Tonopah bonanza. [volume] (Butler City [i.e. Butler], Nev.) 1901-1909, 1904-08-20
THE CAMP BIRD NINE.
Notes on a Great Property by
III. A. TitcOmb.


I'm the southwestern part of Colo
RADIO lies the San Juan region, long
known as a large producer of silver,
and in recent years gold as well.
The district shows evidence of former
volcanic activity on a gigantic scale.
The lowest exposed rocks are AL
gonkian quantities. and states. Above
these are limestones (Lower Carb. or
DevonianY; then conglomerates,
sandstones and quartzite Jura-
Trias), and quartzite and shale (Cre.
taceous). The highest Of the sedi-
mentaries is in the thick bedded red
conglomerate known as the San
Miguel formation (Eocene). Over
lying these aqueous strata is a vast
thickness OF igneous rocks which &C.
cur in almost horizontal LAYERS.
These lines Of stratitication are sup
posed TO mark the periods OF the
successive flows and eruptions which
buried the s~edimentary rocks thous.
ands Of feet deep beneath the brec-
cias, tufts and other volcanic debris.
The entire mass Of aqueous and
plutonic rocks has beer subjected to
stresses which have resulted in
numerous zones Of fracture. Many
of the fractures have been filed with
vein matter, commonly quartz and
evidently deposited from solution.
The veins seem to weather away
more easily than the surrounding
country rock, and the melting SHOWS
wash away the di~sintegrated vein
matter, leaving miniature canyons
with smooth, regular walls, and some
times broad couloirs near the lofty
SUBMITS, packed with snow and ice.
This popularity often enables one to
see the veins for miles extending over
mountain and valley. Many Of the
veins carry precious metals in guam
tity to be commercially valuable.
In the vicinity Of the Camp Bird
mine the andesite breccia and the
intermediate series are generally re
garded as the most productive hori.
IONS. Higher up, where the veins
enter the rhyolite, they often seem
to be narrow and comparatively bar
rem Of their valuable contents. With
the Camp Bird as the most notable
exception, the San Juan has been
almost entirely a silver producer. In
the case OF the Camp Bird, however,
almost the entire value OF the ore is
in the gold. Since the country rock
is the same in both classes OF veins
andesitic breccia-a different subter-
ranean origin Of the ~ore-bearing solu-
tons would seem to offer a plausible
explanation Of the varying occur
rences.
After the volcanic activity had
ceased, erosion began its work and
an enormous amount Of material was
removed by the action OF waters,
leaving canyons and cliffs and lofty
peaks, which render the scenery of
the "silvery San Juan" among the
finest In Colorado. Avalanches are
OF yearly occurrence and are a factor
in the general degradation.
The Camp Bird mine lies in Imogene
basin at an elevation Of about II, 800
feet above sea level. From the town
OF Ouray (7,712 feet elevation) a good
wagon road leads southwark up the
steep valley of the Uncompahgre for
five miles to the Camp Bird mills.
Thence the road continues two and
one.half miles farther up to the mine.
The mill and mine are connected by a
Bleichert tramway some 10, 900 feet
IN length, which transports the ore
down to the mill and carries supplies
up the mine.
Pay ore is not continuous through
out the extent Of the vein, but the
values are concentrated in certain
areas of the deposits, these areas
constituting ore Shoots" Often a
cross vein occurs at or near these
pay areas, and these cross veins may