306 



MINERALS AND GEOLOGY 



stratified clays and sands, are largely distributed ; and it is chiefly 

 where these occur that the district admits of agricultural occupation. 

 Glacial strise of this period are seen on the exposed surfaces of 

 many of the harder rocks. In some localities, as in most parts of 

 Renfrew and other eastern sites, the striae have a very general south- 

 easterly direction ; whilst in the west, as about Lake Nipissing and 

 Georgian Bay, and in the northern parts of Hastings, Peterborough, 

 and Victoria, the prevalent direction is towards the south-west. 



Economic Minerals : This district is especially rich in deposits of 

 iron ore ; and, in addition, it contains auriferous mispickel, galena, 

 apatite, marble, and mica, in workable quantities The iron ore con- 

 sists chiefly of magnetite (see page 83), but valuable deposits of 

 hematite replace this at some localities. As a rule, these oxidized 

 ores form large irregular masses or " stocks," and are very generally 

 associated with the green pyroxenic rocks and the crystalline lime- 

 stones of the district. Many are exceedingly rich and pure, holding 

 from 65 to 70 per cent, metallic iron,* with consequently very little 

 intermixed rock-matter ; and although pyrites is occasionally present, 

 the amount of sulphur and phosphorus is in general quite low. But 

 some of these magnetites are rendered unmarketable in consequence 

 of the presence of titanium in comparative excess. An enormous 

 deposit of titaniferous magnetite occurs on lot 35 of the 4th con- 

 cession of Glamorgan ; and another in the Township of Tudor 

 in North Hastings. t The deposits of workable ore, however, far 

 exceed in number those which are unavailable from the presence of 

 titanium. These workable deposits occur all over the district, and 

 their presence in new localities is constantly being discovered. Some 

 of the best known occur in the townships of McNabb, Bedford, Crosby, 

 Sherbrook, Wollaston, Faraday, Glamorgan, Tudor, Madoc, Marmora, 

 Belmont, Limerick, Minden, and Snowden.j 



*The maximum percentage of metallic iron in perfectly pure magnetite is 72.41. and in 

 hematite, 70. See descriptions of these ores in Part II. 



t See descriptions and analyses by the author, in Transactions of the Royal Society of Canada 

 for 1884. Analyses and brief descriptions of many of the iron ores of Central Canada, by the 

 author, will also be found in the Transactions of the Royal Society for 1885. 



J Other townships will no doubt be rapidly added to those of the present list. It should be 

 pointed out, however, that as these iron ore deposits are essentially in the form of "stocks,'' 

 great care should be exercised in determining the probable dimensions of a deposit, before 

 purchasing, or putting up expensive works in connection with it. Happily, in the diamond 

 drill, we have the means of readily testing the size and purity of ore-masses of this character. 



