The Michipicotcn Huronian Area. — Willmott. 19 
gaming, while indecisive because of poor exposures at the 
critical points, confirm Murray's conclusions. Only I would 
explain the facts by the later consolidation of the eruptive 
granite-gneiss — not by a fault. 
Several geologists have divided the original Huronian in 
two, making the break either above or below Murray's lime- 
stone band {e). While it is true that occasional pebbles of the 
limestone occur in the Upper Slate conglomerate I do not 
think the break is at all an important one. It is what Van 
Hise himself has described* as an intraformational conglomer- 
ate to be carefully distinguished from a true basal conglomer- 
ate. The two slate conglomerates of Murray are so much 
alike that they cannot be distinguished. Where the limestone 
band is absent, as it often is, they join, and Murray himselff 
confesses that he could not draw the dividing line. The real 
break, I am convinced lies at the base of the Lower Slate con- 
glomerate and associated quartzytes. The Huronian of lake 
Huron is thus nearly all Upper Huronian. Logan's Huronian 
at Michipicoten included, however, a lower formation, charac- 
terized by its banded jasper and iron. 
The succession of Michipicoten would thus be : 
Keweenawan, volcanics and sediments, 
Laurentian, eruptives, 
L'pper Huronian, 
Lower Huronian. volcanics and sediments. 
In this arrangement, I know that I am ignoring the con- 
clusions founded on a supposed basal conglomerate at Thessa- 
lon described by Pumpelly and Van Hise. J The evidence here 
does not seem to be very decisive, since Barlow § interprets it 
in an opposite manner and after a recent examination I incline 
to his view. Moreover, if true it is almost an isolated case 
against which scores of observations have been made pointing 
to the eruptive character of the granite-gneiss. The . con- 
clusions of Barlow II in the district extending from the Missis- 
saga to the Ottawa, seem to apply equally as well to the region 
from the Mississaga to the Michipicoten and beyond. 
May 50, igoi. 
*Prin. Pre-Camb. Geol., p. 728. 
iRep. Geol. Sur. 1858, p. 94. 
t.Am.Joiir. Sci. 1892, xliii, pp. 224-232. 
iideol. Siir. Can. x, 1897, p. 93, I and references. 
iilb. pp. 59, 60, 92. I. 
