Coiiglomeratesin Gnelssic lerrcmes. — A. WincheU. 259 
ment, beyond the Canadian border, I feel sure that the case is 
different in cis-Canadian territory. It may be well, however, 
to ascertain from the documents precisely what has been "so 
well and so long known." In his description of the Lauren- 
tian system,* Sir William Logan says : " Notwithstanding the 
general crystalline condition of the Laurentian rocks, beds of 
an unmistakably conglomeratic character are occasionally met 
Avith among them. * * * On the twenty-fourth lot of the 
tenth range of Bastard (in the valley of the Ottawa) a bed of 
conglomerate is interstratified between two of the beds of 
limestone." The following is an abstract of the more detailed 
succession given changed here to descending order. 
Limestone, coarse-grained, white <> it. 
Limestone, fine-grained, arenaceous . 4 in. 
Sandstone, fine-grained, calcareous • - iu. 
ConfirZom<?roie, coarse, of Avliich the matrix is a fine-grained, 
qxiartzose sandstone. Contains among others, pebbles 
of sandstone. These are flat, and lie on their flat sides 
in the general plane of the stratification 1 ft. (5 in. 
Quartzite, somewhat fine and calcareous 2 in. 
Quartzite, coarse, granular 4 in. 
Limestone, white, crystalline, coarse-grained ■") ft. 
Again, he speaks of a locality north of the village of Madoc, 
at which, in a higher geological position, a somewhat mica- 
ceous schist occurs, which holds "numerous fragments of 
rock different in character from the matrix, all being without 
calcareous matter, and some of them resembling syenite or 
greenstone. North from this ridge another succeeds, consist- 
ing of micaceous schists, beyond which for 300 yards, ridges 
of a decided conglomerate, with distinctly rounded pebbles, 
enveloped in a matrix of micaceous schist, alternate with 
ridges of schist containing few or no' pebbles. * '- 
Still further north, another band of conglomerate occurs, 
associated with fine-grained, soft, micaceous, feldspathic schist. 
The matrix of the conglomerate weathers white, and ap- 
pears to be a dolomite. The pebbles, of which the largest may 
be six inches in diameter, are cliiefly quartz, but there are also, 
pebbles or masses of feldspar, and a few of calc-spar. The 
quartz pebbles are for the most part, distinctly rounded.'' 
It will be noticed that while these occurrences are em- 
braced, in a wide sense, in the Laurentian system, we learn of 
no pebbles or conglomerates embraced directly in Laurentian 
gneiss. They are contained in beds whose aqueous origin 
MJeology of Canada, ISG.'i.pp. 22-4!) 
