Montana oil and mining journal. [volume] (Great Falls, Mont.) 1931-1953, 1940-12-21

The field work was done by
Goddard in company with Glenn
Reed E. P. Kauser and w. T. Pc
cora. The work was under the d.
rection Of J. T. Pardee.
1.-The Philipsburg district, in ives
tern Montana 4 5 miles northwest OF
Butte. is primarily a silver camp,
but since 1916 it has been the chief
source of manganese ore in the I'm
tied States. says the abstract.
During the World War it produc-
ed about 100000 tons of metallur-
gical ore, and. since 1919 it has
had a small but steady production
Of ore used in making dry-cell bat
teries. The total output of high
grade ore has amounted to about
Ar, 900 tons.
"The district is in a region OF
rather complex overthrust, but the
local structure is relatively simple.
A low arch of PalecZoic limestone
has been cut and deferred in the
east and south sides by a small
batholith of Tertiary granOdior-
tie. The southern part OF the arch
has been eroded to express early
Cambrian and pre-Cambrian quart
zites. The manganese deposits are
confined to an area of about
souare miles underlain by sedimen-
tary rocks and adjacent to the
granodiorite body. They form ir-
regular and tabular bodies in the
limestones bordering east-west
steeply dipping silver-zinc veins.
The ore. chiefly pyrolusite, was ap-
parently derived from rhodochrosite
that was abundant in the veins and
had replaced the adjacent lime
stones The oxide ore is found
chiefly within 500 feet of the sur
face, though one small body was
mined at a depth of 700 feet. Be
low the oxidized zone Thodochrosite
is locally abundant in and along
some of the veins. but no CONNER
cial, bodies have yet been found.
Most of the ore mined has con-
tanned between 80 and 81 percent
of manganese, but recently ore
containing as little as Is percent
has been taken out. The crude ore
is milled at Phillipsburg to concen-
trates containing about 70 per cent
of manganese dioxide (Mn02) which
is equivalent to A per cent Of me-
tallic manganese.
Production at Philipsburg has
followed development work so
closely that there is little reserve
ore in sight. However, the reason !
ably possible reserves of minable
oxide ore probably amount to sew
eral hundred thousand tons. Work |
able bodies Of rhodochrosite ore
may also possibly be found at
depth.
History and Production
Mining activity in the Philips |
burgh district began in 1864 with !,
the discovery OF rich silver ore at
the Hope mine. just north of the |
manganese producing area BY 1890 !
the district had become one of the I
most productive silver camps in the /
country. After the decline in the
price CT silver in 1892 mining ac-
tivity was greatly curtailed and re-
manned largely dormant until a
demand for manganese was created
by the World War in 1916.
The presence of abundant man
ganese oxide at Philipsburg was APP
parenuy unknown outside the dis
trict until a small shipment of ore
was made from the Coyle mine in
1900. The extensive production
that began in 1916 in response to
the demand for manganese in the
steel industry increased rapidly to
a peak in 1918. when 127.415 tons
of high-grade manganese ore was
shipped After the end Of the war
Philipsburg, owing to its distance
from the principal steel manufac-
turing centers, was unable to com
pete in the metallurgical market
with other sources of manganese:
however, the ore after concentra-
ton proved to be well-suited for
use in dry batteries, and since be-
tween 5000 and $4,000 tons of
manganese dioxide concentrate for
battery use has been shipped an