410 DESCRIPTION OF THE COUNTRY BORDERING 
The slates on the no-thwest side of it, appear to be overlaid for some distance by 
trap, and some of the beds are changed to a compact hornblendic-looking rock. 
The portage is five hundred and ten paces long. 
a. Greenstone. 6. Slate. c. Metamorphosed slates. d. Slates with breccia. 
The third portage of Pigeon River is six hundred and thirty paces long, and 
passes over a very low ridge, formed by a greenstone dike traversing clay slate. 
There are forty-eight feet of clay slate here, a portion of which, in proximity with 
the dike, resembles slaty hornblende. 
The fourth portage is seven hundred and fifty paces long, and is made to avoid 
a rapid, in which no rock in sitw was seen, nor is any exposed in the low ridge over 
which this portage passes. Between the third and fifth portages there are no rock 
exposures; both sides of the river being bordered by extensive swamps, which ex- 
tend back to high greenstone ridges on the American side. 
The fifth portage is two thousand two hundred paces long, and passes over low 
ridges, composed of clay slate, somewhat altered at some places, and highly meta- 
morphosed at others. Toward the upper end the slate is overlaid by greenstone, 
and occasional large fragments of slate are seen enveloped in the trap, which appear 
as though they had been partially fused. 
ESCARPMENT OF SLATE, LAC DU COQ. 
At the lower end of Lac du Cog, where this portage terminates, the rocks are 
clay slate with hornblendic beds, overlaid by greenstone. The outlet of the lake is 
between high vertical walls. The summit of the precipice on the Canada side is 
three hundred and six feet above the lake-level, with a wide talus, one hundred 
feet in height at the base; on the American side the escarpment rises from the 
water to the height of ninety feet. The range here is composed of a number of 
