until the Missouri Indians made an incursion into the country, and had 
several battles with them; after which, the Chippewas left the country, with the 
exception of ten or twelve families. 
On my way from Mr. M’Dermott’s, by the river, to the colony, I disco- 
vered, not far from a salt spring, loose slabs of limestone, much of the same 
appearance and composition as those found on the Rapids. On splitting these open, 
I disclosed an Orthis, like the O. planumbona, a Leptena (species undetermined), 
and casts of discoidal bodies, which may be the impressions of Orbiculas. The size 
and angular form of these slabs indicate that they are not far out of place. The 
mud on the brink of the river looks, too, like decomposed marlite, such as is often 
associated with the shell-beds of F. 8, of Wisconsin. The same kind of limestone 
projects from several points of the shore, near some rapids, a few miles further 
down the stream. 
At the top of the left bank of the Assiniboin, close to its mouth, I found beneath 
the soil some large slabs of limestone, similar to those formerly discovered above the 
Great Rapids of Red River; but, on closer inspection, it was evident that they were not 
in place, but had probably served as an underpinning to some house which formerly 
stood there. I could not learn that there was any quarry in the vicinity whence 
they could have been brought, but I afterwards observed many large slabs, of the 
same kind of limestone, about ten miles below, on the immediate bank of Red 
River, evidently not far out of place. I have no doubt that they were brought from 
that locality, which is the nearest spot I could find convenient for transportation to 
the Assiniboin, where limestone fit for such purposes could be procured. 
The mean of five observations, at Upper Fort Garry, at the mouth of the Assiniboin, 
for latitude, three by meridian altitude of the sun, and two by Polaris, gave for the 
latitude, 49° 53’ 24”. Mr. Calhoun, who was attached to Major Long’s expedition, 
in 1823, made it 49° 53’ 35”; but, according to a record in the possession of one of 
the officers of the Fort, Le Froy placed it in latitude 49° 58’. 
As the preparations for the further prosecution of our journey could not be com- 
pleted for some days after our return from the Pembina Mountain, I took advan- 
tage of this time to drop down to Lower Fort Garry, for the purpose of making 
some further geological investigations, in the hope of collecting additional evidence 
of the age of the limestone of Red River. 
Some eight to ten miles below the mouth of the Assiniboin, the debris of cal- 
careous rocks are seen on the shore in abundance ; also at various points below this, 
especially where there are some slight rapids. There can be little doubt that the 
formation from which they are derived, forms the basis of a large portion of the 
prairie country of Red River. 
About twenty miles below the mouth of the dates. near Lower Fort Garry, 
solid ledges of limestone are exposed, of a light buff colour, sometimes mottled, 
spotted, or banded with light brown. Immediately opposite the Fort, a considerable 
amount of rock has been quarried, and used in the construction of the building. 
In these beds, I succeeded in finding several well-defined and characteristic fossils, 
sufficient to establish, without the least doubt, the age of the Red River limestones. 
