Reviews—Geological Survey of Canada. 135 
part, Lower Devonian, but are now recognized by their uncon- 
formability to the Silurian, as well as by their fossil contents, to 
belong to the Cambro-Silurian. Intrusions of granite are common 
in the rocks of this system, and there is frequent evidence of meta- 
morphic action in the condition of the sandstones and limestones. 
The Cambrian is represented by slates, sandstones—sometimes 
quartzose—quartziferous schists and conglomerates. The latter are 
generally unconformable to the slates and limestones of the Cambro- 
Silurian above, and to the “underlying ridges of crystalline rocks, 
from the débris of which they are largely formed.” The pre- 
Cambrian rocks form some of the mountain ranges of the district 
(Stoke Mountain, etc.), and are composed of hard felspathic schists, 
gneissic felsite, granitic gneiss, talcose and micaceous schists, with, 
in some places, masses of granitic and dioritic rocks, ‘the whole 
presenting a marked resemblance to Huronian strata.’ The 
“copper-bearing rocks” of the Eastern Townships, which are of 
pre-Cambrian age, are described by the author of this report as 
strikingly similar to the Archean rocks of England and Scotland, 
and those of Wales known as the Dimetian, Arvonian, and Pebidian, 
of Hicks. “Whatever may be the exact age of these altered 
rocks,” adds Dr. Ells, “their present aspect entitles them to be 
classed as very ancient sediments.” The crystalline and igneous 
rocks consist of granitic, dioritic, and serpentinous rocks, and they 
constitute lofty ranges of hills, such as Megantic Mountains, Orford 
and Victoria Mountains, etc. Some observations upon the drift 
deposits are supplied by Dr. Ells, who endeavoured to ascertain 
their connection with the auriferous character of the sand and gravel 
which are widely distributed in the region he explored. He con- 
siders that the probable source of the gold of the Townships is in 
the areas of Cambrian slates which flank the old ridges of the Maine 
and New Hampshire boundary and the central axis, and that local 
glaciers were probably instrumental in effecting the disintegration of 
these slates and distributing an auriferous débris over the “ great 
Cambro-Silurian ayea of Compton, Stanstead, and Beauce counties.” 
Besides gold, the following minerals, viz. copper, silver, chromic 
iron, antimony-ore, asbestos, soapstone, slate, etc., occur in the 
district, and are of more or less economic importance. 
Mr. R. Chalmers’ report (pp. 1 M-389 M) treats of the surface 
geology (Post-Tertiary) of Northern New Brunswick and South- 
Eastern Quebec. It is illustrated with two maps each on a scale of 
four miles to 1 inch, having the locality and superficial extent of 
the various formations defined upon them. The surface deposits 
met with are divided by the author into two series, viz. those of 
fresh-water, and those of marine origin, the former comprising peat- 
bogs, shell-marl, lacustrine and fluviatile marshes, river-terraces, 
kames, etc., the latter, estuarine flats, salt marshes, sand dunes, 
Saxicava-sand Leda-clay, and kames of marine origin, ete, and 
lastly till or boulder clay, moraines, and erratics. 
Messrs. L. W. Bailey and W. McInnes report upon their explora- 
tions carried on in portions of the counties of Victoria, Madawaska, 
