The Wallace miner. [volume] (Wallace, Idaho) 1907-current, 1918-04-04

Il
miles west of the town Of Mackay in
the broad agricultural valley Of Big
Lost river, where the elevation Is about
5000 feet, and with which II Is con-
nected to the Oregon Short Line rail-
way shipping point at the foot Of the
mountains by Shay railway on a 6
per cent grade six miles in length.
Copper Basin Mines.
Extending west from the Empire
Copper company's property for Is
miles to Copper Basin is a series of
rugged mountain crests and canyon
exposures of limestone quartzite and
intrusive dixie conditions that present
an exceptionally favorite field for
prospecting effort
Immediately west Of the Empire pro-
perty Is the recently developed large
bodies of new lead ore previously de-
head of the East Fork of Lost river,
the Copper Basin Mining company is
operating and developing deposit of
copper ore that exhibits somewhat
similar geologic conditions to the ore
occurrence on the Empire property.
At this point a mineralized zone, sew
eral hundred feet wide, traverses a
rather low mountain spur near the
border Of broad, open, grassy basin
10 miles in diameter The formation
consists, in crosssections, Of series
OF highly siliclfed limestone and soft
lime shale beds. bordering the buried
crest Of body of granite porphyry
that is known to be 700 or 500 feet
broad by a crosscut tunnel section
but shows no conspicuous outcrop.
The strike Of the zone Is nearly
north and south. On the western
border Of this main igneous mass
glory hole quarry has been opened at
the surface and tapped at depth of
60 feet by a crosscut tunnel that ex-
hibits an ore body 80 by so feet In d.
mension, from which several thousand
tons Of mineral have been shipped
crude, obtaining an average value of
about per cent copper in the form
Of copper oxide and carbonate with a
strong mixture of magnetic iron.
On the east side Of the big porphyry
zone the main copper bearing zone
exists. This is several hundred feet
wide and carries series of vertical
assures and one thick dixie Of black
diabase rock with numerous shallow
surface developments and manifesto
lions Of copper carbonate and red
oxide mineral. The principal opening
is vertical shaft, 100 feet deep, start
ed on surface manifestation of red
oxide ore In a hard silicious gangue
slopes and crude ore shipments
amounting to over 1000 tons, ranging
in value from to Is per cent copper
A drift along this fissure at the 1907
foot level encountered a series Of To-
degree flat dipping beds of soft, black
lime shale quite uniformly mineralized
with a dissemination Of pyrite and
chalcopyrite, in which stope has
teen opened and the entire product
shipped crude, and has maximum di-
mansions of 40 by 80 by 60 feet. The
total length of this body of mineral
Is demonstrated to be 120 feet in the
drift. The stopping value Of this OPP
ening averaged 3 per cent copper. The
gangue is friable and disintegrates
rapidly on exposure to the air. and
with its bright, live sulphide contents
presents an attractive material for Or
binary concentrating methods. Anoth-
er vertical orebearing contact assure
traverses the zone a few hundred feet
east of this sulphide ore body, and is
the probable source of the sulphide
mineral here exhibited that has re-
placed the soluble lime shale after the
manner Of naturalization common to
the Park City lead silver and copper
ore deposits.
Sims Copper.
In Lemhi county six miles south of
the Gilmore lead-silver mines, and d.
rectly in the strike Of the same fissure
system, at an elevation of 10000 feet,
there is exhibited body of eruptive
granite 1000 feet long and 1000 feet
broad, bordered by quartzite to the
west and heavy bedded limestone to
the east with numerous spur bikes of
intrusive igneous rocks of finer grain.
Along the margins of this great body
of eruptive mattel for several thous-
and feet in length there is exhibited
succession of lense- shaped bodies of
massive magnetic mineral up to 100
feet thick, with fairly uniform dis
semination of copper carbonate min
eral and liver colored copper oxide |
spots that is said to give this great |
body of iron ore where 1t Is 100 feet |
wide, an average value of IN per cent |
copper and about $3.50 gold and silver |
per ton.
On the opposite eastern margin of
this igneous outcrop on the Tempest |
claim of the Sims group a broad
zone Of garnet rock is exhibited with
considerable soft brown iron and cop
per oxide. from the surface of which
several carload shipments of hand