SECTIONAL TRANSACTIONS.—C. 387 
EOZOIC OR PRE-CAMBRIAN 
Present Classification of pre-Cambrian Logan's Classification of 1857, 
Rocks at Cobalt and Lake Timiskaming. based on visit to Lake Timis- 
kaming in 1845, and later to 
Lake Huron. 
Nipissing diabase, &c. 
[Nipissing 
Upper + ANIMIKEAN Huronian 
| Cobalt series—conglomerate, Conglomerate, &c. 
&e. 
GREAT UNCONFORMITY 
( MATACHEWAN 
Diabase, &c. 
ALGOMAN Laurentian 
Middle ap hourai granite. 1 Granite, gneiss. 
AILEYBURIAN 
Lamprophyre, diabase, &c. 
TIMISKAMIAN 
Conglomerate, &c. 
GREAT UNCONFORMITY 
LAURENTIAN 
Represented by granite peb- 
bles in Timiskamian conglo- 
merate. 
LoGaNIANn 
Grenville — iron formation, 
&c., in minor quantity, else- 
where much crystalline lime- 
stone, &c. 
Keewatin—Basic lavas, &c. 
Lower 
While the Keweenawan in this area is represented only by diabase and related 
rocks, in the Sudbury area and along part of the skore of Lake Huron there are 
large intrusions of granite of this age, and arcund the shores of Lake Superior 
Keweenawan igneous and sedimentary rocks occur in great volume. 
Beneath the Keweenawan and above the Algoman in Ontario there are series 
of sediments to which the name Animikean is given in the table. These series 
have not been satisfactorily correlated with one another. Unconformities are 
known, but they are not of the magnitude of that at the base of the Cobalt 
series or of that between the Timiskaming series and the older rocks. 
The relationships of the Timiskaining series have been worked out over a 
large territory, and it appears to occur, in more or less isolated areas, across all 
the northern part of Ontario, and extends into Quebec on the east and apparently 
into Manitoba on the west. 
The Keewatin, with iron formation, is found over a large region across 
Ontario and to the east and west. The Grenville series occurs in greatest volume 
in south-eastern Ontario. 
The name ‘ Huronian ’ is not used in the table, as it has been applied indis- 
criminately to what are now known as the Cobalt series, the Timiskaming series, 
and the Keewatin. Even at present it is employed in different senses by various 
authors, and some of the so-called Lower and Middle Huronian may be Timis- 
kamian. 
(b) Dr. J. S. Fuerr, F.R.S.—The Pre-Cambrian Rocks of Britain. 
(c) Sir Tuomas Houuanp, F.R.S.—The Pre-Cambrian Rocks of 
India. 
It is assumed that sedimentary systems like the Cuddapahs (Gwaliors) and 
Vindhyans are unfossiliferous because of their probably pre-Cambrian age 
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