NATURAL HISTORY AND PH YSIOCJRAPH Y OF NEW BRUNSWICK. 
445 
Island. As to the age of this hinge line, we are at present in doubt, 
but it is likely that further studies will determine it, and tentatively 
we may assign it to the period of the uplift of the Cretaceous pene- 
plain, though it may be a cycle later. 
It remains to notice the warpings parallel with the Appalachian 
trend.* As already mentioned, one of these probably helped to form 
the Bay of Fundy ; the Southern Highlands owe, probably, a part of 
their height to an upwarping, while the Carboniferous plain along 
the Richibucto-Grand-Lake-Oromocto axis, and again in the part 
occupied by the Miramichi river, represents either one, or, perhaps, 
more, syncling.1 downwarpings. An extensive upwarp raised the 
Central Highlands and the great Silurian plateau, and these Central 
Highlands perhaps owe their height to the fact that they stand at the 
intersection of the two great lines of upwarping (the one parallel with 
the Appalachian trend, and the one at right angles), while on the 
other hand the great depression of the region where the branches of 
the Southwest Miramichi come together (and, indeed, the peculiar 
manner in which they come together), may be due to the fact that 
that region is at the intersection of two lines of synclinal warping. 
If the cross warping parallel with the great hinge line followed the 
elevation of the Cretaceous peneplain, probably the longitudinal warp- 
ing accompanied the elevation of the Tertiary peneplain, but the 
reverse may be the case. 
In a general way, then, Daly’s theory applies well to Xew Bruns- 
wick, and it will form a valuable working hypothesis. Much investi- 
gation will, however, be needed before it can be either on the one 
hand applied in detail, or on the other, disproven. 
50. — The Physiographic History of the Miramichi River. 
(Read June -1, 1901.) 
In earlier notes of this series (Nos. 33, 37, and 45) the attempt 
has been made to trace the probable physiographic evolution of the 
Nepisiguit, Restigouche, and Tobique rivers; a similar treatment of 
the Miramichi here follows. It is, of course, plain that the deductions 
* It is of interest to notice that the axes of these warpings and of the crystalline rocks 
do not coincide. Thus the axis of the crystalline rocks is on a line drawn from Belledune 
point to the mouth of Eel Rii?er, in Oarleton County, but the axis of the greatest upwarping 
as on a line from Mars Hill to Miscou Island. Thus the branches of the Southwest 
3Iiramichi are strictly parallel with the warpings, though not with the crystalline rocks. 
