The Wallace miner. [volume] (Wallace, Idaho) 1907-current, 1913-10-16

secondary calcite in veins and irreg-
ular bodies This is the only district
in eastern Nevada that l have visit
ed in which lead ore occurs under the
conditions common to the great lead
districts of The Mississippi valley.
was told that the ore contains almost
no silver or gold.
In Clifton district, in Tooee coun-
| ty, Utah, besides the typical contact
metamorphc copper gold deposits
and a lead and silver bearing depos-
! 1t probably due to a small vein cont
ing up through granite and spread
ing out into a fat-lying lenticular
mass in the limestone, there are, IN
the granite area, a score of prallel
assure veins and altered granite
carrying galena said to be fairly rlcn
in silver In granodiorte in the Cor
tez district, Eureka county. Nevada
n there are small veins of white quartz
carrying coarse blende, galena and
pyrite and said to be chiefly silver
ore In these two cases, unless one
assumes a downward circulation for
the solutions. there seems no escape
! from the conclusion that the veins
derived some lead from the eruptive
! rock. II is to be noted however that
in veins of this class the lead content
| Is relatively low and the precious
metal ratio high There are many
/ lead bearing veins and chimneys III
| the limestones of eastern Nevada that
may have had deep-seated origin
and they almost invariably have a
high silver and often high gold ratio.
II f. Balm. among others, has called
attention to the fact that the igne-
ogenetic type of ore deposits is char
acterized by the presence Of consid-
cradle gold and silver, while these
metals are likely to be absent or UNI
important in the sedigenetic type. In
the practical absence of gold (the
Terrible Edith excepted) and the low
silver ratio where not complicated by
! the presence of tetrahedrite. the lead
and zinc deposits of the Occur dAlene
are more like the McGill than the
Clifton and Cortez types as describ-
! ed above, more like the Missouri and
Wisconsin ores than like the major
! ity Of lead and zinc bearing veins of
! the western half of the United states.
1t Is another count in the indictment
against the magmatic hypothesis.
Elko County, Nevada.
In 1906 | made reconnaissance OF
the Bullion silver mining camp of
Elko county, Nevada, where a small
truded into the Palezoc sediments.
The contact appears to dip eastward,
under the limestones. at high angle.
The mineral belt extends from the
] gained the impression that near the
contact, deposits of iron ore and of
copper sulphide ore were formed by
contact metamorphic action, that at a
distance from the contact these de-
posts pass into larger deposits il.
which the lead silver minerals arc
mixed with the copper and finally
along the extreme eastern border of
the belt galena rich in silver occurs
alone in thin seams In the limestone.
From this l inferred that the solu
tons may have issued from the mag
ma prepared to deposit iron and cop
per minerals and that as they rose
through the limestone they derived
lead from it and deposited it higher
As w r. Emmons has since studio!
the district and not noted such a
relation my inference may not he
warranted.
At the Keystone mine, Is miles
south of Cortez. Eureka county, Ne
vada, sulphides of copper, lead and
zinc, and iron occur with contact
metamorphc silicates in a point Of
limestone projecting into granite
mass, and at short distance from
the contact one of these deposits 2r-
proaches the form Of an ordinary
vein, with a proportionate increase ir
the lead content. At Spruce noun
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