
2292 B. N. A. BOUNDARY COMMISSION. 
Also many splinters of Pembina Mountain shale, being fragments of 
disintegrated pebbles. 
507. The limestone resembles that of Fort Garry, of Lower Silurian 
age, but is also indistinguishable from the Devonian limestone oceurring 
north of that place, and from the Upper Silurian debris already mentioned 
as appearing in the vicinity of the Lake of the Woods. The fragments 
included under No. 2, are no doubt Laurentian. Nos.3 and 4 are also pro- 
bably Laurentian. No. 5, derived from the limestones. No. 6 probably 
Huronian. Nos. 7 and 8 are local. The great quantity of limestone here 
present is remarkable, but will be found to be characteristic of many 
other localities. 
508. In this vicinity, and westward toward Turtle Mountain, the un- 
dulations of the prairie become more striking and apparent, and often 
form rather steep-sided little hills. These are also frequently grouped 
together in miniature ranges, or form more or less definite lines across 
the plain. The whole of these surface features, so far as could be ascer- 
tained, are due to the arrangement of the drift deposits. It is also ob- 
servable, that wherever the ground rises slightly to form elevations of the 
kind mentioned, basin-like swamps, and small ponds, are almost certain 
to be found. They do not therefore, as a rule, occur on the lowest parts 
of the prairie surface, but rather the reverse. It is also a curious fact, 
that the hill-tops and swamps should be often equally characterized by | 
the abundance of boulders, while the intermediate slopes, and the general 
surface of the prairie, are almost free from them. A similar observation 
has also, I find, been made by Prof. Bell in a part of the second prairie 
steppe, considerably further north. As already mentioned, sub-aerial 
denudation has taken place to a very slight extent, and the association of 
these features, would appear to indicate slight erosion by currents, 
while submergence was still complete. These might easily scoop out 
hollows in some places, leaving the boulders and heavier masses ; and at 
the same time be removing the finer debris from the exposed surfaces of 
hillocks. 
509. An examination of the constituents of the drift about ten miles 
east of Turtle Mountain, and seven north of the Line, gave the following 
result :— 
1; White limestane. os ojo bie d oa Minswdt es oben se eee 45.63 
2 Granitic and gusiWMiDTOCKBy «xicngh x 5 istesann +\s,9:7 hcg Soles Ca 27.18 
3. Dark, grey and greenish, compact or schistose altered rocks 16.50 
4, Quartz and quarhathees'siiutcws cus idigerelsw ice pale mene 6.80 
5. Orystalliae diorite.: .::'.,<.»:=,s.5:0\s,0'5 ws ae hss» 5, ee ee 1.94 
6. ‘Reddish decomposed TOCK. 1:01.04. 0ss cise » ficaste civcmanign «pa pleee 
7. Fragments of nodules (probably Cretaceous)............ «. 0.97 
