The Wallace miner. [volume] (Wallace, Idaho) 1907-current, 1914-05-07
Economic Geology Of the MuIan Copper Belt
Omitted States Geological Survey

With the interest now centering
around the great copper belt at Null
Ian the following extracts from the
L. S. geological survey report OF the
advance chapters on economic geolo-
Ky of the region around Mullan VIII
be found interesting. The report is by
+. c. Calklns and t. l.. Jones, Jr, ana
Is an advance chapter on Bulletin 5io,
which can be obtained by application
to the survey. At the time this dis
trict was examined the National mine
had not reached its present favorable
development. Following is a'portion
of the report relating to the copper
belt.
Snowstorm Copper Belt.
The Snowstorm copper belt runs
northwestward along the south slope
Of the ridge north Of the South Fork
of the Occur d'Alene river at an av-
erage distance Of about mile and
half from that stream. Its only pro-
ductive mine Is the SnoWstorm, the
bulk of whose ore comes from
ouartzite stratum about 40 feet thick,
in which cupriferous sulphides and
carbonates are disseminated. The
copper bearing stratum appears to eX-
tend for considerable distance north
westward and is apparently tapped by
the Snowshoe, Missoula Copper and
United Copper prospects; but Its tenor
Is uneven and 1t has not yielded ore
of proved commercial quantity and
quality except in the Snowstorm mine.
In the National tunnel of the United
Copper property, however, 1t shows
good promise. The Copper King
prospect, farther west Is conveniently
grouped with those mentioned be-
cause Of its position and its copper
content 1t does not show, however,
the continuation OF the Snowstorm
ledge and contains considerable ga
lena, so that it may be regarded as
Illustrating the transition from the
copper belt to the lead bearing area.
East Of the Snowstorm mine the ledge
is f0uited down and its eastern con-
tinuatien has not been found, SO far
as known. The so-called East Snow
storm and Pandora prospects are in
higher beds south of the fault and no
commercial ore was seen in them,
Some prospects north of these were
not visited
Snowstorm Mins-Economic Features.
The Snowstorm mine is of especial
interest because it is still the only
producer of copper in the district, be-
cause of the uncommon character OF
its ore, and because it presents an i'm
portant practical problem of geologic
structure, 1t is for the last reason in
particular that a reeNamination has
been desirable, for the great amount
of development work done since 1904
has revealed structural details that
were not then apparent.
The mine is situated In Daisy gulch
which empties into the South Fork OF
Occur d'Alene river, about 8 miles
above Mullan. The present working is
a tunnel 1850 feet above sea level
near the entrance of which has beer
erected large boarding house ane
several other buildings used in work
ing the mine. The ore is Transported
by aerial tramway to Larson, al the
mouth of the gulch where there Is ,
station on the Occur d'Alene branch
OF the Northern Pacific railway Lar.
son consists of buildings owned by the
Snowstorm Mining 4 Milling company
including the mill and the principa
Office. In the fall of 1912 about l0'
men were employed at the mine ant
about so at the mill.
Information supplied by the com
pany concerning the production OF tn,
mine in recent years is given in The
table below, Each yearly interval be-
gins on July /.