NATURAL HISTORY AND PHYSIOGRAPHY OF NEW BRUNSWICK. 
317 
some of the worst rapids on this part of the river; but below, as far 
as Nepisiguit Brook, the terraces are very few and low. It seems 
clear, then, that this terrace and the boulders are remnants of a great 
Glacial dam at this point. That there was such a dam somewhere 
along this river is mentioned by Mr. Chalmers, but he puts it at the 
Narrows, a long distance below, an impossible theory as it seems to 
me, because of the different character of the terraces above and below 
this point. Below Nine-mile Brook, to near the Narrows, the valley 
becomes very narrow and the banks almost precipitous, so that one is 
inclined to consider this part of the river as post-Glacial. It is not, 
however, a true post-Glacial gorge, and the low terraces are against 
this view, but certainly it must be geologically one of the newest parts 
of the river,* indeed excepting only the post-Glacial gorges at the 
Narrows and at Grand Falls, the very newest part of the whole river. 
At Nepisiguit Brook, half a mile above the Narrows, the valley 
suddenly opens out and assumes the shallow, ancient appearance which 
it holds to its mouth. This part of the river, from Indian Falls to 
Nepisiguit Brook, is very puzzling, and I have not been able to form 
any clear idea of its probable mode of formation. Considering, how- 
ever, the general parallelism of Forty-four-mile, Forty-mile and Nine- 
mile Brooks with the branches of the Northwest Miramichi, together 
with the extremely limited extent of the drainage basin of the river 
on the south side, it seems very probable that the aforementioned 
streams were formerly branches of the Miramichi, which have been 
captured to the Nepisiguit by the gradual backward extension of the 
lower Nepisiguit,! though I can form no idea as to the influences 
determining this peculiar extension. Certainly all this part of the 
main Nepisiguit must be comparatively new, much newer than the 
upper part of the river. J 
* This part of the river crosses a band of rocks considered by Ells to be probably pre- 
Cambrian, but this fact does not in itself explain the peculiar newness of this part of the 
valley. It is just possible that an older valley exists between Nine-mile Brook and the 
river below Nepisiguit Brook, or even between Nine-mile Brook and just above Grand Falls. 
t One must not, however, put too great faith in the accuracy of the maps, for they 
have many errors. All such studies as the present are greatly hampered and rendered 
uncertain by the absence of a good map of the province based upon a unified survey, 
% It is of course possible that the branches may have connected with the Miramichi, 
but by routes very different from those shown by the shading on the map. The other 
possibility is that there never was a connection of this river with the Miramichi, but the 
main river is a part of an ancient stream flowing eastward from the edge of the pre-Cambrian 
highlands across the Cambro-Silurian region into the Carboniferous sea ; but the new part 
between Nine-mile Brook and the Narrows is very difficult to explain on this basis. 
