NATURAL HISTORY AND PHYSIOGRAPHY OF NEW BRUNSWICK. 
181 
ian River. This conclusion is fully sustained by the studies of 
1903, described in a later note (No. 77), but with a modification 
there indicated, namely, it was not originally the entire South 
Branch which formed the head of this river, but the part of it 
from its mouth to near Paradise Pond, together with the con- 
tinuation of that valley southward, the latter part being now occu- 
pied by the head of the Northwest Miramichi. The upper part of 
the present South Branch seems originally to have formed the head 
of a distinct river, the Nictorian River (Note 77), though it early 
became united with the present South Branch. These relations 
are shown by the shaded bands on the accompanying map. There 
are still two points to be determined in this connection ; first, as 
to the location of the head of the easterly branch, which was 
possibly in the narrow-walled valley a little above Mount Denys, 
(or perhaps nearer Indian Falls), and second, the period at which 
these waters were turned down the Nepisiguit, whether in glacial 
or pre-glacial times. So low is the drift barrier separating Por- 
tage Brook from Upsalquitch Lake (Portage Brook could now 
be turned into Upsalquitch by an excavation of only a few feet), 
that I am inclined to think these upper Nepisiguit waters must 
have flowed into the Upsalquitch up to the glacial period, and 
that it was some form of glacial action which produced the 
change.* 
The present Upsalquitch is the only considerable river of the 
Province having a northerly flow, a phenomenon with a well- 
known glacial explanation (viz., the tendency of the southward 
advancing, and of the northward retreating, ice-sheet to dam up 
northerly flowing rivers and send their waters in southerly direc- 
tions). It issues from the deep valley of Upsalquitch Lake over 
a typical drift dam. Immediately, the valley opens out greatly, 
and the river, here very small, wanders about with a gentle cur- 
*The change could not have been simply due to the damming of the Portage Broolc- 
Upsalquitch Valley by glacial drift, for this would necessitate a post-glacial outlet to the 
eastward, which does not exist. The change appears rather to have been of an “inter- 
glacial ” character, such as is being found to account for the peculiarities of valleys in New 
York State. Another possibility is that the advancing ice-sheet coming from the north, at 
the opening of the Glacial period, blocked and dammed the Portage Brook valley, sending 
the upper waters over the lowest outlet, which happened to be at the eastward, and that 
those waters kept that direction as a sub-glacial and inter-glacial river, thus cutting out a 
■valley much larger and riper than a post-glacial valley could be. 
