Lake Superior Stratigraphy. — Laivson. 325 
naga granite upon which the Animikie rests unconformabl}*. In 
other words the break which Prof. Van Hise describes is within 
the Keewatin group and would seem simpl}- to divide that group 
into an upper and lower series. Corroborative evidence of this 
is' seen on following the clastic slates which accompan}^ the Ogishke 
conglomerate, through to Basswood lake. There they are seen 
in contact with the Basswood area of Laurentian granite-gneiss 
and the contact is again irruptive. These observations are 
given in advance of a geological report on the Hunter's Island 
region which I have in preparation but which may be delayed some- 
what in publication. Other arguments might be advanced but I 
have, I think, given sufficient to demolish the correlation of the 
Ogishke or "Upper Vermilion" with the Animikie. 
As to the Kaministiquia rocks I have simply to sa}^ that Prof. 
Van Hise's visit to that district must have been very hurried or he 
would have observed that the same fragmental rocks which he re- 
fers to, come out close to the shores of Thunder bay and form the 
basement upon which the undisturbed Animikie rocks rest with 
the same strongly marked unconformit}^ as that exhibited at 
Gunflint lake. They are here intimately and apparently insepa- 
rably involved with other Keewatin rocks and the whole group is 
again invaded by Laurentian granite so that there is no possibility 
of correlating these rocks with the Animikie. With reference to 
the Huronian of lake Huron I have long been of the opinion that 
there were probably two groups of rocks included under that 
designation. As to the geological position of these Huronian 
rocks I have always been in very much doubt and am as far to-day 
from any settled opinion on that point as I was when I first looked 
into the question. The earliest descriptions of Huronian and the 
investigations of Irving go a long way to show that some of these 
rocks are the equivalent of Animikie. The original observations 
of Murray and the more recent ones of Barlow* indicate that there 
is a portion which bears the same relation to the Laurentian as 
does the Coutchiching and Keewatin. On this latter point the 
evidence is more explicit and satisfactory to my mind than that 
favoring the correlation with the Animikie. The unsettled condition 
of the Huronian question is a great hindrance to the progress of 
clear and correct ideas in an extensive field of geological research. 
*On the contact of the Huronian and Laurentian rocks north of Lake 
Huron. Am. Geologist, July, 1890, Vol. VI, No. 1. 
24 
