107 
by the waters accompanying the igneous intrusion and 
re-deposited from solution, along with the graphite. This 
calcite has a distinctly different appearance from that of 
the ordinary Grenville limestone. 
About 200 feet (61 m.) southeast of the main pit is 
another opening, in which one of the blue ‘‘quartz veins”’ 
is seen cutting Grenville limestone. A dense aggregate of 
graphite flakes reaching a thickness of one foot was found 
on both sides of the vein. 
At the swamp pit, not now exposed, highly altered 
limestone is in contact with a biotite-gabbro, which is cut 
by “blue quartz veins.’’ The ore, which attained two or 
three feet (-6 to -9 m.) in thickness, was entirely within 
the gabbro. 
An interesting section is to be seen at the opening in the 
south face of the Pre-Cambrian area. At this point, where 
the rocks have a dip of 60° to the north, there is a band 
of ore one foot (-3 m.) thick at the contact between silli- 
manite-garnet-gneiss and an overlying limestone. Near 
the ore the limestone is dark blue in colour with lighter 
yellowish patches in it up to the size of a hazel-nut. Above 
this the limestone is coarsely crystalline. The cause of this 
colouration is not known. 
The Dominion mine was opened up in I910 and the 
mill was erected in the latter part of that year. Work 
was continued until the latter part of the summer of I912. 
The ore is roasted in kilns at the top of the hill so that it 
may be more readily crushed, and passes by gravity 
through a series of crushers. On reaching the mill the 
graphite flakes are flattened and separated by a dry 
process, the fine rock powder passing through rotary screens 
which do not allow the graphite to pass. 
iecagq  NNOTATED GUIDE (continued). 
Wectsineite’. 
154-6 m. Immediately west of Buckingham Junction 
247-5 km. station the Lievre river falls over the Pre- 
Cambrian margin just before joining the Ottawa 
river. Continuing westward, the railway fol- 
lows the Pre-Cambrian margin, which is more 
masked by the blanket of post-Glacial deposits 
than it is to the east of Buckingham. 
158-4 m. Angers—Alt. 183 ft. (55:7 m.). 
253°5 km. 
