_ 192 ROYAL SOCIETY OF CANADA 
In Pontiac county in the province of Quebec, Mr. A. $. Cochrane 
obtained specimens of a gray shaly sandstone, chloritic, and hydro-mica 
schists along with dark green schistose diorite which have since been 
classified in the Huronian. In the districts of Nipissing and Algoma, 
we have classic ground for the student of Huronian geology. It was 
on the north shore of Lake Huron that the original Huronian rocks, as 
described by Sir Wm. Logan, Alexander Murray, Dr. Bell and other 
Canadian geologists were first studied. The Huronian is very 
extensively developed, and forms numerous, wide, more or less inter- 
rupted bands between Lake Huron and James’s bay. It is in this region 
that the Huronian system attains its greatest development. The 
Huronian is well described by Dr. G. M. Dawson in his summary on the 
Archean of Canada, read before the British Association for the Advance- 
ment of Science, Toronto Meeting, 1897, in which he writes: 
“The Huronian comprises felspathic sandstone or greywacke, 
more or less tufaceous in origin, quartzites, and arkoses passing into 
quartzose conglomerates and breccia conglomerates, often with large 
fragments of many different varieties of granite, syenite, etc., diorite, 
diabase, limestones, and shales or slates changing to phyllites in con- 
tact with the numerous associated igneous masses. Over wide areas 
altered greenstones and their associated tuffs preponderate, often with 
micaceous, chloritic, sericitic and other schists, many of which are of 
pyroclastic origin, although some may represent ordinary aqueous de- 
posits, and all have been affected by subsequent dynamic metamor- 
phism.” 
It will thus be seen that the Huronian system is partly sedimentary, 
and partly igneous. 
In the Nipissing and Lake Temiscaming regions just recently 
described by Dr. Barlow, the Huronian rocks were found to be widely 
developed, especially in the north-western part of the region. They 
consist of the basal series made up of “ breccia-conglomerate, con- 
taining pebbles and fragments often angular though usually subangular 
or rounded in outline, of granitite, diabase, diorite, etc., embedded in a 
matrix composed of the same materials in a finer state of division, while 
the more minute interstices are filled up with scales and flakes of 
chlorite and sericite.” 
This fragmental rock passes up and into a greywacke which in 
turn merges above into an exceedingly compact and fine grained rock of 
similar composition which gradually assumes a banded and slaty char- 
acter. The latter forms the slate or shale division of the series. Super- 
imposed upon these directly, a quartzite grit made up chiefly of granitic 
quartz and felspar, resembling arkose, are found. 

