82 MINERALS AND GEOLOGY 



line or semi-crystalline masses, but only 1.0 - 2.0 in the earthy and 

 ochreous varieties. Sp. gr. 4.3-5.3. BB, becomes magnetic, but 

 on charcoal remains unfused, although a very thin splinter in the 

 forceps may be rounded at the point. One hundred parts contain, 

 normally : oxygen 30, iron 70 ; but many specimens, it should be 

 observed, are intimately mixed with quartz, chlorite slate, or other 

 rock matter, by which the parcentage of iron is much reduced. 



This valuable ore occurs in Canada in strata of various periods of 

 formation. One of its more important localities is in the Township of 

 McNabb, in Renfrew, where it forms a bed of about 30 feet in thick- 

 ness, associated with crystalline limestone of the Laurentian Series? 

 and overlaid by a magnesian limestone of Lower Silurian ago. It 

 occurs also in the township of Bristol, and in Templeton and Hull, 

 on the opposite side of the Ottawa. Other Laurentian localities 

 comprise various spots in the counties of Addington, Hastings, 

 Peterborough,* etc. ; and on Iron Island, on Lake Nipissing, where 

 it also occurs in connection with crystalline limestone. In Huronian 

 strata, it has been found near the Wallace Mine on Lake Huron, 

 and still more abundantly on Lake Superior, as in the Bachewah- 

 nung District on the east shore of the lake ; on the north side of 

 Michipicoten Harbour : and in widely-extended beds in the vicinity 

 of Pic River : mostly in green, chloritic, pyroxenic, or hornblendic 

 slates. Micaceous and other varieties occur in the metamorphic 

 strata of the Eastern Townships : as in St. Arm and, Brome, and 

 Sutton, mostly in chloritic schists, as well as in the auriferous 

 copper-ore veins of Leeds and Halifax. In Silurian strata, hematitic 

 or specular iron ore has been noticed in small quantities in the 

 Potsdam Sandstone of Bastard and Ramsay. Lastly, it may be 

 mentioned, that an earthy impure variety is found in bands and 

 small masses interstratified with the red ferruginous shales of the 

 Clinton or Middle Silurian Series, near Dundas, in Flamborough 

 West. 



Note. Small octahedrons, and related crystals, having the com- 

 position of Red Iron Ore, are occasionally found. These form the 

 species Martite of some authors, but they are probably due to the 

 alteration of Magnetic Iron Ore. See under that mineral, No. 31. 



* Special localities in Hastings and Peterborough counties are given in a paper by the author, 

 with analyses of the ores, in Vol. III. of the Transactions of the Royal Society of Canada, 1885 



