The Salt Lake tribune. [volume] (Salt Lake City, Utah) 1890-current, 1906-10-01
Bullfr0g District Is Described
in Eastern Journal as
Low-Grade Camp.
DISTRICT NO PLACE
FOR LEASING SYSTEM
Country Rock Around Rbyolite
Consists of Series of Vol
canic Flows.

covery, July 81, 1904, has steadily in
creased in Importance, for the more the
veins have been developed the more as
surcd becomes its future. Unlike Gold.
| field, TO the north, the BulIfrog dis
trict, of which Rhyolitc is the principal
Town, and near which are at present
the largest mines, has become famous
not on account Of fabulously rich ore,
but because OF its large veins of good
milling grade of gold ore. However,
1T also contains a good deal of high
grade ore. AS a consequence of the
small amount Of rich ore which is char
acteristic of the camp, the mines have
been developed by companies, instead
Of by leasers as at Goldfeld, says the
Engineering and Mining Journal.
There are three main ore zones near
Rhyolite. In the west zone aro the
Original Bullfrog, the Gold Bar, the
Hcmestake and the Daisy, while on
Bonanza mountain are the Tramp Cor
solidated, the Gibraltar, tho Golden
Sceptre, the Peerless, the Bonanza
Mountain, and the Rush groups of
claims, in all Of which considerable
Rhyolite is the Montgomery mountain
Ladd mountain belt, In this belt are
situated the properties Of the Bullfrog
Mining company, the Bankers Ma
tional, The Diamond, the Montgomery
Shoshone, the Four Aces, the Amethyst,
and several others.
Geology Of Country Rock.
The country rock around Rhyolite
consists Of a series of volcanic flows,
principally of rhyolite, with some ande-
site, basalt and dacite. Through these
flows cuts series of basaltic dikes,
apparently running in all directions,
the relation of which TO the ore bodies
is not known as yet. Sometimes they
occur adjacent TO the ore bodies and in
many cases the ore near the dixie seems
to be richer than farther away. How
ever, the district IS too young as yet
for any assured statements in regard
to these dikes, The veins are strong
and persistent and usually wide Some
OF the ore bodies, such as the Tramp,
the Montgomery-Shoshone, the Gold
Bar and, to a less degree, the Original
Bullfrog and the Rush, are immense
veins of good milling ore.
All these veins have northerly
strike. The gangue is principally
quartz, together with some calcite.
Much Of it is strongly stained by
brown oxide Of manganese. The gold
is quite free and is a bright yellow,
differing greatly from the rusty gold
characteristic OF Goldfeld. Some shoots
of ore carry considerable silver, es-
pecially ct the Original Bullfrog, but
are found in the bottom of the Shoshore,
and in all probability pyrite is the
original carrier of the gold in many
OF the veins, although at the Original
Bulltrog probably tetrahedrite will also
be one Of the primary sulphide miner
ais, In the veins Of the camp the ore
is as yet practically all oxidized. The
veins are strong and in the majority of
cases can be traced for long distances
ore IN all these veins except the Sho-
shone tale vein is of milling grade,
going from $S to $25 per ton, although
OF course lower grades occur, Scat
tered through the milling ore are shoots
of rich ore going well over 500 per
ton, besides which seams of tale rich
in gold occur through the quartz. Con-
siderable of the high-grade ore has been
sacked and is still piled up on the
dumps.
Veins Are Low Grade.
\ conspicuous point in connection
with the veins in the vicinity of Rhv-
olite has been that the vast majority
of them have been very low grade at
the surface, the value becoming normal
at short distance below the surface.
In some mines of the district there
seems to be an increase in value with
depth, but on account of the great size
of most of the veins and the compare
lively small amount of development
upon them, this is merely supposition
as yet. In some of the mines rich ore
has outcropped at the surface, particu-
larly in the Original Bullfrog, where
the first strike in the camp was made,
and also at the Gold Bar, while at the
Montgomery Shoshonc some rich shoots
of ore came to the surface.
The country rock is mainly rhyolite,
through which the veins generally
strike north and south, with high dip.
There is also series of northeast and
southwest veins, which have q dip of
about sixty degrees TO the west The
walls Of the veins seem to be good,
which will aid materially in mining
these large deposits. The veins appear
TO be mainly formed along d strong
limo of fracturing, with almost pure
quartz at the center, and toward the
edges gradual transition, in many
cases, into rhyolite country rock, In all
the veins the ore is tested by papning,
which is checked from time to time
by assays.