GOLD ELSEWHERE IN UNITED STATES AND CANADA. 255 



called kernels, which have been shown by F. D. Adams to be mass- 

 es of less altered granite, almost without pyrite. Both varieties 

 show abundant cataclastic or crushed structure, as an evidence of 

 having suffered from dynamic movements. Adams concludes that 

 the mass was originally a hornblende granite that has been sub- 

 jected to solfataric action, which has brought in the gold. The 

 gold in itself is in irregular masses in the pyrite. The Tread well 

 mine, located here, is very extensive, and the chief source of Alaska, 

 bullion. 1 



2.13.05. Example 45c. Nova Scotia. The southeastern por- 

 tion of Nova Scotia is composed of Cambrian slates. They stretch 

 from Canso to Yarmouth, and, together with associated granites, 

 cover from 6000 to 7000 square miles. There are two well-marked 

 divisions. The upper, 3000 feet thick, consists of dark pyritous 

 slates, with beds of quartzite and small irregular veins; the lower, 

 8000 feet thick, has quartzites, sandstones, and slates, which in 

 parts contain the veins. The slates are folded along east and 

 west axes. The veins are not large, averaging from 4 to 8 inches, 

 while 20 inches is very exceptional. The gold is both free and 

 associated with the usual sulphides, among them often mispickel. 

 The assays are not high, but with careful working the mines pay 

 good returns. 2 



1 F. D. Adams, "On the Microscopical Character of the Ore of the 

 Tread well Mine, Alaska," Amer. GeoL, August, 1889, p. 88. G. M. Daw- 

 son, "Notes on the Ore Deposits of the Treadwell Mine, Alaska," Amer. 

 Geol., August, 1889, p. 84. Mining and Scientific Press, San Francisco, 

 Sept. 27, Oct. 4, 1884. 



2 J. W. Dawson, " On Recent Discoveries of Gold in Nova Scotia," 

 Canadian Naturalist and Geologist, December, 1861. E. Gilpin, Jr., "The 

 Nova Scotia Gold Mines," M. E., XIV. 674. Rec. H. Y. Hind, "Report 

 on the Mount Uniache, Oldhara, and Renfrew Gold Mining District," Hali- 

 fax, 1872 ; Amer. Jour. Sci., iii., IV. 497. D. Honeyman, "On the Geol- 

 ogy of the Gold Fields of Nova Scotia," Quar. Jour. Geol. Sci., Vol. 

 XVIII., p. 342, 1862. T. S. Hunt, "On the Gold Region of Nova Scotia," 

 Can. Geol. Survey, 1868 ; Canadian Naturalist, February, 1868. W. E. 

 Logun, " Notes on the Gold of Eastern Canada," Can. Geol. Survey, 1864.. 

 O. C. Marsh, "The Gold of Nova Scotia," Amer. Jour. Sci., ii., XXXII. 

 395. A. Michel and T. S. Hunt, "Report on the Gold Region of Canada," 

 Can. GeoL Survey, 1866. H. S. Poole, "The Gold Leads of Nova Scotia," 

 Quar. Jour. Geol. Sci., Vol. XXXVI., p. 307. A. R. C. Selwyn, " On the 

 Gold Fields of Quebec and Nova Scotia," Can. Geol. Survey, 1870- 71, pp. 

 252-289. B. Symons, " The Gold Fields of Nova Scotia," Trans. Min* As&o> 

 and Inst. Cornwall, III. 80, 1892. 



