28 Captain Bayfield on the 
How then can it be reasonably asserted that the sandstone 
is older than those rocks from whose partial ruin it is de- 
rived ? 
As in no instance, to our knowledge, has a mass of shell 
limestone beeh found in this sandstone, it appears tolerably 
certain that the great convulsion which formed the materials 
for this extensive deposition took place at a period previous 
to the formation of the Lake Huron limestones ; and this de- 
duction is rendered still more probable from the boulders of 
shell limestone which are found, among others, on the beaches 
in various parts of the lake, but principally in the north-eastern 
parts of it. These, we have every reason to believe, have come 
from the north-east ; for we are in possession of specimens of 
this limestone, of the same age as that of the Manitoulins? 
from the vicinity of the height of land between the Michipi- 
coten river and that which enters Hudson’s bay at Moose fac- 
tory. We have also seen large masses of foliated gypsum 
from the same part of the country.* 
It isa fact not generally known, that Captain Parry, R. 
N. found limestone containing similar petrifactions as or- 
thocerz, fossil corals, &c, near the north eastern extremity of 
this continent.t The Boulders of shell limestone which we 
have mentioned, appear to have been brought to Lake Supe- 
rior by the same great torrent or rush of water, from the 
north or north east, which has strewed all the southern shores 
of the lakes with rolled masses of the older rocks ; most of 
which can be traced to their parent rocks, on the northern 
coasts ; and which must have taken place subsequently to the 
deposition of the sandstone. 
Having thus slightly mentioned that which probably has 
been, we shall next give a brief account of operations at pre- 
sent going on in the lake—operations arising from local cau- 
ses 
a nh og ee 
*These were given me by J. Haldane, Esq. late chief Factor 
Hudsou’s Bay Company. 
+ See Capt. Pari ys second voyage. 
