280 Revieivs — Geology of Eastern Ontario. 



Tho metallio minerals contained in the veins, the gangne of 

 -which is mainly quartz, include the following : Native Silver in 

 small spangles, and in a wire-like form ; Argentite ; Stephanite ; 

 FreibtM-gite ; Pyrargyrite (ruby silver) ; Galena (usually highly 

 argentiferous); Chaloopyrite ; Native Copper ; Malachite and Azurite 

 (due to the leaching out of the copper in the Tetrahedrite and 

 Freibergite) ; Iron Pyrite ; Arsenopyrite ; Pyrrhotite ; Sphalerite 

 (zinc-blende). 



The most valuable product of the veins is the silver ; the ferruginous 

 portion of the vein is stated to carry also gold in remunerative 

 (piantities. 



A detailed description is given of the development of the mining, 

 llie general outlook being considored exceedingly promising. The 

 mining conditions are not unfavourable as regards the situation 

 of the veins, cost of supplies, railway communication, and other 

 desiderata. A. H. F. 



XL — Geological Suuvey of Can.vda. Robkut Bell, I.S.O-, 

 I\I.D., F.K.S., etc., Acting-Director. Annual Report, Vol. XIV, 

 Part J. RicrouT on tuk Gkology of a Portion of Eastern 

 Ontario (to accompany Map-Slieet No. 119). By R. W. Ells, 

 LL.D., F.R.S.C. 8vo ; pp. 1-89, map. (Ottawa, 1904.) 



rillllS report concerns the geology and mineral resources of the 

 L rtvea south of the Ottawa River, where it is bounded on the 

 north by a line extending west from the vicinity of Arnpvior to a 

 point a few miles north of Clear T^ake in the county of Renfrew, and 

 on the south by a line east from Sharbot Lake to a point a few miles 

 south of Smith's Falls. It embraces an area of 3,456 square miles. 



The geological formations represented in the area comprised in 

 this map-sheet are the following : — 



Post-Tertiary. 

 Utica shales. 

 Trenton. 

 Black River. 



Chazy shales and limestones. 

 Calciferous and Potsdam sandstone. 



Mica, chlorite, and hornblende schists and amphibolites, 

 with some conglomerates. 



The most interesting part of the report is the discussion of the age 

 of the crystalline rocks, the history of which, dating back for nearly 

 fifty years, is very exhaustively treated, and a lucid account of the 

 views held by the older authorities — Logan, Macfarlane, Hunt, 

 Vennor, Selwyn — is supplied. The later work of Messrs. Adams 

 and Barlow is also adverted to by the author, who himself began in 

 1S91 and the three toUowing years the detailed examination of the 

 area north (^f the Ottawa, in the typical district where the rocks of 

 the Grenville series of tho Canadian iieoloirists were tirst studied. 



