158 NOTICES OF THE MEETINGS [March 19, 
1. The Metamorphic rocks, with the exception of Quartzite and 
Jasper, are the oldest in the lake, and support great sheets of the 
abovementioned sandstone unconformably; all these rocks being 
upheaved and altered by the intrusion of igneous rocks in instances 
innumerable. This group of rocks are entirely destitute of the traces 
of animal life. 
The country they occupy on the south shore, with a general 
NNW. dip, may be best described as a rough table land of the 
various slates, out of which short hills of granite, gneiss, trap, &c. 
emerge in great numbers, with an almost constant east and west 
direction. 
On the east and north shores the metamorphic rocks have a W. 
and WSW. strike, when visible. The slates of the north side of 
Michipicoton Bay ran WNW., NW.., and N. 
The Jasper and Quartzite are merely altered sandstone and there- 
fore younger than the other rocks of this group. 
2. The Aqueous Rocks. The youngest of these is Calciferous 
Sandstone. It exists as a broad band on the south-east shore, resting 
on the sandstone soon to be noticed. It is highly magnesian and 
siliceous in parts. A patch of it in Grand Island contains shells. 
(Logan.) 
The Cambrian Sandstone seems to be the floor or basement of 
nearly all the lake, for the following reasons :— 
‘1. Wherever it occurs, whether in immense sheets on the east 
and south shore, or in smaller areas on the north coast, it 
invariably dips towards the centre of the lake. 
2. It can be recognised, paving the lake for some miles from the 
main in many places. 
3. The soundings of Captain Bayfield exhibit, for large spaces, the 
uniformity of level to be expected from the presence of hori- 
zontal strata. 
4. Because it constitutes Caribou Island, 40 miles from the nearest 
main land. 
This sandstone is very ancient; and is supposed by Mr. Logan 
to be Cambrian on the north shore and lower Silurian on the south — 
a supposition, the latter clause of which, though extremely probabie, 
is not yet established. 
It has no fossils; but its ripple marks, impressions of rain-drops, 
and sun-cracks, are plentiful and perfect. 
It is more commonly red, and is composed of the débris of gra- 
nitoid rocks, in nearly horizontal strata, except near intrusive rocks, 
when it rises to an high angle, hardens, and even passes into true 
Jasper, porphyry, gneiss or quartzite. There is reason to think 
that this sandstone is interleaved with trap. (A Landscape was ex- 
hibited of the Sand stone Rocks, south shore.) 
