Mohave County miner., 1899-06-24
White Rock Silver Mine.

The White Rock Silver mine, near
Drake, New South Wales, which at one
time was floated for million sterling,
has been the despair of numerous
plucky prospectors. Though it has
not returned a profit on the capital
expended, it is of great geological in
terest. E. f. Pittman, the Government
geologist of New South Wales, visited
the mine. "The White Rock deposit"
he says, "has hitherto been regarded as
felsite dyke, intersected by veins of
silver-bearing galena and zinc blende.
had never had an opportunity of in
specting it until recently, when spent
several hours in examining the de-
post, which appears to me of such an
unusual and interesting character that
| determined to pay it a second visit
during the Easter holidays. In my
opinion, the argentiferous material is
volcanic agglomerate or breccia, and
forms the filling of volcanic neck or
chimney.
lho uSsiOhoioocs 10 Vi q sICy-
ish white color, consists essentially of
felsite, and contains numerous round
cd and sub-angular boulders, many of
which show rhyolitic structures; they
vary in size from that of pea OF less
up to several feet in diameter This
agglomerate is intersected by numer-
Gus minute veins of galena and zinc
blende, which in places impart to it
the character of a stockwork, while
occasionally large banded veins up to
2 feet In width are seen striking in var
ious directions. These consist of
quartz, with galena, zinc blende, py-
rites, native silver, ruby silver ore, cal
cite and chalybeate. The agglomerate
has been much silicified by the in
filtration of mineral solutions from be-
low, and is extremely hard and tough.
"In form the mass of ore Is rudely
circular, or rather cylindrical, its diam
eter being probably about 600 feet,
though it is not possible to exactly de-
fine its limits, on account Of its sur
face being in places covered by soil.
1t occupies the floor or center of
circular se-shoe-shaped valley, the
walls OF which rise with regular and
rather steep inclination to height of
from 300 feet to COO feet above it, and
are quite isolated from the surround
ing mountains. The rock of which
these walls are. composed is dark
grey felsitic lava, which in one place
was observed to have a columnar
structure, the columns being vertical.
"The valley has only one opening,
which probably represents breach in
the old volcanic cone, and through
this opening the White Rock creek,
which rises within the circular valley,
flows towards. Fairfield creek. The
diameter of the crater from rim to rim
is probably rather more than half a
mile. The altitude of the White Rock
is about $50 feet above the town Of
Drake, and the altitude of the highest
part of the rim of the crater Is about
GOO feet more. There is every reason
to believe, therefore, that this is the
point of eruption from which all the
lava and felsite breccias, which have
long been known to occur in the vi
cinity of Drake, were derived.
"The White Rock ore deposit has
been worked by an open cut having a
length Of $50 feet, height of 20 feet,
and mean width Of 80 feet. In ad
dition to this vertical shaft has been
sunk to depth of 1856 feet, and drives
of 100 feet and 140 feet have been put
in to the north aud south at the 100,
foot level.
''The geological mode of occurrence
Of this deposit appears to me to be OF
peculiar interest; more particularly as
there are, so far as l am aware, only
two analogous metalliferous deposits
known in the world. These are the
Bull Domingo and Bassick mines
Observation-Disclosures Standard.