Custer weekly chronicle. [volume] (Custer City, S.D.) 1890-1931, 1897-03-06
Our Potsdam Gold Ores.

The New York Engineering and Min
ing Journal, in recent issue presents
the following brief summary Of a very
interesting paper on the Potsdam gold
ores of the Black Hills by Prof. Frank
Clemes Smith, of the State School Of
Mines, which was presented and read at
the late annual meeting Of the American
Institute Of Mining Engineers in Chi
cago:
After describing generally the geolo-
gy of the Black Hills region, the author
says that the gold ores of the potsdam
constitute group of much greater i'm
portance than all of the other silicious
ores together. Most of these cres may
be described as thoroughly reorganized
sandstones. containing quartz crystals,
calcite and fluorite. Those which have
not been oxidized carry considerable
fine grained pyrite and are locally called
blue ores ; the oxidized ores are stained
with iron and called red ores. Analyses
of typical samples of red ore show S.4
OF. tellurium. 007 OF gold and 2SS OF
silver to the ton; of blue ore, 403 or.
tellnrium, 003 OF. gold and 10 55 OF.
silver TO the ton. Copper is usually
found in traces. The occurrence of these
ores is widespread but eccentric. The
naturalization is to be referred to
igneous action.
Recently gold ores have been found
in the carboniferous limestone near
Ragged Top, Mt first in boulders and
later in wedge-shaped lenses. An ana
iysis OF this ore E ON the D.,cy showed
20 2j OF. tellurium, 1874 OF gold and
III OF. silver per ton. Scattered
through the limestone are many flinty
nodules said to be rich in gold. ssla 20
"rhe history ofthe potsdam ores daies
from 1877, when several mines were To-
Gated near Green Mountain. A mill wis
put up in 1876. but did no; succeed IN saw
ing the gold. Various processes were
tried with very little success. In 1856
the Golden Reward COMPANY put up
s''o' ptdHt uuu Iuter cydDlOe
plants were tried by the Black Hills
Reduction company and the Deadwood
x Delaware Smelling company. While
il formerly did not pay to work these
ores for less than $50 per ton, they will
now return profit on SIS. MIXING is
usually not expensive in the ore bodies.
COLONIZATION and cyanide lixivation
have developed into considerable in
dustries in the district.
The tonnage Of potsdam ores treated
is rapidly increasing; i'm 1890 there
were about 2S2,0O0 tons, Of a total value
of over S5.0OO,000. Besides the main
connected area, there are several small
er and disconnected areas of these ores
in the reighborhood of DeaIwood and
Lead City. In these there are some
valuable mines. At Galcna, II miles
southwest Of Deadwood, an old camp
abandoned some ten years ago, has re-
Gently been revived aud a smelter ia
actively at work. These mines are In
the potsdam ores. evidently mireralized
from igneous dikes. This district has
not heretofore received much attention.
Another description OF ores which
may be cIassed as potsdam ores are tho
conglomerates found between the base
OF the potsdam and the afrhean. They
have been worked fol years near the
Homestakc ontcrop and at Rorkerville,
In Pennington county. They are, how
ever, simplv placer deposits ip which
the gold 10 chiefly free"