THE ORDOVICIAN ROCKS OF LAKE TIMISKAMING. 3 
FIELD WORK AND SUMMARY. 
During the last week of October 1914, the writer spent three 
days making a reconnaissance stratigraphic study of the Palae- 
ozoic rocks of the northern end of Lake Timiskaming. The 
following localities were visited: the dolomite outcrops immed- 
iately west of Haileybury ; the outcrops on the beach between the 
wharf at Haileybury and Moore creek \\ miles to the north; 
the east side of Wabi or Dawson point; Chief island; the west 
side of Mann island ; and Farr or Percy island. 
As determined from fossils collected at the above localities, 
the dolomites west and north of Haileybury are of Black River 
age; the upper strata of Mann island and the top of Farr island 
belong near the base of the Niagara; the Dawson Point section 
includes besides undetermined beds at the base, the Niagara 
from its base to the horizon of numerous corals; Chief island 
contains in the patches of limestone resting upon the Huronian, 
representatives of both Niagara and Trenton rocks; a limited 
area of Silurian strata occurs north of the wharf at Haileybury; 
and the green calcareous shales making up the lower part of the 
section at the northwestern end of Mann island and probably 
concealed by talus on the eastern side of Dawson point, must 
be between Black River and Niagara in age. 
DETAILED STATEMENT. 
The best exposures of Ordovician strata are those in the 
vicinity of Haileybury. At the western edge of the town a 
12-foot section is exposed in Farr’s quarry from which building 
stone was taken for the Holy Cross cathedral and other buildings 
in Haileybury. As is the general rule with the Palaeozoic strata 
of Lake Timiskaming, the beds are nearly horizontal. The 
dolomite is light grey In colour, weathering buff, and occurs in 
beds averaging about 1 foot in thickness. According to an 
analysis made by the Bureau of Mines 1 of Ontario, this dolomite 
contains 29*50 per cent lime and 21*59 per cent magnesia; and 
therefore, approaches a true dolomite in composition. 
1 Report of the Bureau of Mines, Vol XIX, Pt. II, p. 107. 
