GEOLOGY OF THE WESTERN DISTRICTS OF CANADA. 507 
canal, enormous quantities of material were thrown in and disappeared, 
producing no effect in formimg a bank, but forcing up the soft 
material in the original bottom of the marsh, to a considerable extent 
and height above the surface. This affords a good illustration on a 
small scale, of what the geologist often finds on a large seale, and 
may be puzzled to account for; I refer to the displacement of strata, 
formed in horizontal position and thrown up into a highly inclined or 
even vertical position. 
Waterlime and Ochre.—Before noticing the superficial deposits of 
this region, I shall direct attention briefly to the waterlime and ochre 
beds of Thorold, which are somewhat extensively worked for com- 
mercial purposes, and occur about three hundred feet above the level of 
the Lake, and close on the line of the Welland Canal at Thorold. 
The waterlime deposit consists of a series of thin layers (each layer 
not exceeding eight to ten inches thick) in all about three and a half 
to four feet thick, of very hard compact dark blue limestone, corres- 
ponding in position and probably identical with the Clinton group. 
These beds are in some places a perfect conger’es of large bivalves» 
called Pentamerus obdlongus, some of them measuring three and a 
half to four inches across, while the partings of the beds are beauti- 
ully marked with fucoids of various species. The limestone from 
this bed, when calcined and ground to powder, forms an hydraulic 
cement of the best quality; owing this peculiar property to the 
presence of a large proportion (over ten per cent.) of silica or silicates. 
Immediately underlying and overlying this bed, are thin layers of a 
softer stone, which, when calcined and ground, forms an excellent drab 
coloured pigment; a rich brown paint, said to be fireproof, is also 
manufactured at Thorold, from material found in the same quarries. 
Whether these peculiar products extend far to the east or west of the 
localities where they are at present quarried, I am unable to say ; but 
at Rochester there occurs an iron ore bed at the same place in the 
series, and Dr. Mack of St. Catherines has ascertained that the stone 
from the drab ochre bed contains forty per cent. of iron. 
Superficial Deposits.—I1 shall now, as briefly as the subject will 
admit, direct your attention to the superficial deposits of this region, 
and the proofs of glacial action which they afford. It is now pretty 
generally conceded, and in fact cannot on any reasonable ground be 
denied, that the thick deposit of clay, sand, gravel and boulders which 
covers the Western districts of Canada, (in many places upwards of 
