The Ely miner. [volume] (Ely, Minn.) 1895-1986, 1904-09-02

avian series which comes in contact
with them and in places overlies them
in this district. The extensive deve-
lopments of iron deposits in these Up
per Huronian formations in the
Mesabi and Penokee-Gogebic districts
has been the basis of hope that
these Vermilion rocks might likewise
prove of economic Importance. In
the Gunflint horizon are found iron
carbonates, bands of jasper, magnetic
ebert, quartz with actinolite and
grunerite crystals. With these are
associated magnetic, hematite, and
limonite. Mr.. Clements concludes
that these iron-bearing rocks are
clearly phase of the Gunflint form
alton metamorphosed by the gabbro
and not related geologically TO the
magnetic iron ores Of the Keween-
avian. In support of this he points
to the absence of titanium in the Gun
flint ores. The author considers s'the
product one of magnetic etc., to have
taken place as result of the meta
morphism produced by the Duluth
gabbro. and. consequently, that the
iron in the rocks must have accumu-
lated prior to the Keweeeawan time.
AS result Of the metamorphism the
rocks were so changed that no furth-
er concentration of iron took place
and, consequently, we find these de-
posits in this part Of the district diff
fer both in Photographic character
and in size from the great deposits of
the western Mesabi or Mesabi proper,
whose concentration was not serious
ly interfered with except locally, dur
ing Keweenwan times, but as coDtinu-
ed on up to thepresent."
The explorations for iron in the
Gunfiint formation have been extern
sive, but so far without any success.
The formation extends into Canadian
territory, where it is better developed.
A chapter is devoted to the Keween-
avian series, although these do not
properly belong in the Vermilion dis
trict, because of the occurrence of the
considerable masses of titaniferous
magnetic in the gabbro member of
the series which succeeds the Upper
Huronian in the eastern end of the
district. The extensive Duluth CAB
bro, is conclusively established as in
truSive Its effect on the iron-bearing
series with it is in contact has been
great. and, as has been pointed out,
has generally interefered with the
contained iron was concentrated into
deposits of economic Importance. In
the gabbro itself are formed masses
of titaniferouS magnetic which are
clearly segregations from the original
magma. The report does not recog-
nize any large continuous masses of
this ore as has been reported by the
explorers. More than that, the large
"content of titanium would prevent
hem from being of value at the pre-
sent time, when according to modern
iron-smelting practice, titaniferous
ores cannot be smelted economically"
Analyses by Wincheli show that
the titanium binoXide in these ores
runs as high az II per cent. The re-
port Of nickel in the ores in economic
quantities is not seriously considered,
nor is anything said about the claim
that vanadium is associated with
these ores in quantities to make ii
profitable to utilize the ores for the
production of ferro-yanadium.
This portion Of the report, though
not exhaustive, will be considered OF
special interest because Of the recent
a tempt to exploit these
| titaniferous ores, 1t Is to be
regretted that the report die
not go more exhaustively into the dis
cussion of these Keweenawan deposit.
in order to definitely clear the public
mind on the question. The report
makes clear that in the Vermilion
district there are three distinct iron
bearing horizons-the Soudan in thu
in the Archean series, the Agawa il
the Lower Huronian, and the Gun
flint in the Upper Huronian-not con
sidering the titaniferous segregation
in the Keweenawan rocks This il
an important point for explorers ant