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which is quite obliterated, and which indeed often resemble diorite from 
the coarseness of their crystallization. This zone of intrusive rocks, may 
run eastward a long way, and probably forms the nucleus of the chain of 
large islands which here extend across the lake, but are not correctly 
represented onthe maps. This supposition is confirmed by the circum- 
stance that the northern shores of these islands are composed of soft and 
fissile rocks, which could hardly have held their ground unless so 
supported. 
Huronian Rocks from Ka-ka-ke-wabec to Rat Portage. 
81. The north end of Ka-ka-lke-wabec Island, is composed of rough 
green chloritic rock, not showing any appearance of excessive alteration, and 
forming the southern margin of another extensive belt of schistose strata. 
The comparatively small distance to which these rocks are altered, north- 
ward from the intrusive mass, would almost lead to the conclusion that 
they have been brought into contact with it by a fault, nearly following 
its northern edge. The next rock observed, which occupies a position 
somewhat inferior to the last, is a chloritic slate, of rusty appearance, 
caused by the weathering of dolomite, with which it is minutely inter- 
leaved. A short distance north of this, near the main shore, is a soft 
thinly bedded talcose schist of a grey-green colour, almost nacreous in 
places, and including particles of dolomite. It has a strike of N. 88° E., 
and is vertical. A mile and a half west, and nearly on the same strike, a 
gumilar thin-bedded talcose schist appears, again showing traces of dolomite, 
and on edge. North of this, and about a mile north of the eastern end of 
Ka-ka-ke-wabec, is a somewhat micaceous schist, with greenish-white 
felspar, like all the rocks in this part of the lake, vertical. Strike N. 85° 
W. Near the horizon of these schists, and about a mile south of Lacrosse 
Island, is a whitish thin-bedded talcose slate of rather remarkable aspect. 
Strike N. 82° W. Passing northward from this toward the south end of 
Lacrosse Island, the rocks, so far as could be ascertained from an 
examination of the islands, were:—Thin fine-bedded chloritic schist, 
including lenticular masses composed of dolomite and quartz, round 
which the layers of rock bend—vertical, strike N. 77° E. The rocks here 
bear the appearance of having been intersected, while still nearly 
horizontal, by jointage planes at right angles to the stratification, and 
cutting it neatly ; which, now that the beds have been folded through an 
angle of 90°, produce on weathering, in some places, almost perfectly 
horizontal areas. These are as smooth as though subjected to the action 
