The White Pine news. [volume] (Ely, Nev.) 1906-1910, 1909-09-26

Ely, Nevada, like Bingham, in it's
early days was well known on ac-
count of it's silver-lead and its gold
mines, and now both are famous for
copper bearing porphyry ore bodies,
says Mines and Methods of Salt Lake,
in it's current number. While Bing-
ham also has heavy sulphide smelt-
ing ores, such as those at the High
land Boy mine and the sulphide ore
body of the Boston Consolidated
company, at the Alpha shaft deposit
of the Giroux Consolidated Mines
company is the only copper Ore body
in Ely camp that is sufficiently rich
to be smelted directly. This ore body
has been oXidized to a great depth,
being so where seen On the 1000-foot
level, and contains much native cop
per. The ore is high grade for much
of it assays over 20%o copper. The
property has been opened to a depth
of 1880 feet, but sinking had to be
discontinued because of striking too
large a flow of water for the pumps
to handle. A new shaft, the Giroux,
is being provided because of the
small size of the Alpha shaft and the
weak nature of the ground through
which that shaft is sunk. The Giroux
shaft is in the limestone about 500
feet southwesterly from the Alpha
shaft. 1t is being advanced by rails
ing from the 1O00-foot and the 700
foot levels and by sinking from sur
face.
But it is with the porphyry ore
bodies that we are at present con-
cerned. As has been said. the ore
occurrence at Ely is not nearly so
similar to that at Bingham as many
seem to think. At Bingham the in
trusion of monzonite porphyry was
nor laccolithic in character, while
at Ely the intrusion was more in the
nature of a dixie. 1t cuts persistent
ly across the bedding planes of the
different horizons of the limestone
country.
The whole area has been subject
to much Undertaking. action, and the
monzonite has been much kaolinized
in places so that it is much weaker
than at Bingham. In fact most drifts
in Ely monzonite have to be timber
ed, while at Bingham most of the
drifts stand without any need of sup
port.
The ore bodies at Ely are due es-
sentially to secondary enrichment as
is clearly indicated by the sudden
change, within a vertical distance of
five feet, from Gaping carrying only
a trace of copper to ore carrying LIS
per cent copper. This secondary en-
richment occurred at water level. and
so the top of the ore bodies is fairly
fiat, rarely undulating through a YER
tical heigth as great as 80 feet in the
ore bodies neal enough to surface to
be worked by steam shovels, but be-
ing somewhat greater in the de-
posits covered by Gaping 80 feet or
more thick.
This fiat character of the top of
the ore body, the fact it bears no re-
lation to the fluctuations of the sur
face Immediately above it, and the
general rolling character of the sur
face at the places where the Gaping
is thin enough to permit economic
stripping with steam shovels, makes
Ely an ideal camp for the use of
shovels wherever the Gaping is not
too thick.
The depth of the Gaping varies
throughout the district being only
80 feet thick in some places and over
700 feet in others, depending partly
upon the height of the local ground
water level when that particular ore
body was formed, but mainly upon