No. I] GEOGNOSTICAL OBSERVATIONS. 503 



Swampy Lake, the river changes its name from Hill to Jack River. At the 

 Lower Portage in Jack River, a red granite occurs ; and at the Long Carrying 

 Place a little higher up, a granitic gneiss, having disseminated iron pyrites, 

 alternates with a compact grey micaceous gneiss. The strata of gneiss are 

 much contorted at their line of junction with the granite ; but their general 

 line of direction is north and south, and they apparently dip to the eastward. 

 At the Upper Portage, the strata of grey gneiss have a direction from E.S.E. 

 to W.N.W. and a northerly dip, but they are much convoluted and contorted. 

 They contain a bed of primitive greenstone, having disseminated iron pyrites. 

 This greenstone contains diallage, and is therefore passing into diallage rock. 

 The rocks in Jack River are low, and sparingly covered with soil ; the woods 

 thin, and the surrounding country flat, and destitute even of the moderate 



elevations which occur in Hill River. 



The borders of Knee Lake presented the same appearances that were ob- 

 served in Jack River. In one place, which we were induced to examine from 

 the unusual luxuriance of the trees, the soil was very thin ; but the subjacent 

 rock consisted of primitive greenstone, with disseminated iron pyrites. This 

 rock, situated about fifteen miles from the lower end of the lake, forms a low 

 cliff which has somewhat of a columnar structure. Nine miles farther, verti- 

 cal strata of mica slate rising a little above the water, formed a number of 

 smooth flat islands. The direction of its strata was E.N.E. and W.S.W. The 

 magnetic islet near the knee of the lake, referred to in page 36 of the Narra- 

 tive, is composed of the same rock highly impregnated with magnetic iron ore, 

 and having its thin layers alternating with layers of that mineral. The strata 

 of this islet are vertical, and very much undulated in direction. The gneiss 

 rose on the borders of the lake into roundish eminences, whilst the mica slate 

 formed even islands scarcely appearing above the water. At the upper end 

 of the lake the gneiss exposed is grey and compact. 



The same rock was observed in Trout River (the name which the stream 

 now assumes), and half a mile above the Lower Carrying Place it was found 

 impregnated with magnetic iron ore. The strata have a direction from E.S.E. 

 to W.N. W.— the dip, if any, is to the north. At the second portage, in Trout 

 River, the bed of the river is formed of vertical mica slate, whose thin layers 

 lacerating the boatmen's feet, have obtained for it the name of Knife-edge 

 Portage. At the third portage, the ground is strewed with large boulder 



