The Calumet news. [volume] (Calumet, Mich.) 1907-1938, 1913-10-13
IDAHO MINING GROWTH.
Railroad Extension Opens Up Rich
Mine District.

I
Lemhi county. Idaho. which in general
Is one Of the more important mining
regions Of the west. Situated In the
! cast-central part of Idaho. the county
has until recently been difficult o. ac-
cess, but with the extension of the
railroad 20 salmon in 1910 mining ac-
tivity in parts OF the area took on
new life. In this connection impor-
lance and interes. attaches 10 the
comprehensive report on the geology
and ore deposits OF Lemhi county, by
J. b. Cmpleby, Just issued by tho
Crited States geological survey as
Bulletin 52S.
Placer gold was discovered at Lees
burg In 1866 and soon thereafter lode
deposits were recognized Lc,td-sil-
Yer deposits were worked actively in
The eighties, but not until tho advent
OF the railroad did this industry reach
IFS maximum Importance. The total
production Of the county las been
about S20,000.C0V. tvo-thirds Of
which has come from gold. three
fourths OF the remainder from lead,
about t4O000 from copper. and the
res; from silver. The ore deposits
of Lcmhi county may be grouped as
gold placers and lodes. lead silver
veins ana tabular requirements, cop.
per-bearing gold veins. cooalt-nickcl
deposits. and tungsten-bearirg veins.
Important placer deposits occur about
Leesburs, on Moose Greek. and along
some of the streams which flow from
the Beaverhead mountains. Lode de-
poslts on the other hand, arc widely
distributed n the county, each of the
nineteen mining districts containing
several
The most important gold veins are
widely distributed in the northern
part OF the county They are pre-
dominantly veins Of ooarse-textured
clear-white quartz, along which ore
shoots occur at irregular intervals.
Fow bonanzas have been found in
these deposits, although many OF the
ores are of substantial grade.
Large Deposits Of Lead Ore.
Probably 80 per cent Of the lead ore
mined i'm Lcmhi county is the product
Of the oxidation and CarbOnatiun of
galcna, pyritc and zinc blendc. The
olc is remarkable for its even tenor
averaging about IS per cent cf lead
and - ounces Of silver 10 tie tom
Tho deposits arr large and show cv-
'ry evidence Of continuity. In most
Of the mines about zoo feet Of oxi-
oizcd ore remains between the deepest
Workings ana tho water level. below
which primary orc may be expected. 1t
is q matter Of considerable importance
TO know in what respects the primary
ere Will differ from that now being
mined
studies of the volume changes in
volvad in the oxidation aud carbona-
ton of galena, sphalerite, and pyrite
lead 20 the conclusion that teaching
has been important in the oxidl2ed
zone. From a consideration OF the
RELATIVE soluDility u the oxidation
products it appears that lead has re-
maiucl essentially stable, that iron
has probably been removed sOmcw hat,
and that zinc has been removed IN
considerable quantities. II follows,
therefore, that below the zone OF OK
dalton lead viii decrease appreciably
!n amount per ton or ore, iron will in
crease somewhat. and zinc viii prob
ably increase considerably.
The copper deposits Of the county
havc not proved Of great commercial
Importance. Cobalt nickel deposits are
confined 30 the Blackbrd district.
The arc little developed but some
OF them are known to contain about
" per cent each Of cobalt and nickel.
Tungsten is mined iu the Blue Wing
district where H. is associated with
zinc, copper. lead, moiybdonum iron,
and silver minerals ia lenticular
quartz veins. \ little gold is also
present SiXIy-thtoe mineral species
arc recognized in the ores Of Lcmhi
county