CORUNDIFEROUS NEPHELINE-SYENITE FROM 
EASTERN, ONTARIO 
A CONSIDERABLE area of nepheline-syenite was discovered 
about six years ago in Dungannon township, Hastings county, 
Ontario, by Dr. F. Adams, who described the rock briefly in his 
‘Report on the Geology of a portion of Central Ontario,” and 
more fully in the American Journal of Science.* In 1896 corun- 
dum was found in the same region by Mr. W. F. Ferrier, and in 
the following year Professor W. G. Miller was instructed by Mr. 
Archibald Blue, director of mines of Ontario, to examine and 
report upon the corundum-bearing rocks. In the course of his 
work it was found that the corundum occurred not only in ordi- 
nary syenites but also in nepheline-syenite.* In November 1898 
the present writer examined an outcrop of the latter rock for 
the Bureau of Mines on York branch of Madawaska River at 
the northeast corner of Dungannon township or just within Car- 
low, several miles from Dr. Adams’ localities, and presenting a 
number of new and interesting features. 
The rock forms a ridge running nearly north and south for 
about 350 yards with a width of about 20 yards, and having a 
well defined schistose character, so that at first sight it would be 
called gneiss. It is light to dark gray in color, the darker layers 
containing much biotite, the lighter ones more nepheline and 
plagioclase. On much of the weathered surface numbers of 
small crystals of corundum stand out, having resisted weather- 
ing better than the other constituents. In hand specimens of 
the unweathered rock, however, the corundum is scarcely noticed, 
and the rock has quite the appearance of fresh gray gneiss, the 
nepheline looking like quartz. 
*Geol. Surv. Can., 1892-3, Part J, p. 5; Am. Jour. Sci., Vol. XLVIII, July 1894, 
pp. 10-18. 
? Bur. Mines, Ont., Vol. VII, pp. 210-212. 
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