Pioche daily record. [volume] (Pioche, Nev.) 1872-1876, 1875-06-23
WHAT Is QUARTZTTE.


From the Scientific ProssI
There appears in the Press of MAY
10th an interesting article under the cap
ton !" Geological Formations-Q Quartz
lite, by Mr.. William Teal, of Bingham,
=. T., in which he sententiously asks,
What is Quartzite?"
The query Is a relevant one at the
present luncture, seeing that its proper
constituents are So little understood,
Notwithstanding the increased and in
creasing spread of geological informa-
ton. The subject is one that admits of
wide range OF discussion, because there
are no two miners of this coast who prob
ably would be found agreeing in their
estimate regarding the nature of quartz
lite. Dana defines il as belonging to the
order OF sandstones, aud where composed
OF pure quartz, sandy particles, as a
species OF silicious sandstone, which has
Deen at some remote period in the
earth's history firmly consolidated" by
the action OF the great heat, the same as
crystallization has been produced in
rocky substances.
QUARTZ,
We know, is pure silica, Of which there
are many varieties, differing in form and
color, and easily distinguished from all
the other minerals by its hardness, in
fuslbility, insoubllity, and entire absence
of cleavage. Quartz is also granular, but
this is not one of the characteristics of
the variety of quartzite commonly met
with in the mining districts of Nevada.
The massive or solid and vitreous struc-
ture are the distinctive features of the
kind that il most frequently Encountered
III this State, though one occasionally
meets with laminatsd vein or belt, but
this structure is found more often at and
above the outcrop wherever it rises to
any great hight in vertical qualifications
above the surrounding formation. There
are many of the varieties of this rock
that are regarded as of igneous origin,
while none of them can be said to be, in
the strict sense of the word, as belong
ing to the metamorphic family of rocks.
oUARTZITE
Is not, that am aware of, usually con-
sidered as metalliferous bearing rock,
and is not, as far as my experience has
extended, the chief ingredient or constit-
uent of the geological formation of any
of the mining districts of Eastern Ne.
vada. 1t is, however, often seen running
in immense belts, ranging from few
feet to one hundred feet or more in thick
ness, and raising to great altitude in
huge, irregular shaped masses above the
line of the hills. 1t is, however, associ-
ated with many of our most valuable |
mines, in the character of either the foot
or the hanging wall--chiehy the former.
oh Sc, t1.. Oh IL A.
county, and such too, am informed, is
the case Mt Phoebe, in the Raymond &
Ely and other mines. At Eureka it is
entirely metalliferous, limestone being
the prevailing formation. though a
quartzite gangus is often found in place
with the ore, but this peculiarly is no.
ticeable only wherever the lode is broken
or at fault, or wherever. the material is
poor. Here lime and porphyry are the
chief rocks, though the former is the
actual geological formation. The G
mine has silicious lime hanging wall,
and a porphyry foot wall. The latter
is also the hanging wall to the Gila mine
at Reveille, while the foot wall is semi
granular and semi vitreous quar,zite,
which at the apex of the lode had q
standing or shelving dip to the east.
Below this point it extends smooth and
unbroken. while the porphyry of the
foot wall IL largely impregnated next
the ore with tale, manganese and the red
oxides of lead and iron. The quartzite
belt is, rs | said above, over or about one
hundred feet thick, and has q Longitude
nal course for several miles, or from
north to south examinations OF the dis
trict, which embraces space of eight by
four miles. The porphyry dixie runs
side by side, and is distinguished by as
bold projections as the other. While the
lime formation runs parallel to both at
the east and west sides.
GEOLOGICAL FORMATION
Does, of course, afford some index to
the practical or experienced miner,
whereby he is nearly always enabled to
arrive at just or partially Just opinion
OF the mineral attributes of the section
of country over which his peregrinations
may sometimes extend in his search after
the mineral wealth which nature has
scattered with no niggard hand through
out the vast area of Nevada.
There are, however, no two districts
alike in any respect SO that no parallels
can be constructed where there are no
common conditions found to exist. The
order of venous formation also differs in
different districts, and in some instances
have found the mines of the same dis
trict to differ just as widely, and this too
with regard to the proper method of de-
veloping them. There are also many
endorsements caused in metallic min
ing by the displacement of lodes. These
occurrences are most frequent in lime
stone formations, and from a variety of
causes known to the trained miner and
skillful mineralogist. Experimental min
ing can alone determine the structures of
lodes by tracing them in their various
stages of development, from their incip-
lent conditions to their fullest expan-
sions, and is also the only sure method
of measuring the quantity and and value
of their ores. These things are, of
| course. facts that are within the knowl