376 DESCRIPTION OF THE 



forming a gorge from eighty to one hundred and twenty feet in depth, and from 

 fifteen to twenty feet wide. The rock, being soft, and easily acted on by water and 

 atmospheric agents, has been worn down to an inclined plane, and no bold cascades 

 occur in it, as in most other gorges met with. On the northwest side of this ridge, 

 No. 172 comes in. It is in regular beds, from six inches to a foot thick. They 

 appear to lie horizontally, or, if they dip at all, it is towards the ridge. A quarter 

 of a mile further on, the rock met with is softer, amygdaloidal, and more like that 

 at the gorge. Just beyond this is an exposure of thirty feet of volcanic grit, over 

 the upper part of which is a fall of fifteen feet. The stream is divided by a rock at 

 the top of the fall into two chutes, which meet at right angles about halfway down 

 the descent, and produce a unique and beautiful display. 



Immediately above the falls, a high ridge of clay and marl occurs, which rests 

 partly on the grit-beds and partly on metamorphosed shales, which emerge from 

 beneath the grits. The clays and marls then conceal the rocks for the distance of 

 a mile, where a very hard, flinty, porphyritic rock (No. 173) comes up, making 

 rapids; the water descending through a narrow gorge, about twenty-five feet in 

 fifty yards. This rock has a schistose structure when seen in the mass, and re- 

 sembles very much the altered slates of the Wisacode River, and those seen in the 

 neighbourhood of Grande Marais, and on Spar Island. The rock here, however, is 

 much more compact and flinty ; in other words, is more highly metamorphosed. It 

 bears great resemblance to the Palisade rock. 



The next rock met with resembles the volcanic grits of the lower part of the 

 river, but appears to have been much acted on by a dike of No. 174, which crosses 

 the river, bearing north 45° east. The beds near the dike are very porphyritic, the 

 embedded crystals being felspar. For the next two miles no rock is exposed, where 

 No. 175 shows itself at the base of a hill, intercalated among beds of altered sand- 

 stone, resembling, in all respects, the altered sandstones of Black River. It conti- 

 nues for the distance of five hundred yards farther up stream, where it assumes 

 more of a slaty character, is laminated, very hard, brittle, and, when struck, rings 

 like phonolite (No. 176). A short distance further on, there is an exposure of 

 twelve feet of argillaceous slate, slightly altered, but still maintaining its original 

 characteristics in everything but colour. It is thinly laminated, with vertical 

 joints, and cleavage planes dipping northeast 46°. This rock is exposed at various 

 points off from the river, in the low hills which bound the valley. Its dip could 

 not be ascertained. Continuing to ascend the stream, the slate is found to be inter- 

 stratified with amygdaloidal shales (Nos. 177, 178), and two hundred yards beyond 

 this a ridge of No. 179 crosses the river, bearing northeast and southwest. Beyond 

 this the metamorphosed shale (No. 180) is intercalated with a bed of No. 181, 

 which resembles some of the greenstones found near the Lake, and also with a bed 

 of No. 182. For the distance of more than a mile beyond this no rock is visible, 

 but numerous fragments of No. 176 occur, and at one point I noticed fragments of 

 unaltered red sandstone. 



The next rock seen is an exposure of about twenty feet of greenstone, which soon 

 rises into a low ridge, and crosses the river, bearing northeast and southwest. It 

 makes a rapid, with a fall of eight feet in thirty. It is jointed, the joints being 



