PEESIDEISTTIAL ADDEESS. H 



bouudcary Hue in the Thunder Bay district, aud again on Brushy Creek, north of Seine 

 River. (See report by the writer in the Reports of Progress of the Geol. Survey for 18*72). 

 Grrey quartzites occur in considerable volume in a îluronian belt on Missinaibi River. 

 (Geol. Su.rvey Report for 18*75). Around the northern part of Temagami Lake, and between 

 it and Montreal River, as well as along that stream, light grey, reddish and greenish- 

 grey quartzites are met with. On Lake Temiscaniing, a greenish-grey variety is largely 

 developed. The late Mr. "Walter McOuat stated that an isolated mountain which he 

 examined on the height-of-land just west of the canoe-route between Lakes Temiscamiug 

 aud Abittibi, consisted entirely of quartzite, aud that the same rock occurred on the point 

 in the latter lake, on which the Hudson's Bay Company's post is built. (Report of the 

 Greol. Survey for 18*71-2, p. 120). Mr. E. B. Borron, informs me that in going west- 

 ward from the above moutain last rummer, he found a continuation of the quartzite iu 

 the direction of Frederick River. White quartzite occurs at Red Lake among various 

 other Hurouiau rocks resembling those of Lake Hurou, which are there associated with 

 schists of the Lake Superior type. (Summary Report of the Greol. Survey for 1883.) 

 Quartzite with iron ore is found near the Hurouiau Mine west of Thunder Bay. The 

 existence of white quartzites on Goulais and Batchawaua Bays on Lake Superior has been 

 already referred to. 



Some of the Hurouiau quartzites might be described as sandstones, but most of them 

 are hard aud close-grained aud even vitreoiis iu appearance on fresh fracture. They are 

 characterised by holding grains of felspar more or less thickly disseminated through them. 

 On exposed surfaces, these grains weather out, and sometimes give them a finely pitted 

 appearance. The almost constant presence of these felspar grains is of interest in con- 

 nection with the origin of the quartzites. The felspar grains often become so abundant 

 as to constitute a grey wacke. Sometimes one part of a bed will consist almost entirely 

 of quartz grains, while in another part, felspar predominates, there being a more or less 

 distinct passage of the one into the other. Indeed the origin or formation of the quartzites 

 appears to have been connected with that of the grey wackes, which are on the whole 

 more largely developed than the former. The latter are very frequently associated with 

 stratified quartz diorites ; and from this circumnstauce, as well as from their microscopic 

 characters, they would appear to be of volcanic origin. Thus, even the quartzites would 

 seem to partake of the general igneous nature of the system of rocks to which they 

 belong. Some beds of the white aud grey quartzites, especially on the east side of Lake 

 Superior, aud uoi-th of the Bruce Mines ou Lake Huron, contain small red jasper pebbles 

 thickly diffused. They are mostly longitudinally banded and resemble the jasper in the 

 thin beds alternating with equally thin beds of iron ore found lower down iu the series 

 in some localities, a good example being that described by myself as occurring on the east 

 side of the Kamiuistiquia River, just below the crossing of the Dawson Road. (G-eol. 

 Survey Reports for 1869). Some of the other rocks, such as the limestones, serpentines, 

 steatites, argillites aud plumbaginous schists are, like the quartzites, irregularly or locally 

 distributed in the Huronian Series. But the presence or absence of any one or more of 

 these members in a given district can scarcely be held as a reason for separating the rocks 

 of such a district into a distinct series. The varying proportion in which the different 

 sorts of rocks occur iu the diflereut Huronian areas is to be considered as a difference in 

 degree only and not iu kind, affecting the whole system. 



