The Salt Lake tribune. [volume] (Salt Lake City, Utah) 1890-current, 1910-01-07
SOME INFORMATION
ON "PORPHYR|ES'
Class of Mining Which Has
Made a Great
Record.
UTAH CAN BOAST
OF TWO PROPERTIES
Many Advantages Gained by
Work on Grade Prop
OsitiOns.

Though the so-cailed ''porphyry" cop
pcrs are compa rativeIy new, they have
been for some time past. and arc at
present. attracting the attention of the
mining public, and they have. in fact.
earned the favorable position they now
hold in the speculative and Investment
held by actual accomplishment Mines
Of this class, which have been in opera
tion Ton only four or live years PAST. are
now producing copper AT the rate Of
about leo, 900. 000 pounds annually and
the average cost per pound has been less
IMAM the average OF all other copper
mines.
Utah Copper and Boston Con are the
Two Utah representatives OF The por
phyry class and are representative mines
oi the country. in fact, OF those in tho
list OF porphyries.
Commenting on this branch Of copper
mininsr George L.. Walker Of Boston
says:
The name "porphyry" is mlsnomer
as applied 10 many OF the new low grade
mining propositions The term dissent
mated copper ore bodies" could much
more properly be used q general :erm.
pie. and was originally adopted by geoo-
Eists to designate a fine grained fcldsite
having scattering large crystals OF field
spar or quartz. II was later used as q
name for almost any intrusive or igneuos
rock In minerali5ed areas, which could
not he readily recognized. II Is now
specifically used by biologists TO desig
nate quartz -porrhyry, AN intrusive rock
the mincralogical structure of which In
dicatcs that II came from n place deep
down in the earth. where a great deal of
water existed. the quartz crystals hav-
ing almost perfect ends.
Evidently these porphyry intrusions. or
dikes breaking up through the crust of
the earth, brought with them copper
and other metallic minerals which were
dissolved quickly by oxidation, washed
out by tho immense flow of water, and
4 a.
assures In adjoining rocks, or as replace
nents in limcstones in the form OF highly
enriched ore bodies.
True Porphyries.
THE Utah Copper, Boston Consolidated,
Nevada Consolidated. Cumberland Ely
find their orc in true porphyries; while
the Miami. Inspiration. Live Oak and
other mines OF the Miami district are
opsGinE sd1i, uG their PRINCIPAL ore bodies in
largo porphyry intrusion. The Chemuug,
Burro Mountain. savanna. Mangas De-
Nelopment and other companies operat
ing In the Rurro Mountain district. are
understood TO be finding their copper in
true granite formation, while Chinos
orc arc in diorite.
"A feature greatly in favor OF the dis
seminated ore mines or porpryrics is tho
fact that the ore reserves can be demon
strated rapidly and accurately by drilling,
and their extent and value determined
auires a tremendous inves tment TO start
ore OF these companies on a producing
and proht-earninC career. such an in
VcsJmcnt is justified and the capital, OF
course, can be raised readily after the
existence OF orc in sufficient quantity
has been demonstrated and when hon
est and efficient management is guar
antced
Econ omical Mining.
When porphyry ore deposit is found
10 lie within sixty or ninety feet of the
surface. it can be stripped and mined
ny steam shovcls much more economic
ally than by any underground mining
method so far devised The thickness
Of the ore body and climatic conditions
may cause variations OF this rule, how
eyer. steam shorcling is very rapid
1= wcll as an economical method OF MIN
ing these big ore deposits, The Utah
Copper company has demonstrated that
II can strip. mine and treat disscminat-
cd orc bodies averaging only y per
cent copper and make "A good margin OF
prodi, even when the metal Is selling
Proof has been supplied by the results
attained by Utah Copper and Nevada
Consolidated tlat these disseminated
portani factor in the copper situation;
that they will produce their metal at
relatively lower cost than most OF the
companies working on higher grade ores
lher output will increase very rapidly.
and thai the best OF them will be regu-
I3r ann continuous ul9locnd payers.
There arc now seventeen conpa MES
opcrati on and developing disseminat-
cd ore bodies whose stocks can be pur-
chased on the stock exchanges or the
curb. These arc; Utah Copper. Boston
Consolidated, Ohio Copper, Nevada Con-
solidatcd GirouS Ray Consolidated
ella Ray Central. Chino. Miami. Inspir-
alton. Keystone. Live Oak Cactus, Che
mung. Savanna and Maneas Develop
ment.
NevadaG in San Fancisco.
lanes A Pollock & 60 bankers and