386 DESCRIPTION OF THE COUNTRY BORDERING 
Continuing to descend the river, metamorphosed slate, alternating with trap-beds 
(Nos. 129, 130), again comes up, overlaid by red sand-rock breccia. No. 131 is 
from one of the layers of trap, and No. 132 from the greenstone ridge. This last 
rock is the same as No. 115 found on the lake-shore below the mouth of this river, 
associated there, as here, with amygdaloidal sand-rock. 
Below the mouth of Cut Face River, on the lake-shore, the metamorphosed rocks, 
with intercalated beds of trap, make the shore, nearly to the mouth of Oginekan 
River. At one point there is a small pocket, with mural walls from thirty-five to 
forty feet in height. Here the sedimentary rock (No. 118) has been completely 
fused, and resembles in colour and structure the slag from a furnace (No. 117). 
For some distance the metamorphosed rocks have been greatly disturbed, and pre- 
sent the appearance of having been melted. Sometimes the beds stand vertically, 
and at others recline at all angles to the horizon. The overlying trap-bed varies 
from eight to twelve feet in thickness. For the last two miles the lake-shore is 
entirely composed of siliceous shales (No. 103), overlaid by volcanic grit (No. 114), 
except at one point, where these rocks are traversed by a trap-dike, six feet wide, 
and bearing north 45° west. The underlying amygdaloidal shaly beds, throughout 
the whole distance, weather into caverns, arches, and pillars. 
19. Oginekan River.*—Opposite the mouth of this river, are some small rock- 
islands, the upper beds of which all appear to be metamorphosed rocks (No. 94), 
such as are found on the main shore. They form a chain, bearing northeast and 
southwest, and if prolonged southwesterly, would strike the point making the upper 
side of Oginekan Bay. The projecting points of the main shore are formed by a 
low ridge of basaltic rock overlying metamorphosed slate. Both rocks assume the 
CORUM AR BASALT AND ALTERED SHALE, LAKE SUPERIOR. 
columnar form, the columns being nearly perpendicular. Inside of the ridge, in 
the bottom of the bay, is an exposure of altered shales and sandstones, overlaid by 
a bed of trap, as seen in the preceding section. 
* See Sect. 3, Plate 1, N. 
