The Diabasic Schists— H. V. Winchell 19 
jasper and iron ore beds of the Vermilion lake region in Min- 
nesota. The jaspilyte and the enclosing rocks have both been 
considered sedimentary;* the jaspilyte has been called eruptive 
and the green schists in v^hich it lies sedimentary ;t the jaspi- 
lyte has been regarded fragmental and the schists eruptive.J 
A few considerations on the subject prompted by recent ex- 
plorations and developments in this region may be of interest. 
In the western part of the iron region the ore is nearly all 
in the sesqui-oxide state, and it has been supposed to be such 
throughout the range. The schists which enclose the ore and 
jasper beds (jaspilyte), are frequently iron stained to such a de- 
gree as to render it impossible to form an opinion as to their 
original nature and appearance. Dr. Wadsworth refers to 
them as ''baked" by the intrusive action of the eruptive jas- 
pilyte. They are very generally soft and schistose. In places 
there is a banded structure nearly or quite coincident with the 
schistosity. This has been accepted as proof of aqueous dep- 
osition. 
Going east along the iron range the green schists are seen to' 
be less strongly impregnated with iron rust and less schistose. 
There is also seen in them a coarse conglomeritic structure in 
which the boulders all seem to be of the same material as the 
schist itself, but contain calcite amygdules around their peri- 
phery and to a certain extent in the boulder-mass. The iron 
ore is no longer hematite only, but is inthnately associated 
with magnetite. 
Around Ely, in the vicinity of the Chandler mine, on the shores 
of Long lake, north of the mine and a mile inland south of the 
mine and lake, this coarse conglomerate is seen to have an im- 
mense development. East of Ely the iron ore becomes more 
and more magnetitic, until, in township 63-9, west of Snow- 
bank lake, are found large lenticular masses of jasper and 
magnetite included in the green schistose conglomerate. 
In this township the green schist also assumes new characters. 
It is seen to rise in hills or ridges 250 feet or more, stretching 
for three or four miles toward the east-north-east. In it is 
*A. Winchell, 15th Annual Report Geol. and Nat. Hist. Sun, Minn. p. 193. 
tM. E. Wadsworth, Bui. Mus. Comp. Zool., Geol. Series i. 
JN. H. Winchell, 15th Annual Report, Geol. and Nat. llist. Sur., Minn., 
p. 221. 
