388 SECTIONAL TRANSACTIONS.—C. 
They are comparable to the Animikies and Keweenawans of Canada in position 
and general features, but there is independently indirect evidence of their being 
older than Carboniferous. 
With these are considered the highly folded and foliated basement complex, 
which is separated by a great erosion interval, assumed to correspond to 
Lawson’s Eparchean interval and the interval between the Algomans and the 
Cobalt series in north-east Ontario. 
As the whole pre-Cambrian has now been worked out more satisfactorily in 
Ontario than in any other part of the world, the classification adopted there is 
taken as a guide in the attempt to find analogies among the old formations in 
India. The possibility of a general correspondence between the great ‘ breaks” 
is thus recognised as a preliminary working guide, qualified by the probability, 
almost certainty, that correspondences even of the partial exactitude accepted 
among fossiliferous formations do not occur. 
With this working hypothesis in view, the assumption that the Dharwars 
in India are our oldest sediments merits reconsideration. The doubtful nature 
of this assumption was indicated in 1913 (Compte-Rendu, Congrés Géologique 
Internat., 378), and in the absence of continuous mapping, deformed eruptives— 
granites, anorthosites, nepheline-syenites, &c.—associated with the basement 
complex were referred to as petrographical provinces Archean in age, but of 
unknown relations in age to one another and to the Dharwars as a whole. 
Unconformities of a major kind like that now recognised as separating the 
Laurentian and Timiskamian in Ontario were also indicated in 1913 as occurring 
in the basement complex of India. Recent work in Canada will enable workers 
in India to examine more critically the formations grouped together as Dharwar 
because of their general lithological resemblances. Some possibly correspond 
with the Timiskamian and others with the immensely older Loganian schists. 
Reasons are given in this paper for confirming the dual group correlation 
adopted in 1913. It is urged that the interval between the Dharwars and the 
Gwaliors in India and that between the Timiskamian-Algoman and the Cobalt- 
Sudbury series in Canada should be recognised still as a main group boundary 
of greater practical importance than that between the Loganian and 
‘Timiskamian. 
The additional modification of the term Archean, which has followed recent 
work in Canada, suggests the adoption of new group names, one for the pre-Cambrian 
abeve the Timiskamian, and one for the enormously larger group of foliated rocks 
below. 
(d) Dr. M. E. Wison.—The Grenville Pre-Cambrian Sub- 
province.* 
By far the greater part of our information regarding the geology of the 
Canadian Pre-Cambrian shield has been obtained in the territory lying 
along its southern berder and chiefly in four districts or subprovinces : (1) the 
region north-west of Lake Superior; (2) the region south of Lake Superior 
in United States; (3) the region extending north-east from Lake Superior 
and Lake Huron to Lake Timiskaming and Lake Huron—Timiskaming Sub- 
province—and (4) south-eastern Ontario, the southern Laurentian highlands 
of Quebee and the Adirondack region, which together form the Grenville sub- 
province. These districts are geographically and geologically separate from 
one another, for between the Grenville and Timiskaming subprovinces there 
intervenes a belt of banded gneisses, between the Timiskaming subprovince 
and the western subprovinces there is the wooded Pre-Cambrian highlands, largely 
underlain by granite and granite gneiss on the north and the overlapping 
Paleozoic sediments on the south, and between the north-western and south- 
western subprovinces lies Lake Superior. 
The purpose of this paper is (1) to outline briefly the geology of the most 
easterly of these subdivisions—the Grenville subprovince—and (2) to indicate the 
most probable relaticnships of the formations of the Grenville subprovince to 
those of other parts of the Canadian shield and more particularly to those of 
1 Published with the permission of the Director, Geological Survey, Canada. 
