Mesozoic and Cenozoic Geology and Paleontology. 207 
envelope detached particles of sand, small pebbles and aggregations of 
particles of sand. Above the fine stratified clay, yellow clay and un- 
stratified sand occur. ? 
Bowlders are found on the Qu’Appelle and its affluents, below the 
Moose Woods, and north of the Assiniboine, measuring from 10 to 25 
feet or more in diameter. 
In Lake Winnipeg, ice every year brings vast bowlders and frag- 
ments of rock of the Laurentian series, which occupy its eastern shores, 
and distributes them in the shallows and on the beaches of the 
western side. In Lake Manitobah, long lines of bowlders are accumu- 
lating in shallows and forming extensive reefs; the same operation is 
going on in all the lakes of this region, and is instrumental in 
diminishing the area of the lake in one direction, which is probably 
compensated by a wearing away of the coast in other places. 
A remarkable beach and terrace, showing an ancient coast line be- 
tween Lake Superior and Lake Winnipeg, separates Great Dog from 
Little Dog lake on the Kaministiquia canoe route. The Great Dog 
portage, 55 miles from Lake Superior by the canoe route, rises 490 
feet above the level of the Little Dog lake, and the greatest elevation 
of the ridge can not be less than 500 feet above it. The difference be- 
tween the level of Little and Great Dog lakes, is 347.81 feet, and the 
length of the portage between, one mile and 53 chains. 
The base of the Great Dog mountain consists of a gneissoid rock, 
supporting numerous bowlders and fragments of the same material. 
A level plateau of clay then occurs for about a quarter of a mile, at an 
altitude of 283 feet above Little Dog lake, from which arises, at a very 
acute angie, an immense bank or ridge of stratified sand, holding 
small water-worn pebbles. The bank of sand continues to the sum- 
mit of the portage, or 185 feet above the clay plateau. East of the 
portage path the summit is 500 feet above Little Dog lake. 
. Here we have a terrace 500 feet above Little Dog lake, or 863 feet 
above Lake Superior, or 1,463 feet above the sea. Another beach or 
terrace occurs at Prairie portage, 104 miles by the canoe route from 
Lake Superior, 190 feet above Cold Water lake, or 900 feet above Lake 
Superior, or over 1,500 fect above the sea. 
In the valley of Lake Winnipeg, the first prominent beach or terrace 
is the Big ridge. Commencing east of Red river, a few miles from the 
lake, it pursues a southwesterly course until it approaches Red river, 
within four miles of the Middle settlements; here it is 674 feet above 
the prairie; on the opposite side of the river, a beach on Stony moun- 
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