The Wallace miner. [volume] (Wallace, Idaho) 1907-current, 1914-06-11
Mines of Custer, Lemhi, Fremont and
Blaine Counties
From Report Bel, State Mine Inspector

RAPID development Results. These prop
critics carry close set series of paral
lei fissure veins that dip from so de-
grees to nearly perpendicular and arr
/ enclosed in a series of limestone bed.
of opposite dip 1000 feet thick, ex.
/ tending from the underlying Cam.
f brian quartzite through well repre-.
sented horizons of succeeding geolo.
gical age up to the carboniferous
, period.
The ore bodies are lenzy in shape
, and vary from a few inches up tt
. twenty feet Of clean ore
: In the Pittsburg Idaho mine, per-
manent water level appears to have
been struck in a Wine below the 900
foot level, with an accompanying
change to sulphide minerals, consis-
ting of coarsey crystalline loose tex
tured galena with strong mixture
of zine and iron sulphdes, very much
resembling in character the live ore
horizons Of the Park City deposits In
Utah. The geology, however, of the
ItItipHillS lDilldlIDHS 10 dlHlOSl All "a
act counterpart Of the wall rocks of
the Titanic ore deposits in Utah, which
have been profitably operated for SO
years and to a depth of over 1000
feet.
These Gilmore ore bodies have been
persistent, although occasionally in
Iterrupted by short faults in their
downward course to the maximum
The limestone series is 1000 feet thick
and the underlying Cambrian quart
ute, where it has been exposed by the
erosion of the limestone beds further
ore associated with porphyry bikes
that contain higher values in both lead
land silver in some shallow Develop
ment than is found in the limestone
deposits of this class.
Intrusive dikes of the same charac-
ter penetrate the everything limestone
series, and these connected conditions
afford the strongest evidence Of the
bodies entirely through into the un-
DERIVING quartzite formations, indica-
ting a long life for these mines and a
continued and profitable resource Of
desirable lead-siver ore to great
depth.
The principal producing veins In
this district in the limestone formation
are practically blind at the surface,
their position being indicated by iron
stain and gossan blossoms of limited
extent, and it looks as if the total val
liable resources of the deposits were
intact and unhurt by erosion in the
full sections of the limestone beds.
This district carries a number of at
tractiVe prospects; in fact, it Is min
eralized for several miles along the
north and south strike of the ore
courses, which are situated on very
high and rugged range that reaches a
maximum elevation of 1000 feet a.
bove sea level, The producing mines,
however, are well down toward the
ioot VI lllt rang, near lle euSe Oh Il
broad grassy valley and are very con-
Venient of access, with a railway ter
minal within a few hundred feet Of
the works.
The lead-silver vein system is &C
companied by closely parallel ore
course of important size and deve-
opment that carries no lead and on
ly trace of silver, but with gold val
refer under gold ore deposits of the
state.
In another portion of the district
some remarkably interesting copper
ISOLATED with gold and silver values
and free from lead.
Viola Mine.
y notable occurrence of lead orr,
which made quite Il stir in mining cir
cles after its discovery in 1882 for sew
eral years, was that of the Viola
mine, on the opposite side of the
broad valley from Gilmore and about
fifteen miles distant.
This deposit was a fiat shoot of ore
500 feet long, from few inches to
thirty feet in thickness and filled al
most exclusively with sand carbonate
of lead and soft brown iron oxide.
Within two years after its discovery
in 1882, it shipped 5000 tons of 60 per
cent lead ore carrying to 10 ounces
OF silver per ton. 1t was subsequent
ly equipped with q smelter and tradi- I
ton says produced a total value of
S5,000,000 in something like five years
operation. AT that period the mine |
was eighty miles from the nearest
railroad transportation and the market |
value of lead ranged somewhere a
round cents a pound.
The deposit was cut off on its dip |
by nearly vertical fault and has since
remained an unsolved geological pro-
blem.
At the back of this fault a deposit
Of soft brown iron mineral occurs, 200 ,
feet thick and contains light values
in lead, silver and gold. and the pro-
position indicates very attractive OPP +
portunity for further exploitation af-
Ter a systematic geological study,