NORTH SHORE OF LAKE HURON. 187 



shore of Lake Huron, of which I have made the following 

 abstract : — " The north shore of Lake Huron, on which 

 twenty-two mining locations have been claimed of Govern- 

 ment, presents an undulating country rising into hills 

 which sometimes attain the height of from 400 to 700 feet 

 above the lake. These occasionally exhibit rugged escarp- 

 ments and naked rocky surfaces ; but, in general, their 

 summits are rather rounded, and their flanks, with the 

 valleys separating one range from another, are most fre- 

 quently well clothed with hard and soft wood, often of 

 large growth, and of such species as are valuable in com- 

 merce, in many places giving promise of a good arable 

 soil. Many of the slopes are gentle, and many of the 

 valleys wide. The Thessalon, of the reported length of 

 200 miles, and the Spanish river of 120 miles, flow through 

 this country, with three other rivers of from 50 to 60 miles' 

 length each." With respect to the rocks occupying this 

 country, he says, that "for 120 miles from the upper 

 end of the lake one great formation, having a breadth in 

 some places of ten and in others exceeding twenty miles, 

 exists. It is composed of sandstones, conglomerates, slates, 

 and limestones ; the sandstones often vitreous, and pre- 

 senting the character of a perfect quartz rock. These are 

 associated with greenstone trap and other igneous rocks, in 

 the form of overflows, dykes, and veins, and with amygda- 

 loidal trap in layers. The whole reposes on granite, which 

 is the metalliferous rock of the district, and lies beneath 

 the lowest known fossiliferous beds. The Potsdam sand- 

 stone, Trenton limestone, Utica slates, and Loraine shales 

 are exposed in successive deposits, resting on the tilted 

 beds of the quartz rock in a nearly horizontal, unconform- 

 able position in the Grand Manatoulin, La Cloche, Snake, 

 Thessalon, Sulphur, and other islands, and at the east end 

 of the lake. Medina sandstone and Niagara limestones 



