NATURAL HISTORY AND PfI YSIOGRAPHY OF NEW BRUNSWICK. 467 
Big Lakes there is only a few feet of elevation obviously composed of 
boulders, while just to the east of Holmes, is another small lake, and 
eas^t of that comes Pear Lake emptying into Renous, all with insignifi- 
cant elevations, apparently solely of drift, between. 
The outlet from Big Lake is a very rough stream flowing over 
trains of immense boulders (and according to Hind, over schistose 
ledges), with occasional quiet pools to the junction with the outlet of 
Jacks Lake, below which it continues, though with more frequent 
pools, but with many bad boulder rips, to the junction with the 
main stream. Just above the junction it breaks up among islands, 
and enters the main stream by two or three inconspicuous mouths, 
even the principal one of which is so small that it resembles a small 
brook. It is, no doubt, for this reason that Berton missed it in 
1838, as would anyone unaccompanied by guides acquainted with this 
peculiarity. This part of the river is so narrow and shut in by woods 
that views of the hills are impossible, though the actual banks are 
everywhere low. It appears to me to be a new valley made across 
great beds of glacial drift, and prevented from cutting deeper by the 
great size and hardness of the boulders of which that drift is largely 
composed. 
Physiographic Origin. — We turn now to the very interesting 
question as to the mode of origin of these lakes. First, as to the 
origin of the valleys in which they lie. It is plain that the Big Dead- 
water, Jacks Lake, Big Lake and Renous valleys, all approximately 
parallel, have been cut deeply (at least more than 500 to 600 feet) 
into the surface of an ancient peneplain, which still exists in great 
perfection immediately to the westward of them, and of which facets 
are found in Braithwaites Mountain, and in the range running eastward 
from Lyles Mountain. The lesser elevations between the other valleys 
are due, of course, in part to the greater proximity of those valleys to 
one another, leading to the interference of their rims and the more 
rapid erosion of the intervening ridges. Their general northwest and 
southeast direction was, no doubt, determined by the slope of the 
peneplain at the beginning of the present cycle of elevation and 
erosion. The valley from the Crooked Deadwater to the Big Lake 
has a difiFerent direction, but its consideration must await further 
knowledge. 
