4 
MUSEUM BULLETIN NO. 8. 
formations in Timiskaming region is to connect these three dis- 
tricts by study of the intervening areas, to determine thereby 
the equivalences of the three systems of names, and to select 
from them a single system that will serve for the whole region. 
The interval between Cobalt and Sudbury districts was 
covered in 1913 and the correlation thus made possible was given 
in the paper already referred to. During the summer of 1914 
an effort was made to correlate Cobalt and Sudbury districts 
with the Original Huronian district, the results of which are set 
forth in this paper. All this work has been done in accordance 
with instructions from the Geological Survey. Estimates of 
thicknesses given in this paper are based upon measurements 
made in the field, but, since indirect methods of measurement 
had to be used in most cases owing to the low relief of the country, 
the results are not to be regarded as exact. 
GEOLOGICAL DESCRIPTIONS OF AREAS. 
The whole interval of 125 miles between Sudbury and the 
best known part of the Original Huronian district could not 
be examined in one season, so a chain of five smaller areas, 
spaced at such intervals across this distance that comparison 
of the formations in one with those in the next could be reliably 
made, was selected for study. The relative positions of the 
areas are shown in Figure 2. In order from west to east they are 
named the Bruce, Blind River, Whiskey Lake, Espanola, and 
Round Lake areas. The unexplored intervals between Bruce, 
Blind River, and Whiskey Lake areas are only 10 and 15 miles 
respectively and correlation across them was accomplished easily. 
A gap of 27 miles separates Whiskey Lake and Espanola areas, 
but this was partly bridged by incidental geological observations 
along the Canadian Pacific railway. Likewise the gap of 24 
miles between Espanola and Round Lake areas was filled in by 
a study of the shore geology of Penage lake. 
A brief summary of the geology of each of these areas is 
given below and the geological sequence and principal structural 
features of each are represented graphically in Figure 3. 
