DALY: PHYSIOGRAPHY OF ACADIA. 95 
If the lowland were existent in pre-Cretaceous time, it must have 
been submerged to greater or less depth during the Cretaceous cycle, | 
and sediments of that age must have been laid in the trough. While 
most of such a filling might have been removed during the Tertiary 
cycle, we should hardly expect that every trace of it would have 
vanished. Nor is it conceivable that the present surface of the low- 
lands represents down-warped or down-faulted portions of the Cretaceous 
peneplain. Neither faults nor warps would so faithfully occur only 
where the soft Carboniferous rocks appear; yet in this part of Acadia 
the Carboniferous rocks and the lowlands are coextensive. No fact 
regarding the lithology of these sediments is more strikingly brought 
home to the field-observer than their similarity to those of Triassic age 
in the Fundy trough, —a similarity which goes far to explain the long 
delay in transferring the red sandstones of Prince Edward Island from 
the Triassic to the Carboniferous division, where recent determinations 
would place them. The rocks of both periods are about equally con- 
solidated and equally resistant to atmospheric wasting. If the Annapolis 
Valley be the product of erosion in the Tertiary cycle, we must agree to 
the possibility of similarly profound dissection of the Cretaceous peneplain 
in the Carboniferous tracts. 
For these reasons, and on account of the agreement of summit-levels 
on Triassic and Carboniferous rocks at the head-of the Bay of Fundy, it 
is highly probable that the lowland surface from St. Mary’s Bay to 
Northumberland Strait belongs to one great plain of denudation dating 
from the end of the Tertiary cycle. This plain is a secondary peneplain, 
and is believed to extend over Prince Edward Island and the Carbo- 
niferous lowland of Central New Brunswick. Its longitudinal valleys 
described by Sir William Dawson are regarded as the product of adjust- 
ment. Surmounting the plain are monadnocks like Springhill (610 feet), 
Claremont Hill (565 feet), Windham Hill (600 feet) in the Cumberland 
district, Indian Mountain north of Moncton, and the 500-foot hills in 
the interior of Prince Edward Island. The Cobequid Plateau is of the 
nature of a ‘catoctin.” The steep-walled gorges through the plateau 
at Wentworth and at Halfway River are conceivably of the nature of 
“shut-ins,” and due to the erosive work of transverse streams let down 
from the levels of the Cretaceous peneplain. The latter notch was low- 
ered as fast as the soft Carboniferous rocks were removed in the lowlands 
by a stream persistent in its course until glacial times. The rock-basin 
of Folly Lake seems to show that the Wentworth notch early became a 
wind-gap during the Tertiary cycle. Chalmers (’95, p. 13) suggested an 
