356 DESCRIPTION -OF THE COUNTRY 
ceous shale (No. 334) comes up, and extends for some distance up the river, 
making rapids. It is occasionally amygdaloidal, and, in some places, of a steel- 
gray colour, the latter colour prevailing as the river is ascended. This rock, 
in consequence of the river following the bearing of the ridge for some distance, 
forms the channel to a point estimated to be two miles from the Lake. About 
half way to this point, there is a fall of thirty feet over a dike of greenstone, 
(No. 337.) In contact with the dike are some beds of greenstone porphyry. 
(No. 336.) At this place there is an anticlinal axis. No. 338 is seen in the 
banks of the river overlying No. 334, and a little further on, an altered conglo- 
merate makes its appearance, presenting, at some points, a brecciated aspect, but 
composed principally of rounded pebbles. The conglomerate and shale dip north- » 
west 17°. About one hundred yards beyond this point, there is interposed between 
them and No. 334, a very soft, friable amygdaloid (No. 339), with occasional bands 
of a calcareous rock, bearing considerable resemblance to chert (No. 340) running 
through it in the plane of stratification. It is hard, compact, of a light yellow 
colour, and without cells. The cells of the amygdaloid are all compressed and 
elongated in one direction, and are filled with thalite and other minerals. This 
rock is very decomposable when exposed to the weather, degenerating into a bluish- 
coloured clay ; and seems, in fact, to be nothing more than clay-beds, which have 
become indurated, and assumed the amygdaloidal character, under the influence of 
the neighbouring igneous rocks. The thickness of this rock, including the overly- 
ing conglomerate, as exposed in the river-banks, I estimated to be two hundred 
feet. Resting upon these rocks, at the point where the amygdaloid is best exposed, 
is a deposit of drift, marl, and red clay, about two hundred feet in thickness. 
Beneath the amygdaloid, and emerging, as the river is ascended, is a metamor- 
phosed shaly sandstone (No. 341), of a brick-red colour, with a trappous look, and 
an effort towards a columnar structure. It contains small cells filled with laumo- 
nite, and alternates with beds of a dark-gray altered slate, showing the lines of 
cleavage and of stratification with the greatest distinctness. It has a nearly ver- 
tical dip. 
About three hundred and fifty yards beyond the point where the metamorphosed 
sandstone (No. 341) shows itself, is a greenstone uplift, producing a perpendicular 
fall of about twenty-five feet. At this place the slates are much contorted, and as- 
sume still more the appearance of trappean rocks. The greenstone (No. 343) is 
rather fine-grained, and contains seams of chlorite, occupying fissures, which appear 
to have been formed by some convulsion, long subsequent to the upheaval of the 
rock. 
Two rods above the Falls, on the south side of the river, a vein five feet in 
width, composed principally of caleareous spar, with seams of quartz, is seen run- 
ning northwest and southeast. It also contains traces of green carbonate of copper 
(No. 344). 
A few yards above this is another fall, or rather a precipitous rapid. The river 
at this place is not over three feet in width, the stream running through a channel 
made in the course of a decomposed vein which traversed the greenstone. A 
