The Goldfield news and weekly tribune. [volume] (Goldfield, Nev.) 1911-1947, 1918-07-27
MANGANESE ORE
IN WHITE PINE
GEOLOGICAL SURVEY EXPERT
EXAMINES EASTERN Ne
VADA DEPOSITS

ty, New, in the Ely Tor hoDlnSonJ
district and the Siegel Cor Schell-
bourne or Aurum) district, was
made by ]. T. Pardee. a geologist
of the United States Geological Sur
vey, Department of the Interior.
early in June of this year., according
to a bulletin of the Geological Sur
vey just out. His reconnaissance
covered an area about so miles long
from north to south and 20 miles
wide, comprising part of SteptCe
Valley and the mountains that Dor
der it on the east and west.
The floor of Steptoe Valley
ranges in elevation from 5000 TO
$500 feet and the mountains rise
abruptly from 5000 to 5000 feet
higher. The Ely district occupies
a rather low and only moderately
rugged part of the mountai,.s. The
Nevada district lies along the foot
hills of the Shell Creek range, On
the east side of the valley; the
Siegel district lies in a high and
rugged area.
The mountains on both sijes of
Steptoe Valley are composed chiefly
of limestone and unfortunately of
i~nterbedded quartzite and shale and
later igneous rocks. The valley is
underlain by Quaternary alluvium
of unknown but apparently great
thickness. The sedimentary rocks
in the Ely district range in age from
Ordovician to Pennsylvania. SINH
lar rocks were observed in the Ne
vada and Siegel districts. Intrusive
monzonite of probable Jurassic G
itic rocks are reported in the noun
tains east of Steptoe Valley, though
in the areas examined nj granite
rocks except a few small bikes of
diorite or monzonite porphyry were
seen. Territory lavas, chiefly rhyo-
lite, are rather abundant through
out the region.
The sedimentary rocks in general
are moderately folded and are near
ly everywhere dislocated by faults.
The manganese ore extends from
more. Practically all the deposits
occur in limestone and are associat-
ed with bodies of jaspery quartz.
The manganese minerals have re-
placed both the wall rock and the
quartz. The orebodies are irregular
pipes, pockets, and lenses that range
from. a few feet to 20 feet or more
in length and from a few inches to
10 or 20 feet in width. Several of
the larger bodies contain from 500
to 1000 tons or more. Water level
has been reached only in the Siegel
mine, where it stands 200 feet below
the surface.
The bulk of the ore is composed
of the softer manganese oxides, py-
rolusite being predominant in some
mines and wad in others. The
wad is generally rather compact and
tough and can be whitfield like wax.
Psilomelane and m~anganite, though
rather widespread, occur in subor-
dinate amount. Fairly large masses
of a very hard, compact black man
ganese oxide, tentatively regarded
as braunite, are found in the Bowen
and Holmqufst mine. The ore below
water level in the Siegel mine is
composed of r%hodonite, rhodochro-
site, and a~lbandite.
Jaspery quartz, calcite, and iron
oxides are generally associated with
the manganese minerals. In the
Siegel mine cerusite and massicot
were observed above water level
and galena and pyrite below. Most
of the pres contain more or less sill
yer.
The ore mined contains from SO
to As per cent of manganese, 3 to
16 per cent of silica, 3 to 5 per cent
of iron, a moderate amount of lime,
and very little PHOSPHORUS. Parts of
the orebodies not now mined or re-
jected in sorting ore for shipment
contain more than 16 per CEN of
silica. Ore containing 25 to 80 per
CEN of manganese and Is per cent
or more of iron occurs in several
places.
A total output of 2,10S short
IONS of 40 per cent manganese ore
was produced by seven operators up
to June l, 1918, the first shipments
having been made late in 1917. In
addition 1900 tom was produced
by the Siegel mine from 1902 to
1908, but this ore, though high in
manganese, was smelted for silver
md Load the manQanQSa hainQ lost |