Eureka daily sentinel. [volume] (Eureka, Nev.) 1871-1887, 1877-02-15
GEOLOGY OF PROSPECT MOUNT.

EDITOR SENTINEL: The elements that now
form our oceans, lakes and rivers, and the
gases that entered into the solid structure of
our planet, once formed a dense atmosphere
impenctrable to light, enveloring to a depth
not Of Is miles, as is SOW estimated, bat Of
thousands Of miles. The best Authorities on
geo.ogy inform us that there was . time in
the history Of our planet in which it was a
mol en-. fiery mass, without seas or oceans
or a solid crust. How was this thin crust
formed At this point Of the investigation
the geologist must al peal TO the astronomer
for the history of the origin and birth of our
planet, 'or in this vague and ncbalous bor-
der land. whore tho very rocks have no def
mite forms or Substances, and flow into ca h
other, there the two sciences meet. AstroDo-
my shows us oar planet thrown off from the
sun in "A molten. fiery state, to move in an in
dependent orbit Of it's own. Thence arises
the question, did that incandecent world con-
tain lat mt heat within itself? The elements
of life strdetural forces certainly lie latent in
the n"iten mass, Whetber or not those forces
reach to the extent of forming a planet or an
animal. Astronomy began with so Id crys-
taliine spheres. Look at tho wond erful and
beautiful architecture of a crystal! Ailthe
marvels of crystalline force, all those won
derful branching irost-ferns which cover or
window panes on O winter morning., and the
exquisite molecular architecture of lee es
latent in water and comes into play when the
water is sufficiently cooled. Grayitation ana
polarization which blend in harm ny in the
WORKING forces OF the universe. both chemi.
cal, electrical, magnetic, and even mechanical
forces, are so welded tia they act 10 concert.
Thus the teaching Of science is that the
worlds constructing forces are latent within
itself, ard that he formation of an lnhabita-
hle world is not loss wonderful than the for
nation of a or stal; crystaIlization performs
Il very i'm p%ortant and active part 10 tho for
nation OF tho matrlx gangue or vein matter
OF a metallic lode. Without crystalline struc-
ture there would not be much OF tho precious
metals In our mines, for gold and silver are
crystalline.
The geological structure of Prospect Mount
ain comprises the four great classes OF rocks
the fossilliferous, volcanic. metamorphlc and
plutonic, ami are all conspicuously displayed
wi hin a very small area, and with their Pc
culiar characters strongly contested. FOSSIL
~liferous limestone is found neat tn, apex of
the western slope: on the TANKS OF the mount
ain are ore belts of q~uarrz1s rocks and con-
glomerate, to which, or the east side, succeed
helts Of argillaceous shale. finked by belts
Of quartzite, metamorphic limestone, and
other strata containing lllcate OF lime. lie
em,rgence of granite at the sur ace, until 1t
has become exposed to view in the north
west spur of the mountain, Is an intrusive
rock of later date than the other, and bears
from the Windsail shaft Eureka Consoli-
dated west southwest, distant 3V0 yards. This
granite is underlying Ruby Hill and sends
out dikes of porphyry or spurs OF the granite
mass itself; one Of these is known to exist
about one and one-half miles north of Ruby
Hill.
precise method of granite up lift, whereby
the fossIIllferous limestone of Prospect
Mountain became shaped into a dome or arch
Of ten or twelve miles long. and an altitude
of seven to eight thousand feet above the
sea level. Prospect Mountain, as seen from
q distance east, or west, has the arch or
dome shape Of the iurasslc or cretaceous
period, and by the OF a little fossil
sholl of the sea, characteristic OF the crota-
ceous period, the bivaive Of the CLAN or cookie
species, demonstrates the fact that Prospect
Mountain was Mt ono time as low as the ocean
There are at least the wsil-de6ned parallel
metallic belts running nearly northwest and
southeast, represented in the veil system OF
Prospect Mountain. Tn lodes of Secret Can
yon ON the south. and those OF Ruby and
Adams Hill to the nor h, yielding gold, silver
and lead. The age or origin OF the assures OF
Ruby Hill is precisely the same as the series
or assures Of Prospect Mountain. The dy-
namical cause is the same, tor the reason thar
those parallel to each ether were formed at
the same time, and the age was that OF axis OF
uplift.
The Richmond mine. the first in present
produetiveness, and among the fir t II rich
ness of tho argentiferous and plum biferOus
deposits, in the State of Nevada, is a contact
vein (irom the fact of its walls b ing formed
of d%issimilar rocks,) situated on Ruby Hill, a
spur of Prospect Mountain. he strike of tbs
lode is nearly northwest and southeast, mag
nelic, and dips t. the northeast. Next to the
Richmond, IN point of present Importance, Is
the Eureka Consolidated, being part OF the
same lode; it has much thu same strike and
dip as the Richmond. The X X is next and al
parently GU the same ore channel. 1 he acl-
son is u little south Of the X X. The indica-
tons at the opening Of the mine promised a
bright future. 1t appears that there are
vIci>situdes in the working life OF a mine
similar to that OF Il prospocter, who, after
batting a long time against the ebb-tide OF
fate. suddenly becomes rica by the food-tlde
OF fortune lowing 10 his favor; AMI again,
after a short and recall ISIS career, becomes
suddenly poor. such has been the experience
oi the Jackson Company. Uuder ths efficient
Saperintendencc of the present manager, this
mino will soon become one OF the productive
mines of Eureka county, Prospect Mountain
is not cOmple'e e, and is not finished yet; the
memorable and remorseleaS forces that mfde
it what it Is. are sill at work making it what
1t is yet to be; the winds an rain, the heat,
frost and snow are doing their WORK in denu-
dation and disentcgratiOn.
JOHN NJ. FOLEY.
Eureka, February 6, 1877.