HURONIAN FORMATIONS, TIMISKAMING REGION. 
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Wanapitei Area. 
For comparison of the successions found in the above-men- 
tioned areas with those of Sudbury and Cobalt districts, the 
following summary is given of the sequence found near Lake 
Wanapitei, which is fairly representative of both these districts. 
A more complete account of this area may be found in the Sum- 
mary Report of the Geological Survey, 1913. The pre-Huronian 
basement consists of an ancient complex of igneous schists and 
a probably younger, thick arkose formation (Copper Cliff for- 
mation of the Sudbury series), both of which are invaded by 
granite-gneiss. Upon a greatly eroded surface of these rocks 
lies a Huronian sedimentary series (Cobalt series). No measured 
section of the Cobalt series was obtained from this area, but, as 
indicated in Figure 3, there is a total thickness probably of 4,000 
feet, * consisting of a thick boulder conglomerate, greywacke, a 
thin band of siliceous limestone, greywacke, finely laminated 
greywacke sometimes conglomeratic, and a very thick felds- 
pathic quartzite, all in conformable relations. The quartzite 
in other localities between Lake Wanapitei and Cobalt, 
contains a banded cherty quartzite like that found above the 
upper quartzite in Bruce area. The gaps left in the geological 
column in Figure 3, as in the other columns, represent uncertainty 
regarding thicknesses, not of the order and manner of succession. 
Sills and dykes of diabase invade both Huronian and pre-Huron- 
ian rocks. 
CORRELATION OF AREAS. 
Which formations in the areas just described are to be 
regarded as equivalents, and what is the importance of the 
erosional gaps, or unconformities, that interrupt the sequences? 
To make the answer to the first of these questions free from 
uncertainty the areas selected for comparison are so close to- 
gether that there is little likelihood of the order of succession 
or the lithological characters of the formations changing suffi- 
ciently across any one interval to render correlation doubtful. 
Formations, especially distinctive ones like the limestones and 
