Lyon County times. [volume] (Silver City, Nev.) 1874-1907, 1906-12-29

finished product in New York at a cost
somewhat lower than Ely's. The recov-
cry at Ely is 80 per cent of the copper
content. At Yerington, Captain De
Lamar's electromagnetic plant claims to
be recovering 95 per cent.
-
The copper at Yerington is not re-
cent discovery. It's existence has been
known for nearly 80 years-was known
to the early California immigrants, for
one of the old overland trails led up this
Walker River Valley and the copper of
the district blossoms extensively at the
surface as the blue and green carbonates
that challenge the most casual and mex
perienced glance. But those immigrants
were out for gold, and immigrants as
class are not usually people who can
house more than one idea at time in
their migratory heads. But in truth the
wealth of copper which they beheld at
Yerington was an entirely unavailable
wealth for them, or even for the gene
ration that succeeded them. 1t is only
in quite recent years, through improve
ments in the means of recovering the
copper from the ores, and the extension
of transportation facilities that such de-
posits as those at Bingham and Ely and
Yerington have become available sources
of wealth. The same is true today of
the many valuable iron deposits which
Nevada contains. A generation or two
hence they will have high commercial
value.
1t is not possible to say what the aver
age run of workable copper ores through
out the country may be, but probably
not far from three per cent in copper
content. The average at Ely will be
about two and half per cent. But the
average of the primary ores" that are
worked on large scale to good profit
at Bingham is, believe, close to one
per cent. s. ,,-
What the average at Yerington may
be on the large scale no one can yet say.
All that has been shipped (probably
80, 900 to $4,000 tons) has probably ex-
ceeded an average of 20 per cent, but
that, of course, was selected ore and fur
nishes no reliable indication of the aver
age of the mass, which fancy will not
much, if at all, exceed four per cent
where it occurs extensively in the lime
by replacement.
There are copper mines in this country
whose average is less than one per. cent
less than 20 pounds of copper to the
ton-yet SO favorably conditioned that
they earn large and steady dividends.
All depends, as / said, on the cost of
laying-down the finished copper in the
city of New York.
THE SOURCE OF THE ORE.
1t seems perfectly clear to my mind
that the origin of this great Yerington
copper deposit is substantially the same
as that of the great deposits at Bingham
in Utah and Ely, in Eastern Nevada
that is to say, that the primary source of
the ore is, in each case, vast laccolite,
a body of eruptive rock lying close to
the surface that once was completely
covered by the sedimentaries, but which
erosion and faulting have exposed.
Observe that said Substantially the
same" not identically. The superficial
expressions of the geology of the three
great camps are quite distinct.
All rational mining is undertaken on
some theory of the source of the ore.
But such theory-or any theory at all
is never anything but generalization
from things known to things unknown,
but supposed to be like them. In min
ing matters only development can prove
that theory is true. The science of
geology can go no further than to show
that it is probable.
The purpose of our U. S. Geological
Surveys in the mining regions is to grad
ually assemble such mass of proofs as
will enable mining geologists, finally, to
generalize correctly and with confidence
If it isn't precisely that, the work is
senseless, because the studies are made
after the camps are developed.
BINGHAM AND ELY.
The study of the Bingham field by the
Geological Survey was of great value in
giving confidence to investors at Ely to
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