176 Reviews — Iron-ores of Canada. 



veins of quartz were intruded, and some iron and copper were intro- 

 duced into the matrix. Finally the whole mass was again brecciated 

 by further folding. 



The post-Tertiary formations which, cover the old rocks over a 

 great part of the area are partly the old alluvium of the Ganges and 

 partly blown sand ; a considerable amount of Kankar is found near 

 the outcrop of lime-bearing rocks. 



The district contains a fair number of minerals of economic 

 importance, but unfortunately only in small quantity. 



The irregular patches of Rialo limestone altered to haematite, 

 which contain seams up to 7 feet in thickness, appear to be a 

 workable proposition. A fairly large amount of iron has been 

 smelted in this region in past times, but all the mines are now closed. 

 Copper was mined on a considerable scale in ancient times, but none 

 is now extracted. 



The ore was chalcopyrite with pyrrhotite occurring along the 

 junction between quartzite and slate at a horizon low down in the 

 Alwars. Some kaolin is dug from the pegmatites, and steatite and 

 a variety of building stones and marbles are also quarried in the 

 district. 



The memoir is illustrated by many excellent drawings and 

 photographs of the scenery and structures in the field, photographs 

 of specimens, and photo-micrographs of thin sections, and also by 

 a geological map and a number of horizontal sections. 



W. H. W. 



Canadian Ieon-obe. 

 III. — Ieon-oee Occtjerences in Canada. Voh I. By E. Lindeman 



and L. L. Bolton. Department of Mines, Canada, pp. 71, with 



23 plates and 1 map. Ottawa, 1917. 

 f nHE literature of the Canadian iron-ore deposits has till now been 

 JL very scattered and difficult of access, and the Department of 

 Mines has rendered a useful service by collecting all the available 

 data in this convenient form. Iron-mining was not seriously 

 developed in Canada till 1896, but since that date it has made rapid 

 progress. Nevertheless, even now the proportion of ore mined in the 

 Dominion is only about 15 per cent of that smelted in Canadian 

 furnaces. The greater part comes from Newfoundland and the 

 United States. Among the provinces Ontario is the largest producer : 

 the most important source is the Helen Mine in the Michipicoten 

 district. The ore is haematite, probably derived from siderite and 

 pyrite by oxidation. Prospecting of large areas of banded jaspers 

 and magnetite schists correlated with those of the Vermilion and 

 Mesabi ranges in Minnesota has led only to disappointing results. 

 The only promising occurrence of this kind is the Akitokan iron- 

 range in Western Ontario, a magnetite ore with rather high sulphur 

 content. In British Columbia there are some promising contact- 

 deposits of magnetite which lie near coal and limestone, suitable for 

 use as fuel and flux. The great furnaces of Nova Scotia chiefly use 

 Newfoundland ore, but they were once supplied by local deposits of 

 haematite, limonite, and ankerite in strata of Devonian age. These 



