190 CRUISE OF THE NEPTUNE 
archaean. 
Hudson Bay and Hudson Strait. 
The territory comprised in this group includes the islands 
of Southampton, Coats, Nottingham, Salisbury, Charles and 
Resolution, along with the shores of the northwest part of 
Hudson bay, and the south shore of Hudson strait. 
The geological information concerning this group obtained 
prior to the present voyage- is contained in the reports of Dr. 
Bell, Tyrrell and the writer. 
Crystalline gneisses, schists and granites occupy the eastern 
and northern parts of Southampton, extending northward from 
Seahorse point to Frozen strait at the northern end of the 
island. The rocks near the junction of the Archaean with the 
Silurian at Seahorse point are largely a very quartzose, light- 
gray mica-gneiss, associated with bands of rusty- weather ing, 
fine-grained mica-gneiss holding graphite in small flakes, the 
rusty colour being due to the decomposition of small grains of 
pyrite disseminated through the rock. This rusty gneiss closely 
resembles that found in the vicinity of Cape Wolstenholme at 
the entrance to Hudson strait, and both appear to be similar to 
the sillimanite gneiss of the Grenville series of southern 
Canada. Both of the above rocks are cut and twisted by masses 
of a coarser granite-gneiss pink to red in colour, with pearly 
feldspar and smoky quartz. All are cut by dikes of feldspathic 
pegmatite containing much of the pearly feldspar. 
The only notes relating to the Archaean area to the north of 
Seahorse point are those of Parry and Back, both of whom 
mention the occurrence of granites and crystalline rocks in 
several places to the northward. 
The band of Archaean rocks which crosses the eastern part of 
Coats island has never been examined closely, and our know- 
ledge of it is confined to observations made from the ship in 
 
