1907-8.] THE GEOLOGY OF THE LAKK WENDIGOKAN REGION. 351 
small grains and many very small pieces of feldspar. The arkose bands 
show distinct angular fragments of quartz, pieces of feldspar, much pyrite, 
chlorite and fine-grained material. The bands of slate and arkose vary 
greatly in width, some being as much as three-quarters of an inch in 
width, while others are extremely narrow. 
There are, besides those associated with the slates, some arkoses which 
in the field have been placed with the schists because of their schistose 
condition and the impossibility of separating-them from the schists, but 
their age would place them with the arkoses of the Huronian. 
THE GREEN SCHISTS. 
These very old rocks are green from the presence of chlorite and 
secondary hornblende. Their origin is partly from sheared greenstone 
and probably partly from ash rocks and other volcanic detrital materials. 
They do not now possess their former constituent minerals and are en- 
tirely unsuitable for study in thin section. 
On the portage between Lake Corrigan and the small lake to the 
east there is an old hornblende schist green with chlorite and containing 
much calcite in the cracks. Along the southern side of location HF20, 
there is a distinct hornblende schist of which quartz and hornblende are 
the chief constituents, and south of the northeast corner of the same 
claim there was taken a specimen of sheared porphyrite which had con- 
tained large cystots of plagioclase. Farther to the south again a large 
schist hill about too ft. high has originated by the shearing of a hornblende 
porphyry. . 
No estimate of the thickness of these rocks can be formed.. The dip 
is usually about 90 degrees, but in the southern part of the region it is 
nearly 70 degrees southward. The strike in the southern part is about 
70 degrees but about 600 paces east of the southeast corner of location 
HF31 the strike changes from 70 degrees to about 95 degrees and this 
strike is common in the northern part of the region. 
THE CARBONATE SCHIsTs. 
The name carbonate schist is applied to those schists which are 
distinguished by their quartz crystals, greatly weathered condition, and 
yellowish brown colour. They are sheared rock containing considerable 
carbonate and oxide of iron and correspond closely to the Wawa tuffs 
of the Michipicoten region.* In the Wendigokan district it is impossible 
* Bureau of Mines Report, 1902, ‘‘ Michipicoton Iron Range.” 
