Miles and 
Kilometres. 
186.6 m. 
298 km. 
16720) TH. 
300 km. 
190.7 m. 
305 km. 
IIo 
Tenaga—Grenville limestone is exposed in 
the bed of the small creek to the west of the 
track. The Gatineau river has a large and 
strong whirlpool at this point. 
The chute below Kirk Ferry owes its exist- 
ence to a band of Grenville limestone, followed 
on the upstream side by a band of syenitic and 
granitic gneiss. The strike of the contact is 
approximately at right angles to the river, and 
the different resistance of the two rocks to 
erosive forces has given rise to the fall. The 
limestone is exposed in a cutting just below the 
fall, where associated intrusions of binary 
granite and gabbro, the latter with typical 
veins of the mica-bearing type, can also be seen. 
A two foot (‘6 m.) vein of mountain cork in 
the same cutting is worthy of passing mention. 
Immediately north of the cutting, vertically 
disposed gneissic banding is excellently displayed 
in the face of a small cliff to the right of the rail- 
road track. 
Kirk Ferry—Alt. 294 ft. (89.9 m.). After 
crossing the river and climbing up a bank of 
Leda clay the road runs along the edge of a hill 
of granite-gneiss which is typical for the district, 
though in some places, for example the north 
hill of the Nellis mine, gneissic banding is more 
strongly developed. 
Tourmaline pegmatites are a feature of the 
district, and several of them, cutting the granite- 
gneiss, can be seen from the road. 
Near the bend in the road can be seen an ex- 
posure of very impure limestone. In addition 
to carbonates this rock contains pyroxene, 
plagioclase, microcline, light brown mica, titanite 
and pyrite. On the roadside approaching 
Blackburn creek, Leda clay is exposed. This is 
one of the few points in the district where the 
lamination can be seen. Granitic gneiss is 
exposed just east of Blackburn creek, and the 
exposures to the south have similar rocks much 
injected by pegmatitic dykes and veins. 
