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PROCEEDINGS OF THE GEOLOGICAL SOCIETY. [Apr. 9, 



and conglomerate, various traps, a large lump of silvery mica, the 

 La Cloche quartz-rock, and gneiss with garnets from the French 

 River. The last is from the north-east ; all the rest are from localities 

 in a N.W. direction ten to eighty miles distant. 



The French River, on its way from Lake Nipissing to Lake Huron, 

 passes through a desolate country. There is, however, some miles 

 distant easterly a very large and high table-land, covered with fertile 

 deposits. While descending this river with great rapidity, I was 

 chiefly struck with the effect of cold upon its shores. The rocks 

 (various forms of gneiss, &c.) were usually split up into large sharp- 

 edged, oblong masses, often piled by freshets one upon another. At 

 one place they almost dammed up the channel down which we were 

 passing. Among the innumerable islets off Parry's Sound, still further 

 east, I noticed two great piles of sharp-edged slabs of gneiss, having 

 all the appearance of having been brought there and thrown down 

 pell-mell ; but they are, most probably, the work of the ice during 

 spring-freshets. 



On the beaches (west of the Key on the north shore of Lake 

 Huron), eleven miles east of the French River, we saw no more jas- 

 per-pudding-stone, and little quartz-rock, but various forms of green- 

 stone, granite, and gneiss, and two blocks of impure labradorite ; 

 one of the blocks weighing 250-300 lbs. 



On the rugged north shore near Hen vey's Inlet, about twenty-five 

 miles east of the French River, the beach is strewn with black, brown, 

 red, and white slates (either argillaceous or of greenstone), various 

 porphyries, granite, gneiss, and labradorite ; the slates and porphyries 

 forming two-thirds of the whole. 



There is not, as far as I could ascertain with care, a vestige of lime- 

 stone, loose or fixed, on this part of the north shore ; although it is 

 in situ on Limestone Island, ten miles south of Franklin Inlet ; and 

 Cabot's Head, which is composed of limestone, is fifty miles to the west. 



The labradorite occurs in a fixed state on a group of pine-covered 

 islets, thirty miles N.N.W. of the Giant's Tomb, a little way within 

 the lake, opposite Parry's Island*. 



From near Henvey's Inlet, and still more characteristically from 

 near Parry's Sound, the labradorite boulders overspread the north 

 shore and its isles, in company with gneiss, trap, granite, and the 

 quartzy hornblende that we find imbedded in gneiss on the N.E. coast 

 of Lake Huron. 



* This group of islets is five miles long. The rock is unstratified labrador-fel- 

 spar, forming whole islands. It generally contains interrupted lines of plates of 

 black mica, and occasionally large imbedded masses of hornblende. Its outer 

 surface is apt to weather soft and powdery white ; but it is as often sound and of 

 a shining green colour, with a few iridescent (blue and red) spots, which when the 

 rock is wetted, overspread the whole surface ; as was the case on the rainy day 

 when I passed by. This rock occurs in great quantity in Essex and St. Lawrence 

 Counties, in the State of New York, and was first described by Dr. Emmons in his 

 survey of the Second Geological District of that State. Mr. Hunt, in his Report 

 for 1848 on the Geology of the Canadas, notices the existence of a boulder of this 

 highly ornamental rock in Bathurst, near the Rideau Canal, to the N.E. of Lake 

 Ontario. 



