570 REVIEWS 



The book bristles with new suggestions, and as such is a contribution 

 of stimulating value. Necessarily, however, many of the conclusions thus 

 put forth somewhat tentatively must be received with reserve. 



R. T. C. 



The Whitehorse Copper Belt, Yukon Territory. By R. G. McConnell. 

 Canada Department of Mines, Geological Survey Branch.,. 1909. 



These very interesting copper deposits are located in the southern part 

 of the Yukon territory, extending along the valley of the Lewes River for a 

 distance of about twelve miles. The rocks of the district are limestones 

 probabl)- belonging to the Carboniferous period, cut by three sets of intru- 

 sions of Mesozoic age. Of these the second set, consisting of granites 

 and granodiorites, are economically important. Overlying these rocks 

 are basalt flows belonging to the Tertiary, and glacial silts and bowlder 

 clays. 



The ore deposits are all contact metamorphic in origin, chiefly in the 

 limestone along its contact with the granite. Two types of deposits are 

 noted, the magnetite ore bodies and the siliceous ore bodies. In the former, 

 the chief minerals are magnetite, bornite, chalcopyrite, serpentine, calcite, 

 clinochore, rarely pyrrhotite and sphalerite. In the latter, associated 

 with the ore minerals, bornite and chalcopyrite, are andradite, augite, 

 tremolite, actinolite, epidote, and calcite. The granite itself is mineralized 

 for some distance from the contact, the same minerals being developed as 

 in the limestone. The deposits are peculiar in having bornite as the prin- 

 cipal ore mineral, and in having little or no secondary sulphide enrichment. 

 The values in copper range from 3 . 20 per cent to 1 2 . 90 per cent, the 

 richest being from the Valerie Mine, in which bornite is absent and chal- 

 copyrite is the only known copper sulphide present. 



E. R. L. 



Eigh'eenth Annual Report of the Bureau of Mines, Ontario, 1909. 

 Vol. XVIII, Part I. 

 The Report contains the following papers: "Statistical Review, by 

 Thos. W. Gibson, Deputy Minister of Mines, pp. 5-78; "Mines of Ontario," 

 by E. T. Corkill, Inspector, pp. 79-140; "Iron Ranges of Nipigon District," 

 by A. P. Coleman, pp. 141-53; "Iron Range North of Round Lake," 

 by E. S. Moore, pp. 154-62; "Black Sturgeon Iron Region," by A. P. 



