File:The Quarterly journal of the Geological Society of London (12684836304).jpg

1852.. DAWSON — NEW RED SANDSTONE OF NOVA SCOTIA. 399
found no fossils in these shales ; but in their continuation eastward,
at Noel, they contain a Lepidodendron identical with one found in
the similar shales of Horton Bluff. The position, as well as the
mineral character of these shales, leaves no doubt that they belong
to that remarkable band of pseudo-coal-measures found in the lowest
part of the Lower Carboniferous series at Horton, Windsor, Rawdon,
Five Mile River, Antigonish, Strait of Canseau, &c., and described
in papers formerly read before this Society *. Succeeding these black
shales, in ascending order, the Lower Carboniferous rocks are seen
in the above section, fig. 1. These beds probably underlie the
gypsum and limestone which would recur on the north side of the
anticlinal formed by the black shales if the section extended suffi-
ciently far. Before reaching the extremity of the point on the east
side of the river, however, the edges of the beds sink to the level of
the sea, and the lower members of the New Red are unconformably
superimposed upon them. It is a somewhat instructive fact that
the beds of the underlying series are at this place both redder and
softer than the overlying New Red Sandstone.
Fig. 2 shows the appearance of the section on the west side of the
mouth of the river, as viewed from a distance.
Fig. 2. — Section on the West side of the Mouth of Petite River.
a. New Red Sandstone. b. Carboniferous strata.
At Salter's Head, near the mouth of the Shubenacadie, the sea-
cUff shows a considerable thickness of the New Red, which is there a
soft bright red sandstone, some of the beds containing calcareous
sandy concretions, which cause them to weather with singularly un-
even surfaces. In these respects they perfectly resemble the rocks
of the same formation seen between the Shubenacadie and Truro.
The New Red does not appear, in any part of this coast, to extend
more than between one and two miles from the shore, and in most
places its breadth is much more limited, being often only a ies^ hun-
dred feet.
When in Hants County last summer, I revisited the great mass of
gypsum at Big Plaister Rock on the Shubenacadie, described by Sir
C. Lyell, in company with whom I visited it in 1842. Since that
time a large part of the mass has been removed by the quarrymen,
and the highest part of the rock, about 100 feet in height, seemed
tottering to its fall, the excavations of the quarry having completely

• See Quart. Journ. Geol. Soc. vol. vi. p. 347 and note.