CRYSTALLINE SCHISTS NORTH OF LAKE SUPERIOR. 399 
too are Huronian in large measure. My own suspicion is that in all of this 
region there are two distinct kinds of schists—the iron-bear- 
ing schists of the Huronian, and the schistose greenish phase 
of the older gneiss. These having been taken together by the 
Canadian geologists, and the whole region being relatively 
so poorly known, it is impossible now to separate them. 
But the decision that both the flat-lying Animikie slates 
and some of the more northern folded iron-bearing schists 
9 STSITPS MPUTLTAG UDLT 
dky Suraoys ‘uoroos pozrpersu9y— "pe “Ol 
are Huronian renders it necessary that I should present g § 
some suggestion as to the structural relations of the two. 2 % 
Though my knowledge of the region and of the nature of : 
the older rocks is yet too limited to allow of very confident 5 
generalization, I have but little doubt that the relation is = & 
some such as indicated in the accompanying diagram. That : 
this is the true relation is rendered probable not only by the y 
lithological similarity and present attitudes of the two groups, 3 * 
put also by the fact that at several points a curving upwards 
of the otherwise very flat Animikie beds, where they come 
into contact with the underlying granite and gneiss, has been 
observed. I saw this curving myself on the north shore of 
A 
NL 
Thunder Bay, where the two formations come together ; N. 
7 
‘al 
H. Winchell, if I have understood him correctly, observed 
we, 
22282 
Sas 
something of the kind on the national boundary; and Mr. 
G. W. Stuntz again at the Mesabi Range. The same sort 
of relation must certainly subsist on the South Shore be- 
a 
Paris 
“NS 
NR ek 
tween the eastern extension of the unfolded rocks of the 
—--=2: 
Penokee Iron Range and the highly folded iron bearing 
f=) 
schists of the Menominee region.’ 
On the South Shore the relations of the different schistose 
dnoLg ery2Iwmypy 
1 This was written in 1881. Since then (1882) N. H. Winchell has published 
(in the Tenth Annual Report of the Geological Survey of Minn.) some notes on 
the geology of the vicinity of Gunflint and Saganaga Lakes on the national bound- 
ary, in which region the unfolded Animikie and folded schists approach each 
other closely. Winchell notes the peculiar lithological similarity here obtaining 
between these two sets of rocks, and suggests their possible identity. 
‘SUSUI[OS OV] UO[UMI A OY} 07 Cnosy oTyLUMLTY oY} Jo WoLyR[or [BO}OTT}O 
