
GLACIAL PHENOMENA AND SUPERFICIAL DEPOSITS. 215 
boulders imbedded in it. Section 2, is from a point about twenty miles 
east of Red River, and is a good typical one. The lower irregularly 
bedded series, was here composed of yellowish-grey, fine arenaceous clay, 
so hard as to form a perfectly perpendicular front ; and where it had been 
undermined by the water, it had fallen down and actually separated into 
slab-like masses, along the planes of bedding, like a soft sandstone. 
488. About seven miles above Roseau Lake, on the East Roseau 
River, a little section showing the former extension of the waters of the 
lake, and their gradual recession, was observed. The lower layers aie of 
yellowish-white, fine, arenaceous clay, like that forming in the beds of the 
present lakes. - Above this, lay about a foot of laminated peaty matter, 
showing the swamp or ‘“muskeg” stage, and then about two feet of 
coarser arenaceous clay, forming the present soil, and indicating the de- 
position of matter still going on from the occasional overflow of the river. 
A similar series of events, is slowly taking place over the whole of this 
flooded region of the drift plateau, as the streams draining the lakes cut 
down their beds ; and lakes and swamps in every stage can be found. 
489. Forty miles northward of the Roseau River, where crossed by 
the road connecting Winnipeg and the North-west Angle of the Lake of 
the Woods, the drift plateau appears to retain much the same structure 
and altitude. It is, however, much less uniformly covered with swamps 
and lakes, the flooded region being confined more closely to the vicinity 
of the actual watershed. 
490. The surface of the plateau, is very generally strewn with a 
profusion of erratics, and some of them are of great size. They are 
chiefly derived from the Laurentian and Huronian to the north, but 
there are also many of white limestone, with regard to the origin of 
which the remarks mace in connection with the part of the district more 
immediately surrounding the Lake of the Woods, will apply. 
General feutures of Glacial Phenomena East of the Red River. 
491. The rocks of the Lake of the Woods region, lying on the south- 
western side of the great Laurentian watershed, follow in their contour 
its general direction of slope. The bare rocky hills forming the northern 
shore of Sand-hill Lake, seem seldom to exceed 150 feet in height, and 
the average level of the country, as seen from the lake, probably falls 
below 100 feet. The rocky substratum of the region, slopes away 
gradually toward the south-west, till in the southern part of the lake, 
but one or two, low, rounded masses, rise at all above the level of the 
