SF and Star District Pages from USGS PP-111

8/14/2019 SF and Star District Pages from USGS PP-111

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SAN FflAX CISCO AXD ,\ D.JACF.NT I)J STRICTS. 5 0 ~ &, Nebrllslm ~ I i ! , i n g CO., 3S clllilllS h'' ' 'ing been erected in I.he smnmer of 1873 (dosed 1877), .locllted by 1873, but nOlle ""as ~ v , ' r pnt year nfter t.ho discovery of the HornSilYor mine. Frisco is the t.own und post office.(Seo PI. XLI, A.)

11bn:t1n.U"iu d from nutlor, n . S., GeToo enrly history of t.ho mines hus been reviewed by Ilutlor, who prepared the output.fig:Jres in t.he subjoined tllblo f,'Om the recordsof tho Uuited Stat(J.q Geological Survey.J TPnllt ~ I 1 J ' U S U. S . , \,01. 1:1, pp. I;:!- l i l . \AA:.. ' , ~ ( . The l'I1eWIIll'..ty of arunt llt.rolls p r C ' r tS'J l .

:I p-rcJuu d in the Frannn a7UI l J . ~ S di8trid Ji , Ut llh, to t l clost of /911 .

1 j 1 Le:ui Rc('oy(:r-YE."'l r. 0 ( , Goltl (fine e - f i . Copper d I\ulo zin c_________ I_'_O_'O_D.S_..j __ _U_D_C""__.I OU}CC.' ) .. (pouud. ). (poUll . ). (pound,).. I ~ : : : : : : : : : .... s;2i'O. 3 , ~ ~ 1 1 3 1 ~ ~ ~ m : ~ ~ ~ : ~ ~ : ~ ::::: :::::::' ' ' ' ' ' ' ' ' ' ' ' ' ' I?,:H! 807.86 96,027 432,'09 5 , ; ~ ~ ~ ; ~ ....3ili;G76l.905 ' . .. . . . . .. .. . . . . . . . . . 1;),912 54.5. 04 110, 011 I , [tSS, 287 7,4 " .I 'J. . . . . ... . . . . . . . . . . . . . . , 141,519 1, 610. 00 137,412 3, '127,918 4 G 4 . 0 ~ 7 I 1,:158,600iW/.... .. ...... ... .. .. .. 236,229 2, G07. 07 289,1 65 5, log, 127 4, 762,488 780,276" " " . 215,204 2, 3 ~ 4 J 73 279,379 4, 026,736 3: ~ ~ , ~ ~ i 933,1361109. . . . . . .. . . . . . . . . . . . . . 2'ZO.OO:; 2,0:12.19 106,377 r" G09, 611 1, , 4 . . . . . . . .4 ..

l1\U .. . . &3 , : ~ S J ) 647. 26 20:>,974 1,114,05-, 3, ~ ~ , nO) ~ ~ ' , s ~ ~ 19U .. .. . . . : . . . . . . '" 77 , 7S! 500. 75 249,1G6 984,310 ''''''"'' .til., .. .. .. .. .. . . , 2Jj4,625 1,853.66 136,585 3,64.6, Olfl 2,472 , 617 1 ~ , g ~ ~ 19U""" .. .. . . . . . . . 189, 446 I, 4.jO. 89 183, 780 2,210, 11)1 1, 7303: 7921 !,497 62"" 1 '0 '"" 9"k:.' . < 167, "'"7 2, 1H4, 166 6,561,6 a , , )1911 . . . . . . . . . . . . . . . . . , , ' ~ 2 7 143 746IW . . . . . . . . . . . . . . 86,810 579. 23 153,812 1, 43b, IH5 5,494, 2;; "11:. . .. .. . . . . . . . . . . 46 076 453.90 171, 1H9 221,798 6, 10.1, ~ 8 1 5' ~ ; ~ , mI . . . . .. . 2 ' I' 090 1 264. 72 303, 867 I, 72f>, 515 4, 1 I, . . ' . .911 . . . . . . . . .. .,,) 31 ' 30::6139.') 3 j3 S 898. . . . . . . . . . . . . . . . . . . . . 266,3.j9 ?:I7.52 21;,110 2,141, , ; ) , '} ' , " ,220, 486 I 1,822. OS 16,639,054 141 , 307,719 i 61,079,295 1 2S, 264, 277 I

Tot.'\1 v:llue.$:10,142,479

29:1.6HO347, U ~ 8 417,9028D4,088I 003 8M1;.15:4Gtl9IS.039452,4164ilS 2,15681:,,:K}BD2.7.i81,033.559ali6, 6fJ7773 462l , 39t; 4221,458,48633,917, 814


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504 ORE DEPOfilTS OF UTAH.The Horn Silver mine (see PI. XLI) ","9discovered in J87.5 and ior about 10 yr"'" ,,"usone of the most producti,e mines of tho SltltC.After 1885 its production grerttly deCl"cused ,but it htls been in nlmm.t continuous Opcflltion

to the present time. To the c1oso of 1913 ithall yielded metuls of 0. totlll vlllue of 520,-768,471 nnd ha(l puid in di"idend. S6,892,000.The BellveI' Carhonate mine WUg discovered.in the full of 1878 ulld the following yenl' WIllipunbllsed by the Frisco }filling & SmeltingCo. for 81.50,000. It wus nn nctil'c produc.erfor neurly seven YOIlI'S bu t was dosed aboutIRS., lIno I'cmuincd idle till 1908 , when consirlernhl" del'dopment work lI'ns done hu tlit.tlc metul produced. It s total metal outputis estimated ut 2,593 tons of leud Rnd 5:13,910ounces oi sill'"r, wit .h a total value of about~ S O S , o o o . Other mincs i,,I.ho


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o. s. Gf.OIAJGIC.\ I . SUTtVS Y PROYESS ION.U. JAP tm II I

.t. HORN I L " " ' MINE AND VfLL.\GF. OF' JoiUSCO; CONTACr OF QUAfiTZ MOi'i7.0Nrre Ai"'D LIMl'S1'ONE IN lOWSADDLE; SQUAW SPRli'\GS PASS AT LI:: .,,,.


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.'

1111JI1III11IIII1I111

Year. QuautiLY(sbort10'"').

. 8 6 0 - 1 8 7 ~ . . . . . . . .. .. . . . . .~ ~ : ::::::::: ::1::: :::::::~ ~ L : : : : : : : : : i : : : : : : : : : :880. . . . . . . . . . . .1 .. . . . . . . .88 1. . . . . . . . . . . 1 . . . . . . . . . .882. . . . . . . . 1 ' 10,500883 .. . . . . . . ."I 43, 9008S-j, . . . . . . . . __ . b4;{,9801!85.. .. . . . . . .. . . . . . . . . . . .886. . . . . . . . . . . . 1.05,110887. . . . . . . . . . . . bo,440888 . . . . . . . . . . . . bG,3JO889 . . . . . . . . . . . . '12 , RSO890. . . . . . . . . . . . '2 0, 057891. . . . . .. . . . . . bZ-,j , {;20892............ .. . .... ..B93. . . . . . . . . . . . . ,. , ......~ 9 L . .. . . . . . . . . . --_ .. . .. .B 9 ~ . . . . . . . . . . .. .. . . ..... .! ~ : ::::::::::t:: :: :.:::: : ~ : : : : ~ : ~ : : :1:: :::::::lOl.. . . . . . . . . . . .........10'1. . . . . . . . . . . . . . _-- . . . . .)()3...... . . .... .......) ~ H . . .......... _...... . . .lO5. . . . . . . . . . . . 143, :?33JOG. . . . . . . . . . . . 2H,7i7107. . . . . . . . . . . . 234 ,0 92)08. . . . . . . . . . . . 223,021JOO. . . . . . . . . . . . ffl ,867110 . . . . . . . . . . . . 83, 748HI.. . . . . . . . . . . ~ ; ) ~~ 1 2 . ... . . . . . . . . 20 9,568913 .. . . . . . . . . . . 168, U.S9U . . . . . . . . . . . 94., 021915...... . . . . . 63,81-1

Q1u:z-nti./y of ort $ov1 or t r f ' . l l t ~ d in B earer Counfy, //(1./., 1860-1917, and total Olltput of Tlu /(lls 'Ta:cnxTro.

Gold . Sil ver. Copper. Lood . lWcovernblo zinc .

Fino Value. Fino Value.ounces. OllDC"es . Po\Ulds. Value . Pounds . Vo.luc. Pouotlt!. Value .I7 6 ~ . 0 0 $1;:), 814 207, TJO ~ , 1 1 2 1 1 .. -- ....... . . . . . . . . .3 ,7 00, rxYJ , 4 0 0 .. ....... 1 .... .....' 340. 00 7,0'28 .22G.G25 2()2 ,8 M ....... -- -., . .. __ . . . . __ 5, 176)000 315 , 736 . . . -. - ...... . . . .. . -- .2Si).OO 5,891 "'20, (MXJ 50-1,000 .... - - ...... .. .. .. . . . . . 0.00 11,370 bdl, IOS ,.'I3O 1. Z74, ro9 . ........... . . _...... "r-lO, 505,0177 .... . ....... . ..... ....t.4!?5 .0 0 8,78:'5 bd l , M)1,341 1,600,515 . ....... . .. . .. . . . . . . . .. b ~ I 2 , 570, 86-1 GOO,40 1 ............ .. .. . .. . ..'067.00 19,990 , , S 8 6 2,117, &18 .... - .. --. . . ........ . . . ) be.J5, 428 , 988 2, :?'.tS, 771) .... . . . . . . . .'580. 00 11,990 bd!,652,9SQ I, &14, 80S b 10, ()OO 600 be30, HYT, 000 1,298, -171 . .... .. . .. .. , .. . ....'4&1 .00 10, 005 bdl,625,300 1J 8(K, 083 be5,OOO 6:;0 ht.".!4, 800, 650 917 ,624 .. .. . . . . . , . - ..'125.00 2 b&.t20,OOO 119,400 be O, 000 I,OgO bcQ, 800,OOO 3S2, :!00 ........ . . . ........./300.00 6:202 /250,000 217,500 bc'27,000 2, 9il7 hrj, HOO, 000 178, 710 165,3g5 ::: ::::::::r::::::::310.00 (j, 108 132.),330 305, 810 bcS50,OOO . 114, 750 1.0 c9, 1:29, SOO 356,002/250.00 5,168 1000, 880 588,9 24 ,., "'27-1,290 ,12,789 be.lO, ~ l ~ UOO 486, 510 . .. .. .. . .'.... ....../110.0 0 2,274 itSn, It)() '670,3S8 '853, 00.1 110, G91 bt'15, 1505, 7GO 1 ) ~ 8 , . . .... .... .... ......1130.00 2, G87 . '736, 2"'" 640,1>13 beOO, 000 6,OGO . ' IS, R9:l, 760 705,7.;0 . . . . . . . . . . . ......../170.00 3,511 J7'!0, 144 661,112 befiO,OOO 6, 400 brl-1,2GJ,OOO 527, lia7 " .. . . . . . .. . . . . . . -, . ../125.00 2,584 bd4"ll , 82"1 !.1I6&,7OO be87,786 8,340 "10, 800 33S, 441 .. . . . . . . . . . . . . .. . . ----

1712. 00 14,718 Iod700, 0!H ,155, 061 bclO,OOO 1, 070 ',elI, 691, tmo 170,13 1 .... . ...... ... .. -,.,/506.00 ]0,439 /330,5JO 22-1,747 b.t:5,OOO 540 10 "'9, 115,000 273,450 .. . ........ . .. , ......./827. 00 17, 096 1296,824 178,094 b'8, I94 885 br12, I8O,000 4 : ~ 8 ! 480 .... ........ ..........1720.00 14,884- 130:!J,086 182,802 '/139,291 17 ,272 ' /8,15.1,030 309,815 .. . . . . . . - . . . ........fl , 0&1 . 00 2'2,408 1244,939 146, 963 ~ , 2 \ ) 2 157,0'28 '/'1,9&3, 453 224,2 55 . . . . . . - .... . . .........i281. 00 6,800 bdl'16,932 91,008 '/769,648 127, 7Gt cl3, ~ l ( j , 510 172, 326 . . . , , , . . . . . . ......./ 1,003.00 20,734 / 427,382 256, ,129 '/932.296 , 6 9 3 '[6,907,060 297,043 .. -.. . .. , . . . .. --_ . .i i , 28.1. 00 26,522 /22 1,867 11 7,590 r 1 9 1 4 IH,M9 c/;", 022, 76$ 20;,938 . . .. .. . . . . . .. " ""1835.00 17, 2m il00, 214 68, l-I6 c/466,369 53, 756 ,1,202,1, 5fi i ,l, 71:3 ,1,01 2,003,(pl(),S29,I , 11 S,

],1,110,1, OCH ,

2I9ij'3:jI,1o3.1

'so653i:H5'92'1672J92I"1'j33

'"C>

l7.1'"'""if>o."a...;Il


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~ ~ ~ ~ ~ ~ ~ ~ - - - - ~ ~ ~ ~"". . f m . 1, 913 4, LGZ,003 . . . . . .. . . . . . . . . . . . . . . 8, H l . ~ 1 7 1001- 1910. . . . . . . . .. . . . . . . . H i 922.16 ;;OS, oi65 2, ,190. 361 I, 18.\ 599 2G, CIIl. 30B 4,326.995 fi.!, 112, 42:3 2. 4,,0,314 8, 507,656 $.'04,340 9.066. 7131011-1917. __ .. . _ . . . . . . .. . 10,!)17. 3:\o 2 2 , ) ' ~ 6 8 2 2,O'1!),!l70 1, 270,389 7 ( . i : l 3,f,30, 264 &1,838,894 2,61-1,3% 1 2- , '199 ,863 2,rn:l:2,689 9,753, 405

I 37.1.19.01 787.739121,160,906119,558,392119,638.383 8. 47S,5!131 411,403, 954 17.ns o, 774 1 33 ,ao7.519,2.577,029 ':'19,392, fJZ7

rJl>"'I:0>'"il">Z"8E;'"H"ilH'"

eno"


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508 ORE D .;POSITS OF UTAH.CflAR.\CTF.R ,\XD ;\IET,\L C O N T r . ~ 1 ' (W ORF.S.

DRY OR SILICEOUS ORES.Th" r per ( IX'I \ 10,, ) ('ent). r.. ,d(per('l."nO.

AvIlg"",p"'- - -,--- 1------ ------

1005 . . . ..!!lOO. . . . .l!J07. , . ' .H1OS .. . ..1009.0 .. .1910 . . . . .1911. . . ..1912... , .WI:!.. . ..19l1. . . 1915 . . . 191 6 . .1917 . . . .

1006 . . . ..1006. . . ..1007 . . ..1908 . . . . .1009 .. . . .1910 . . . . .1 ~ 1 1 . . . ..1912 . . . ..1913 . . . . .1 9 1 ~ . _1915. 1916 . .1917 . . .

, :!t10157Z7,2:n4,126205M6!J25 , 2 ~ 2 1S, 18 1I ""33;078

27 , 00132,3US

16,89720 . 36921 . 12621.8824, :J074,!l2221. 1I111.5218.0n6,4172f;44,2826,650

$"l,8:>.661. 35.711. 85.96.09.021. 01.08.35. n

$1.572. ): j1. 36) . 4Q1. 171. 521. 511.2:1. 1-1. 71I. 37I. 211,G7

2.705. 091.1. 641. 3810. 053 . ~ 9 1.301. 193. 70L;;8J. 13. 61

1,962.09I.GS1. :).11. 1M1. 291. 391. 29]. 181. 392. 131. 882. 16

2. 00 . . . . . . .8.015. :15 "0 '-08'10 . . . . . ..9.00 .. . . . ..12. 72 . . . . . . .11. 14 .0;;2. i4.2. ( ) . ~ 13 . l3. 492. 6


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SAX FRANCISCO \ ~ O AI1.JA t:N'T DISTRICT3. 509Oneida, Lower Cav e, I ll rlillll QUCO Il , Ul)llI l..tad Of1 trnd ronttnl1aU3 lI:illa Ql t I (/ .prorJ/lQ.d i" B e ' . - ' ra!Je me a .e coolte-IU J.Volunteer . 1M3 19/7-C' m ,tn ' O101. tg and .hipped to ' fIlLIl IT ,Jh' . - outlOucd tThB lend tOIl('elltmtt" W"I 'LI C lefly f" om t ]", .I B C t A k O ! D n a f ~ lIol'll Silver I ll" (',1'' ' ' ' )' "rbolla!." dump' t Frisco but in t-hllied a (, ,; t lo t of s e < >oro from the StUI' tli . k ict . Qllunt i l )'(lthort.

t.lI IU).

Gold S-ilvf'rIVlllne (ou(lcru;- (oppe f I . ~ O gTOI!",sYid ll OYe:\r ,'l'he nn:...nge gl'udo of 1.he or r...;.; ilud C O J \ C < ~ I 1 - pe r JX'f (p (>rton). ton). cenl). Lend{pCTcent).trnt es WiiS os follow :>; portou.r.iCfl or' am/ WT(L7/.t ratcr. 1I.Jilh ftl,ragc mdaUic c01lIenl.,.produ.d i , ~ .Bcr'-'J


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510 onE O);POSITS OF UT.U! .COPPEll-LEAD ORES.

Th e copper-leud orcs nrc cltl


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512 ORE DEPOSITS OF UTAH.IG:NEOUS ROCKS.

INTERRELATIONS AND AGE.The rebtinn of tho intrusive and extrusiverocks is far from clear at many points in thearea. In the Rocky Rnnge, however, dikes

from the quartz monzonite stock. intrude ~ h e In.va. flows, and in t.he San FrancIsco dL.;;trlCt,ju


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~ A N FR":\'"CISCO AXD AD.JACENT DISTRICTS. 513iog" (the engulfment, sinking, and dissolvingoi the invaded rock) proVIded splice fOl' theentering materiul is no t deGnitely knO\\")), butthe writer is inclined to the ,'iew th"t itseffect wus of minor importnncc, us iloutwell'belie,'es it to have heen in t.he Purk City dis-Iriel, FAVLTS.

associat.iun wit.h other stocks. In t.ho StardIStrIct t.here h ~ l S becn ~ I O \ ' c m e n t ulong planesthut nre. o.ssentlul\y hOTlwlltol but that hnvemeguhmtIes resembling n wHI-pcd surface.The rocks along the fnult plnnes nre highlypohshcd nnd gI'oo"ed, bu t it is not demonstroted t.hat thoro has been extensive move-I ment.The most im;>ort!\nt stmcturol features of Fault'In II' b hi I ., . l ' g t l ~ pro n. y )efm I I I pl'ogres.s overthe regIOn arc tho result of flluhmg. N o r m ~ l a long poriod. SOlUO import.nnt. fauIts doubtlilultillg is usuaUy n,socintcd WIth t.ho BuslIl less formed before the intrusion of tho quartz,,I,I

ft(;C!1! SJ .:-Oan&ro.lI&ed ~ t a r t O l : , ' T I I D l roprcsenitl'lg tbe ( o l l l U Q n . ~ 01 lho rofIlm!WlIS in port of U!.c ~ a n F r a D r 1 S ~ J Rlll"Jgo north ot S,\UBW S p r 1 n ~ Pass.Range structure I1ml is he.lievcd to out.Iine t.he mOllZonitr., I1nd others hove ccrt.uinly occurredSon Francisco Range both 011 the eust nnd since. The faulting doubtless extended ;nlwest. A fault on the eost, exposed in the Inte Tert.iary timo and mny be still in progress,workings of the Horn Silver mine hilS a knownU I ' FISSURES,tsp ncement of 1,600 feet und doubtless nluchmore. (See fig. 53.) Another notable normal Fissures nro importnot in the area, as theyf.ultpMSes northcnst t,hrough Squnw Springs hnve furnished channcIs for the passage of t.hoGnp In Ibe San Francisr.o Range and throws ore-bearing solutions. In the Stur districtlho.l.vas on the south of the J'tlllge down most of t.he imporlaot fissures strike nourlyngamst the limestone on the north. ensl. Ilnd dip vertically or very steeply. In Ihe

Tbe intrusion of t.he quartz monzonite other districts the fissures show less unifonn-b ,. .OGles IS believed to hllve laterally displo.ced it.y of direction. Fissures in tho sedimentary:hc 5urrou.nding rocks. Such n displacement rocks w ~ r e prob"bly formed for n;'ost port'. 'bown In the central portion of t.he Star fit the tIme of the quar(.z mon7.OIute mtruslOn.dl.!;lflct, and similar displacement" are pos- by stresses in t.he limestone resulting froIll the~ l y present, though less cleurly shown in injection of t.he igneous materi.1. Some littleI lIot;l",.t11 J . fissuring, especiully nCllr t.he contact., may be

4.lJbt1 "Otab.. ~ ' I S t t - \ h ~ ' T a p h r ~ n d $tructnroo( the I'ark City mlnlng. t" b ted to the stresses cilused by t,be shrink- . lOUr. G ( ' O l o g } vol. l;j, p. 458,1907 a "rl U3(;416'-19----33


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514 ORE DEPOSITS OF UTA A.ago of the cooling mass. Probably s ~ m i l a r causes led to fissuring in quartz monzomte.

) t J o ' ; T A I i ' O M A T l S ~ l .

ALTERATION" OF QUARTZ 1I0NZONITE..In goneral tho quartz monzonite has beenli((,[o wtered except along fissures and zonoo offmc(ure, where, in its mo't highly a l t o r ~ d l l c o n -clition, it hIlS boon chunged to e s s e n ~ t n y aquortz soricito rock wi(.h vll.riabln n.mounts ofminor e,(lnstituen!.. Such zones aro O'peclUllywell sho"" in Coppor Gulch in tho San Francisco

Ran"" and in tho 0. K. zone in the Deaver Lake"lountoins, t.hough they nre present at manyother loclllities.In PflSSing from llnwlcrcd rock to a highlyIlltc]"cd zone tho st.ngoo of the olt.oration can bescon. The dark gilie-Iltes oro usually firstattneked and pllSS over to (,hlorite and curbonate and eventunlly largely to sericite; thofeldsp.ml become more and more &cricitizedtill t.hoy oro composed la rgely of (,hat milleral;and finally ovon tho quartz cryst.nls nre brokenup Itnd filled with "oricito. In tho two zO:J.esmost corefully oxamined tho most markeddiiToronco in tho nlterfttion is that r a t h ~ r abundant carbonate W,IS formed ill tho CopperGulch zone nnd nono ut nll il l tho 0. K. zone.The chomical composition of tho fresh andaltered rock ill tho twozones(pp. 164-105) showstl18t silica (SiO, ) has decreased somowhat inboth. Alumina (Al,O,) shows littlo change;in tho ClICtus deposit it hIlS slightly incr3osod,in t.ho 0. K. doposit slightly doereased , the resulting differences, however, being no groaterthall might bo fOlmd in two samples from thosarno rock mllSS. In tho Coctus doposi t theoxides of iron havo remained noarly constnnt,but in t.he O. K. dl1PQsit iron has been removed.~ I a g n e s i a ()lgO) hilS been reduced in bothzones, Wldoubtedly by tho altoration. Bothlimo (CaO) ond sodn (Nn,O) havo beou almostcomplotoly removed, but potuslt (K,O) especially in the Cactus zono, and combined wittershow mltrkod incrense. Titaniwu oxide (TiO,)romains noarly constant, Carbon dioxido(CO,)hus boon ITlMkedly added in the Cudug wnebut not in the 0. K. zono. Sulphur n.nd COpporhavo been udded in both zones. The sllmplo.

solected for analysis con tltill(,d littlo sulphnnd in this respoct do not r"present t.ho UVeof t.ho t>ltered rock.'TIlo chumiclll and mineralogic chllngesha,o taken place in tho rock give some i.lIdtiOll of the composition of tho solu tions thatduced them. Elemonts that havo boon utIdethe rot.k by theso solu tions were necessarilyried by them. Elements thatwororemovedm.have boon nlrcndy contained to Barno extentho solutions, though probably not ill largegree. From this i.t may be inferred thatsolutions contained potassium, sulphur,copper I1nd in tho Coppor Gulch oro ZOllOiron a.nd carbon dioxide. I t is proba.ble ttho iron and c"rbon dioxide wero presont insolut,ions that produced the altemtioll in ozones but not ill sufficiont qUflntity to be adto tho rock. The fact that tho solutionsmoved neither silica nor alumina. might weldicate that thoy wero not doficien tin thoso sstances.

ALTERATION OF LAVAS.The II1vos have suffered mrtensive alteratin several aroos, ( I , ~ p o ( " i 8 1 1 y along tho bllSthe SI111 Fmncisco Range near Frisco andtho central portions of t.he Beaver L

~ l o u n t a i : n s and oi tho sou thwcsternFrnnc.isco RI1ngo.Tho characterislic alteration of tho lavaa pronounced sericit.ization and silicificatIn the early stages the dnrk silicates nitechlorite and carbonate a.nd il l advancstages magnesium, cnlcium, and sodiumlargely removed. In ~ x t r e m e phases of , ~ l tion tho rcsultltTlt rock is composed essentiof quartz, andalusito, and sericito. Andaludoes not nppear in tho rock so long as feldis prescnt. App.u-ently mica formed sou.s tho rock comained sufficient sodiumpotassium to rombinc with tho ,uuminafreo by tho breaking down of the feldspand only when t.ho feldspl1t" hnd entirely o.ltdid further rcmovll.l of tho bases l'csult mfOlID,\tion of andalusito.Tho following tubles gi\TC a partial analysetho IflvltS in diff01c.n, stages of alteral10ntho miuCl"ll! eomposition ealenlated fromanalyses:


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516 ORE DEPOSITS OF U T ~ H . h C O I I P A R I S O ~ OF ALTERATION OF DIFFERENT lD}loll'bdcflite, sph,,\erite, ond gU\(lllIl nl'O rat Cl ' OF ROCI


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SAN FRANCISCO AND A.DJACE:h"T DISTRICTS. 517nt only two plnccs- in t h ~ Ciletns oro mno in ~ e n g t h of 2 feot. 'rho body as n whole strikCoppor Gulch (sec PI. XLr, B) find in till' lugly rese.mbl l's CO llh;


17/30

518 ORP. DEPOSITo OF UTAH.and pressurc, llnd t.ho s u c c ~ s i o n might natur-ally bo at.tribulet! to u g r n " " ~ 1 reduction ofthe hellt and pressuro irt tho zone. Opposedto this hypothesis, how over, is the presence ofanhydrite, whieh, diffcrcnt.ly from mo st salts,decreoscs in solubility wit.h incrensc in tem-perature lind nllturally wuuld not precipitatefrom u tooling solut.ion. Lindgren 1 says:"It is suggested IlS n possibilit.y thn.t duringthe latnr p"lt of minernlizllt,ion the IlllhydriteWIlS procipitnted by n rcnction bot-wee.n usccnd-ing so lutions of sedium sulphate and d,'sccnding. solut.ions contll ining calcium em'bonate."Tbo iorrn"t;on of hurite, nnhydl'ite,and other sulphll!.e" liS primary rnincrlLisin oro deposits is d i s c U l ~ s e r l on pngo 184.I t is concluded t,hat. at comparatively lowtcmpcn!ture they mlLy form from igncousemnnlltions.

DEPOS[TS IN SEDIMEtrTA.RY ROCWI.co 1 \ ~ r ACT Il t: l'OSIT.4.

Tho typicnl coutllet deposits Oee,ur asveri' vuriable rcnl"""lncnts of the limestO;IOneur the q l 1 ~ l l t monzonito in 1\ 7.0HCdilTcring grontly in t l : i c k n c . . ~ In mostpit",,,,, t.ho I'Cpitu'clncn t r.onsists Inrgely oflime und mngnesiuIL silicates with vnrinblenmounts of sulphide., butiocnlly, as ft t theOld Hickol'Y m no , it consists itu'gely ofmagnetite.

mn.."i,o Topacho limest{)ne, which, thougshows :l. pronounced s\"olling or extensiosome beds, also replucos the in teITeninG'to a considerable e;"tent. bRepl,wement nlung purticuiJ:,r beds isshown in tho Ho.l'I'ingt{)n-Hickory mineill the mines in tho limestone undcrlyinG'~ r o w i t z l \ shulc, especially tho Rerl W:rnnd lI[oscoW mines, i" whicu the replJl


18/30

""Si0'"

.....!l::\-

oz-(

.......

";:i5',,>',,,

z

.;, -----,.,'",,/

.. " ' ~ " , /" , /

",/

'') >u, ') ') ') ') ') ') '),Q. l> ' ,'),' ) > '.-- ') ')> , . . ~ )'',. -') C/) ') ')

, ,,

-


19/30

SECTIONGENERALIZED OUTLINE Of" ORE BOOI ES ANDREAS OF MINERALIZED GROUND

" " I~ " ' .. v v" ... y '" '.' v ,,"';1v" v:.,: ;""'., "Y,.,'''

w.

N.

1P:\lriice-sil,er cr.:.

I

/II

TRANSVERS

AlterJ


20/30

SAN FRANCISCO A ~ D ADJACENT DlSTRICTS. 519posits hn.,o undergone extensive secondaryJtcl'atio!l.

T R A . ' l S - I T I O ~ DJ::l'08ITS.

limestone which forms the footwnll f hd .hOias beon bu t ~ I i g h t l y silicified. The.lteratlOn seems to hll\'e olToct.c!! mainly thopermMblo brecciated lavas lind to havo cit dh '. . r u l ~ t 0 masslvo limestone bllt little_ "In tho Benver Carbonate mille 011 tho thhd ,o . eran , tho wall !'Ock shows much I'ss n' tI . . - L ~ a 9. tOl'at.lO\I. The homblondc h,," been chlol'itizcdand tho plagloclllso partly sericitized, but t.heorthoclaso and hiot.ito show little o.ltcrMion.

ORE )lINRRALS.

DepOsits that may bo considered transitionalBre fonncd like tho replacement-fissure deposit" as It replacement of limestone ,ilongfissures, bu t involve the formation of contact.minerals such lIS' garnet, mngnetite, /l1I0I1te,and muscovite. Theso deposits OceUI' at nOgren t. dhit.ance "rom the igneous rock. Suchdeposit, are present in the Wild Dill and Hubmines, Where, in fact, they merge into true con- !n the H o n ~ Sih-cr deposit tho plineipaltact deposits. The Harringtou-Hickory and p n m a ~ oro mmeruls aro galonn, pyrito, and:,[oscow m.ines mny also be considered of this s p h . a l n ~ c , alld tho Ios.q important aro sulphtype, for they contain contact miner"ls ill con- anilffiomdes and sulpharsen.ides. Tho ore minsiderable amount, though lIS contl'asted with omIs occur al.most entirely: as a :opillcementtho Wild Dill and Hub mines they resemble the ' of thc. volemnc rocks and Ilrc believed to bercplocoment-fi.ssul'e type rather than the con- ?",,,"ntlally ~ n t e m p o r a n e o u s in origin. Thetact type. Though the replacement deposits Importa.nt pnlllarr ganguo mnteri"ls ".1'0 qnllrt,z,in sedimentnry rocb nre confined maiuly to banto, and tho nltorod COWl try!ock. .the limestones or highly calcareous sediments, In ~ h o Donvor Cll.rbonnte. J1llne t.ho P I ' I I U ~ r y some oro oceurs as n replacement of qUllrtzite ore n u n e r ~ s go.lcna, PYrlto,. nnd Spho.loflio,alld the general relations are similar to those and tho prIncIpal gangue matenals aro cltrbonof tho deposits in limestone. oto, qUllrtz, and tho Il!tered cOllltr), rock.Cherty quartz, sulphides, ""d crucite, dopositedin general in tho ordcr namod, fill tho oponspaces betweon the breccia fragments. Theporiods of deposition Ilre no t sharply defined,hm"e"or, as somo sulphide \VB.:! deposited withtho quartz, some calcit.o with tbo sulphides, Ilnd

"Iittlo quartz , , ~ t h the calcite.

!4lNERALlZATION IN LAVA FLOWS.GESERAL C!lARACTt:ll.

Mineralization of cOlumolcjal i.mportance intho volcanic rocks is, so .far us kuown, con1inedto t.wo deposits ou the oustem fiat,k of the SanFrancisco Range-the Horn Silvo1' IUld theBoayer Carbonate. ORIGIY OF THE ORES.

The deposits aro replncement.-fissure veins All tho ore deposits of the region are believodin which the ore and gnngue minerals in part to have heen formed during the snmo generalfilled opon fis.,ul'es IUld in part "cplaced the period by solutions having 0. common origin.brecciated rock adjncont to tho fissures. In Tills community in origin is indicnted by thetho Hom Silver deposit the ores occur in a.nd similarity of tho solutions that effectod theadjacent to d strong north-south fault whoso alteration in the quartz monzonite a.nd in thedisplacement exceeds 1,600 foet. Ll tho Beavcr conta.ct zones in the limestone, and by theC1II'bonato deposit thoy lie along on east-wost. fact that th" contact deposit.. grado into thefault of nndetermined (lisplacement. replacement-fissuro deposits in tho sedimcntaryTho alt


21/30

520 ORE DEPOSIT,;:; 0::,' 1::T,\H.h I I . tl " h ' " ftho f1ssure:-::. lnay logically lJC 8uppo.:wd t.o rc(W n t 10 same lllme ,1e (' Imney' 0 qua

that roc:k at dept.h; in fact. it seoms highly with sulphides of copper "'HI molybdenuProbahle that the fissuring W ,3 the result of which forms t.ho "ore chulluel," has "Vf .the intrusion. Thc_", relations, t,hough hy no "ppoaruuco 0 fI COlU'lO pegmatIte, nnd it seemeans conclusive, ccrt(dnly suggest fL genetic reasonll.ble and logicfLl to consider this u. furthcOllnection. Sueh!t connection for simibr de- stuge in tho diJTerentiut.ion of t.l1O ml\gma.posits is IIlso shown in t,he ~ [ u r y S \ T o . l e district the same solut,ions th . t c"'Tied und deposito tho O!tst.' the pogm"titic quartz undouhtedly deposi

Thnt tho solutions :.dTect.ing tho rocks at I the ore n:inerllls in this qUttr.tz nmll1ilcred tdifl'erent points were ex ..c[.iy tho 81tmo does ?ot, ~ U l : r o u n d l l l g rock find dcpmlted tho .Slliphihowever, seem prob"hle. As t.he solutIons lUlt t.hey wero proh!thl)' " d,ffel'entl"tlon oftl'ltverso the rock they are constantly taking qunrlz monzonite m!tgm!L.up I1nd depositing mnteriul; I1nd 11 solution Tho similarity of the C"ctU8 deposit to thdeficient in fI p"rticuh,r element nt one point of the O. K. minolenves no room for doubt lmav he rich in that element fit some ot.her the solutions h .. d n similar origin, though thpoi;,(,. Diflerenccs in tho eharacter of the rock passed through" more vnried cyclo of p h y s ifind in the tempemturo and pressure may also conditions, the later minerllis of the Cacaff,e(. the solutions by checking or hastening deposit not hnving been formed in tho O.deposition. For ex"mple, in the contact zones deposit. Moreover, the presence of tounnalithe solutions deposited copper und iron sul- and copper mineru.ls intimllt


22/30

SAX F I1AXC 1::'(:O .\Sn A D J A E ~ T DISTTIICTS. 521WATER L'&VEL.rei\t1y ill composition fl'ol11 .th.o aplitic dikes

in the qunrl.z m o n z o n l t ~ , ItIld It IS !1lORt nfl-turn.i(0 suppo;e thllt they h"d It simihtl' or igin -\hl.t is, t.hr.t they were I' dillerentil.tion fromthe quartz r u o n z o ~ i t e magma and indic:lIO thegiving off of O I ~ t I O l l S compet.?nt to effec t t.hersi:lling r.itenltlon of the lim es tOile:;. Thesimilarity in tho compositjoll of th e solut ion sIhnt. effectc,l the ,,It.,,.:ttion ill tho qUintz mon-

The p.>ition of t.he ~ r o u d - w " t Ic,'cl haslargdy. dc.tcrmined the limi t of sccondnrynl terlitlOn In th e ore bodies, for Illtcmtion hasprobubl)- lIot extended very fllr below this levelthough if given suffieient t imo it would rellcht.his leyel rrganlless of other conditions. Ot.her

7.onile nnd in th o limestolle point s 1.0 ntomJnon origin.The doso relation between the differen ttypes of deposit in the sedimentary rocks indicote. u similar origin for ench t)1)O, ont! it isbdie\"ed that the metal content of nll thedeposits was derived from the qunrtz monzonite magma, though it is entirely possibleIh t meteoric ""!>ters m"y have pl!tyed soruopurt in the formot.ioll of deposits ut 0 distallce(rom the intmsivc body.In metnl constituents tho deposits in t.be

6,750

,,50

6.000

lava flows nrc similul' to the l ' p l " c e . m e n l r f is i t s in lillicsOOne, both t.ypcs beLng ehnr- ] . , . .!cteristicolly l 1 d - s i l y e r - z o ! > p e r ores with i .

very little gold . The genernl relations of the !ores in the Illya 00 those in the intrusivo rock t 5,500suggest derivation from tho quartz monzonite ...m n g m ~ und ngrees wit.h ob8e l.,otions iu otherdi, tric (s. Such un origin for the deposits inthis regioll L ~ , however, not boon positively .demollStrnted.

S E C O ~ " D A I t Y ALTERATION" OF ORES.GENERAL FACTORS.

'.2>0~ . c o o

4,750

.... ion c

~ ' " '\\\\' \ ,

'"I

~ / ~ '\ "J. I \ ~ ' " \\ 'L .,... \l\ '., \\ \/i / '

'-'--'-ralfl 8o!'I.llivil1e baeh .\Approximalt> i!cnt\on 6f WUford V I., \,

rIThe chunge produeed in tho minoral depositsof this region by the u.ction of surfuce solutionsbus been fin importnn t though variuble elementUJ the production of the ore depos it.s os t.hey f ' > o ~ : 61 .-DIagQm ......... Ibo . . . . Jon 0100."'", olt.. f1.n I.Ilow exist. It is u.. st.rikina fnet thnt some of r o f o t ~ b J C ! y a n c l t o " l l r ! e o . o I t n S : J , D F r . 1 D f . . i s r o t ! . n d O O , J ; J ( ' 6 n t tho deposits hllve been b ~ t little uffected by dlI"lcU.such !uterntion, tholluh the churnetc.r of ncinoh- fac. tors have been of "reot importanre, how-

E ~ , . t i o n J,"" JB rDllg depos its hos been completely ehllngcd . ever, in determining the rute or alteration.!ha ser.oudllry luteration h1\8 been dependent Tho level hus beeu delermined in butor. scveml f"eOOrs among the more important few mines of the district. Figu.re 57 shows the0( hi 'IV eh aro tho position of the "ronnd-water clC"lltion above sen level of the outcrop of~ h l e , tho rapid ity of erosion, "the physicul sevoml of the deposits, tho lower limit or im-l a ~ ~ of the deposit, and the mjneml com- portollt secondary .!torutioll, and the upper

r'lhon or th o deposit. All these fa ctors hU" e limit of the ground-waler lovel (t.ho uetual()U.btless hud sonIC effect on euch of tho deposition may be considerably lower).

POSIts, htlt in several of the deposits some one I t is not likely that tho waLer lewl 1m3 refaor seems to huve becn dominant. . mained r.onstout for long periods ill the post.


23/30

522 ORE nKPOSrT,S OF UTAH.In fncL, there are good reasons for believing~ b a ~ has heen hoth highcr ulld lowcr ~ h l l J l is now. The beuches of the old L"ke Bonneville ure I L b o u ~ 750 feet IIbovo the p r e s e n ~ sm'fRee of Sevier L"ke. On the ot.her b"nd, theg r e a ~ alluvi,,1 concs at the moutbs of tbe ville)"supon wmeh the Bonneville b e o . c b e ~ were dep?sitec! testify 10 a long period of a r I C l ~ t y y r e e e d t n g the Luke Bonncville epoch, and It 19 n o ~ unlikely tbllt at that timo the wat.er level waslower than present.The inahilitv to determine ~ h e position of ~ h e wlLter level in- t.he pust makes it impossible todetermine tlceumtdy t.he. rdlltion of the waterlevel t{) secomll,r), ulteration, bu t is practically certain thut in somo of ~ h e depositssecondllry ultcmtion hils never renched ~ h e ground-water level even in its h i g h c slues.This is especinlly truo of the Cue.tus mlDe,where the waleI' level in Lake Bonneville ~ i m e must have bcen eonsi(leruuly below the presentzone of alteration, and it is doubtless true ofthe I-lorn Silver mine nlso . On tbe othe.r hund,tho Harrin"ton-l-Iiekory mine oxidized orcs" .are present on the sixt.h level, 100 feet belowtho present position of tho ground "'[1ter, indicilting a lower wu ter level at Iln clulier period.The Coruom,to mine is tho ol1ly one in tho region where the present water level nnd thezone of Qxidlltioll show 0 dose relr_tion. In ~ h a t mine tho wnwr level is bu t slight.ly below thesurface, lind ~ h i s has prevented anyexwnsivea l t e r l L ~ i o l l of t.he ore body.

~ R O S I O N .

The 1"1.te at which the surface is lowered byerosion muy b" importllnt ill determining theextont of the ZOllO of nlterut.ion, for if erosionis sufficiently uctive the ,Jtcred rock mny beremoved " I m o s ~ liS rapidly us it is formed.There is lit.tle doubt thut erosion is loweringt,he SUrfllCC in the San Frllncisco Range morerapidly th,m in sOllle other parts of the urea.From ~ h i s it is to be expected t h , , ~ the zone ofnlterntion will be thinner in the SILII FranciscoRange t.hUIl, for inst.unee, ill the Beuvor L.keRange; and oompurison of t.he yery similllrCnctus und O. K. deposits pl'OVes this to be thecnse. As will be shown )',ter, however, it isthought thnt the shlillo\VllCSS of the zone ofnltemlion in the Cactus mine is due in par t -possibly in lorge pnrt-to causes other thanrupiC! erosion, UIt.hOllgh its sit.untion in the

hoUom (If C.)pper Gulch .is favoruule to re.rosioll.

PHYSICAL OHARAOTER OF DEPOSITS,

It. is rendily a p p l l r e l \ ~ t.hat the physicol cact.er of a d e p o s i ~ will htlve Il D importantfluenco 011 the mte Ilt which it will yieldsecondary !llterat,ioll. A mussive, denseposit or one for somo other reason relativimpervious to solut.ions must n e c e ~ s t l . r i l y nmore slowly thun all open, porol1S one, ocondit.ions being eq unl. As exumples ofdiJfere.nce may be cited massive gnrnetiierdenosit. like thut of the Imperiol mine, whh,,;'e suffered rel"t.ively superficial uIten,tund more open fissure deposits like somthose in the St,ll' district, which hnvo baltered for Ilt l e " s ~ severnI hundrcd ied bethe outcrop. The influence of ~ h e physcondition, however, may bo offset by . ofllet.ors, li S in the C,.et.us deposit, which ulthoopeJI und reurlily permellble hilS beensuperficinlly nltered.

MINERALOGIO OHARACTER OF DEPOSITS.The mineralogic eh!>r"e!er of a deposit m

be irnportfl.nt in determining both t.!le ratethe chllJ"aeter 01 secondary "Iteration.A L T E n A T ( O ~ QU."-UTZ : \ I O N Z O ~ I T E .

III t.he O. K. deposit, to a depth of fullyfeet, the sulphides, pyrite nnd chnlcopyrI"'e nltered mninly to hydrous iron oxidein rek tively sligh degree to copper cUl'bolllexcept in tbe lower part of the ZOlle, whthe carbon"tes become a h u n d a n ~ . Undeing t.his zone of hydrous iron oxide is " zof enriched sulpbides (covellite and c h " l c o c ireplacing chlllcopyrit.e und pyrit.e. Benethe enriched sulphides nrc primllry sulphid

In the Cllctus mille there is u shuliow zin whieh the sulphides hayo been lllteredhydrous oxides of irolllllld c"rbonates of copthe oopp'er mineruls bcing relatively abundtlnd thc ore showin" little loss in eopper Ct.cnt. DiJ:cctly b e l l e ~ t h the zone of oxidecurbonote l l 1 ~ e primary sulpbides. Noriched sulphides ure present.Tbere seems to bo nothing in t.he phYSchul'neter of the d e p o s i ~ or in the po:sit.ion~ h e wnter tnule to uccount for this dillerc,,Th . II f I ' 'o f oxireIn Llve sllu owness 0 t 10 zone .and cnrbonllt89 in t.he Cudus d e p o s i ~ r o ibe cxplnincd by the morc rnpid erosion of


24/30

SAN FRI\)[ClSCO AND ADJACENT DISTRICTS. 523t fOP' bu t tills in no wise explnins the E O " " ; ~ T 4 R Y ROCX'...cnce' of eIlIiched sulphides. The C(lUse for ()OLlOe b h ' h' O1l/ac/ depoSil$.-Oxidation in the contactthe


25/30

SAN FRANCISCO XKD AD.JACENT DISTRICTS. 623t op ' but t.his in no wi so expluins the 8>:D"IESTARY ROCK au cr J absence of enriched sulphIdes. The for Coni-act deposils.-Oxidati(\n in the contact

Ibo differences ml us t bo sought I I I the nunernl deposits h,ls generally b.on relatively shallow. . f t 10 ore5 d .comPCSl tIOU 0 . . IIU conSISUl commonly in t.he {ormotion of c . r-The mincrals of t.he 0 . K. deposIt orc mnmly bonntes nnd hydrous o,'ld d I ul., _ . . - es nn secon( fily S -ch,lcopyritennd pyrIte 111 .". !lungue ot qUllrlz . prudes oppnrently in a monncr s imilar to thlltand mU SCovIte ( s e ~ ' l e l t e ! - rhe Cactus deposIt in the Cnetus d" posit. Where cllleite "'os oncontains, in u(hil t.IOU, I m p o r t ~ n t I l ~ l o u n t s of important gnllgue minernl curbonnks resulted;

cnrbonntt'S ( ' a l c 1 U ~ , n l l l o u e 5 1 ~ 1 D , Iron, nnd where tho contnct s ilicntes were the momDlangonese) m a t ~ t e , t { ) u r m ! l i n e , and I;-"or gougue Coppel' migmted dowllwnrd on (l formed.lDounts of unhydnto nnd bante. IS no enriched sulphidl's . ]n the subscquent ox idareason for b e l i v m g thllt. the hematIte, tour- t.ion of the enri ched sulphides the oxid" of coprr.olino, ollhydnte? or bunte haye I \ f I ~ t e d no- pt'r is a common product. }[ueb of the orot"bly l.ho .lteratIOn pr?ducts resultmg from thus fn.r c"tructed from the .!ont.nct 7.oncs hasoxidation of the sulphldcs. The ~ a r b o n a t been considembly enriched by these sel'ndnrybowever, scems to have been I\n unportant processes.(netor. . . R t ' p w c m e " t - f i , , ~ u p o S ' i ~ , . - T h e roplnce-In the 0. K. depos It t.he n ~ t e r n mny b" us- mcnt.-fissure deposits ha Ye been extensively ,,1-,wued t{) have tilken plaeo m the gene.raUy nc- tcrcd and primlll'Y ores nre exposed in rclatively' .pted lllllnnm', namely , pynte wus OXIdiZed to few plntes in tho area. Probnbly, howe"er,,,,Iphul'ic ncid nnd ferrous sulphnte, and ch nl - the.y consisted of sulphides of lend, zinc, iron,co p)"'ite to cuprous and ferrons sulpbate. The and copper in a gnn"uo of ct,lcito nnd qunrtzfcrroussqlphate upon further oxidot.ion yielded and in some plnccs cl co ntllct silicntes.ferric sulphate, wruch in turn formed bydrous The oxidized-ore miner,lls nro mainly limooxide lind sulphw'ic ne. id, and the ocids thus nite, cerusite, smoU amounts of copper and{ormed ussisted in the further oxidation of the y, in c, usuaUy os cu rbonotcs, ond still smallersulphide. The copper !lnd iron sulphates were omounts of sulpho t.cs, including ang lesit.e andcu rried to lower portions of t.he orc body, where the moro compie" jnrosito and plU01bojurosito.Ibe reducing effect of the sulphides on the solu- The chnnge tho t has taken place hil s beenlions caused t.he precipit.ation of the copper llnd essentially from galena to !lngles ite aod later{ormed tho zon e of enriched sulprudes. to cerusite, which is t.he commo.1I lead mineralIn the Cactus deposit the sulphnric aeid re- of oxidized om, or to some extA>nt has combinedsulling from oxidation of pyrite rencted with with iron in the complex sulphate plumboja

the corbonate gangue to form sulphntes of rosite. Pyrite has altered to limonite, aodlime, mngoesin, and iron. The relati"ely chalcopyrite to limonite and copper c"rbonllte oble lime and mngnesia sulphates \ \ de- In some places jnrosit.o hns n.ppal'l,nt.1y been anpOIlited or carried out of tho ore zone, and the intermedinlAl prodne.t between iron sulphideiron sulphate in turn broke down. This pro- and limonite. Zinc is present to some extel)tCts9 remoyed the acidic radical in the oxida- in the oxidized ores as smithsonite and o..nlation proc""" either by depositing it as sulphllte mine but has been Inrgely removed from theor by removing it in solution. Tho copper sul- upper portion of the ore body. .p41t.e reacted witb the carbonate, yielding cop- In general it may be said tbat lead, lfon, audjIeI"carhonote !lnd sulphntes . Tho rc1lltively copper hi,,,e roigrllw.d only slightly ou(l thutltablo COpper carbona to remained in the 9ulphm' nnd zinc haye been lllrgely removed.D.idation zone. 80 long as it was abundant it Zinc hos possibly been depositeel ot grenterprevented the migrntion of t.he copper sulphate depth ns cllrbonute nnd silicute.solutions to the zone where the copper con- AllTEIIATIO' '" L.


26/30

524 ORE DEPOSITS OE' UTAff.h No ,..j ne WI1B iound; th e qu an ti t y i:i ce rtai nly V('T)' swnter ta.ble if; nenr th e surfnce nnd orc 8 OWS and di ll not fllow i tself. nl t.h ouf;h a ::;fw('iaLd t! t.crmin:U,c.omporntil"e1y slight ulterlttion. .In the Horn Wl.:i made to l l I ~ c r t a . i n i t. The DlQt.alIic lend, arsenic,

Silver deposit the water tl1hle deep! und :mt.imony in the ore are 1M follo\\'s : Lend , 50.00 per CI1lterll.tion hus been an importllnt fRctor i l l the "",enic, per n ~ ; antimouy, 0.26 p..-


27/30


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SAX ~ j \ X C I S t . : O A}:n ADJACE1{T DISl'RlC'rs. 525Enriched' Itlllphide zone.- J 1 the zona of Th('Se i l l ~ ( ' S t i ~ a t o r s find that so far dd h un Is h . . Q..'i e-,ulphi e enrichment t a ('opper.!1 ern ave tel mIned \\TJll'tzll e 18 nlwa"s deposited (f I hnl t .eli . J rOIDformed n.'! 1\ replacement 0 P)'1'1 e, Sp UI'I C, nn acl c ~ o l u t J o n . Tn the oxiun: ion of the

WUI'tzitc, nod galella. Tho copper entered sulphides, mduding pyritl', fl"l'u sulphuric ncidthe zona ns sulphate deriv,'d frolll tho altera- ,;,form:d. Thisreucts inpnrtwithsphakritototion of cO!,pe r mineruls llhove, lind, reacted z,ncsulphate.nnd h y d J ' ~ l ' n sulphidu nnd,with the sulphides forming zinc .nnd iron sul- \\Ilh these, pnsses U1 solutIOn Into tho sulphidophalcs that migru.t.t'd to soma dlStllnce. The zone. By renltion with the minernls the fr('olend ~ u l p h a t e , on t.he o:.hor hllnd, a p p a r e ~ t ! y o x y ~ n n is used up and Uw acidity reduced,remaJucO very dose to Its plnee of format.lon. cnu5mg t.he hydrogen sulphide in the solutionsIt, is probable that som? of the 1cn.d sulphate I to pr?o ipit.t" pnrt of tho zinc from thesulph"teof t,ho hIgher ~ o n e wus hkcwJSC f o r ~ c d by the solutIOn ns wurtzi", . That the pre c.ipitut.ionreact ion of tho copper sulphate ' T I ~ h gaknll procee ds much more slowly than thut of thenther t.hun by simple oxidlltion. I t IS eq ually copper sulphides is iudicated bv the muchprobable that sarno of the zinc nnd iron sul- greater vertiCil'! extent of tho z o n ~ of enrichedpbat.es were formed by the reaction of lcu.d and zinc sulphide.Cllppr.r sulphates with sphalerite aud pyrite In somo of I.he zinc orcs gnh'ua hIlS heenmther than by oxidation. deposited in both sphalerite nnd wUrtzit"Tho rieh zinc orcs nre those in which wurtzil.e practically certninly I1.S " lc,placement mthc;i.i relatively abundnn t.. Th ey nrc largely than a simple filling of fiSSWCR. I t is no teonfined to brcecia ZOlles llSSocintc.d with faults , believed t,hut this ult.erMion hilS rrsulted inin which tho wurtzite ,'ery commonly surrounds llny importnnt concont.J'lltion of lend, but it

t e r s of sphalerite or fills spaces between muy have been important ill the 'llterntion of'phaleri!e g1'Uins. (See Pis. XLII, XLIII.) tho zinc sulphides- thnt is, tho zinc sulphn!"The.e rdutions suggest thnt the zinc sulphate may hnve Ix ...n formed in purt by the rendionsolutiolJS working downwurd alollg the more of zinc sulphide wi t.h lend sulpl",te rnther thnnopen chanods, nomely the brecci'lted areas, by simple oxid.tion, or tho lI.ct.ion of sulphuricdeposited their zinc contcnt around the sphal- acid orcopper su\phnkel ito grains. The cryslllllographie c.hamcters. No favorable opportunit.y was observed forof the two sulphides of zinc urc vcry similor, the study of secondury silver sulphides, andand it ,eems probable thu.t in muny places t.hey aro not believ


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526 ORE DEPOSITS OF UTAH.ParLiJJl record ty k , : i l ~ of kad , .::r.PPlr, silnt"., ond gai-l /a,hnfrom lite Flom SUrtT m ~ l I t .

Cave . . . . . . . ".. . . . . . . . . . . . . . . . . . . . . . . - . . _. -Finlt level. . . . . . . . -. .. .. . . . . . . . . . . . . . . . . . . . . . -. . . . . . . . . - .. . . . . . . - . . . . -Se('ond Il\'el. . . . _ . . . . . . . . . . . .. . . . . . . . . . . . . . . . . - . . . .. . - - _ . . - .'J'bird Il \cl . . . . _ . . . . . . . . . . . . . . , . . . . . .. . . . , .. . . . - _ . . . . . . . -Fourth level. . . . . . . . . . . . , . .. " . . . . . .. . . . . . . . . . . . . . . . . . . . . . -. _ . - -Fif th l c\cl . . . . . . .. , . . . . . . .. . . . . . . . . , . . . . . . . . . . . . . .. . . . . . . . . .SiXf_h level . . , . . . .. . .. . . . . . . . . . . . .. . . . . . . . . . . . . . . . . . . . . . .Se\cnl.h level .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . - . . . . . . . . . . . _ .

Load. I i l" . r , Gold, C oPa unt. 'Oz. palen. Oz. prr t()n . Prr46. ;17 2:1. 01 O. OOolf, . . . . .36. 07 e!, 39 .. . . - .. . . . . . . .:15.12 :Jr..20 . . . . . . . . . . . . . . . .40 .3 2 33, 19 . . . . . . . . . . . . . . .

1 3. 45 20. 20 . . . . . . . . . .32. 94 4:1. R8 . . . . . . . . . . . . . . .37.63 26.16 .002565 o31. 91 31. 02 .011-14 234'.18 28 .63 .0097328. 21 22. 88 . 03223 6~ : ~ ~ h h J ! ~ ~ I ~ : : : : . ' . . . ' - ~ : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : - - - : - -36.61 I ~ \ . 98 .003131_ __ _ ___ ________ _ _ _ __ - - - _ .....c- --UnfortullIltd.l' sarno of the figures in these i from the ninth level is stnted in a n o t h ~ r t,ables seem to repro"ont tho love.! from which ' of the company's report to have come fromthe are wos hoisted ratber thon that from seventh and eighth kvcls.

which it WllS oxtrrLCtcd. For example, thc The following table s hows the mei al concopper ore thot i. S h O " ~ 1 iu tho tables as co ming of seveml lots of ore hlken from the mine:J{et.Jll ctmicnt of 801M OTC3 from the. T/orn. S ~ l l . minco

1 2 3 4 .) 6 7

0 .0002, 83 117.41 1

m 23123. 7 . . . . .Gold . . . . . . . . . . . . . . . . . . .OUJUCS ver Ion. . . . . . . . . . . . . . . . . . . . (a{ 0.013 0. 000Silver . . . . . . . .. . . . . . . . . . . . . . . . . .do.. . . 783:i 51.00 ('.lJ 6. 60 5 .')[)~ : : : : : : : : ...:.: .. :.: .......... r < r d ~ u ~ : r ~ ; ; g 4 : g g 4g 3 ~ 1 & Iron . . . . . . . . . . . . . . . . . . . . . . . . . . .00 . . . 3. 36 (b) 4 (alilicn. . . . . . . . . . . . . . . . . . . . . . . . . .do.. . . 10.7 (. / 20:J5 (aSulphur . . . . . . . . . . . . . _ . . . . . . . . . 00.. .. . . . . . . . . .. (. ) 28 15 (aCopper. . . . . . . . . . . . . . . . . . . . . . . . . do .. .. I....... .... ........ " ........T ........ ......... .

II. O:tidizcd ort!K. A n n l y ~ ( l s (rom report by W. A. Hooker.2. A y c r ~ ' Q of al l oree' to 300foot lC\'(l1 Q8 determined by Hooker.S. A \ ' e ~ yieldlof roo ton1'l of zinc orlJ. from IICventh lo\ 'el . EmmoI18,.s. F. , Am. I nst. Mi:l. Eu g. Trans., "0p. G5.8, '1902.4. Approximato Rverngc of ,d nc ore !rom 7Qo...foot level, byAt. C. Morr;", general DUUloger. Tho sulphur ll , ,';dtoo ~ O W , ad it ishot lUi1kient to combino with th e me!.u.ls form I1Jlphide.o!,I though .tho l i & . u a J y 8.umspradillal100 find other general EUlrWySC8 and tho study of th e eros show t hat the metaLS are pre:JOnt u th e IUlpbidclII.5. Avemge o( zinc ore shipucd iul90.j. from comp:luy'. r e p o r t6, Av e ~ or ('0-ppor oro shlopc-d in 100" from conipnny'8 leport.7. Averagtl of 8hlpmont of zlllI: )ca.d ore L'QfJl1N)O -(oot level; f i g u r ~ fUTllilili cd by )l. O. Morris. geool"l\1 fDOllSo fill' OS tho sto.!isti(:s inclucl e.d ill these tables l and silver 32.04 ou.nees pel' ton. I t eviIlro concerned tho o x i d i 1 . ~ d zono mny bo conBid- from t,hese figures that the ores in all po.rored 8S inc.Jnding the tir8t fivo levels. Tho av- t,he main oro body "how a delini te relut,ion

erugo metal content recorded from theso level" twoon lead and silver content of approximais lead 38.99 per cent and silver 38.63 ounces an oUllce of silver to eaeh pe r cen t of lendpOl' ton. The !lvcrage in lead aud silver of orcs ]f on are similar in composition to thoshoisted from t.he ninth love l Onrgdy prim.U'y) the lower levels, which are r egarded as esWIlS silver 22.88 ollllces per ton ond lend 28.24 tially primary, should have i l l tho zincper cent; aM I-he .wel11gB of cert"in shipments phiclo "n d " port of tho iron removed nndof prinmry zinc-lead ore from tbe 900-foot Hilica content reduced to 15 per ce nt (as lowlevel shows siln:r 10 ollllecs 1>


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WAH WAH RANGE. 527thut the lend and silver conte.nt ?f ore in t.he orscd by tho road from Newhouse to Osrrolnoxidized zone hus been mntermlly 1 . n ( r r ~ l s c d by and Ely, Nev.the process of a1tcmt.ion lind that the 7.InC nnu Water . is scarce, the supply being derivedcoppel' huva been lurgely r emoved . . from sprIngs and small 5t renms thllt ~ i n k intoIn tbo rclnl.i,-cly small slIver-or? borh"s t.herr granls as soon os they It'IWO tho mOlHl-b". been a marked ineren.dilitinGuiNloo from . ~ r o c n s o! ho B:l1D.6 !peClt-l oecurT. ),1"ddl Qunbrian limeilOO. In Tenncesce .J\d AlabalIl,Tub ' 0._,01 ()('Cur 10 both the OTT iormlLtion ( U p p l ~ r el!Om6 r - - - . C b ' )01C4lmhri:m) .O(! n",W o ii""",tono ()hdd\e . am n ~ n ted

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SF and Star District Pages from USGS PP-111