NATURAL HISTORY AND PHYSIOGRAPHY OP' NEW BRUNSWICK. 337 
in which runs the South Inlet of North Branch Renous Lake 
and other waters. It can be traced westward into the upper 
part of the Tuadook Branch of the Little Southwest Miramichi, 
as shown in an earlier note (No. 86, Bulletin XXIII, 326), and 
also eastward, though less clearly. From the South Inlet, 
and also from other places to the northward, one can see clearly 
the great abrupjt lofty slope of the edge of this plateau. This 
valley, by the way, doubtless owes its existence to the fact 
that all of this part of this country is built of intrusive rocks 
which came up in great parallel northeast-southwest ridges, 
occasionally leaving between them a line of softer rocks which 
have since eroded away to leave a cross valley, an arrangement 
which explains other valleys as well,— notably the Tuadook 
farther north, and the Main Southw'est Miramichi above Fall 
Brook. The original drainage of the country was, however, 
to the southeast, at right angles to the later-formed cross valleys, 
which explains the prevailing directions of valleys, lakes, and 
ridges. Since this part of the highlands is the part Avhere they 
slope abruptly down to the low country, the ridges left between 
the valleys project out like fingers, which end more or less 
abruptly. Jack’s Mountain is one of these fingers and others 
can be seen therefrom, looking like abrupt hills from the east- 
w'ard. Finally the ice of the Glacial Period swept the granite 
from the top of the plateau down to the low country, dropping 
it largely in the angle between highlands and lowlands, thus 
damming the valleys at that place, and bringing it to pass that 
many of the lakes lie with their heads in niches of the highlands 
and their feet in the open country. 
