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Whitman, Alfred Russell

Final general geological
report on the area above

Cobalt Lake

1916

 
BIBLIOGRAPHIC RECORD TARGET

University of California at Berkeley Library

Master negative storage number: 03-67.70
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CUsScCU
SbDISS.WHITMAN.GEOL 1916

1 Whitman, Alfred Russell, $d1882-1940.

10 Final general geological report on the area above Cobalt Lake.
$cl9l6.
57 0D. :8c29 cn.

20 University of California, Berkeley.SbDept. of Geology and
Geophysics$xDissertations.

0 Dissertations, Academic$xUCBSxGeologyS$y1911-1920.

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I ave RT TE SE

ine 1 veneral Ge Dxss
jgical Report on

| the Area about Cobalt WHITHAN

)916
EART

 

F1EAL GENERAL GEOLOGICAL REFURZ
ON THS
ARCA ABOUT COBALT LAXS,
BY
ALFRED R.WHITHAN.
1916. M5. 7

LIBRARY COPY

 
       

    
  
 
    
   
   
      

LoTTER OF TRANSLITTAL.

—

   

To the
Nipissing lining Co.,Ltd.,the Le Rose Mines,Ltd.,the Chanbers-
Perlaeni Lining Co.Ltd.,the Lining Corporation ef Canale, ltd.,

the O'Brien line,Ltd.,the Hudson Bey lLines,Lti.,and the licKinler-
Darragh-8 Savage l.ines, of Cobalt,Ltd.

August 3lst.,1916.

—  —  — — —-——————
TE —————

   
    
       

Dear Sirs:=

     

 

In SeeOTRangs with the contract ani understanding between us

nude Scrtember 1lst.l915,1 have worked twenty lars each month con-

        
    
      
     
    
      
      
   
    
   
   
  
  

tinuously from that time to the present to the best of ry ability,
in attempting to solve the geologicel problems relating to tie findi-
of cre in the region about Cobalt Lake. 48 Was rutually under-
stood on that occasion I have from time to time rendered information

and aivice in geological matters relating to current developuent

  
 

sperctions,and have finally arrivel at what seen to ne the golutioms

ort
dN

of the problems uniertazen,which in the accompanying general re
I respectfully submit as the fruit of my work and the final Iischirze
of my contract obligations.

i In sijition to the general report which was agreed uron in writ-

inz.I have attempted to answer the wishes of the various rmanajers
£9 & ;

TAY

subnitting to cach one a confiiential report covering my apulicetion
to his properties in the locality mentioned, of the geological deduci-
ions worked out for the district. These individual reports vith

maps,sections and other 11lustratione are respectfully submittel

unier other covers.

 

 
“Sw

In carrying on this co-operative work I have met with the

cordial and ample support of each menager ani his staff,and the
courtesies of the neighboring mines not included in the scheme,
ani I wish to take this occasion to oxpress my hearty thanks to
all parties.

Respectfully yours,

 
INTRODUCTORY REILARKS.
PURPOSE OF THE WORK.
ihe purpose of the geological work was to learn the gecu-
logical conditions in the region about Cobalt Lake and to endeavor
to render to the participating mines such information as would
assist then to find ore. 1t was understood that I should be
allowed a free hand,and a year's time in which to execute this
undertaking. The region had already been studied and reported on
by the Provincial Geologist;and each mine had accumulated a mass
of local 3ata in the course of its developments since the publicet-
ion of thc Government report.
I was expected to make use of this and other current inform-

por
Se

ation and to 233 to it my own studies to the end of making geology

serve the uses of the participating mines in finding ore at min-

imum expense,and avoiding futile exploration.

This undertaking resolved itself into a set of geological

problems,and a method uf procedure as follows:
METHOD OF PROCEDURE.

The method employed was,briefly,this. The District ani
particularly the areu around Cobalt Lake was thoroughly reconnoit-
corel to ascertain the general conditions and requirements. These
were then resolved into several inquiries the subject of which was,

| deposition of
the factors controlling they, ore, since those factors must control
the place and manner as well as the quality of ore depositions.
fhese inquiries were then resolved into problems,and the problems
analyzed into propositions to be proven by data. The next phase
of the procedure was to collect data to prove the propositicns
esScontial to the solution of the problems.

The propositions were working hypothyses cr theories,and

 
--

the aiw wes not to start with ou favorite one ani attempt to
prove it,but to gather ani create ull possible theories to
explain a given phencmenon and let the evidence prove which
Of the verious theories was the correct explunution.

In following this course I took account of the theories
published and current amonge# thosc operating mines in the
District; ard I employed assistants to gather datu under ny

direction along the lines indicated by the various thecries.

In the following report I shall not uttenrt to state

&ll the various “heor’~s for eich phenomenon,but only those
essentiil to the discussion. And illustrative cases of th
prenorena menticned will be generally omitted out of regari

to the confidential nuture «f such information.

 
-3.

ANALYSIS OF FROBLEIS.

What factors aontrolled the distribution ani jis-
position Of ore bolies,and their sttitudes about Ccbelt Lake.
CONTACTS.
OSITIONS 1. That the ore bodies in the
Within it and chiefly near the base.
2+ Thut the core bciies in the Zeewatin lie chiefly
within 30C ft. of the upper ¢r l:wer contact of “he
diubase.

on me

3 hot the ore bodies in the iicbase lie chiefly
Within 300 ft. of its margins.

4. That the contacts were lcci of fractures
available as seats of depcsition.

5. That the ciutacts were uvenues of circulut-
ion for.nre materials.

(fF) That the contuet regions were favorable to
deposition because they were points at which soluticns
passing from one rock tv another experienced u change
¢f ehomical conditions.

FROPOSITIONS 7. Dhat ore exists in ull classes of faults of
Steep attitude,but is distributed in them according to
their attitudes and the stresses extant during the
period of Jeposition.

&. That orc bodies of importance wero
forme

in favorable fractures in the walls

paralleling or diverging from them.

 
Bs

a. ZAULTS (CONT. )

9. That such faults are genetically related to the
folds in the 3iistriect,striking diagonally acrose them
from East to West, or approximately paralleling thoir
axes.

FOLDS.
PROPOSITIONS 1C. That ore is to be found in eeconomic quantities
only in areas of strong fcliing.

11. That within such uress the nost favorable sites
for oro are the slopes ¢f folids,und particiularly the
gteeper ones.

12. Thut on these slopes the most favorable spots
are ninor folds,end that the most favorable of these ure
srwall cross folds. |

1%. That veins in these situations tend to parallel
the dipsf the sides <f these minor folds being influenced
by the major once similarly but to a less extent,or that
the veins tend to cross the axes of the minor folds, save
@8 they may tend to parallel the axes of certain ninor
unticlines, or to purallcl faults.

14. Thut these sites are the best fcr ore bodies
particularly when they are associated with contacts us
discussed above,or with major faults.

15. That the slopes ere better sites than the ux
of major £0lis because cn the slopes the deformation is

the greatest and the best opportunitics arc afforded for

the same rcgsons the stecper slopes are the better.

 
JUINTH .

PROPOSITIVLG 16. That the fractures in vhiich the ore

 

were formed were chiefly vertical joints produced by t
cor: resgive stresscs which produced the folis an? fuulius
& that the; are related to these ther structures in
following RohRet i

Shear Joints (0) - viear joints on the lixbs of follds,parallel
to planes of folding end of low angle faults.

Split Join s. (d)- Major. Parallel or nearly so to lines of
compression, and verticul,regariless <f local dips.

Le
Diz Joints (X)= lLinor. Vertical,end striicing normal $0.7:

: v : : 0 2
Conpression Joints. (WW)= Vertical end 45° to

Strike J.ints {)\)- Vert. ani perellel in ctrike to A

PROBLIL 1 (COWT.)

17. That suck structural plenes of weakness as contacts,
slate bels,end major faults,tosether with the slopes of
£5138 constitute loci of ctrain and raxirun jointing;anl in
such regin»ns,rerticulerly where twe or more of them coinciic,
the vertical joints will have been converted into cre

18, That the @ wd J. joints are the chief
of depoiition of ~re in joints.

19. That ihe joints in the Euronian are the rost favor-
able seats cf jepositicn, those in the diabase next,end those
in the leevatin least.

eC. That che joints nov oren an: uncemented exyress chief-
ly the final relicf of the rocks from the original Jdeforrative

streusec.

 
SUURCES OF LUT.LS.

PROPOSITIONS ; ~

(21) That the ores were isrivei by segregation ani trans-
ported by ascending solutions fron batholithic masses of granite
or gabbro.

(2; at the ores wero derived by segrogation ani trens-
portution by descending solutions fron the diubasc £ill itself.

(23) Phat ike veins were originally derosited fron acceni
ing

(24) That the veins wors originally deposited fror solut-
ions Jeseending after leaching the Jiubasc sill,ani were subseruent
ly enriched by iownwarai circulation.

“0+ That the veins were forvej through the daffusizn of
constituents from the cold sill to seats cf Jerositicn,ani that
the native silver,eni silver rinerals were 3erived fror. the crigin~
ully argentiferous arseniies through their breaking down unier con-
ditions cf low Iressure, unl the rc-segrepation by diffusion of the
“&llver into favorable situations in or near the veins.

LODO OF DE2UbIPION.

FRUZCSILION 2€. That the veins were formed under conditions ¢f too
A ——————— A ———

great pressure for the existence sf large open sypaces or for the
free opening of small fractures,ani that they were forred by the
metasonatic replacerent of the walls of tight fractures.
ATTITUDES 0 CHALNZLS.
hot od 1 in joints,those that are tie
richer,anl tre nost flatly inclined are the pocrer,

otherwise similar coniitions ,the richness being proportional

v0 the degree of the dip,and the veins being thus classifiable wit

 
oy pe

A. ZITUDSS OF CLANIBLS (COnT.)
FROFOSIZION 27.(COND.)
regard to both ii» and contents:-
10° to 30° quarts, celoite,little sulphide

&
30° to 50° quartz, omleife,nuch sulphide, little arsenide,
traco of silver,

+
50° to 70° no quarts,caloife,11tt1e sulphiie,much arsen~’

ide,notuble silver.

70° to 90° no cusrtz,caloife, no sulphide ,ruch ergonile,

muck silver,

#6. That foults are not good seats of joposition for
these ores,ani that of faults With narrow shear zoncs the gtecp-
er silio=thrustg faults ere the Lost favorable,and in the wile
ghoar cones of othor faults, ores have forme] only in spots
locally relieved of cauyrossive otross.

J, That the stress ooniitions of the rocks offcoted
their metasomatic reylacomont by ore minercle in the geneo that
replacement was retariei by molecular stress,ani that this
expleins the phonorone eited in Propositions 26,27 & 28.

CEOIICAL TINZUTHCS OF ROCKS OF DIPOLITION.
FPRUIVEITIH,

#0. That the replacement of rock b7 ore minercils
wag freest in more coij rook,end ost reluctant in r.ore basic
rook, yroceeding in the latter case only wherc the coniition
of stress and sunply were most fivorable. |

PROSISH 2.
Thct factors controlled the dietribution of silver

and mineral in the veins.

 
8.
PROBLEI 3.
“rut are the directions ani ages of faultings.
PROPOSITIONS 31. That the faults cre 211 due to ecorprassion or fo

foliing torsion.

32. That the eastuvest faults are side thrusts.

33. That the other faults are up thrusts or jown
thrusts.

od. That faults long folding axes on a given horizon
dip with those gxes.

25. Thut the sije thrusts were the first faults,
usually preccding the folding,that the folding torsion
faults were next in age, and thot the thrusts on tke uxirl
plones of folds were the last ,but thut the folding con-
tinued through all the faulting sni after it,and tho

mineralizuticn followed wll the deformation.

 
9
yy op tw Ro apy '
SOLUZIOES OF TROSBLILG.

 

IRUSL. 1. ‘hat factors cont:olled the distribution end Jisposit-
ion of ore bodies, and their attitudes sbout Cobalt Lake.
AlS ZR. Segregations of emaltite ani niccolite in calcite with
sociated silver,in aijacent rocks are almost co-extonsive with

the iipissing; diabuse in Horthern Ontario. The veins are the
largest anid richest ani most thiekly distributed in the areas of
strongest folding. «nd within such areas the opols rost favorable
for ore arc minor transverse fclig on the slopes of najor folis,and
tLe nore acute both foliingse,the more favorable the conditions.

Llso it i. ossential that these conditions shall
exist near one of the contacts of the iisbase £ill,that is within
300 feet {znd the nearer the better] or in the Luroniun near the
jiabasc,and a most favorable situaticn is the Huronicn formation
near ite oontaot with the Zecwatin,particularly in conjuncticn
with strong fracturing and faulting.

4nd within such an area the prrincipel veins ekedd will
stand erect or at steer angles. being better when steeper,and will
parallel or branch from faults at small angles,nore particularly in
their hanging walls when the” are up-thrustf faults, or will lie

2lonz the axes of minor anticlines or with the 1ips of the siles of

rinor synclines,exceptions constituting less than 30% of the cases

ani bein; essentially covered by the cases enunerated under pro-

positions 18 and 28.

 
nen
Poh

Aa Le
EA ——————— LSE ELS]
(FA.TIBIZIVHS 1 to 3C.)

i ‘the

f - WL Emr
whecial enw. leg

it is well imown that this a - lie: neers 11 {le veins

at Ty ine 4 la i PL 2 ps aie rt wig ; ih ay oo 4
sbout Gobaly Lace. 3 8 ¢. Tor .gertione whére ioint

veins have run olor : ance Into the lee. wilin;but fror
their unyroductiveness ther onl: ton] to rove .le :ule.
Ure boiies on #efoultei oconticts betueen 1 ondem nd Tee=
watin ere rot true erccjtions.
Lot the ore wodies in th lee 2tin iie chief:
fl.0f tie upper or lower contaot of the 3icbise.

fhe onl; cuses in the area covere:,.iicrh were covuel ir
stulied,were tilowe in the O'Brien [.ine,namely,t
betwcen the iain ni . 0.16 glhefts, vein 0.20
vein in [0.72 sheft,all of .iick end witli in 25)
contact,ae far ow ore iz conuvernei.

which fol.ov were either in

elie vere nine? out hLefore this work

wiitle :i-iusing

v . oh » Vom gane of “n
~erver o Ulidskaning.

 
lL 11.
2. (COH2.) 7

—Xperience hes chown that ore found in the Zecwatlin at
‘3istences of wore than H0C ft. fron the Jiabause contaet is
only in swell scottered boiies whieh are cxpensive-to find,
énd ultimately unprofitavile.

5. Thut the ore bodies in the ilubase lie chiefly within
30C ft. of the margins.

The only-oescs in the area examines were in thie O'Brien
Line,namely the brench of the Lain vein east of No.16 Shaft;
Veln B. & Viof lo. 6 Shaft, Vein No. 20 2nd: the -vein botween
the Lain & llo.16 Shefts.

he chief outside cases are i=

Pena-Cenadiun

bailey Cobelt

Beaver
4+ & 5.That the contacts were: loci of fractures available
as seats of derosition,ani were avenues of circulating for

ore materials.

The illustrations in su: port of this are obscure in

1:08¥ cases beceausc,sinec the vein-forning period Joints have
Opencvd in other.situations to sueh un extent 48 to appear to
contralict this’ stetemént. However since tle vein-foruing
reriod wae & period of combntation it nay be inferred that ull
fractures then open were cemented,and that frescturce nou oryen

in the vieinity of cemented fracturcs have opened: since that

period.. It iy generally founi that both sets of fractures
agree,vikich rust imply cither that the stresses whieh produced

the first set were renewed on the sare lines,ofter the perici

 
4 & 5 (CONT.) | 12.
of ccmentation,or else that the stresses set up in the rocls
by the deformative forces wore only partially relieved by th
first fractures before ccuentation,an3 finally founi relief
in more numerous 2nd less extensive Jointings duc to the
subsecuent elimination of restraining pressures.

“he existence tlroughout the iistrict of recent
faults of insignificant throw which constitute troublesonc
water courses bears evidence to the renewal of deformative
stresses since the rerio? of cementation. On the other henj
it seens probeble thet both caugee of subsequent Jointings
were uctive,since there geems to be eviience that the veins
were forred unier a Leavy overburden. Thiet evijence concists
in the feet that ihe fracturcs Opened ,were persictent ani

usually spsced at naxinun strees,and producing a winimunm of

open 8pdce,pince crustification is a rame rhenowenon in the

ore boiies,ani where existing is better exylained b7 local
Jisgolution of the vein walls than by mechanical influence.
t may also be argued in this connection that the foliding
is equally iuportant as the faulting,fron the structural
point of view,ani that the folie are esesentially of the tyre
called by Leith “sirilar folds" rather then of the parallel
type,indiceting great Jerth of formetion. Thus the existing
open joints mey not be altogether indicativeof the loci of

greuiest fracturing before the ore.

 

 
It has Leen chown that the contacts ere the moet favor-
able regione to look for ore bolies. Thic nay de due
either to th greater albuniance of fractures or of ore
materi: is, or due to cleriezl coniitions; but the greater
apunience of fractures ue be argued fron tue feet that
contects «re lines af weakness.

If a thicl horogenious forretion lie the iiabrue is
folded in conteet with = relstivel: Tlestic one live the
Leevatin ni a relitively ragid one like ike ruronian,it no,
be anticipated that the conticts of these nasses vill beer
the brunt of 23justments between them, rartioulerl, since the
folls cre of the olasss of “‘siuiler folds' in whioh tlere ie
& waxinum of ghearing on the 1irbe of the folie. THiL in
faoir hos been foun? to Le the case.

alrio.t univertelly in the vicinit; of Cob~1t Like the
Zeevatin-iuro.ian contact hes been shetred, while in tle
v'S.1en Line tle 3iabose contsct hus ex;erienced the sane
Frocosses, as is evilenceld by souge on the conteot £ni eure
faces of shearing within the 3iabase close to the contact.
4iuL the contocts wore zones of eewm vtredin,end it follous
that Joints must huve been 2roduced in greater abuniance
there than else.ltere.

Jip en’ strike joints cre universally s.societed with the
steer Joints of low angle,which porellel surfecoes of foliing;
“nl such are the attisules of the veins which: lie nesr the
contacts. OJSuch fractures,as will be 8x7 loined under tue
eviiences bearin; on Iroposition 16,ave readily evailetle
as peels of Jeyosition of ore rnaterisls which ray be ocir-

culeting in the neighborhsoi.

a UL ll —

Np

|
|
|
I

 
4 & 5 (COL) 14.
Tersistent joints in core cases,wore certainl, wvenues of
circulation for ore ucteriele,but in a8 rue as the: veldon
are ver, extonsive,rsrtioculrrly as corpcred with feults und
sheared oontucte, the latter rust have served us the trunk
channe 1s for thet eirculation.
Tes TDVAJTH SURSLCT.

a discussion of the Deeviatin~-Euronicn corteet woul? not te

 

cor; lete without & Jdeserirtion of its oontour, ana ite config~
uration in relation to the folis of the district.

on beginning this ork it wee foun! that the contaet ves
irregular znd tret cone of the irrejularities were suvrurt.
Some of the mine rnunsgers referred to Zeowatin hills rnd vi lleyo
underlying the .uronia:., Chere secred to be an intererting y1ro=-
g;eot that the _roluetive conglomerate could be forecenct benecth
the dizbase in certain srots throuzh the ocretul Soriing out of
01d drcincge systens curved in the Zeevatin surface,in sliieh
duronian gravels azd finer sediments hed been jerosited,

Investisations were frneldatel; started elong tiie line; but
it soon bezwi to a peor that the 1iea wre untoncble, The fzet
that the 31:6 of the Ziner selinents conforved with the couteot
was ot Liret ainitted as consistont with the su position thet
the first layers of sediment in a body of weter would necesee
aril, confor. precisely with the sloging floor of the besin,
aovever 1t as recbgniic? that this raralelider wae not confine
€d to the fine sediments lying on ihe Xeevetin flour,but top
also shared by those 10¢ ft.or ore above 4it,anl dy cocrse

boulier layery as well, Thece focte obvivusl, could not de

reconciled,end the 1ice of folidng ves 83opted and subsecuently

proved,

 
10.
The evilences in fevor of foliing sre (1) the interbed’-
in: of Tine sedifrents with thiel layers of heavy bouliers,
and the paralellisn cf tke whole series to the contect, for
& distance of 100 #t.:n3 nore fron it, (2) the ievelorrent of
Joints in the sedirents 2s viell a8 in tho Zee &tin inj the
dicvase,purallei to the <ecwatin-_uronien econteet,and ghowins
evidences of sheer in tle direecticn of ur-thrust faulting on
the sides of uniulations. Thee flat=1ying checr jointe in

Liny ctses can be seen passing tarou i. peldles in ihe Iuroniun

 

conslorerete ani faulting tlon short iistances. Alco in many
cases these Juinte show distinct striae perullelin; tidder din.

(U)Lhearin, on the contoct itself.

dhe inference from tris coniormity of bedding with the

ee —

contact 1s that the contiet was viriuall: a horizontel I'lone

R———

when the seliuents were 1ail jown. ind this by long coreful
relecron hag been founi to Le the rerarioble fact. Jliere sre
e few exce:tions to tris rule;one of thew is & srell Je: reus-

ion, reriicye 100 Tt. lon; by 1L0 ft. wile ani £5 ft. in Jeptl,

EE A a Bt Sa

lying on the west sije of the Coniagas ..dne about 1/5 of the
way from the ‘orth corner to the South corner. another Jderrecs:
ion of about the sarc depth urparcntly exists in tle ~Onecas
Supericr Line unier Curt _a'e. a corresponding rrouostory

0X siriler heiyht lies alon; the brow of dipiseing L411 above
tle north end of thre hizher tailings jaw,

A Tew other ninor irrcgulurities in this old lon3 sur-
face have been noted hut for all rur-oses significent to Line
in; operations the surface Ley bo assured to Lave been Oris=
nelly a nearly arooth flot surface folie? nl; afier the aie

vent of the 3iuboue.

 
16,
(6). That the contucts were favoriile tc Jerosition ueccuse ther

Iron one roech to

Se!

wore 1oints &% which solutions neusin,:
nother exrerienced a charge of chreriocal conditions.

“his lice is untenable in viow of the cvidences beuring

on Frorositions 2H ani 30.

hal ore exists in feults of steer ettitude , but ig Jdstrie~
buted in then cocordin.: to their cttituldes,ond tle strevtos
extent lurin; tle reriod of Jeposition.

deulti for the rur:cse of jrosent Jigouceion «Ye ¢lacteified

thus:

(1) Lijor upethruet foults., of this ind tte only one

in thi. sree 10 the Cobrlt Lele Poult, This cut

A a A orn

eH pa a m———

across all forratione oni throws tho ruronien wverd
about 40C ft.et un angle ar roximating 46° ‘

Jude foult conteine eonviderchlo ore.

Lino» ure*nrust foulte. There oro ueny of thie oluss
With throws varying from o few incites to twenty or
tidrty feet, ilo ore on threge.

seldin; foults «re wvovenente on scdimentery vels;
hey have resulted 7row tho torsion stresses about
kLorisontal axes conforidng to the strike of the beds,
Bet ur by the fol2din; of the bede. Shese faults ere
Glveys ur-thrusts. Souetires the. heve thiois of

0 or 100 ft.without the production of notzlle gouge
or breccia, They usually oecur in the beled
durorian pediuents on the lindbs cof folis, They 31ip
at low angles ani have no ore.

Deun=thrustsfaults,othervice known cg Llock faulteg,

 
7.(CuI2,) 17,
These have ¢ jown=-thro. on the hanging wali side, but
result from comparative forces. The only notable couse of
this is the "“iest Jault" whioh scvers the PBasterly veins of
the l.eyer group of tre ilipisein; i.ine,eni pespes :i.rough the
24 Vein workings of ihe City of Cobalt Line. This hes 2
1 one thy ow sf 110 ftydirs ot about 45° en carries no ore.
Siie-thrust faults. These are an irportant clact which
usually strike 2: proxiotels cet ond vest, ’iring at steer

an; les,enl constitute conspicuous features in nearly all the

 

nines. On these the iispluceuent was silewise ut lov ingles,

nowhore exceeding 100 ft. Zour noteble oxuuples of this oluw

ere I vein of the Cobelt Lake lLine,64 vein of the Hipiveing
Line, 50.1 vein of thc .udwon Bay an? 0.6 vein of the Lo Roce

On 64 vein whose diy ie 65° the Koewatineiur onion contact
wad iis; laced horizontally 216 ft,end souge end grooving ere

' vigible on the walls, The ore body 4s « noteble ome,

on Lo.1 vein of the imdeon Bay howe ip 1s about 66%0re
wag fopowitel on 6 fault surfecc on whiol the secre eonteet
was thrown Borizontslly 4 ftv After the ore had foried,
snother neorly horizontal movement coourred eliczensiling
ans grooving the metallic ecntents of the vein; ond follows
ing that,c third movement out grooves toross the oli ones ot
an angle of ebout 20°, The cre 1o3y 1& & noteble ones

dre ococours on Cobalt leke Poult and clso $6 an insignis
fi0ent estont on tho West fault, The sbsence of sre in dpm
portant quantities on the Jest Feult is regeried ns the

 
7 {C.0T.) 18.
normal thing a8 will be oxplained under evildencos bearing on
Provosition 27. Sut the occurrence of ore on the Cobuli lale
Pault requires ¢ special explanation,since the ore is of
highor grade *hen wcull be exrected on ¢ fault of thot 3ir,
ani it is in larcer cuentity.

In looking for an explanation of this anormal ys i WES
jiscovered thet the Cobalt Leke Peult lies along the axicl
plane of Cobult Lake Synoline,vwhioch being usymetrioc énd
stoaper on the southeast side gives ¢ dip tc the axial 1 1rne
and to the fault,towaris the southecegt,of about 46° . The
vrincipel movement on the fault occurred imuedietelr £o1loving
the flexure,in further relici of the wane strecseu. "hile
this deformation wes in progress pressure vee also coming frou
the north eest ani southwest ,ond wae tending to produce minor
oross Tolls on the sides cf the Cobalt _gke &yncline and aoxosr
{its reloeted folds, [hic tendency succeeded in prolueing ite
effoet ae soon as the other stresses hal found couylete
uonentery 1elief along the faoult;and tlose effoote were certaly
transverse folis whidhL Jeforuecd the foull surface ituelf,
Following the production of the tremeverse folie vhich warped

the feult surface,bulring it slightly toward the northuest

on their axes, t1ight rovementes were renewed along the fault,

but these were only after o oconeiderable interval in which ihe
orc bolies wore fcorued,unl wero of small amount.

ince the warpings of the fault surface ococourred cn
the axes of transverse synolines,the lefarning strese was

chiefly downward ut those points somewhat along the iy cf the

 

 
7 (sont. 19.
feult,and probably tended to couprress the feult .alle;dbut
on either side the stresses wouli be in the opposite 3ircot-
ion end tle fault walls would be abnorrally free fron Gore

Jression, us will be exvledined uniler Iroycsiticns 26 & 29

 

such fractures ,relativel; free fron transverse ccemyression,
are tle rnost favorable yluces for the feposition of ‘003
.ore bodies,end thus ore corr-lainel the ores oecuring on tle
Cobe1lt ake Fault.
Jurther liscussion of this gubjeot will be found under 20,
i & 0. That ore bodice of irrortance were often formed in
favorable fracturce in the wzlis of faulte,perallelin: or
diverging fron then,ond thet such foultoc are genetically
related to the folie in the 3ictriet striking diagonully
across them frou: east to vcet or &, 1roxim8tely parclleling
their axes.

The primary structurcl stresses in the iistrict were

:
|
#
|
i
|
i
i
|

¥

aligned on two axes, ome strikin: northeast rerallel to
Cobalt Laikte,nnt the otler ~orthwest poraliel to Crowe Lake,
“hese two axes porallei iurortant structures all over the
csenerdl resion and Province,zni even throughout the ;laciat-
ed pro=canbrian areas of Cenaia.

it has been found that the etresces exrressed in
defornations are zlso ex;ressed in torography 4m tis crea
Yoounst the Jefarrations have given risc t¢ numerous Joint
blocks lying parcllel to folis and faults un? the ;lacial
lige hes plucked out, these blocks thus causing the topograrhy

roughly to conforr. to tlie structures,

 
& 9.{C0H2)

This valleys nou occupied br rivers «nd 1ciWes were  wujed ouy
by tre continental ice cheet;snd the intervening. hills fre-
cuontly eunforn to feult blecice ond to folls.

“rhrough an analysis of ile structures in this ve: end
through the corroborative detailed tudies of tic Londaicn
and Irovinclal geological surveys,it ¢:pcers thet in ony given
re ion in the ‘Ganciisn Shield there orc either ome or 1.0
joninant sets of perallel structures whose axes strike
nd II'-85 or elee K~8 und T-l+ And tlhe clLief lines ol ex-
pregsion of theie foces are yrobably fault lines.

It stems likely that these faults cre rerely suriaces of
adjustment of regionsal streeses,end thet noverent has oceurreld

gt various timesund in various Jirections on thei ,snd that

foliing parallel to then has 2l1s8¢ frecuentl: occurred along
w 5)

then.

This arpears 10 te the situation in the Cobalt Dictrict,

West shore of ke lenisiioting,the chain of lekes

and decrressions northvest and southeast of Crows Zake,tuc
l.ontresl River and ey .aize all lie parallel to the I'=-5C
structures;and Cobalt :sie,leterson alc, Kerr oie and
Jiroux Lake in the inuelicte viedinity of Cobalt,sll lie par=-
allel to the NZ=-8\ structures.

In this locality the cliief lines of exyrcssion of these

4

two sute of structures sre Cross Leake and Coball Like,the

latter being locally the stronger,thouch regionally the
Sinee in those roelts the chief line of ex~ression of ihe

-

structural foreos is ¢ line uron which the etreins vere ile

-

greatest,ithe re;ion between Cobalt tnd Crocs .egite has geted

 
& (CON) £1.
mechanically es if tetweor tne Javse ¢f a nut cracker,cnd
seconiary set of .truetures hes been rroiuced stretening
acrose between these uxes in an Delf direction, like the bridge

f an A,and thesc I-97 structurcs have tazen the forr. of steer
faulte on which the novenent was 8ldewlise, or nearly hori-
zontal.

{hue the structural relations arc essentially thescithat

 

> x

tlicre hos been folding prarnllel to the Cobult Laie axis, the
~uffalo-hiuison Bay Ridze,the idpiseing and Leilinley-Darragh
hills,Dicbasc Lit. ond the Keeuatin area southwest of it,ani
the hill southeast of err Lae,being enticlines,oni ths
intervening leiresaions being s;mclines.

The Cobalt Lake syncline ruptured ‘along its oaxis,«ni the
ruptuse is the Ccbelt Lake IPault.

Apvrozimately yaradlel with thie fault are severcl others

0X lows extent,the wore injportant of then lying in the foot-

wall oide,that is vn the northwest limb of the g;neline. Thes

are chiefly the “Test Pault,and lo. I ani the Carbon aults
of the lL.cyer workings of the sirisving compeny;but genetically
agtociated with them are certain flat fuults on bedding planes
of the "slates" ,thece having displacements of fror 4C to 100
ft.urward on their 3iys due $0 the torsion stresses incident
to folding.

ouperirrosed on these UZ folis ere minor HY fo
were produced by cubsciuent deforrations which 21s
surface of the Cobalt Luke Fault.

The I~ sije-thrust faults cut indiseriuinately ucross

 
9 {CullT.) 22.
the Tolis, but being carlier than any of them,are thrown by
the i 3 faults, particularly the Cobelt Lelke fault, on which
the vovement was oesentially upward tc the forth.

iho bearing of these phenouena uron the situetion of ore
bodies in the wells of the faults lies in their structurcl
relations and the wcchanics of their formation.

nteerly inelincd 6 Joints tend to open perallel of
nearly prarullel with tho walls of side~thrust faulte,in
relief of the cousrossive stresscs acting along the frult

surface# in a nearly horizontul 3irection. Thece ray lie in

cither wall ani also in oxtension of these faults, notable

examples boing 40.10 vein of the Lafiose line, the brenches
of I vein of the Townsitc Line &ni the Rice and other voine
ef the Xuison Ba: line.

“hie class muy iubiously 4inecluic a number ¢f veins forvei
on a’ Joints, on which there Las teen e slight amount of
moveuent,such as Ho.1d of the Chambersg-Terlani ani ome or two
othors.

Vertical strike ani 1ip jointc open in the wulle of the
H5~5. faults related to the folis,oand constitute an inporiant
class of veins. 4 notable exorple of & winerelized faulte
strike joint is Ho.l vein of the IoEcue, The 31iy joint
veins are 3iffioult to iiseriminate Iron thoso connectel with
folie,and in tiis arbiguous elsse belon; ¥2e.Z ani 4,03 the
leionald veins of tke Lallceo, the east brenches fron Ho,98
vein of the Lipissing,o.14 of the Charibers~lerlani,an? others,

 

 

 
13.

“ket ore is to be found in econorde cuantities only in
arcas of etron: foldin;.
Lhe obvious results of exploration, pointing to the
of

Cobelt district us the chief locality for the oceuriénce of

Silver veins,can:ot be Jecorted us proof of that condition;

und geologicul study should show whither that is truc,sn? if

adv,why not,and what other loczlities there rey bo.

« Stud; of other liutriete for ihe purpose of co :arison
of .;eologiesal féaturcs hes been inpossible under the circun-
stances, but,ss elscwhere shown in this rej ort,the ‘orc viitrin
this area has been found to be accoeiatsl chiefly with the
most strongly folici localities,its abunisnce being proport-
ional to the Toliing,zni the structures in which 4t lies
being consequent upon the £213ing.

ihe field was stuiied with special reference to the
originel source of the ores,ani ss will be discussed later
under Proposition 25,the ocnelusion wes rescl.e] thut the
orcs were derived by processes of solution and diffusion from
the Jisbuse sill,bein; uvailable ut every locality in thre
iiabase covered region for the {oration of ore derosits,if
only seats of jorosition ani avenues sof distribution are
surnlici by the structures. Lut as learnci froy. tre struct-
urul stulies,rni shown ebowe anid in the following raragrarte,
such structures can exist only in strongly folded er-as since
they wore dcveloped by foliing procesges,and their strength
is proportional to the dcgroe of folding.

That within such areas the wost favorable sites for ore

are the slopes of folds,ani rarticulerly the steerer ones.

 

 

 
11.4

ONT.)

LxXenplco in illustration of this constitute all tre
Ore bodies in the district. except the Scnccc Supericr, the
Cobalt Lake Fault orc bodies,iic.64 vein of the Lipissing,
the luwson l.cin vein,eni a few others of leus irportence,
cxecerting tuuse 20% studies south of Zerr Loke.

That cn thesc slopes the ncst favorable spots are ninor
folis,anld that the Lost fovorable of these are srall cross
folls.

The le:linley-Darragh veins lie chiefly along &nd neer
the crest of a rinor cntieline situated 3isgonzlly on the
limb of « fairly steer syncline,eni £10 in pert strike up
the cowblned slope. The Cobalt Lake orc bolies lie portly
along the ercst of a minor unticline diagonal to tke lind of
a woicrately steop synoline,rartly spanning the saddle
between this miner anticline &nd the rujor syncline,an?
partly on the Cobelt Lake Fault. The mein group of Townsite
ean Citys of Cobalt veing arc an intricete group lying alrost
wholly within an acutc minor syneline pitching down the sloye
of & major anticline. The ii0.24 " inze veins cof the City of

Cobalt are a .grour lying along the crest ¢f & entle ninor

anticline pitching dia;onelly down the sloye of @ nmajor

Eiacline.. .2he 41L.0307 Juli veins of the iipicsing lie zlong
the crest of & ninor anticline pitching 3diegonally down the
gloyre of & major syncline. The l.eyer &nid No.98 vein grour
lie in the hollow betwoen two ninor anticlines pain; e
slightly obtuse angle with cach other on the jentle slope of

a major syncline. The Cherbers Jerland veins liv across the

 

 

 
12. {Cuit.)
steerer sloje of un usymetric rinor anticline whieh stretehos
along the gentle slore of a raujor syncline.
Probably these ceases will suffice as an illustrati n of
the propodsiiviou.
lo. That veins in these situations ten] to porallel the
irs of the sides of these rinor folis,beiny influences

by thc major ones similerly,but to a less extent, or that

the veins tond to cross the xcs Cf the ninor folig, save as

thoy ray teni to rarcllei the axes of certain Lins» auntie
c¢lines,or to parallel faults,
Ia the Tounsite-City of Cobalt Srouy the veins forr.
network which is rather Jifficult t0 analyze on zccount of
the variation in the strikes of veins and thc dips of the
folded contact ani selinents. Eowover a ceéreful study hus
brought out the fact that 1.081 of the veins lie along the
dips of the sides of ite rinor symone while several lie
across the axis of the Eyncline,an3 2 few lic at other angles.
The roost southwesterlr of the Lelinley-Darre;h veins tond
to strike across tke axis of a minor syncline on the slope
of the najor syneline. In the adjacent portion of the Townsito
vac Frineiial veins strike acroes the uxis of a rinor
syncline. The Chenbers-i'erlend veins Nos.14,15,18,01n3 18
strike along the diy of the steeper silt of an asynotric
minor gntieline. The Leyor and 98 group strike across uo

syncline between intersecting minor unticlines.

In moot of these cases the directions cof the veins

 

 

 

 

 

 

 
15.1 {COT
appear to have been influencei By the surerpositicn of
na Jor stresses over local ceg,as will be discussed unier
ron ositdon 16,

It has 8lrealy been shown in the : G lon of {he
preceding proposition that the crests cof rindr wntielines
arc usually the sites SE ine striking
those folds pitch jown the
lie along other lines of comprossicn.

“hat these sites’ are the best for Ore bodies
1y when they are associated with contacts, zs
Sr vith major faults.

The casos cited ubove ney be used as illustrations

this since they fulfil those condivicns perfectly,

required major faults being the Cobalt Lake, the
the Carbon faults end those in the “slates”,

"or obvious reasons the contrasted cascs cennoct be

and the best opportunities arc
are
major folds the sags ave

py wt gn “of Tn ey aa
Slopes are areas cf ghos

“4
rh

 
15. (Cult. )
either interscet or rc ellel the sides of the fold;inl
stiuctures are the r.oet favorable for ore dictribuiion
ioposition.
thet the freeturc in wliiel. the orc bodics were rormed
were chiefly vertical joints rroduced by tre corrreusuive
stresses which produced the f013s anl feults,end thst tiey
are related to tuese other structurcs in the fclloving
nanney ;-
Shear Joints (& j- Shear joints on the lirbs of folis,parallel
to planes of folding ond of low en’ le Taulis.,
Split Joints tq’) - Lajor.Parfallel or neerly 80 19 lincs of con-
pression and verticul relje.rilese to local dirs.

j 2
Dip Joints. ({ )- Linor. Vertical &nl striking normal to

Compression joints ( Y )- Vertical ani 45° to d

Strike Joints (X )- Verticel =ni parallel in to A

During the reconnaicance which preceedcd the Jetailed
stuiies it was noticed that therajority of veins chown on th
government may of the district lay on the sides of najor rolis

he

parallel with their dirs. In etteupting tc correlate the
structures with torcgrophy it was noted thet as a generel rule
the Llopes of ‘hills were oprroxXimetely paralleled br ao typo. of
joint on which striations indicated slight thrusting mcvenents.,
two observations lead to & coursc of investigation in
viidich it was learned that thi. Jisfrict suffered corylex
f0l¥ing and faulting iti: accoixanying jointing,all of which

was exrresseld by the topographky,due to ihe

b, iio cuatinental ice sheet.

 
16. (Cus. )

Ym

Vans
x
whic)
Ja --

y whiel

i " wan “~~
al YTOoXir U0

& recognition of the fact

veins;end tiis in turn, by

unser iieniin,; of

s. 4. i
Jjlints a5 a neans

Zuide 10 the finding of ore

shear Joints. In tris stud it

 

in; paraliei to surfaccs

roxirating tle slopes
ani recognizing

folds to which most of then:
to rlanes of fcliing

is to adjust shouring

arount of n.ovement on thor,up their ir.

icsignated by the symbol AP

Joints.

vortical,ani strile alo; the iin of KP

ng to relieve the tensi

i joints by eorjproesive streoecs

shearing on the 0 joints.
1 A joints.

———- o£
LLOE0

are vertieel und purzliel {10 the

To thom

in

A’ joints.

stood vertical an:

the hill

indicating

it
cy

stresses

le stresses

cre indicated

a on dS
fume CATH.

veing usuclly occu) ies

4 Ty ra
Vi.

aralieled

s1

ores, lead
the structures anteivics

the importance of an

bodies.

was receognized thet the joints

£013ing, ich. are the ones cite!

of hills,we.c the funiimentzl 7
’

the other joints as well es the

&re roleted. They lie rerullel

and inclined faulting;and their funet:

,there ususll; 8 sii

Le ins ”
ran v * » po 0 “
“rese neve buen

(Beta).

2
These joints irniicated b; the syubold {elphe two.

joints, thoir
set up along;

tending

Yo’

They ere usually xu

{ 2,4
1 laxb390 + )} Ld

of A joints ani o:

 

are not vo extoensiv.

 
16 4(C 20.) 2o.

(gorru). They are vertical uni strike ot ap roximat
0 - - ”~ -
45 to the diy joints. They ure ususll; srall anid

corpression Joints, These ore indicated by the symbol >
tely

of winor importance.

Split Joints. The use Of this nare is un dnnovation but

 

it 10 employed on account of the fact thut these joints
are not usually reeognizcd by geologists. Irotably heir
reeognitisn here is due t0 the oceurrcnce of inportant
ore boligs in then ,as Otherwise ther certainly would have
gone unnoticcd. The Word was chosen as expressing best
the function of the joints. Ther ure indicated by the
syrbol d' (.lpha onc).
“hese inportant joints have & vertical anttitule,

and orient theuselvec partcllel to the ininunt lines of con=

pressicn to relicve the tensile stresses normal to thou ,set

 

up by the tenicney of roc te olongete at right angles to the
of corrression. These juints arc lize the a joints i
Tunetion,cxgert thet they exist om 2 lercer scel
$0 1088 local forecs of coyressicn. Thre. therefore cut in-
Ly
discririinately across the a Joints save us ther are locally
Jecflected.

Thus the split joints are found crossing the
axcs O0f minor gsynolines Or following the axes of ninor anti-
clincs according to the corivhtetion with refercnecs to uxes of
princinul stress. Jor oxanyle he case of the 4th of Jul
veins whi ok lie in split joints along the axis <f 2 rinor unti-
¢linc whieh pitches 3own the slope of the Cobalt Leke synclinc.

<he mechanius of the cuse probably is that 4 winor unticline

 

 
16.{CJ 7.)

 

lying across a uajor syneline which juring the furiler om
areseion of the syncline acts us a rigid chord aecrose the bzsin
ani recoives the full thrust of the conrressing forces. The
reason why such a joint could not,in this case, open widely
is probably thot the general presoure under whicl: all the
poole omicted at that time,3ue $0 their derth belcw the surtnce
of the zarth,iyrcvented Open ficeurcs, but perritted in their
place numbers of rurallel tight fissures to develop. «nd this
gvnuars to huve boon what havpened cince there ere severul
varallcl veins in this cise On the same anticline.

That such structural planes’ of wcaknesy us contacts,
slat: beds and ni jor faults,together with the slopes of
folds constituto 10ci of strain «nd of maximum jointing;
and in suci regions, particularly where two or more of then
ccincilo, the vertical joints will Lave baen eonverted inte

ore boliocs.

In surnort of this propositicn it nay suffice to say

that every known ore body of those studied fulfils these
coniitions,end wherever the slope cf « transverse £C13 co-
ineiics with anothor <f these coniitious,ore exists,ss fur
+8 has been shown by cxploration.

That the nost favorable joints for 3epoeiticin were the
gtrike joints connected with faulte,the dip joints connect~
03 chiefly with rinor folds or najor folis,and split joints.

Uyon Te stotemont of this proposition it will be recull-
si that these points have variously becn covercd in the

above iiscucsione.

 
19. “hit the joints in the Hurenian are the most fuvorable
scates of Jdeposition,those in the Diabase next, and those in the
Keewatin least.

It is difficult to say whether the grcater abundance of
veing end their greater richness in the Huronian is due to its
physical or chemical peculiarities as contrasted with the other
rocks. It has both,aend perhaps both are factors.

Physically the Huronisn is non-homogenious, but its

general character is elastic and refractory on a small scale,

but yieliing to 2 verying logree in different directions as «
terrane, on. account of its brittleness and the existence of
meny slate beds in it. The Xeewatin is similur in choracter
except that it is somewhat less elastic on a small scile,and
ig much more plastic as & terrane on account of the fact that
it is composed of igueons snd sedimentary units standing on
edge. The Diabase is the most homogenious of the rocks;es
terrane as well as on a small scale it is the most clastic
The mechanical effects of these characteristics during
the deformetion of the region,would probably be the most ready
jointing ani faulting of the Huronian,and its conformation to
folis,chiefly by the slipping of one bed over another;on the
other hani th. Xeewstin would be expected to fracture poorly
and irregularly on joints,because of the itregular nature of
its components,ani to deform vertically more easily
horizontslly,in contrast to the Huronian,acting
more plastic terrane] while the diabase belng elastic and
homogenious would deform ani joint with 3ifficulty,the joints
having a tendency to curve #n account of the tendency to con-

choiial fracture. This hos worked out most interestingly.

 
19+(CONT.) 22.
If it were set down as e rule thet iiabase ani Keewetin
joints are not persistent the me jority of known cases could

be cited as exceptions. However it seems to be true thet

persistent joints in these rocks are only split Joints and

occur only in situations where the stresses were concentrated
to make only single strong fractures,for clsewhere the joints
are few and short.

The chemical differences of the rocks are less certainly
faotors in the formation of ore bodies. In this connection
it is o notable faucet that good ore bodies in either the
Keewatin or iisbese a0 not exist more than a few hundred feet
from the liabase contact,which as expleined later,is pre-
sumed to be the source of the solutions,while in the Huronian
they exist meny hundred feet away from it.

" Por these two basic formations the rule secms to be that
ore forms in the most favorable fractures only where the
mineralizing influence is exceptionally strong.

Thet the joints now open and uncemented express chiefly the
final rolief of the rocks from the original deformative stresses.

This matter was fully discussed in the first puregraphs
of the discussion on Propositions 4 ani H,Pages 11 and 12.

That the ores were derived by segregation and trans-
ported by ascending solutions from batholithic messes of
granite or gabbro,

On the shore of Giroux Lake on the University property
a dyke of granite as mappcd by the government ani which is

jescribed as probably & product of the segragation of the

 
21. (CONT. ) nz,
diobase magnmse,cuts through the diabuse. The government finds
in this district und others such seid dykes and certain basic
dykes cutting the diabase,which it considers to be the pro-
Jucts of segregation of the 3isbase.

In as much as the visible Jdiabase is porphyritic in textur
and shows no indications of having undergone segregation;seni
since it is more usual for segregation products to be cxpelled
upward rether than Jownward,it is probable that if these seid
and basic dykes were derived by segregation from the 3iabuse

nagnu, they came from its plutonic source.

" . As no large post-3iiabise intrusions are known in this
\

region the most reasonable explanation of these complimentary

dykes appears to be that they are segregationg products from
plutonic chambers of the 3iabase magma. Admitting that segrcg
ation occurred it would be the natural thing,in view of geo-
logical experience,to look for ore dcposits representing the
aqueous cmanations which are presumed to be given off in that
connection. And finding orc depcsits it would only be logiccl
to connect them with that source.

But against that deduction these objections are raised,
that although the ore bodies are somewhat grouped into mineral-
ized districte as the Cobalt District,the South Lorrain Distric
the Gowgenda District ond so on,as if having been derived from
hidden local plutonic masses which perhaps may have been the
local sources of the sill,yet the orc bodieg in any given
district are not grouped nor 3Jisposed as if origineting in
that menner,and there are meny scattered veins to be found

outside the limits of these districts over a large grca,e.g.

 
21. (Caz)
the Grecn-lieun and Aguunica in Bucke Twp.and the Casey
Cobalt in Casey Twp.,28 well as immuncrable failure
"prospects.

The wide listribution of cobalt-silver veins is not
offercd as a conclusive ergument sgeinst a plutonic source
for the ores,although it must be given weight in that oon-
neoetion;but the nature of the ore bodies and their mole
of occurrence in & mineralized district is offered as
being tneonpativle with the theory of plutonic origin. The
chief features of this situation are (1) Thet although
there are strong faults penetrating probably to cousider-
able depths,end ulso strong contacts penetrating perhuyps
jecoper,neither of these neutral channels ere mineralized
to zny notable degree. (2) The ore bodies have avoided
strong structures and chosen weak oges in preference,and
the weak fractures preferred far Jdisposition,in most
cages have no free inlet nor outlet through which ascending.

golutions couli circulate,but are virtually closed vessels.

 

(3) Orc boiies abfitting against impervious obstructions
are not uniformly confined below them,but in the oggregate
lie as much gbove as below then e.g.a gouge seam or "slate"
stratum may jam an ore body below or above 1t,Jamming
snother not fer away on the opposite silde,the two cre
boiies not being severed portions of the same ore body,

but of independent origin, (4) the agents of deposition

hai but little power to replace large masses of country

rock, (5) inclined beds,faults, joints or contacts show no

tendency to iéflect ore into concentrations in anticlinal

 

 
“1. (CONZ.) 35 »
These facts seer to be sufficient to exelude the theory of
plutonic origin,and for the sake of brevity other arguments
will be omitted.

These three propositions can best be stated together as
follows,and cnswered collcetively; That the ores were
originally derived frou the diabase sill by magnatic
segregation or by leaching through the medium of circéuleting

solutions,were decpositied by circuleting solutions,znd were

subscquently enriched.

that the ores resulted from the nmugnmatiec
gation uf the sill has already been answered in the
The idea that they were derived from the sill by
through the medium of circuleting solutions, ro-
Several usnswoers:

If eirculating svlutions were to collest metulli-
ferous solutes from the sill,these must have been uvaileble
to the solutions along their channcls,vhich would require
at least incipient segregation, or else the netalliferous
materiels must héve been. leached from the minerels of the
dizbasc along the fractures through which the wuters circul-
ated. But no segregatioms of the sill have been recognized,
and no changes in the charccter of the rock or its components
have been observed along barren fractures in the sill.

(2) The current conception of the circulation of sub-
terrancan waters is that they ere of two scurces,und cir-
culate away from their sources. That is,thet the plutonic
waters oscend to the ground water level or to the surface,
and that the meteoric waters descend to the ground veler level,

and by slower processes below it, perhaps to the zone of rock
4 I ’ -

 
LE,E5 & 24 (CONT. 36 .
flowage,the circulation above the ground water level being

gs8entially downward,and that below it being essentially

upward wherover a 3istinct flow is possible,ug slong a fis-

sure, but thet the meteoric waters have no meegns of causing
en active circulation below the ground water level, heot
being the only agency competent to do that save ourrents
cending from the depths.

Af orc has been found within the dicbease in notoble
guintitics 2nd also on the contact of the granite q7kes which
cuts the sill on the University property,the region is pre-
sumed to hove becn free freer locel heut capuble of sgtinulut-
ing local water cireulation,and perhaps entirely free from
agneous heut,at the time the veins were forced.

Circulating watcrs,therefore,cre considered to have
been incompetent to transport anid deposit ore meterials
from the Jiabuse sill through devious paths to &« depth of
gover four hundred feet below its lower surfuce at o time
when tho ground water level was ubove the upper surface of
the 3isbase

There can be no doubt that surfecc leeching of the sil-
ver veins,anld even downward onrichment is procecding at the
present time. But the ground weter level up to the time it
was disturbed by mining operations, has probably alweys been
#ithin 100 ft.0f the surface,and descended with tlic surface,
never héving becn below ite present level. Also for the
reasons just stated sll circulation of solutions bearing
naterial for cnrichment must have been limited to within &

short listence of the ground water level,énd cannot be pre-

 
In?
babi y

ry

23 & 124 (CONT.) | z7.
suncd to have carrici its influence $0 a depth of over B00 £1.
below the present level,st which depths ore is now being mined.

If the degradation of the lund surface in this region hed
procecded at the slow rate prevalent in the western mountainous
regions where running water and atmospheric agencies urc the
chief factors,it mey be conceivable that gradually the uprer
portion of the ground water would becone so cnrichcd in nmetiLllie
nuterials that the physico-chemical process of diffusion would
be competent to carry these foreign elements to ecnsidersble
distances within the ground water,bclow tile limit of wetive
water ciroulaticn,un? thus cnrich veins hunlireds of feel below
the water table. But my observations on the influence of gleeict-
ion on the topography hive convinced me thet the ice sheet of -
feotively parcd down the lend surface to the extent ¢f @ lousy
100 ft.,anl that this Process wus gore repid than the oxidation
of the orcs. This loves not excluie the ides of downword curich-
ment because thc amount of glacial errosion is difficult to

estimatc,and I have zllowed & minimum so low as tacitly to

ainit thet enrichment might have occurred by diffusion;but the

matter cen better be taken up from the point of view of the foll~
owing paragraphs in whieh I will attempt to show by other meLns
that no secondary enrichment has occurrcd.

That the veins were formed through the diffusion of the
constituents from the cold sill to seats of doyposition,and thet
the notive silver,ani silver minerals werc derived from the
originelly argentiferous arsenides through their bresking down
unicr conditions of low pressure,ani thc re~segregation by diffus-

ivn of the silver into favorable situations in or neer the veins,

 

 
25.0001.) 58.
As shown above,there is evidence that the ore deposits
originated after the lest igneous rocks of the region. But our
only proof that they arc pre-Silurien in age is that no deposits
are found in the 1oanul lime stone greas;but that is negative
ani rather unsubstantial proof. All we cen sgy is thet it scenms
probable thut the ore derosits are pre-Silurian.
It would be hard to prove thot during the degradation of the
land surface whieh preocedcd the deposition of the Gilurian lime
stone ,the orc deposits were not formed by diffusion 1 ownwara

through the grouni water of metalliferous miteriuls derived from

the surface oxidation of other deposits or of rocks rich in these

materials, such vs the diabuse itself. However it seoms certain
from the arguuents alrcaiy presented,that diffusion must be in~
voked to expluin the dcposits. That mode of origin is signif-
icant from the ceonomie point of view,ond for that reuson must
be discusscd,elthough in the bricfest manner.

Whether the ore metorisls were derived fron the digbase in
the region above the ground ater level,or from the disbuse
below it cannot be proven. It is a matter of importance,eince
it relates to the depth cot which ore deposits may be ¢xpeeted.
The chief argument sgainst it is the experience of the district
in finding good ore bodies in the Xeewatin only negr the Disbese
but 28 much above it as below it; for were they derived from
the weathering of the diubase they should be found chiefly
‘below it,and not sbove it,nor ot great listances from the
nearest outerop,as th. veins southeast of the point where the

upper contact pitches under the Kecwatin south of Kerr Lake.

 
£5. (CUNT. ) 59.

The idea which seems most plausible to me,anld which, by the
way,1ls significant in that it admits the possibility of good
deposits existing near either of the -disbuse contacts for as
great a depth as they reach,is one which I have becn compelled
to adopt ,accounting for the derivation of the ores by diffusion
from the diabase itself. In order to avoid an academic discuss-
ion which would be out of place in this report,I will present
this idea in as fow words as poseible.

Geologists ure agreed thet igneous magmas often contein not-
sblo amounts of uscful metals. They arc also agreed that in
piutunic chembers, masses of magma on cooling undergo & process
of segregation in which the metalliferous constituents are coll-
ected in a resildium consisting largely of water, silioe, carbonic
acid and other materials ,which is expelled through fracturcs in
the solid portions of the mass to seck its way up towards the
garth's surfuce as best it cen. And it is also accepted that
mugmas which 30 not hove an opportunity to cool so slowly in
these deep chambers 30 not -have an opportunity to segregate and
expel their excess metalliferous materials. It is &1s0 known
that the minerslls which compose ignoeous rocks ere freguently
quite full of metalliferous inclusions which represent the
entrapped excess materiels not capable of entering into the
composition of essen.ial rock minerals. Certain constituents

of the magma which are not esscntial to its composition,arc

crystollized as distinct minerals,somc stable and some perheps

unstable ,among the crystal grains of other minerals.
It is their excess metalifferous materiels which ere en~

tranped in and smong the crystal grains of porphyries such as

 
4B. (COUT, ) pina 40.
the Nipissing diabase,which I regard as the source of the ures
found in proximity to these intrusive rocks. And Jiffus’_. on is
the process by which they arc presumed to have been transferred
Sha avposited.

In ny investigation of over onc hundred veins in the districsy
I have failed to find eny consistent evidence of vein formation
by crustificution. Such anomalous cases as I have Touni, I belicve
to b¢ capable of explanation as crustification in local open
spaces due to chemical dissolution or freaks of mcehanical def crm-
atiin. The fractures, beginning in small open spacce,and widening
by accretion through the metasometic replacement of the well rocks

Since the process of vein growth was by metesomstio accretion,
there clearly could have been no appreciable flow of solutions
along the growing margins of the veins;but there could be o flow
of metalliferous ions in a stagnant solution,ani this is the means
by which I presume the ore bodies to have been built up.

It has been found by geologists in roscarch that rocks below
the ground water level contain water in all their open spaces sand
pores. And microscopic studies of glterci rocks seem to bear out
the fact that water penetrates even into the cleavages of rock

crystals and glong their surfaces. This water may be supposed to

reach these points by capillaerity and diffusion,but to be virtually

incapeble of flow or voluminous migration. In this imprisonment
however,it constitutes a medium facilitating the migration of
netalliferous ions.

AS water flows most readily in larger channels where it en-

counters the least resistencc,its flow being proportional to the

 

 
LS)
v
&

t

J

9

7 ) ! 41 ¢

£1
{C A we Bp

[
gic of the orifice &nd the channel,so must the flow of iong mi-
crating by diffusion,be proportional to the size of the channel

through whick they flow,end to the rate at which they are &ble to

escape from it by deposition from solution. In a system of cqual

water ohannels the flow will be greatest toward the largest out-

let, as if the outlet attracted the water to itself. Similerly

the flow of ions must be greatest toward the best seat
ion, following the routes of freest flow,

Thus the distribution of metalliferous materials Et be
through trunk and brenoch shamnels shiefly to the best scat of
position;and to a less degree to the poorer seats of deposition;
ani contribution to trunk channels must be by tributary chunnels
from the seats of most available supply.

It is a resognized principle of diffusion that the process
takes place from oenters of concentration, radieting outward oy
an expansive forve,as if the ions cf diffusing substance were
impelled by mutual repulsion,the tendency being to invade every
available space snd to seeure the grestest possible Jilution of
the medium of transfer. Thus,if a scat of deposition is pro-
viied there will be a direct flow of ions from the centre of con
centration to the seat of deposition.

It follows from these conditions thet if the diebase origin-
ally contained a greater amcunt of metalliferous meterial than
the adjacent rocks,and that if these noterials were in the form
of unstable minerals or were in the form of inclusions in the

rock minerals in association with the materials of & solvent,

 

 
lA el is rt b——— .

solution in the water contoined in the pores and open spaces of

the rock,and would slowly daffuse outward into the «djacent rocks

along trunk channels,flowing chiefly. in. the direction of the most
favorable seats of deposition,there being deposited by metasc-
matic processes &s ore bodics.

Thig is presumed to have been the mode of origin of the
15cal eobalt silver deposits.

In regard to the matter of cnrichment ss against rearrangement
4f silver and silver minerals,it is o significant faot that the
"ila rockTstoped with a vein consists of country rock in the
crevices of which leaf gilver.anid silver minersls,chiefly prous-
tite, have been jeposited for equal jistances on cach side of the
vein. This argentiferous materiel joes not usually penetrate into
the mess of the rock but lies on fractures and cleuvage surfaces.
There it occurs in csleite without the presence of arsenides it is
usually near arsenides sither in the same veln Or neighboring veing,

and there are no rules for the occurrence of greater quantitics
of silver in upper or lower Or intermediate portions of velns.

These faots are taken as indicating that the silver concen
trations do not represent a separate period of vein-formation in
which silver was the chief substance precipitated, and that they 49
not represent the usucl zonal jownmard concentrations associated
with vadosc cnrichments.

I interpret the evidence 10 show thet the concentration of
silver end silver minerals is 3Juc to a re-grrangement,and outward
jiffusion of these materials with respect to the arsenidc veins
in which they were originally deposited.

I have thisgexplanation to offer in that oonnection, that

 
i A A AMAA

2b. (CONT. ) 43,

sider wag originally deposited with the cobalt and nickel ad

complex argentiferous arsenides and antimonides in a calcite (or
dolomitic calcite) gangue under conditions of high pressure,which
was effective 8s a factor in the operation of the phesec rule of
ph¥sical chemistry beeasuse the pr esence of volitile substances,
ani iLot these complex substances broke down causing a re-arrange-
ment of materials when the pressure was relieved,as indloated by
the facet that the silver migrated out cqual distances on both side
3f & vein into minor fractures whieh were oOpencd in consequence

uf the gencral relief of pressure. This re-arrongoment snd local
migration was accomplished through the facilitation of the diffus~
ion process by water contained in all rook pores and Open spaces;
and ‘the unequal concentration of this migrating meterial was due
to the original unequal distribution of argentiferous minerals,
and the subsequent unequal distribution of fraetures,clcavages,
and stresses influencing deposition.

That the veins were formed under conditions of too great pres-
gure far the cxistence of large odpen spaces or for the free opening
of small fractures,and that they were formed by the metasomatic

replacement of the walls of tight fractures.

The non-oxistence gt the time of ore deposition, of notable
open spaces, has already been discussed. (See pages 12 and 40.)

Ovilcnccs of metasomatism 1s abuniant,as discussed on pages
12,40,45 & 48.

That of veins formed in joints,those that are the stecper are

 
 

(CONT. dato

the richer,and the most flatly inclined are the poorer,unier
otherviise similer conditions,the richness being proportional to

the degree of 1ip,and the veins being thus classifiable with regari

to both 3ip ani contents:-

10° to 30° quartz, caleite,little sulphide

il 0 : : : :
30° to BO" quartz, calcite,much sulphilde,little arsenide,
trace of silver.

0 0 . : ; :
BO" to 70° no quartz,caleite,little sulphilde,much arsenile,
notable silver.

) 0 \ . . i
70% to 90° no guartz.caleite.no sulphide.nmuch arseniie
’ ’ . ? 9
nuch silver.

Ixamples of the first class are the innurerable joints
of the district,us well as many unimportant flout faults,as for
instance on the 4th.level of the llipissing keyer shaft.

Examples of the second class are the vein in 40% incline
on the west fault in the Licyer workings,and also a fault vein in
the south stopes of Lo.Z shaft of the O'Irien liine.

Zxamples of the third class are part of 64 vein of the
Nipissing, the west end of Ilo.14 vein of the Chambers-Terlani I.ine,
tke mein part of X vein of the Townsite l.ine,the l1lst.and 2nd.
swamp veins east,the Lake vein,the lendall vein,and vein <6 II of the
licZinley-Darragh liine,the [No.6 vein of the 0'Biien i.ine below the
5th.enl 6th.levels,and others.

Cxamples of the 4th class are to be found in the most veins
of the district.

That faults are not good seats of jeposition for these ores
and that of faults with narrow shear zones,the steeper side~thrust

faults are the fost favorable,and in the wide shear zones of other

 

 
28

 

(CURT. ) 40

faults ores have formed only dn spots locally relieved of ©om-
pressive stress.

This is a re-statement of what has been s88id elgewhere, pave
as nlasborated in the following paragraphs.

That the stress conditions of the rocks affected their
metasomatic replacement by ore minerals in the sense that rer
placement was retariel by mcleculsr stregs,and that this explains

En)

the rhenomens cited in Propositions 26,27 & 28.

d

hen the remarkuble relations were recognized as slat

under 57 ani 28 above,it seemed apparent that the explanation

ay

must lie in an analysis ef stresses. It was early recognized
that certain mineralizations were essentially different than
certain othersg,that is,that certain veins contained sulphides
and no arsenides,that certain veins contained quartz and pink
calcite,and others no qUaT 2 and both white anid pink calcite,
ani 80 on respecting other constituents, An explenation was at
first sougcht in seguence;but this hai to be abandioned on
asceount of the fact that in many instances veins of one cluss

were confluent with those of another in sueh munner as to

de
|

show conclusively that they were of simultaneous origin. It

finally even appeared that all the significant structures ns

been developed before any of the veins had formed,and that

2h Not

there was but one period of cementation,

Ra my on
Heel

idea of gssive periods. Of cementation having

of and it being impossible to retain the
? Oo

og if a my 5 oe ot nt A EE pi gy) 4+ ; 2 cnt A ka
structures favorable to ore IJeposiuion
with perl ods of cemenyvaticn, tio
[3 gga 8 en . . ge ee a 3 n ou of As 2 Bens a d- vpn role i
OL vel: ants to the atiitulde of the fractures

ASL lon

which the zing we formed seemed to call for an

 
 

on the basig of differential strosgesiand the explanation
jevised has been found to agree sO consistently with all the
cases ani related phenomena found,that it is presented as the
true explanation.

Three essential sets of Stresses ere assumeld,all being
compressive: (l)Gravitetion acting downward (2) folding stress
gleng IW-SE lines,and (3) folding stress along NE-SV lines,
Compression along g given exis tends to produce contraction
along that axis and distension in all directions on a plane
perpendicular to it. And those induced tensile stresses com
plementary to the compression tend to. open joints pargllel
to the compression by pulling their walls apart. Vere it not
for the vertical compressive stress due to gravity,the hpri-
yontal compression would tend to open fractures parallel to
itself din strike,will all possible dips, but gravity being en
active factor snd tending to open on its own account fractures
parallel to its uxis and to close others,the result is that
the three sets of compressive forces acting simulteneously
teni to open only vertical fractures striking along the axes of
the two horizontal compressions or compromising them,all other

/
fractures tending to be closed by compression. Thus the €&

and ef * joints would be. the only ones entirely free of com-

pressive stress in the walls;and any fracture would be subject
to a vertical closing pressure in proportion to the flatness
of ite inclination.

Of course it must be borne in mind that on account of

the nature of the media of expression of these forces many

 
. RA BE aaron rr ——————. rt othoat aA
Ey ——————— v .
: %

 

£9 (CONT, )
local irregularities will produce exceptions te this rule.
In the case of joint veins the only proof of this ideas

lies in the almost invariable coincidence of thw two sets of

rhenomena~-vein attituie ani vein contents.

Faults, however, require a Separate analysis. Up-thrust ani
Jown-thrust faults are produced by normal or diagonal ecom-
presigion, being associated with shearing stresses in the walls
parallel to the line of movement ,and tensile stresses normal
to the compression. Thus Such fractures are unier compressive.
sires, like the flat Joints, no matter what their attitude, unless
the forces which produced them are relaxed sani gravity alone is
active,in which case the dip is a factor. The only exception to

this rule of the stresses in the walls of such faults can be due

irregularities of stress produced by: other or subsequent

vlde~thrust faults,on the other hand ,are related to stresses
in this way,that the chief stress is tangential or nearly so,
¢Lo8ing pressure being 3ue mostly to gravity in consequence of
vhe attitude of the fault. But the fault Selvage and breccic
and even the walls are subject to torsional stress resulting
from the friction of movement ,ani this seems to be as unfavorabls
vr replacement by ore as compression, because in general terns
wavorable replacement. The tencile Stresses re-
the walls of a Joints are relieve?

-y

on ‘ A 5 hry ba, G0. Mig po Le
and 80 the immediete walls

mineralized

 
 

\ 7

29.(CoND.) 48,
probably lies in the fact that tangential stresses would have a

tendency to locally relieve the walls of normegl compression.

OU » That the replacement of rock by ore minerals was freest in

more acid roeck,and most reluctant in more basic roek,proceeding
in the latter case only where the conditions of stress andl supply
Were most favorable.

This subject was discussed under 19 (fege 33) but is restated
here for the purpose of snhanging clearness by repetition under
the more proper heading of "Chemical Influence of Rocks on
Deposition”.

ROBLEL II. Vhat factors controlled the distribution of silver
andl minerals in the veins.

The discussion of this problem is not divided into sub-heai-
ings beaause its elements are to0 inter-related ani the processes
too hypothetical.

The essential phases of the discussion have already been
touched on, in 19,25 and £9,in which it wes attempted to show that
the veins formed in tight joints and faults through the metesomat-
ic rerlacement of their walls,that the character of the ore was a
function of the molecular stresses existing in the walls at the
time of deposition,ani that the vein matter was transported ani
deposited through the process of diffusion during a single period
of mineralizetion,the metalliferous substances subsequently re-
arrnging themselves in response to relief from the high pressures
under whicpthey were originally deposited.

In view of the ngture of this report no further attempt will

here be mele to support the theoretical foundations of these ideas;

 
 

 

PROB.2 (CONT. ) 49,
but the results of statistical research may be briefly stated
as follows:=-

The pgangue minerals of the veins ney be regarded as calcite,
smaltite and niccolite. The more significant accessory minerals
are breithauptite,chalecopyrite ani galena. Others are numbdrous
&nd perhaps scientifically interesting but not economically signi~
ficant. The silver minerals sre not mentioned because they. 1ike
the silver itself,are the defining substance.

Chalcopyrite ani Galena occur to a certain extent in the best
veins, but when present in a vein in notable amount are unaccompanied
by good values.

Breitharptite occurs chiefly in the best veins,and more pert-~
lcularly those containing notable amounts: of nicecolite. It mey

therdfore be regarieil as a favorable indication.

Niceolite is less gbuniant than smaltite,and is more often

associated with high values,although often being virtually barren,
It occurs in the upper portions of veins neer the base of the

Huronian,more then in other situations,ani is slso notable in the

 

best ores from the Cobalt Lake fault. Sometines it constitutes
the sole gangue for considerable parts of veins,but usually it
alternates in small patches EOR sua ltite or mixes in various
proportions with it. It is & rere mineral in the digbase and Xoe-
watin veins of the Q'Brien Iiine,and occurs chiefly in the Huron-
ian veing,

omaltite is the chief arseniije gangue mineral in sll the
mines,and is associated with ores of all grades, usually iisplac-
ing niccolite in niccolite veins near the Keewatin contact, A
notable example of this is Vein 24 of the Townsgite liine.

In ettenpting to explain the concentrations of hative silver

 
 

PROB.Z (CONT, )
and silver minerals,I assumed that they had been jerived and
concentrated by 3iffusion ani rearrangement from originally
complex argentiferous arsenides ani antimonides or sulph-
arsgseniles ani sulph-antimonides, which being unstable unier
conditions of low pressure, broke up into simple cobalt ani
nickel arseniles,nickel entimoniie, silver antimonide, silver
Sulphile, silver sulph-arsenide, and native silver. But this
assumption requires the further assumption that the original
complex compounis were unequally distributed in the first ylece;
And the economic side of the problem is chiefly concerne3 with
that primary distribution.

In that connection it appears to be & fairly general rule,
or ot least the mejority of cases will surport the statement
that the richest ore in an ore body is nearest the chief trunk
Supply channel from which the ore may be assumed to have entered
the fracture in which it was deposited,ani is also in the
portion of the ore body where deposition was the easiest,arsen-
ides having gone farther out,and calcite beyond them to the
ends of the vein. Such sources of supply may be assumed to be
contacts, slate beds,ani faults. Thus,if a vein abutts against
g fault,anl is poor within 10 ft. of it,the assumption woulil
be fairly safe that the vein will not be long nor rieh;but if

the vein is rich within 10 ft.of the fault.it ma be assumed
? o/

that it will grow poorer away from it,an3 that the high rede
0 P J ’ & oO

portion will grade into poor or barren arsenide ani then into

barren calcite, or will pass directly into rich ani graiually
vy 8

poorer calcite on the mergins of the vein.

There are known to be nany exceptions to this rule,a very

 
PROB.2.(CON2.) ol.
notable one being found in the o'Brien liine where the silver
oxtenis beyond the vein proper into an otlerwise uncemented
fissure which continues along the strike of the vein. But this
will be ot once recognized a8 explainable on the assumption thet
at the relief of the pressures under which the veins Were formed,
the fracture in which this particular rich vein lay was extended,
ani the silver migrated out along the extension.

Other exceptions must also srise from the fact thet for
reasons not yet expluoined minerals undergoing simultaneous de-
position in veing tend to arronge themse lves in exclusive se-
gregetions, one mineral dominating gertain patches of the vein,
ani another mincral other patches. Thus in one of these veins
niccolite dominates a patch here, smaltite One there,and cal-

cite one elscwhere,sand it must be supposed thet the argentifer-

ous compounds woull have becn similarly jistributed,all being

segregated at some points and mixed at others.

PROBLEM IXI. inet are the directions and ages of faultings.

 

Proposition OL That the faults are all due to compression OF
foliing torsion.
A hat the east west faults sare gide thrusts.
other faults are up thrusts or jown
thrusts.
4. hat faults along folding axes on & given hor-
izon iAip with those uXesS.
These are merely ro-statements of the facts already given in
the iiscussion of the propositions 4,5,7,8 ani 9.
It need only be added that block foulting cecurred in the
Meyer workings of the Nipissing involving the Cobalt Lake,’iest,

carbon,and the bedding faults in this way; the block between the

el
Ce UAB ALO PAIAABAS hi rA tr  Tg naib pra biaei

Sats nator

 

 

uss SeLERIISIRI MAT SRI EEE HELE EE ie A LaLiaiiosis 1s. tid Ltibrariil Le
PROB. 3, (Ono. ) b2.

30.

Cobalt Lake ani West faults is a garben or subsided block,ani

and that between the Test fault and Keewatin contact is an horst

or up~thrust block. But the unier siie Of the horst insteui of

beingbouniei by & single or consistent fault is bounied by 211
the underlying surfaces of ¢ 3justment upon which there has been

up-inrusting displacement. These are chiefly,thc Carhon fgult,

Es frm i ie

the flat slate bed faults, the Keewatin-~Huronian contact, ani
innumerszble shear joints. Thus the Test fault is a Jown=-thrust
with a displacement of 110 f%. in tHe L.eyer workings.

That the side thrusts were the first feults, usually pre-
ceeding the folding, that the foliing~torsion faults were next
in age,and that the thrusts on the axial planes of folis were
the last, but: that the folding continue? through all the fault-
ing and after it,eni the mineralization followed all the ie-
formation.

The side thrust faults are regarded as the first to have
formed,because they 30 not throw the others,but are themselves
thrown by them. They have nowhere been obcervei to have been
warped by foliing,but this ney be because of the impossibility
of securing sufficient data to showy such small deformations.
Therefore it can not be shown tha they anteiate the folls, seve
a8 the other faults were of contenpdrancous origin with the folis,
andl displaced these faults.

Where the side thrusts intersecet the bedding faults the
latter displace them,ani the me jor thrust faults 1isplace a1l
the others.

Sut .he faulting was an expression of acute deformative
stresses which resulted from the more general and enduring ones

which produced the folding. Thus as might be expected, buth

 
35. (COLT. )

f£0liing and faulting went on simu stung ous gly,ond the faults were
warped by subsequent folde und jéspla wed cuch other some times
in reverse order in certain ie §

The statement thet the mineralizgtion followed all the de-

formation is uo hari onc to substantiste in view of the fact

that in the light of all knovm geologieul phenomena the obvious
relutions existing in the mines point to the production of ome
of the faults after the ore,since volus arc faulted distances
from 4 inches t¢ 100 ft. and some are grooved and slicken-
gilded beyond lispute.
On page 2b of Lelths "Structural Geology" ig an 1llust-

ration of & strike joint displuced on 3 shear joint.

presents the condition presumed to have e xisted before the de-

{

position of tre ore in this 3istrict,thc orc having been formed
in the displaced vertical joints und not in the flatter cnes
jispluacing thew. It can be seen that such & condition would
give an illustration of za fa sulted orebody,which is presured 10 be

Cobalt. It need only be proven thut (1) the vertical

flat joint belong to the same Jef ormutive process (2) that
mineralization could discriminate between two SSL TF Fractures,
|

jepositing ore in one und not in Le other,and (3) that ore was
jeposited in the last structures developed.

(1) It has been found by myletuiies in the listriet that
connected with every fold large gr smull,are vertical 3ip ani
strike joints,and flatly inclined ‘sheux joints lying perallel

of foliing. Those three sets of joints are the
chief wni essential ones,and bound blocks on which the mejor
foliing adjustments are made. They are not of exactly simult-

i

- . . . . : wh oy mga o .
aneous origin,since both verticalibets arc usually displeced

 
-r rey \
° (COT. ;
by shear joints and the parellel

80 Cul: wlated Jisplu Qo

mporang ous in: the

pression: of the stress
while the

torsional

(2)
stressus cxisting in their
26 it was the veins
roplgeome al 1s .
shown it ctas
gniitions

Pn CH

to str Ne KD RD 3

runction

CEL

bg A roe —
sta FAN

replace the most highly

. 3 i wat} -
arsenideg and caleitc

wliuto

“Na

»

YT

urn L107
HOVICVOT

that fractures my

don without being

PTE Sune

ctures

Lig eit HELI
feults whi

3 rip Mg Tod yi)
AE 51 119

inclined

Rui i]
* en
Ta —

11%13 11 g

t he

ion ¥etweon at

walls

unlaco

cenente

4 3

regent their

thoy arg

Mo] 4 '
’ but u ANA

faults vhieh rer

con~-

of "elote

joints

vertical

fron tho

ivimeliste ly sabsequent

from the

actunl folding.
-

tituics of fractures
shown undcy 29; and undor

Was

motos onatie

been

forncd by the

Ty 3
CTO

hes

from

; , While the

J

the unstressed rocks
from once extrene 10

Jenonstrated and

and

ohbgseuroe

of all prc

be low the

calcite

neeption of foliing,

cuadrtz.

 
 

 

 

 

OD. (CONT. ) 05.

but the rule is that the class exists in distinction from the
10° to 38 class.

The oxplanation is two foll,lst.that such fracturce were
the most highly compresseld,even beyond the replocing strength
Of quartz,anl Ini. that they are froqueontly covered with thin
venirs of gouge which is soft cnough to transfer the pressure
to poluls wnieh would otherwise bo locally rolicvel,

This explanation is intended to cover the unmineralizeld
bedding "slips" at points where they show no mineralization. But
there are many cascs Wherc it can be shown that pink caleite
exists ¢n other purts of these same "slips" ¢nd in the persllel
joints immediately wljaccnt to them not as dragged material
but as mineral in pluce,and that it oocalesces wt rany points
with veins at their junction with such"slips".- Hotkble ex-
amples of this are the muin bedding "slips" in the Lelinley-
Daurragh,Townsite and lipisg8ing Lines.

(3) That orc vas deposited in the last structures devel- |
oped,can be shown in the casc of the Cobalt Lake anid “lest Jaults,
ani in the Povmsite minor syncline. It hes been shown clsco-
where that the structures developed in this ordcr;side~thrust
feults,iip and strike joints,mejor folis, & Joints ond .beid-
ing "slips or fo 1ing-tors ion faults,major faults (e.g.Cobslt
Lake and Vest IMoults),and lastly minor folds.

On the ‘lest iMault in the leyer workings of the llipissing

ar te

Hining Co.,the charucteristic minerelization is quartz,ctlecite
and & little sulphilde;but cnough small quuntitics ef arsenile

wave been found to show that the minerslizution is of the vein-

i

forming period. On the Cobalt Lake fault,thc Cobalt Lake Lining

LL)

Co.has winced considerable orc of the best Glogs yn ioh lay

 
BB, (CONT. ) 5 «
parallel in strike and iip with the fuult on the surface of
movement , sometimes below and sometimes above the gouge, and
hovingz a bénled structure in which the banis were parallel with
the ouge seam whieh 183 #n the surfacc of movement. The
peXinley=Darreggh Line has also been stoping first cless ore
which lay in strike joints in the shattered hanging wall of the
fault. There eun be mo doubt that these ore bodies were formed
‘after the fault.

The Townsite group of veins is 80 intimately sesocinted
with the minor-transverse syncline that pitches down the slope
of the major Cobalt Lake gyneline, thot therc can be no doubt

whi

that their relationship ig genetic,and thet ull the veins of the

group originated after the es structure,vhich itsclf originated

after or simultaneously with the Tolding-torsion foults vihich

 

jiegrluced the fractures in which the veins were depositcd,end £180
after the Cobalt Take fault ,warping the surface.

Bvidently the vein fracturcs opened sgimultsncously with the
minor foliing und the slipping on the folding slate bols,being
thus rclateld to the Told gs dip joints and thrown by the bedding

and it must have been ufter this thot the veins were
erositced in the already faultel fractures. 1% shoull be borne

in assigning scguences tO yhose structurcs thet no orier
of preccience will be Without exceptions,bccausc the structures
211 represent differcnt cxpressions of the same general stresses,
locally relieved in ifferent gocuenccs There 16 cVen BORG

iifficulty in circumscribing &. he deforration into onc period

 

cni all the mineralizetion into oO subsequent one, since both

proce seceurrci while the region was unicr great stress,end
2 Lo

 
BY.

faults and folis after establishment Vere accentuated;eand small

movements occurred after the veins were formed displacing some
of them slightly with the accompanying production of’ slickensides

andl striac on the vein matter.

 
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