46 ROYAL SOCIETY OF CANADA 



In fact, so far as can be ascertained no nephelme rock so coarse in 

 grain has hitherto been discovered anywhere. Sodalite is also present 

 in the rock in places, occurring in irregular shaped masses sometimes 

 as much as two inches in diameter, included in the large masses of 

 nepheline and having apparently been derived from them by some pro- 

 cess of alteration. The relation of ihis pegmatitic development to 

 tile normal variety of the rock cannot be ascertained with certainty, as 

 the contact is covered l)y drift. A true quartz orthoclase pegmatite, how- 

 ever, occurs protruding through the drift in the immediate vicinity of 

 the occurrence just described and in such a position as to suggest that 

 it is a differentiation product of the same ma^gma. A reddish syenite 

 containing some biotite, and similar to that found in so many parts of 

 the area in association with the nepheline syenites is also exposed in the 

 immediate vicinity. 



Another important and interesting occurrence is that which in the 

 form of a comparatively nan-ow band is exposed at intervals along the 

 Monck road to the east of the village of Gooderham on cons. V. and VI 

 from lot 89 to lot 35, and then curving north with the strike of the 

 countiT rock extends to the front of con. VIII. Just to the north of 

 the road, on lot 29, con. V, the rock is seen as a pale gray gi-anular syen- 

 ite containing in places a little nepheline and also holding a small amount 

 of black mica. So closely does it resemble the crystalline limestone 

 through which it cuts and to whose strike it conforms, that the two 

 rocks are with difficulty distinguished from one another by their ap- 

 pearance. On lot 31, con. VI, it is seen intimately associated with, and 

 occurring as schlieren in, the great quartz pegmatite masses which here 

 border and probably cut the granite gneiss. In places on this lot, it 

 holds nepheline, although never in large amount. 



IV. Tlie Nepheline and Alkali Syenites of the Townships of Harcourt, 

 Cardiff and Wollaston. 



The occurrences in these townships are of comparatively small ex- 

 tent. 



In the township of Harcourt, on lot 15, of concession I, there is a 

 fine exposure of the nepheline rock in a cutting on the Irondale, Ban- 

 croft and Ottawa railway. It is bounded on the north by the heavy band 

 of crystalline limestone which sweeps around the northern end of the 

 Cardiff bathylith, the limestone being seen just north of the railway 

 track in large exposures consisting of nearly horizontal beds. The lime- 

 stone here is nearly pure and free from admixture of silicates, but in 

 some bands is dolomitic. The nepheline rock appears to form a narrow 



