The silver state. [volume] (Winnemucca, Nev.) 1909-1925, 1922-04-29
SURVEY HOPEFUL
FOR COMSTOCK

| famous ComStock lode, at virginia
City, Nevada, the engineering prob
lens of handling the treacherous
| floods of hot mine waters and the
problems involved in the struggle
for the financial control of the
mines have seemed to outweigh all
others in determining whether the
workings should be carried still
| deeper, but even more fundamental
has been the geological problem of
the persistence of the ores with in
crease in depth. If the rich silver
ores were deposited wholly or large
ly from solutions that assembled
from sources far below the surface
deeper exploration is fully war
ranted. If they owed their richness
| to the descending surface waters on
ore that originally contained rela-
lively little gold and silver, then
there is little to encourage deeper
mining. The steady progress in
metallurgy, by which more metal is
recovered from low-grade gold and
silver ores, has given large practical
importance to the question of the
persistence in depth of ores of this
class. No thoughtful observer ex-
poets revival of the gold and sill
yer age of Comstock mining, for
the tremendous fracturing which
created the channels that made the
ore deposition possible was more ex-
tensive near the surface than at
great depths. Nevertheless the
roots" of an ore deposit so i'm
mense are by no means small, and
the Comstock operators have in re-
cent years showed their confidence
in the existence of deep-lying bodies
of workable ore by draining large
part of the lode to and below the
2900-foot level.
In spite of the detailed studies
that have been made of the geology
of the Comstock lode, very little
concrete, tangible evidence has been
presented to show the variations in
tenor or composition of the ore far
below the surface, and little infer
nation has been available for COM
pairing the results of primary depo-
sition with those of downward en-
richment in the formation of the
richer bodies of Gre. Yet as the
downward enrichment has evidently
-heen effective in many silver de-
posits a tacit belief in its potency
at the Comstock lode seems to have
become current among many geolo-
gists and mining engineers.
The early geologic work of King
and Becker on the Comstock lode
was done before the development
of the theory of enrichment of ores
through the agency of descending
surface waters. Later observers
have made only brief examinations
of the lode, under conditions that
were most trying because of the
high temperatures in the mines.
Finally, as most of the ores are fine
grained, it has been impossible to
determine the relations of their con-
stituent minerals by observation
with the unaided eye.
Recently E. S. Basin of the
United States Geological Survey,
Department of the Interior, has
made a microscopic study of the
Comstock ores and in his report,
published as the Geological Surveys
Bulletin 735c, entitled Bonanza
ores of the Comstock Lode" he con-
cludes that in the ores from the
depths greater than 500 feet, which
includes most of the bonanza ores
of the lode, the silver is practically
all in primary minerals. Descend
ing solutions of surface origin pro-
duced large increase in silver con-
tent of certain ores obtained within
500 feet or less of the surface, yet
even at those depths part Of the
silver contained in primary miner
ais, and some rich ores taken from
slight depths, showed no secondary
silver minerals. Gold, so far as OBJ
served, is primary in all the ores.
Although the deeper parts Of the
lode probably contain no ore bodies
comparable in size and richness to
the great bonanzas of the past, yet
the primary origin Of some of the
rich ores encourages deeper develop
ment.
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