
GLACIAL PHENOMENA AND SUPERFICIAL DEPOSITS. 243 
further west, in the neighbourhood of the St. Mary River, at about the 
same elevation, Laurentian fragments were observed in certain places 
in some abundance, but were lost sight of beyond this point. The 
distance of these travelled blocks from the nearest part of the Laurentian 
axis is over 700 miles. 
562. We have here then, as closely as it can be defined in this 
latitude, the most western, and highest limit of the Laurentian drift, 
but not necessarily that attained by the waters when at their highest 
stage during the glacial submergence. Terraces, clearly implying a sea 
margin, are, indeed, found higher on the flanks of the mountains. A 
depression of the eastern region to an extent of 3,000 feet, would more 
than suffice to cover the Laurentian axis, as it is at present, and though 
in pre-glacial times its height was greater, it must have stood, at this 
stage of subsidence, scarcely, if at all, above the level of the sea. 
Glacial Action in the Rocky Mountains. 
563. In the part of the Rocky Mountains crossed by the Boundary- 
line, the effects of glacial action are very frequently apparent, though no 
glaciers, properly so-called, now exist. The streams flowing from the 
mountains, cut through banks of well-rounded gravel, and small boulders, 
similar in general character to that which has been called Quartzite drift. 
The stones were not observed to be glaciated. 
564. Waterton, or Chief Mountain Lake, occupies a deep valley with 
exceedingly steep and precipitous sides, which opens northward. Its 
height above the sea is 4,213 feet, and it is about ten miles in length, and 
fills the valley from side to side, with an average width of about three- 
fourths of a mile. Near its northern end, is a'collection of rounded and 
hummocky hills, which are evidently composed of moraine matter, and 
show rocky fragments of all shapes and sizes; where these are not con- 
cealed by softer material, or the luxuriant vegetation of the region. The 
havd limestone of series B., where it crosses Waterton Lake, though not 
observed to show glacial markings, has the general rounded outlines 
produced by ice action. There is thus evidence that a great glacier 
pushed northward down the valley of the lake, and debouched upon the 
plain, being fed, no doubt, from the numerous smaller transverse ravines 
which enter it. 
965. Without going into detail in every case, it may be stated, that 
in all probability every valley of importance was in like manner occupied 
by streams of moving ice ; and to their moraines much of the contour of 
