502 



APPENDIX. 



[No. I. 



mark that the whole of this bed of rock is of cotemporaneous origin. Hand 

 specimens from one part of the rock might be denominated quartz rock, from 

 another, mica slate. 



After passing the Rock Portage, the clayey banks gradually decrease in 

 height, and in the upper parts of the river they entirely disappear, and the 

 gneiss rises into small ridges on the borders of the stream, and forms nume- 

 rous islands in the small lakes into which the river expands, or rather through 

 which it flows. Whilst the clay continues the country is well clothed with 

 wood, but afterwards, for want of soil the trees are in general stunted. The 

 bed of the river is every where uneven, and composed of strata of rock, 

 which are divided by deep fissures into irregular lozenge -formed masses. 



At the point of rocks four miles above the Rock Portage, a grey gneiss 

 occurs containing much mica, and intersected by veins of quartz. And five 

 miles further on, there are several detached conical hills ; the highest having an 

 altitude of about six hundred feet, is named the Hill, and is the origin of the 

 appellation of the river. From the summit of the Hill thirty-five lakes are 

 said to be visible ; indeed, all the valleys seem to be filled with water, the 

 almost insulated summits of the hills and ridges being alone visible. We 

 had no opportunity of visiting these hills. 



A few miles above the Hill, at the Lower Burntwood Portage, a vein of gra- 

 nite was observed crossing the gneiss, and a similar vein occurs about one 

 quarter of a mile higher up the river.- At Morgan's Rocks the exposed bed of 

 rock appears to be granitic gneiss, and at the Upper Burntwood Carrying Place 

 half a mile farther on, there is a bed of hornblende rock and another of a red 

 granite which is composed of red felspar, grey quartz, and very little mica. 



At the Swampy Portage there is a bed of red felspar, containing small 

 disseminated grains of epidote— and at the Upper Portage hornblende slate 

 occurs alternating with grey gneiss, slightly intermixed with hornblende, 

 together with beds of quartz rock, containing precious garnets. The direction 

 of the strata here is from east to west, the dip about 80° to the northward. 



In Ground- Water Creek, two miles distant, the same kind of hornblende 

 slate is found, having the same dip, and alternating with red granite composed 

 of red felspar, grey quartz, and dark green mica. And at Bird's Lake, and 

 on Sail Island, near the debouchure of Swampy Lake, extensive portions of 

 grey gneiss are exposed, unaccompanied by other rocks. After crossing 



