

226 B. N. A. BOUNDARY COMMISSION. 
6., Hornblende. sehist.... ss t/sikgidiceccdivers neces Hee eee 
4; Y@llowish qdartante . 75 255 To tesa kay swels | ne yo eae ee 
GOTT Gin dnc = 039: in AE ani is ek ee ee Ba vite ts ales oe 
@ Tromstone... . sk cb aa ne ee Vdteaheaicnes aval Ge 
ar 
518. The limestone is probably altogether from the Red River region 
or northward. Nos. 3 and 4 cannot be very definitely placed either in 
the Huronian or Quartzite drift, while No. 7 almost certainly belongs to 
the latter. The introduction of the material included under No. 3, in 
such large quantity is rather anomalous. Nos. 2, 6, and probably also 
most of No. 5, are Laurentian. 
519. The prairie south of the south bank of the Souris River—which 
beyond the Second Crossing runs nearly parallel with the Line for about 
thirty miles—is for a breadth of several miles, strewn with an immense 
number of boulders. These are generally half buried in the soil, and in 
some places over extensive areas they are almost in contact. They con- 
sist mainly of Laurentian rocks, but there are also a good many of lime- 
stone, and some of the harder parts of the local Tertiary s.indstones. 
Some are of large size, though most are not over a foot or two in diame- 
ter. They do not appear to be arranged in groups, but are scattered very 
uniformly everywhere. The north bank of the river as far as I examined 
it, is characterized in the same way; and Capt. Palliser who crossed the 
country beyond it on his way to the Roche Percée, writes :—“ As we ap- 
proached this river, the ground was so covered with boulders that our 
cart could barely get along.”* The region thus evidently strewn with 
erratics, seems to be that which slopes gently toward the edge of the 
steep bank of the river. The boulders are by no means so frequent on 
the general surface of the prairie in this locality, and they would there 
seem to be covered with a finer superficial deposit, which has been 
removed where denudation has taken place. The layer containing the 
boulders, however, cannot be a thick one, as where-waste has penetrated 
to a much greater depth, in the small valleys tributary to the Souris, the 
covering of boulders is not sensibly increased. 
520. Near Wood End, 260 miles west of Red River, some good sec- 
tions of the drift oceur on the Souris. The surface of the prairie here 
rises to form a rather well marked plateau, but of small elevation, which 
may be considered as being the first ascent toward the elevated region 
of the Missouri Coteau. The underlying rocks are here of Lignite Ter- 
tiary age, and as when resting on the Cretaceous, the drift reposing on 

* Exploration of British North America, p. 48. 
