Gilpin observer., 1905-06-22
NEWS FROM THE MINES and MILLS
In the puranoo Ouadranole.

On the east slope of the La Plata
mountains, near the head of Junction
creek, in the Durango quadrangle.
Colorado, lies the Neglected mine.
Forlorn as this designation sounds, the
region Is one Of hopefulness. 1t is in
the small area of naturalization To-
cally known as the "Oro Flno dis
trict." which lies in the western part
Of the quadrangle. This mine and the
nearby properties are described by
Mr.. William H. Emmons in bulletin
mo. 26O) of the United, States Geol-
logical Survey.
Since 1902 the Neglected mine has
been operated. most Of the time and
recently a mill has been installed for
working low-grade ores which can
not be profitably shipped. The mine
is situated near the head Of Gaines
gulch, on the west slope of Monument
hill, at an elevation of 10000 feet
above sea level. The property has
been known as a prospect for ten or
fifteen years, but 1t was not extern
sively exploited until 1902, when an
ore body was struck from which in
the following year 1910 tons of ore
were shipped, the returns from which
amounted to $117,O41.2S in gold and
81 1,6S2.3O in silver.
The ore deposits in the western
part of the Durango quadrangle are in
an area of red sedimentary rocks,
which have been intruded by dikes
and sheets of grayish-green porphyry.
The ore may be developed in the por-
phyry at it's contact or in the sedi-
mentary rocks near the porphyry.
Often 1t appears to be replacement
Of the pOrphyry, which Is altered and
decomposed near the fractured zone.
Both porphyry and sediments are
sometimes impregnated with pyrite
for a short distance away from the
broken zone and through them ex-
tend little stringers Of white quartz.
which carry fakes and specks of tel
luride.
In places where the sedimentary
rocks are impregnated there does not
appear to be any constant difference
between the development of the ore
in the sandstone or In the shale. In
the Neglected mine the shale is con-
sidered the most productive horizon,
while in the Durango Girl the richer
ores so far have occurred in the
quartzite below the shale.
The Neglected mine is worked
through a vertical shaft from which
levels east anu WSSt haNS
been opened at depths OF eighty-fve.
1875 and ITS feet. The most profitable
horizon has been the zone between the
125-foot and 175-foot levels. The prin-
cipal ores of the mine are tellurides
of gold and silver, and of these syl-
vanite is much the most important.
Native gold, pyrite and amalgam are
present.
The ores of the Durango Girl mine,
which is situated in Walls gulch, on
the east slope of Lewis mountain, are
chiefly tellurides and the sorted ship
ping product is very rich, being over
$40O ton. The Jenny Lind claim is
also in Walls gulch and it's ore de-
posisy are said to be similar in char
acter to those Of the Durango Girl,
which lies below. The Ruby claim
located south of Cumberland peak on
small tributary to Junction creek,
is interesting on account OF the oc-
currence of a considerable amount OF
native mercury in the ore. In Leav-
enworth gulch the Porcupine Company
is developing a group OF twelve claims,
and the Londonderry Company, which
also owns large group. has force
of men at work in the same neighbor-
hood. In Fassbinder Stamboul and
| Mineral Wonder gulches, all at the
head of junction creek. are a number
of prospects which have been worked
internationally for many years.