JPUBILICA TIONS. 
Summary of Current pre-Cambrian North American Literature .* 
Smith,? in 1892, reports on the Archean Rocks of Hunters Island 
and adjacent country. The rocks are divided into Laurentian and 
Huronian, and the latter subdivided into Coutchiching and Keewatin. 
The main occurrences of the Laurentian rocks are the Kawagansikok, 
Poo-Bah, Hunters Island and Saganaga areas. The Kawagansikok 
granite is in places fine grained and nearly devoid of mica and horn- 
blende; in other places is a muscovite-granite ; in others is garnetifer- 
ous granite-gneiss. The rock is frequently cut by coarse pegmatite 
veins. The Poo-Bah area is usually a coarse hornblende syenite, but 
in places it merges into a finer grained hornblende-granite. The 
Hunters Island rocks are usually biotite-granites, but the biotite is 
often replaced by, or associated with muscovite, hornblende or chlorite. 
At Agnes Lake angular fragments of Mica-schist or gneiss are found in 
the granite. At various places occur hornblende-granites. There are 
other isolated areas of granite which break through the Coutchiching 
rocks which cannot certainly be said to be of Laurentian age. The 
granites as a whole usually have a foliated character. 
The Coutchiching series covers a large area in the northwestern 
part of the district, and several small areas are found to the eastward. 
The Couchiching rocks are usually mica-schists. In general their 
schistosity is parallel to that of the granites, but at Conmee Lake there 
is a discrepancy between the two which may indicate a structural 
unconformity or a fault. [he mica-schist is cut by granite apophyses 
at various places. If foliation is taken as thickness the series would 
vary from 1.386 miles to 5.548 miles. However the mica-schists are 
regarded as repeated by folding. Although having isoclinal dips, there 
is a considerable variation which may indicate such folding. 
Keewatin rocks are confined to the southeastern part of Hunters 
Island. They consist of quartzites, soft gray schists, quartz-porphyries, 
* Continued from p. 236, Vol. III. JouURNAL OF GEOLOGY. 
? Report on the Geology of Hunters Island and Adjacent Country, by W. H.C. 
SMITH. Ann. Rep. Geol. Sur. of Canada, for 1890-1, Vol. V., Part 1, G., pp. 5-76, 1892. 
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