CANADA. o-io 



the same distance from the latter ; but it is very much disturbed by intrusive 

 granite and greenstone, and, although there are great exposures of rock, it is 

 very ditficult to make out how the stratified portions are related to one an- 

 other. The gneiss extends to the vicinity of a small stream about a mile and 

 a half above Les Grandes Sables, and what is supposed to be the lowest Hu- 

 ronian mass of that part occurs about half a mile aljove the stream. It consists 

 of a grey quartzite which abuts against one mass of gneiss and runs under an- 

 other, and appears to be much broken by and entangled among the intrusive 

 rock ; but judging from a transverse measure in one part, its thickness would 

 not be far from 500 feet." {I. c. p. 55.) 



It would seem that here the Hurouian was found abutting against 

 and underlying the Laurentian gneiss (granite). In none of the sec- 

 tions given do the conglomerates in the Hurouian appear to lie at the 

 base of the formation, but at varying heights in the series. 



The exception referred to above is this : under the head of " Contact 

 of Laurentian and Hurouian Rocks," it is stated that in the upward 

 navigation of the Kaministiquia River 



*' the first development of the Laurentian series occurs at the second port- 

 age, about half a mile above the Grand Falls. At the lower end of the port- 

 age, where the series makes its appearance, the rock resembles a massive 

 syenite, in some parts red and in othei-s whitish, but is probably a hornblendic 

 gneiss in which the lamellar arrangement of the constituent minerals is ob- 

 scure, as the I'ock gradually passes into such a gneiss. Resting on it conform- 

 ably there occurs a series of dark greenish-blue or greenish-black slates, the 

 one rock passing almost imperceptibly into the other. The section occupies 

 upwards of a quarter of a mile on the river bank, and at the upper end of it, 



as well as at the head of the portage, the dip is N. 54° E At each 



rapid part of the river above the Grand Falls there is a greater or less develop- 

 ment of these rocks, most frequently presenting the more distinctly stratified 

 part of the gneiss. The best exposure of the slates is at the Three Discharges, 

 about four miles above the Grand Falls, where the rocks are observed to pass 



from the gneiss to the slate Towards the bottom, near the junction 



with gneiss, the slates are of a bluish and occasionally of a brownish color." 

 (I. c, pp. 64, 65.) 



It would then appear that Huronian in the only localities, except one 

 problematical one {I. c, pp. 52-54, 703), in which it had been seen in 

 contact with the Laurentian, was conformable with and passed almost 

 imperceptibly into, or else underlaid, the Laurentian. 



An intrusive granite is said to occupy 



" a considerable area on the coast of Lake Huron, south of Lake Pakowagaming. 

 It there breaks through and disturbs the gneiss of the Laurentian series, and 



