The Salt Lake tribune. [volume] (Salt Lake City, Utah) 1890-current, 1914-02-17
FRISCO DISTRICT IS
SUBJECT Of REPORT
Beaver County Mining
Region Investigated by U.
S. Geological Survey.

In continuance OF its policy OF assisting
in tho development OF tho resources IN
the rnctalliferous regions OF the country
through scientific Investigations OF the
Ceologc structure and the ma ture OF the
ore bodies, their modes OF occurrence
and their probable extent, tho United
States geological survey has published
report on the Geology and Ore Deposits
of the San Francisco and Adjacent DIS
trIcts Utah"-professIopal paper so.
Brief preliminary Inspections OF lhese
districts were made by the iate .
Erlmons and by Waldemar IlnoSren' ." oo,
the detailed study OF the region mas peeh
carried out by Geoiogist Is. =. Butler. AI.
Buffers report, volume OF L!e s,s' pasvs'
which embodIes results OF work dlslrlo
.lted through three field seasons, presents
much general information on tne region
and may be considered OF especial IN
rerest because II gives detalied accoun. ,..
obscurcIv known, Mine workers. consult
ing engineers and students OF economic
and other branches OF geology Wili Ilhu
1t of especial interest, ooth 10. a us Snt
structure Illustrations, wnlch lncluue
half-tones and line DRAWINGS oil geoioslo
structure, mineral ASSOCIATIONS Hi'oi'
tIons and ore enrichment
The report is not Conspicuous ior
new or radical Ideas as Tor the presenta.
tiou of definite evidence throwing new
sons OF the districts discussed wlth other
districts are also especially helpful. An
other noteworthy feature IS tne uescilp-
lion OF several minerpls, which are new
or unusual or occur in unusual assocla-
lions but which are OF considerable eco
nouIic importance In the San Francisco
and adjacent districts. These minerals,
jarosite, and beaveifte. are adeQuateS
described and illustrated. and their origin
and significance are discussed
q 1y,rfg gl1 1s<-1sC ~
deposits Is of especial value In showing
the relations OF the different types of
ore TO one another and In pointing out
the limitations, both in extent and value.
of each IyToe, The deposits include cop
per ores as replacement veins In quartz
monZonlte and as contact-meta "a inorphic
deposits in limestone, also lead silver
ores. accompanied by little zinc ana
copper as repacements Of certain lime
stone beds along fissures and as replace
nlent veins In effusiye lavas- TRANSITION
and silver-lead deposits in limestone are
of especial interest The discussion or
ore genesis supplies a missing link In
the usual chain OF evidence by showing
The genctic connection between typical
Inonzonlte and ore bodies through transi-
tion types OF aplitic and pegmatitic char-
acter. The conditions influencing altera-
ton OF the ores IN the different rocks
are next considered, with eXpla ma tions OF
chemical processes and changes In metal
contents, and the discussion is Illustrated
by some very instructive ndlI- tones SHOW
ing minerals in process OF alteration.
The section closes with sone suggestions
as 10 prospecting and a well-balanced
consideration of the future OF the region,
encoura cling prospecting and development
In some places and discouraging 1t in
others.
Another portion OF the report Is devoted
10 mine descriptions accompanied by
plans and sections which render them
especially valuable for study by all in
terested in the science of ore deposits.
a copy OF the report ney be obtained
free on application TO the director OF the
geological survey. Washington. d. c.