A. Winch ell en the Anhnike in Minnesota. 17 
lying Animike rocks the equivalent of the perpendicular clastic 
slates of the Vermilion lake iron-bearing schists; but he at- 
tempts to remove the difficulty by stating that broad gneissic 
and granitic masses e\'eryvvhere intervene between the areas of 
the two sorts of schists, and reminding us of the possibilitv that 
the upheaval of them might leave the strata on one side at no 
great distance from the upheaval, still in a horizontal position, 
while those on the opposite side may have been tilted to verti- 
cality. It is useless to discuss the correctness of the principle, 
since it noAv appears that the Animike slates and the Vermilion 
slates are not always separated as supposed. I cannot occupy 
the space in the present article requisite to prove this position; 
since, after explaining to the general reader what the Animike 
series is, it is my sole object to point out some interesting ex- 
amples of its unconforn.ity with older rocks. 
The vertical earthy schists which embrace the vast ha?matitic 
deposits of Vermilion lake, in northern Minnesota, are tracea- 
ble, without an}- important discontinuity, nortl:ieastward to Oak 
lake, which lies on the boundary immediatelv west of Saganaga, 
and eastward to West Seagull and Frogrock lakes. At this 
limit a coarse syenite, with scattered, large angular individuals 
of quartz, intervenes for a distance of about twenty miles along 
the national boundary and south of it. This syenitic belt is the 
crossing of the Giant's Range, which trends from the east- north- 
east toward the west-southwest. At Gunflint lake occur the 
first conspicuous exposures of the Animike. The norhwestern 
swell of the lake stretches easterly and westerly into a couple of 
bays bordered on the north by the Saganaga syenite and on the 
south by hills of Animike slate. On the southern side of the 
eastern, or Black Fly bay, the two formations are traceable al- 
most to the eastern extremity, where a breadth of not over 
twenty rods separates the two shores. The hill on the south 
side is crowned with gabbro. 
The lake is bordered on all sides by dark shales of the Animike 
gently dipping southward, excejDt about a mile near the middle 
of the north shore. Here (Halt 1353, see maj)) a very differ- 
ent formation comes into view. It consists of slates, mostly 
argillaceous and parophitic, standing vertically and striking 
N. 72° E. An excursion of half a mile into the interior shows 
