BORDERING ON VERMILION RIVER. 317 
On the south side, the wall is about fifty feet in height, and thirty feet on the north 
side. The current is very swift, and falls about twelve feet in the distance named. 
The bearing of the rocks is east-northeast and west-southwest, and the dip 36° 
south-southeast. There are fewer granitic intrusions here than at most of the other 
points examined. The few veins are principally felspathic, the felspar being in 
large lumps and crystals, and decomposing easily. The ridges are covered with a 
thin bed of clay. Between this place and “Crane Lake Portage,” one other ridge 
was seen, with same bearing and dip. It is about thirty feet high, and has nume- 
rous granite veins cutting across the line of strike. Where the granite intrudes, 
the stratification of the schistose rocks is nearly or wholly obliterated. 
At Crane Lake Portage we found a high ridge of rocks, almost bare, in which the 
relations of the granite and mica slate were very satisfactorily shown. The ridge 
is about three hundred feet in height, and bears east-northeast and west-southwest. 
It is traversed by granite veins, which, at some points, are from twenty to thirty 
feet wide. These veins do not, however, maintain their width for the whole dis- 
tance they are traceable, but divide into several separate veins, which penetrate 
between the beds of slate laterally, which gives to the granite, in many places, the 
appearance of being bedded, and of alternating with the beds of mica slate. These 
veins also appear always to be wider near to and at the summits of the hills. The 
mica slate is fine-grained, and very compact and tough between the granite intru- 
sions, while the granite becomes very micaceous. Most of the veins contain but 
little mica, until they become subdivided and more intimately associated with the 
mica slate, their constituents being principally quartz and felspar, the felspar pre- 
dominating. 
The rapids here are very difficult, and a portage has to be made of everything. 
Where the river turns around, or, rather, cuts through the ridge just described, it 
is contracted to twenty feet in width, and runs through a gorge, with mural walls 
over forty feet in height, for the distance of nearly three hundred yards. From the 
point where the portage leaves the river above the ridge, to where it strikes it 
again, on the north side, is about a mile and a half by the course of the stream— 
the length of the portage being estimated by the voyageurs at two “pauses.” The 
fall at these rapids, as measured by Colonel Whittlesey, is thirty-five feet. 
A little over two miles below the portage we entered a narrow detroit, which 
leads to Crane Lake. The shores of the lake are bound with rocks, which become 
more granitic in character, and just at the termination of the lake, low ridges of 
granite show themselves. The dip of the schistose rocks, from the lower end of 
Crane Lake Portage, is north, north-northwest, and north-northeast. The bending 
and foldings of the slates by the granitic intrusions, are beautifully exhibited at 
many points on the lake shore, and particularly at the narrow strait which con- 
nects Crane Lake with Sand Points Lake, and called by the Indians Wa-bé-bi-kon. 
At the entrance of this last lake the rocks are all granite (No. 531). 
At the north side of Sand Points Lake mica slate again appears, dipping north- 
northeast, at an angle of 15°. (No. 532.) It is traversed by granitic and felspathic 
veins (Nos. 533 and 534). A short distance further on, the dip varies from 16° to 
44° north, and a little east and west of north. This slate is very finely laminated, 
