Eureka weekly sentinel. [volume] (Eureka, Nev.) 1887-1902, 1897-08-21

ores, which we're more or less mixed with
limestone, ths, the lode had yielded above.
Is is calculated that the subterranean
disturbance which created the Rnby Hill
fault raised the f0otwAll side OF the Pros
pect Mountain limestone. through the Eu-
rekG 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
pect Peak. the highest point on Prospect
Mountain, has an elevation Of 1904 feet,
and the highest point on Ruby Hill reaches
an altitude OF only 1921 feet above Sea
level. II is here seen that the difference
in the elevation Of the two points is ASS
feet.
The ou~.croppings Of the ore bodies Of
Ruby Hill we're larger thsn 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, sre found in the Diamond and Excel
sior mines, about / 900 feet below the top of
the main ore chute and a little over 600 feet
below the main tunnel level. The surface
of Ruby Hill ia relatively fst when COM
pared with that Of Prospect Mountain,
which is doubtless due to the greater ero-
sion OF the former, snd il is therefore fair
to believe that the outcroppings Of the
Ruby Hill ore bodies we're, at one time,
no greater than those of the Diamond and
Excelsior mines at the present.; aud il the
theory generally accepted h~ere-that the
ore solutions were forced up by in6ltrs-
lion and dynamic pressure from below-is
correct. that relating 10 the difference in
size OF the outeroppings OF Ruby Hill and
Prospect Mountain is not without Q ress-
enable basis.
The question of deeper exploration in
Gently been discussed here. and there has
been DO reason adduced to show why the
work should not be remunerative. 1t has
been demonstrated that the ore bodies still
continue going down in the caves. below
the deepest 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 deepeat
workings OF either of the Ruby Hill mines
az valuable ~ those which were excavsted
above. Ii Is manifest that the limestone
bodies Of Ruby Hill and Prospect Noun
tain. at present separated by the granite
and Prospect Mountain quartzite, we're
originally one and the same 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 rpheaval and rels-
tive creation OF the Ruby Hill fault. There
can be bat little question as to the import
ant bearing OF the fault on the present struc-
ture Of Euby Hill aud Prospect Mountain
and the relation OF the ore bodies TO each
other. The former has besn manifested
through diligent Investigation instigated
under national authority. and it is quite
probable that the ascending ore bearing
solu tions passed up through the great ifs
cure and, by means OF ipfltrstion and per-
collation. through the seams in the country
rock, we're 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 lie 1900 feet above
sea level, while that OF the highest point on
Ruby Hill is only 1900 feet or theresbout,
aud the elevation Of the Ruby Hill crop
pings is hardly more than 100 feet above
that OF the deepest workings Of the Dis-
mond and Excelsior mines. In the latter
the ore produced ia relatively improving
in quantity and quality with greater depth.
and the yield OF gold in proportion to the
silver 10 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 10 an augury
that they will become as fAmous and equal.
ly as productive aud lucrative - we're the
Eureka Con. and Richmond mines 10 their
palnnlest days. but deep level mining 10
needed sc much In the one a. In the others.
*The distinguishing names OF the forms
tions OF Eureka District are local aud were
frat adopted BY Mr.. Arnold Hague. the
geologis. in the field OF this division Of the
u. 8. G.. SURVEY Of the Fortieth Parallel. |