Eureka weekly sentinel. [volume] (Eureka, Nev.) 1887-1902, 1897-09-25

ores. which we're more or less mixed with
limestone, that the lode had yielded above.
Il is calculated that the subterrsnesn
disturbance which created the Ruby Hill
fault raised the footwsll side Of the Pros
pee, Mountain limestone, through the En-
reka Con. mine, about 400 feet.
PROSPECT
Rises TO an elevation considerably higher
than that OF Ruby Hill, showing that the
erosion OF the latter locality must have
greatly exceeded that OF the former. Pros
pecs Peak, the highest point on Prospect
Mountain, has an elevation Of 1904 feet,
and the highest point on Ruby Hill breaches
an altitude OF only 1891 feet above sea
level. IL is here seen that the difference
in the elevation OF the two points is 2.313
feet.
The ~outcroppings of the ore bodies Of
Ruby Hill we're larger than those Of Pros.
pect Mountain, but the difference may be
accounted for in the excessive erosion Of
Ruby Hill. In the main body Of Prospect
Mountain the ore bodies generally augment
in size with the increase Of depth. The
deepest workings in Prospect Mountain,
following the ore downward from the sur
face, are found in the Diamond and Excel
sior mines, about / 600 feet below the top Of
the main ore chute and a little over 500 feet
below the main tunnellevel. The surface
of Ruby Hill is relatively fiat when COM
pared with that of Prospect Mountain,
which is doubtless due to the greater ero-
sion OF the former, and il ia therefore fair
to believe that the outcroppings Of the
Ruby Hill ore bodies were, at one time,
no greater than those Of theD Diamond and
Excelsior mines at the present; and il the
theory generally accepted here-thst the
ore solutions were forced up by infltrs-
ton and dynamic pressure from below-is
correct, that relating to the difference in
size Of the outcroppings OF Ruby Hill and
Prospect Mountain Is not without q reas-
enable basis.
The question OF deeper exploration in
Ruby Hill and Prospect Mountain has re.
Gently been discussed here, and there has
been no reason adduced to show why the
work should not be r~emunerstive II has
been demonstrated that the ore bodies still
continue going down in the caves. below
the dee pest workings Of the Diamond and
Excelsior mines. II is also shown that the
ore continues dipping below the deepest
excavation in the Eureka Con. mine and
there is reasonable probability that ore
bodies may be found below the deepest
workings OF either Of the Ruby Hill mines
az valuable as those which we're excavated
above. It Ia manifest that the limestone
bodies Of Ruby Hill and Prospect Noun
tain, at present separated by the granite
and Prospect Mountain qusrtzite, were
originally one and the anne that the dis
connection occurred through excessive ero-
sion above the Prospect Mountain quartz.
lite, and that the difference in the extent OF
the respective outcroppings upon Ruby
Hill and Prospect Mountain is due to the
erosion. Undoubtedly the erosion occur
red subsequent to the upheaval and rela-
tive creation OF the Ruby Hill fault. There
can be but little question as 10 the import
ant bearing Of the fault on the presentstruc-
ture OF Ruby Hill and Prospect Mountain
and the relation of the ore bodies TO each
other. The former has besn manifested
! through diligent Investigation instigsted
under national authority, aud 10 is quite
probable that the ascending ore bearing
solutions passed up through the great ifs
sure and, by means OF iniltrstion and per.
collation. through the seams In the country
| rock, were conveyed to and deposited in
the chambers and other cavities in the
limerick which were created by the pre-
viously occurring subterraneous disturb
ances.
The elevation OF the main tunnel level
ct the Diamond mine Ia 1900 feet above
sea level, while that OF the highest point on
Ruby Hill Is only 1900 feet or thereabout,
and the elevation of the Ruby Hill crop
pings is hardly more than 100 feet above
that Of the deepest workings Of the Dia-
mond and Excelsior mines. In the latter
the ore produced is relatively improving
in quantity and quality with greater depth,
and the yield OF gold in proportion TO the
silver is increasing. The Diamond and
Excelsior mines are making q better show
ing than did the Richmond or Eureka
Con. at the relative points Of elevation,
and their present condition Ia an auguYy
that they will become as famous and equal
ly az productive and lucrative 90 were the
Eureka Con. and Richmond mines In their
palmiest days, but deep level mining IL
needed as much 10 the one as In the others.
*The distinguishing names Of the formA-
tions OF Eureka District are local aud were
frat adopted by Mr.. Arnold Hague. the
~geologist in the field OF this division OF the
U. s. G. Survey OF the Fortieth Parallel.