The Wallace miner. [volume] (Wallace, Idaho) 1907-current, 1912-03-28
INNING INDUSTRY Of IDAHO
(By r. N. BELL State Mine Inspector)
COEUR D'ALENE GEOLOGY AND MINERALOGY.

The United States Geological Survey report the seol
ogy of the deposits Of the Occur dAene which pub
shed in 1905 the result of the Investigations of Mr. Fred
erick Leslie Ransom and f. G. Cakns is very valuable eah
and instructive treatise the economic geology OF this
interesting mineral field Its sharp classification and
cation of the different formations constituting the Occur
dAene series of pref ambrian sediments valuable and
notable feature of this work. The development OF reeen
years in the district has demonstrated that OF the con
lusons of this report well founded and it has been
valuable guide in the subsequent development OF the drc'
Some features of their conclusions however, likely te
be upset. particularly in relation to the bearing ability
the Prichard formation, the general tone Of the govern
mens report referred to deprecated the merits OF this Pae
ular horizon (Which the lowest and oldest Deserved at W
time the Occur dAene seres) ever becoming an important
of commercial bodies and inferred that the approach
of this formation with depth by the established ore channels
in the everything formation known the Burke quarze was
likely to terminate their commercial resources Inc expert
ence Canyon creek with the deep work Of til Frisco Tiger
Pooan and Standard Mammoth mines seems to bear out tins
conclusion However, the problem has not by any means been
fully demonstrated Another result of the publication OF tins
report is it's reference the mozanite at te ana eX
tending north from Gem across the North Fork drainage
which supposed to be the dorsa fin OF an underlying bat
othc mass of similar formation that spreads out ana forms
the floor which the Occur ene series rest ana Whch Tue
pesmstic local authorities of the district conclude VIII ter
inmate any further possibility Of downward extension OF tne
bodies which supposed to be OF later ae 'h 'h
les itself where exposed the surface and for that reason con
sidered an unlikely formation in which to develop pay ore
This mammoth Of eruptve monzan'te is also considered
nv some local authorities to be the primary cause OF the lis
sure courses that carry the bodies III the sedetaV o
nations Personally have decidedly different OPINION
from these conclusions as
glance at the governments geological map OF the Occur
Aene district will show that these monZne exposures lo
low pretty general northeast strike and they represent the
crest of underlying Of the same ornatlo the line Oh
rupture would result parallel assures according to the nor
NAL experiences Of such earth movements while as '"e1
Of fact the main of the district are almost at s
angles to the strike Of these monzante exposures ana IS a
" POSSIBLE that this massive eruptve body had anything TO 90
with the formation and origin of the principal ore channels
In fact there quite conclusive evidence IN the recent deVeo
ment of the Success mine that this monzane erlVe %
later date than the deposits for it shown in several places
in that property send out spur branches that cut fully across
the ore bodies of the Success and the tongue OF the fcard
formation which they enclosed and the only effect mao
IN that ore deposit was the injection Of accompanying so
waters that changed the normal Prcard slate wall rock OF
the Success mine into hard scous rock IN all respects