NATURAL HISTORY AND PHYSIOGRAPHY OF NEW BRUNSWICK. 431 
its valley at its mouth, and from the mountains near Nictor Lake. 
The Main Tobique has cut from three or four to six or seven hundred 
feet into the Silurian plateau in a winding rock-walled but well- 
matured valley, provided frequently with extensive intervales. Its 
age must therefore be at least that of the peneplain into which it 
has cut, which tentatively we may assume with Daly as of Tertiary 
age, and it may be very much older. The question now arises as to 
why it flows southwest into the St. John, instead of northeast into 
Bay Chaleur, as the Right Hand Branch doubtless once did '? There 
can be no doubt, I believe, that the same causes sent it southwest (in 
fact, originated it) which turned the St. John from its proper course 
into Bay Chaleur and sent it through the highlands southward, a 
peculiarity which has greatly complicated not only the physiographic, 
but also the human history of this region.* 
There are three possible explanations of the age and cause of this 
change of course of the St. John and origination of the Main Tobique. 
First, it may be co-temporaneous with the beginning of the elevation 
of the newest peneplain. In this case we must hold that the pene- 
planation (Tertiary 1) of the Silurian plateau was effected by rivers 
flowing into Bay Chaleur, and that all through this period the St. 
John, the Right Hand Branch and the Nictor-Nepisiguit thus emptied 
while the Main Tobique did not exist. With the beginning of the 
elevation of this peneplain, however, inaugurating the present cycle, 
and allowing the rivers to cut their present deep channels, that eleva- 
tion would have commenced, and must been comparatively rapid on 
the northward, thus turning back the slow-moving St. John, Right 
Hand Branch and Nictor from their courses into Bay Chaleur, and 
throwing their waters southwest where they would accumulate, perhaps 
in a huge lake, until this reached the height of the lowest point in the 
highlands, when they would escape southward, thus originating the 
course of the present St. John and the Tobique. The Main Tobique 
would therefore have originated by the turning southwest of the drain- 
age of the Right Hand Branch, while the Mamozekel, similarly 
originated by the same turning of the Nictor-Nepisiguit waters, \/hich 
as will presently be shown, formerly emptied by the Mamozekel. 
Both Main Tobique and Mamozekel would follow the trough between 
this uplift on the north and the higher land on the southeast. On 
* Particularly in connection with political boundaries, as I shall show in a later note. 
