10 
MUSEUM BULLETIN NO. 18. 
doubtless concealed by the heavy mantle of drift and marine 
clays which covers the buried channel of the Ottawa river to a 
depth of 100 to 200 feet. 1 Nine faults are shown on the Ottawa 
sheet alone, which includes a Palaeozoic area about 16 by 22 miles 
in extent. The position of some of these faults and the location 
of the cross-sections which have been drawn are indicated in 
Figure 2. The largest of these is the Hull and Gloucester fault 
which has a maximum throw of about 1,850 feet. 2 This fault 
is the major structural feature of the Palaeozoic area south 
of the Ottawa river and can be traced for a number of miles 
east of Ottawa. Two other faults lying between this fault 
and the Ottawa river have throws which approximate 250 and 
350 feet respectively. The structural relations of these faults 
to each other and to the Palaeozoic rocks east of Ottawa are 
shown in the cross-section, Figure 4. It is due chiefly to the 
Hull and Gloucester fault that the Queenston has been dropped 
sufficiently low for a remnant of it to be preserved from erosion 
in the vicinity of Vars, a few miles southeast of Ottawa. Another 
section, Figure 3, shows the principal faults in a section running 
south from Kings mountain across the Ottawa valley west of 
Ottawa. In the vicinity of the faults the strata nearly every- 
where show strong dips, which, however, die out a short distance 
from the fractures. Elsewhere, as far east as the zone of 
Appalachian folding, the strata approach general horizontality. 
The numerous faults which cut the Palaeozoic beds of the Ottawa 
and St, Lawrence Valley province distinguish it structurally 
from the Palaeozoics of the Ontario peninsula. In the latter 
district no faults of note are known and the beds show a very 
gentle monoclinal dip to the southwest. The cross-section 
(Figure 6) which extends from the shore of Lake Erie south of 
St. Thomas to the Laurentian plateau east of Ottawa brings 
out clearly the fact that the Ottawa River valley lies in a zone 
of faulting, while the area to the southwest of the Kingston and 
Lake Nipissing Archaean shield is free from faults. The profile 
of this section was compiled from the topographic maps of the 
Militia Department and from railway surveys. The geology 
1 Idem, p. 105. 
2 R. W. Ells, Geol. Surv., Canada, map sheet 120. 
