547

The Canadian Mineralo gist Vol. 33, pp. 547-558 (1995)

THEGEOCHEMISTRY OF PHLOGOPITEAND CHLORITE FROMTHE KIPUSHI Zn-Pb--Gu DEPOSIT, SHABA, ZAIRE

MUMBACHABU Inboratoire de Mdtalloginie, Universitdde l,ubumbashi,B.P. 1825,Lubambashi, Tatre

ABSTRAC'I

Phlogopiteand chlorite havebeen found in the Kipushi Zn-Pb-{u deposit"which is hostedby lower Kundelungudolomite and dolomitic shale of Late hoterozoic age, and by karstic chimneys and solution-collapsebreccias. Electron-microprobe analysesof theseminerals indicate that the highestfluorine contents,ranging from 4.4I to 6.39 wt.Vo,are found in ore-related pblogopite,which also is the most magnesian(X"n may exceed0.99) [Xyn: Mg(Mg + Fe)] and the closestto the phlogopite end-member[X"61 (Mg/total octahedralcations) upio 0.95]. TheseF conten-isare compatiblewith the Fe-F avoidancerule and with a disordereddistribution of atoms on the octahedraland OH-F sites. ln general,Xo6, F and Si vary sympathetically, whereasXo, aaduAl arenegatively correlated. Chlorite exhibits a very low F content(0 - 0:73 wt.Vo)and a considerablespread in compodition,with Xyn values ranging from 0.32 to 0.84. The more Fe-rich cblodte is associatedwith Fe-rich (up to 7.86 mol 7oFeS) as the dominantsulfide. Cblorite in associationwith chalcop)Titeores has X14n values around 0.76. The most magnesiancblorite (XMs- 0.83) occursin barrenshale of the "S6rie r6cutrente",above the mineralization.Calculations of log[f(IIzO//(I{D] basedoi calibratedF-OH exchangerelations between fluid and biotite indicatehigher relative activity of fluorine in mineralizedareas than in barren rocks. Phlogopiteand cblorite are consideredto be of metamorphicorigin; their composition is interpretedin terms of 1) increasing/(D and/(SJ as the orebody is approached,and 2) changesin bulk composition.The emplacementof the orebodyprobably predatedthe peak of tle Lufilian (Katangan)Pan-African orogeny (6s0-s00Ma).

Keywords: Kipushi Zn-Pb-Cu deposit, Katangan,l,ower Kundelungu Group, pblogopite, cblorite, XME,F-OH exchange, Lufilian orogeny,Zaire.

Somr,ranr

La phlogopiteet la chlodte se rencotrtrenttant dansles minerais que dansles rochesencaissantes du gisementZrPb{u de Kipushi, localis6dans les dolomieset les shalesdolomitiques, en partie brdchifi6s,du groupedu Kundelunguinf6rieur, d'6ge prot6rozo'fquesup6rieur. D'aprbs les donneesobtenues h la microsondedlecEonique, les teneursles plus 61ev&sen fluor, variant enfte4.4I et 6.397o,en poids, se rencontrentdans la ptilogopite associ& aux minerais;on y trouve dgalementles plus fortes valeursde Xr* [Xrrae= Mg/(Mg+Fe)], d6passantmOme 0.99, et de la proportion du p6le phlogopite(Xo6 = Mg/total descations uAl en sitesocmh€driqries), jusqu'd 0.95. De manibregdn6rale, Xo", Si et F varientproponionnellement. En revanche,4r et prdsententune corr6lation ndgative. l,a cblorite est trbs pauwe en fluor (O4.73Vo, en poids). Elle montre pa:r ailleurs d'importaatesvariations de composition(Xrn de 0.32 i 0.84).Les compositionsde chlorite les plus ferrifOressont associ6€saux mineraisb sphaldriteferrifOre (envion7.867o, teneurmolaire de FeS) dominante.D:ns les mineraisi chalcopyritedominante, la chlorite pr6senteun Xy* d'environ 0.76. l,a chlorite la plus magndsienne(Xrun = 0.83 en moyenne)caractdrise les shales dolomitiquesde la S6rie r?currente,stratigraphiquement au-dessus de la min6rdlisation.lrs calculs de logtf@rol/(I@l fond6s sur les relations d6changeF-OH ente fluide et biotite indiquent une activitd relative de fluor plus 6lev6edans les minerais que dans I'encaissant.La phlogopite et la clilorite seraientd'origine m€tarnorphique.leur composition reflbterait l'augmentationde/(F) et de/(Sr) vers le gisementet la compositionglobale des roches. l,e gisementaurait 6td forme ant6rieure- ment au paroxysmede la tectoniquelufilienne (65G-500Ma).

Mots-cl.Cs:gisement Pb-7^1n de Kipushi, Katanguien,Kundelungu inf6rieur, phlogopite, cblorite, X1,an,6change F-OH, mindrauxm6tanorphiques, orogenbse lufilienne, ZaAe.

INrnooucuoN De Magnde & Frangois (1988) related the Kipushi deposit to the dissolution of a salt diapir, which pro- The origin of the Kipushi deposit is controversial. ducedthe breccia in the anticlinal core. The resulting Intiomale& Oosterbosch(1974) and Intiomale (1982) brines are taken to !s ths mineralizing fluids, and the considered ascending hydrothermal solutions of mineralizationis consideredto be postkinematic.The magmaticorigin as progenitorsof the mineralization. deposithas also been ascribed to depositionfrom fluids

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formed by metamorphic dewatering (Jnrug 1988). phlogopite and chlorite place constaints on genetic Chabu(1990) and Chabu & Bouldgue(1992) suggest- models. ed that the mineralized solution-cavities are karstic feafures"and consideredthe formation ofkarst and the Grolocrcat Sr"rrnvc main part of the mineralizationto be contemporaneous and to predate the peak of the Lufilian tectonism. The Kipushi Zn-Pb-Cu depositis one of the major compositionspresented in this paper support producersof , cadmiumand germaniumin Africa. this hypothesis. It is located about 30 km west-southwest of Many thermodynamicy*1u61"r can i:rfluence the "in southeastem7,aire, on the Lufilian complexgeochemistry of a trioctahedralmica and of a tectonic arc (Fig. 1). The depositlies along the eastern chlorite; their composition may be employed to margln of a body of collapsebreccia that occupiesthe estimatesome of the physicochemicalconditions asso- axial portion ofthe Kipushi anticline and discordantly ciated with their crystallization. In particular, as a transectsthe strataof the northenflank of the anticline result of the experimentalwork of Munoz & Ludinglon (Frg.2). (1974, 1977) and Zhu & Sverjensky(1992), the F The Lufilian tectonic arc, also known as the content of micas has been used to gain hformation Copperbeltowing to its considerablecopper reserves about the nature of the fluid phase during meta- and productionfigures, consistsofnearly 10,000m of morphismand ore deposition. Late hoterozoic Katanganstrata. These are subdivided In this study,we provide analyticaldata on the F:OH into the Roan and Kundelungusupergroups (lable 1). ratio of phlogopite in a sediment-hostedbase-metal The latter consistsof two subunits,the l,ower and the deposit; trends of compositional variables of both Upper Kundelungugrcups. The baseof both the Lower

z

Nohanga fl KUNDELU|!

I EOAN , Oroup

PRE - KATANGAN Ba8om€nt

o Stntllom Cu - ( Col dopoalte

o Zi - lcu- Plrl l/elna & Stratllo"m

It U - (Nt-cu- co I v€tna

Ftc. 1. Simplified geologyof the Lufilian fold b€ll showingthe locationsof major Copperbeltdeposits. Modified after Sodimiza companyrecords, Chabu & Boulbgue(1992).

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t6n

ZAMBIA

ffir W,ffi,ffioHul-_loW, l-F'fs

Ftc. 2. Geologicalmap of the centerof the Kipushi anticline and location of the deposit. Modified after Intiomale (1982) and Chabu& Boulbgue(1992). Symbols: I siliceous dolomite (Lower Mwashy4 2 shale (Upper Mwashya), 3 Grand Conglom6rat, 4 dolomite (Kakontwe), 5 shale and dolomite (S6rie rdcunente), 6 shales ancl sandstones,7 brecciU 8 ore deposrt,9 internationalboundary.

Kundelungu and the Upper Kundelungu groups is before the peak of the Lufilian (Katangan) orogeny placed at the lithostratigraphic markers called the (ca. 650-500 Ma) andwill be referredto asthe Kipushi *Grand Conglom6rat'' and the '?etit Conglom6rat", breccia. respectively.Both units havea tillitic origin (Intiomale As shown in Figure 2, the polymetallic mineraliza- 1982).On the Zurean segmentof the Lufilian tectonic tion of the Kipushi deposit is located in Lower arc, tlle Katanganrocks have been subjectedto low- Kundelungu Group rocks at the base of the "S6rie grade metamorphismduring the Katangan orogeny r6currente", a sequenceof alternating dolomite and (ca. 650-500Ma). shale,and inthe underlyingKakontwe dolomite, where In the axial zoneof the Kipushi anticline,the breccia it is confined to strataboundand discordantpaleokarst body is composedof very largeblocks (up to morethan sfuctures. It also occurs in the Kipushi breccia. The a hundred meters across)of Roan rocks of different mineralizedbreccia is limited toward the westbetween Iithologies.Among them arefragments of white sparry levels -160 and -1800 m by a large banen block dolomite assiguedto Dipeta Group (t efebvre 1975), composedof shaleand fine dolomitic sandstone.It has andarkosic sandstone. Blocks ofgabbro havealso been been terrned the "Grand lambeau" and consideredto found in the breccia. These represent a sill-like belong to the Upper KundelunguGroup by Intiomale infusion of gabbroic roctrs, now completely amphi- (L982). The sulfides in the deposit,in order of abun- bolitized, probably emplacedin the Dipeta dolomite dance, are sphalerite, , , , (Lefebvre 1975). chalcocite, arsenopyrite,tennantiteo galen4 renierite At its easternmargin, the brecciabody is composed with minor briartite, gallite, , carrolite, of rock fragmentsderived from the enclosingLower belechtinite, and sffomeyerite(Intiomale Kundelungubeds. The unit has been interpretedas a 1982, Chabu 1990). They form three ore types: collapsebreccia @e Magn6e& Frangois1988, Chabu (i) copperores mosfly locatedin the "S6rie r6curente" 1990, Chabu & Bouldgue L992) probably emplaced (ii) mixed ores (7n + Pb + Cu) hosted Uy Uppei

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TABLI 1. SCHEMATIC STBATIGBAPHIC COLIJMN OF TEE KATANGAN SEDIMENTARY SEQUENCE ON THE ZAIBSAN COPPMBELT, SOUTSEASTEBN SSABA, ZAIRE

SIJPERGROI'P GROTIP FORMATION IJTHOLOCY sbsle and

K Upper shale A Pedt dlllte T (1^ndldh6Df A KuDdelungu shDl€ N S6r'ie dotronite and G rq6arr A towEr Kakontw€ dolonlt€ a.bdl nlrala N Kaponda dolomltE and ahola

Gband dlltte s Cotur1on6rlat E Mwashya sandstone, a sbolo a,nd dolodte E IXpEta dotronlte, shalE and N sndatone c Boan Mines ehale, E dolonlte antl mndstone

R.A.T. shale aJtd sndst-one

Klbala Supengroup and older rocks (Basement complex)

Ths base of tle B.A.T. Gmup ie uuknoml ln thlg a,rea. ThE tb"lEe bssal Boan Groupa tavartably appear as elabs of vartable slze, up to lgveral tm-aonoss,.ln megabrec.Ies. R.A.T.: rochas a,rgllo-talgueusee {a$i18999qs, l+c-beaung roc,ks; actually, flne-gmlned sandstone). Modified after Chabu & BoulBgus (1ee2).

Kakontwe dolomite, and (iii) zinc ores mainly located SarvrpmqcAND PsrRocRAPIilc Ossnnverrolls in Middle andLower Kakontwedolomite as discordant karstic pipe-fillings surroundedby pyritic ores. The Phlogopite-and chlorite-bearingsamples have been threetypes of ore are presentin the Kipushi breccia. observedboth in barrenand mineralizedenvironments Fe sulfides in ores are representedby chalcopyrite, (Appendix 1). Thosefrom barrenzones occur in shale pyrite, arsenopyriteand minor marcasite.Arsenopyrite and dolomite of the "S6rie rdcurrente" above the is commonly associatedwith Cu sulfides, mainly mineralization and in gabbro blocks of the Kipushi chalcopyrite, and with pynte in pyritic ores. No breccia body sampledin drill cores. Phlogopite- and pynhotite was found in this study, but Intiomale & chlorite-bearingsamples from the "S6rie r6currente' Oosterbosch(1974) reportedblebs of this mineral in have been collected in borehole 750/35 NE drilled somegrains ofchalcopyite. In general,the assemblages horizontally at the -750 m mine level and from expo- of ore indicate a sulfur fugacity too high to suresin mins welkings. Phlogopiteand chlorite have allow the formation of pyrrhotite at this gradeof meta- beenstudied in the threetypes of ore mentionedabove. morphism(see below). They havebeen collected tbroughout the orebodyfrom Widespreadstructural and textural featuresindicate drill cores and outcrops in the mine. In the "S6rie that the deposit predatesthe peak of the Katangan r6currente",phlogopite and chlorite formaminor (2Vo) deformational event. These include the presenceof part of two mineral associations:(i) phlogopite, folded, sheared and brecciated ores (Chabu 1990, chlorite, dolomite and quartz forming pods in shale; Chabu& Boulbgue1992). and (ii) phlogopite, talc, albite, magnesite,dolomite,

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TASIA 2. BFBISEI\ITATIVE EIAcTBON.IIICEOPF'OBE DATA TA3I,E 8, BEPBESEMXATTVEET,ECTBON-MICBOPBOBE DATA ON PEIOCOPITE ON CEIOBITE

88Epl€ 1150? ?60200' 7!02880 99s1816 E3 Bg10 Suple 9921810 8112 8114 81X6 6102rt.g 89.4198.28 40.68 39.30 43.00 41.19 40.82 44.31 45,& 4,27 gO2 N& 14.89 14.90 18.31 16.1516.39 15,2S15.48 13.05 72,n 72,52 wt.t t9,82 30,& 2A.2a 2A,88 21.72 ,55 25,88 28,19 N,N tto2 0.92 0,,17 1.09 0.93 0.88 0.59 0.?9 0.12 0.18 0.07 ,Jlol3 2!,79 20.N 22,?8 22,67 27.83 75.82 19,20 19.74 79.44 - !0aO 0.04 0.03 0,0?. no2 0.06 - - 0.04 - 0.02 0.01 0.07 CUO 0,11lal Dal 0.03 - t4lo 0.04 - 0.06 0.0s - 0.06 0.16 0.07 - ?eo n.d. n..1. - - - 0.1110.M !,d. - - cuo D.d. r.al. D.d.0.&l 0,09 n.d. !.d. l'€O 11.3011.89 8.s4 8.S1 0.86 S.3g 8.63 0.16 0.M O.rl ?fro !.d. !.d. 0.26 - - !.a1. !.d. - 0.64 Mgo 18.t0 1s.48 1S.0t '0.?9 '8.0? 19.11 18.51 25,41 28.45 28.@ - - !'s 9.84 S.68 13.48 13.03 19.91132.02 92,43 52.47 U.3l CeO 0.08 0,01 0.01 0,01 0.05 0.04 0.01 ueo 26.7s 2t.06 22,9 28,79 9.77 9.3:r 10.01 S.23 960 - 0.28 0.18 0,37 0.18 0.08 CaO - 0.0s 0.02 0.@ 0.0x 0.03 - - 0.06 Nrzo 0.1i1 0.07 0.00 0.0it 0.m 0.14 0.11 0,14 0.18 0.08 ",17 BaO - 1.39 0.03 - 0.14 - K2o 9,81 N.98 9,72 1.14 9.?8 9.01 8.?6 9.6? S.59 9.87 - - - - Na2o 0.03 0.14 0.02 0.02 0.03 0.03 F 0.33 0.u 0.s3 t.18 7,u 2,49 4,94 6,3S 6.58 - - 4.08 3.88 4.04 3.09 3.A s,61 2,U 7,92 1.t0 1.80 0.06 0.06 0.08 0.05 \o w - - lbo - -0.14 -0.0? -0.:19-0.?5 -0.82 -1.S -2.08 -2.09 -2.95 E 0.?3 0.4 0.2s 0.85 0.19 0.21 0.10 Tstal 08.88 g?.rllt98.19 0?.69 08.81 gg.F S7.9797.90 S?.01t99.01 g2o t2,s7 12,t8 11.93 19.17 11.89 10.91 10.91 11.10 11.@ FEO - -0.31 -0,19 -0.10 -0.27 -0.08 -0.09 - -0.07 Fmlaa bsed @ 24 (O, OS, F) Total 99.S101.8tr99.68100.S1 9S.S6 98.?l 98.S' 99.70101.17 flAr 6,7S 8.89 !.S0 8,?1 8.(p 8.03 8,98 6, 6,23 6.1? 2.27 2.91 2,70 2.28 7.s1 2,07 3.08 1.?6 1.?7 1.89 Fomr16 baa€d on 16 (O' oE' F) vlAl 0,t? 0.s0 0.52 0.4s 0.30 0.52 0.61 0.40 0.8€ 0.8 sl 6.78 8.83 5.69 5.8{r 8.6:1 6.08 6.81 5.6? 5.88 Ti 0.10 0.@ 0.11 0.10 0.04 0.08 0.@ 0.01 0.0? 0.01 AI 4,8 4,62 6,2! 8.22 5.04 6.10 4.S3 8.03 4.95 Fe 1.39 1.49 1.01 1.00 0,10 1.18 1.05 0.0! 0.03 0.01 tt 0.01- - 0.01- - - 0.01- ug 4.014.31 4.11 4.4€ 6.4 4.r7 6.85 6.X8 U! 6:3i1." *11 *ff 1.56 1.55 t.r3 r.13 2.18 6.84 5.S1 - - - - Mg 7,& 7.72 6.?1 6.68 6.9? 3.lS 3.30 3,22 2.98 Zt n.d. B.aI. 0.01 B.al. D.al. - - - - 0.01- - 0.01- - l0r 0.01 0.01 0,01 0.01 0.0x Cu Y 5.E7 6.18 6,?6 6.08 5.89 6.?8 5.75 E,n 6.?8 8.88 Zt !.d. 0.01 - Ca - 0.01- 0.02- 0.01- - 0.01 86 0.02 0.01 0.0s 0,01 Ba - 0.11 - - 0.01 - Na 0.04 0.02 0.02 0.01 0.@ 0.04 - 0.04 0,04 0.0, Na 0.01 0.06 0.01 0.01 - 0.01 - 0.01 - K 1.84 1.88 1.80 1.43 1.?4 1.88 1.89 1.74 1.?3 1.?6 K 0.0x 0.01 0.02 - 0.01 - I 1.8t 1.80 1.8r 1.'14 1.76 1.?0 1.09 1.?0 1.7s l.?S - o.M 0.28 0.14 0,40 0,13 0.14 - 0.11 16.0016.88 16.72 16.88 16.60 15.8? 18.86 18.fit 15.89 F - 0.1! 0.m 0.ta 0.?9 0.56 1.15 ,.e0 2.aB 2.4 OE OE 4.00 9.85 t.s2 3.5? 3.21 i.44 2.85 1.80 1.14 1.64 xMg 0.8:t 0.82 0.?5 0.?6 0,?0 0.36 0.3{l 0.38 0.34

8.a1.! lqt dotorded, A d4h Fp@ts @@tntloDs 1ss6 the thr alstsstlqE ltdt .f the el@bo! qal 16s6 tau 0.(F1 affi tFt n. d. : mt alstsrdned. A alssh Ftr,@ts @acob8flm less tbs the fo@la udt, The pFIs,U@ od S2O w @l@lai€d. lldt od iiotssdo! d ths el@t&n d@pmbe, l.e., Bd less the 0.@l ato6 ts fomla udt. Ths prcfprtlou of S2o ru @loulatsd.

gypsum,anhydrite and quartzin dolomite at the upper by the sulfide. part ofthis unit. In this latler paragenesis,phlogopite is Fluorite is very rare in the Kipushi deposit and was very sparse,and occursas fine-grained,ragged flakes, not observedin this study; Intiomale & Ooslerbosch whereasgypsum and anhydritetend to form distinctive (1974) reportedits occurrenceas disseminatedgrains bandsparallel to bedding. on the -170 m and -850 m levels in the mine. In gabbroblocks, phlogopite and chlorite are asso- ciated with albite, amphibole (mostly tremolite and Mnwar ColposrnoNs hornblende), epidote, quartz and calcite. Trace amounts(ess than 17o)of disseminatedchalcopyriie, Analysesof phlogopite and chlorite from different pyrite and ilmenite also were observed.Albite, phlo- environmentsof the Kipushi deposit (Appendix 1) gopite and amphibolerange in habit from fine-grained were perfonned on a CamebaxMicrobeam electon aggregatesto very coarsegrains intimately intergrown. microprobe at the Universit6 Pierre et Marie Curie, Other components,such as epidote and quartz, Paris VI, using an acceleratingvoltage of 15 kV, a commonly a1s limited to interstitial spaces.In some beam current of 20 nA, and a counting time of samples,albite porphyroblastsinclude small grains of 15 seconds. Standards used include orthoclase, epidote and phlogopite.Most of the chlorite seemsto diopside, albite, iron oxide, Mn and Ti oxide, havedeveloped as a productof alterationofphlogopite sphalerite,fluorite and syntheticLiF. Resultsare listed and amphibole,and was not analyzed. in Tables 2 and3 for phlogopite and chlorite, respec- Within the mineralized samples, phlogopite and tively. chlorite occur in the following assemblages:(i) phlo- gopite, chlorite, muscovite, albite, quartz, dolomite, Phlogopite sphalerite,pyrite, ,linnaeite, and (ii) phlogopite, chlorite, dolomite, quartz,dbite, chalcopyrite,bornite, Figure 3 is a plot of analyticalresults on the biotite and minor arsenopyrite and sphalerite. Phlogopite quadrilateral delimited by annite, pblogopite, alumi- grains embeddedin sphaleritecommonly are corroded nousannite, and aluminous phlogopite (Guidotti 1984).

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Alumlnous annl{G Alumlnour Phlogoplto foi the material richest in F (which is included in 1 categoryE). Thesefluorine contentsare compambleto 0.0 thosefound by Gunow et al. (1980) in biotite from the

Phlogoplto Hendersonmolybdenite deposif Cblorado. The mol o8 Flold fraction of the pblogopiteend-member (4or = Mg/total cations) in ore-related tL7 octahedrally coordinated phlogopite extends from 0.68 to OJl for relatively a' as lL8 * F-poor compositionsassociated with chalcopyrite a tle dominant sulfide mineral (category A) and from tL6 rL 092 to 0.95 for F-rich phlogopitefrom both sphalerite I andchatcopyrite ores (category E). Phlogopitefound in tL4 the metamorphosedLuisha deposit 45 km 0.3 NNW of Kipushi displays similar values of X*, (Cluzel 1986). 0.2 Phlogopite from barren shale of the "S6rie r6cur- rente" (category C) and from barren gabbro blocks 0.1 (categoryB) is characterizedby the lowest concenfra- 0 tions of F, rangingfrom 0 to 1.0 wt.VoF. Thesesamples 0 0.t 0.2 0.3 0.4 0.6 0.8 0.' 0.8 0.s 1 of phlogopite have Xr" values varying from 0.81 to 0.83 and from 0.73 to 0.76, correspondingto f,Ln Annlte Mgllug+Fo Phtogoptto valuesranging from 0.71to 0.74and from 0.67to 0.71, Phlogopite from barren dolomite of the respectively. 'ng Upper "S6rie r6currente",coexis with talc, rnagne- AEGDE site, gypsum and anhydrite (categoryD) has a low F contentlike that in phlogopitefrom barrengabbro and Fro. 3. Location of phlogopite from the Kipushi deposit in shale,but its.{06 is in the range of thoseof the F-rich phlogopite plane. the field of the biotite Letters refer to: phlogopitedes,iribed above. A: low F-bearingphlogopite associated with chalcopyrite in Figure 4. (sample 9921816), B: phlogopite from gabbroic blocks The above relations are illustrated (sample11507), C: phlogopitefound in banen shaleof the Excluding the phlogopiteofcategory D, fluorine abun- "Sdrie r6currente"(sample 7502002), D: phlogopitefrom dancesand.{06 vary sympathetically,a featurethat has gypsum-, anhydrite- and talc-bearingdolomite ofbarren beenreported by severalother inYestigators(e.g.,Zaut "Upper S6rie r6cunente" (sample 7502351), E: F-rich & Clark 1978,Jacobs & Pany L979, Munoz L984, phlogopite from mineralizedzones, associated both with 1992).This is an expressionofthe Fe-F avoidancerule sphaleriteand chalcopyrite(samples E3 and KH 102). (MasonL992,hu & Sverjensky1992). Among the various mineral assemblages,fluorine exhibits its most pronounc€dconelation vdftr XDn in the phlogopite from barren environments(phlogbpite It shouldbe notedthat aluminousannite and aluminous phlogopiteaxe equivalent to the terms "siderophyllite" and "eastonite", respecfively, used in the older literature @eer et aI. L962). All the mica samples x phl discussedin this paper plot in the compositionalfield ofphlogopite. Table 2 and Figure 3 indicale systematicvariations 0.90 in composition of phlogopile present in the various assemblages,which accordingly has been classified 0.s6 into five categories(A - E), as explainedin the caption to Figure 3. Ore-relatedphlogopite associatedwith sphaleriteas the dominant sulfide mineral exhibits a 0.8E very high F conten! rangng from 4.41 to 6.39 wt.VoF (cat€goryE). Thesephlogopite samplesare distinctly more Mg-rich than thosefrom barrenrocks andplot on 0.76 the phlogopite- aluminousphlogopite join. Their Xyn = value lwhere Xrran Mg(Mg + Fe)] approachesunity 0.06 (more than 0.99). Phlogopite associatedwith chalco- 0r234607wt%F pyrite as the dominantsulfide mineral showsa gxeater spreadin F content,rangng from 1.24to 5.35 wt.7aF, Ftc. 4. Plot of concentration of F versw.{061, defined as the whereastheir X11uvaries from O.77to more than 0.99 ratio Mg/total octahedrally coordinated i:ations.

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o.1 0,2 0,3 04 0.6 0,6 0;t 03 0B 1 xplrr

FIc. 5. Location of the phlogopitefrom Kipushi in .{06 - Xp space.l: Field of disordered distribution of ocahedrally coordinatedcations. 2: Field of clusterformation. 3: Field in which the Fe-F avoidancerule is violated. Modified after Mason (1992). Symbols asin Fig. 3.

of categoriesB and C). F-rich pblogopite from the Phlogopite also is characterized by significant mineralizedsamples (category E) displaysa tendency amountsof Ti, which is enrichedin F-poor micasfrom for an unusual, albeit weak, inverse relationship the barren"S6rie r6currente"and gabbro,as mentioned betweenthese compositional variables. Although this above.Barium commonlyis present but rarely exceeds observation seems to be a violation of the Fe-F 0.40 .xt.VoBaO. This conftastswith the considerable avoidancerule, it probably indicatethat the phlogopite amounts of Ba (up ta 7.86 wt.Vo BaO) found in equilibrated with fluids of different compositions muscovite of this deposit (Chabu & Bouldgue 1992). (Z'tu & Sverjensky1992). The occupancyof the l2-coordinatedsites is relatively When plotted in Xp and Xo6 space(Fig. 5), all the low, varying from L.44 tn 1.94 atoms per formula compositionsof phlogopite from the Kipushi deposit unit (aptu). Guidotti (1984) noted that an inverse fall in the field characterizedby Fe-F avoidanceand relationship exists between very high Xyn and total a random (disordered) distribution of octahedrally l2-coordinated cations. However, the plot of these coordinatedcations (Mason 1992),indicating that the compositionalparameters shows considerablescatter, maximum mol fraction of F that could be accom- castingdoubt on the existenceof the aboverelatio3 in modatedhas not been attained and that no Mg-F and the mica analvzed. Fe-OH clustersoccur. In general,phlogopite with a high Xo61value has a high Si contentand a low Ti content (Fie. 6). Guidotti et al. (1977) and Guidotti (1984) also havereported an antipathy between Si and Ti in biotite with high M/(Mg + Fe) values. In some mineral assemblages, theserelations are very poorly defined; in others, an 0.t4 particularly opposite relationship is found in ore- 0.r2 related,F-rich (categoryE) phlogopite (Fig. 7). In the phlogopitefrom Kipushi, the NAVSi ratio is less than 0.t0 1:3. Octahedrally coordinated Al shows a negative 0.08 correlationwith 4n Gig. 8), as noted by YaITeyet al. 0,00 (1982)and Munoi (1984).In this respec!uAl hasthe sameinfluence on F-OH exchangein biotite a$ Fe2+ 0.04 (hu & Sverjensky1991, L992).The variation in Xyn 0.02 valuesof phlogopitefrom the Kipushi depositis coml 0 parable to that observedin metamorphoseddeposits 8.8 6.? 6,9 5.8 0.0 0.1 8.2 8.3 al (e.9.,Nesbitt & Kelly 1980,Nesbitt 1982, 1986b). Ftc. 6. Relationshipbetween Ti and Si. Symbolsas in Fig, 3.

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X phl

0.90

0.s6

0.04

0.83

0.s2 0.24 0.28 0.28 030 0.32 0.34 0.30 0.18 0.40Vl^, 0 8.05 8.t0 0.16 A.20 8.26 8.30 si Ftc. 7. Relationship betweenliu and Si contents of ore- Flc. 8. Plot of proportion of octaheclrallycoordinated Al related,F-rich phlogopite (caiegoryE). versusXn6 of ore-relatedphlogopite.

Chlorite tions havebeen observed in metamorphosedCu-sulfide deposits @achinski 1976). They do not agree with Chlorite has very low F content (0 to 0.73 wt.Eo) compositional variations resulting from sulfidation comparedto the coexistingphlogopite. This confirms reactions (Guidotti et al. L99L), and suggestthat the that F is preferably partitioned in the mica. Figure 9 Md$dg + Fe) ratio of chlorite could dependon the Fe andTable 3 show a considerablerange in the composi- contentsof the associatedsphalerite. tion of chlorite, with XMevalues ranging from 0.32 to Although no chlorite was observedin association 0.84. Systematicrelationships with respectto the ores with the most Mg-rich phlogopite, the chlorite exist: the chlorite associatedwith iron-rich sphalerite compositionsseem to vary in antipathywith those of (up to 7.86 mol 7o FeS) as the dominantsulfide is phlogopite, which is more Mg-rich (Xun > 0.99) in the most Fe-rich(0.32 < Xyn < 0.76);that associated ores than in the host rocks, in agrebmentwith with chalcopyriteores is moie Mg-rich (Xun = 0.76), theoretical considerationson sulfidation reactions whereas that found in unmineralized shale of the (Thompson 1976u b, Nesbitt 1986a. Guidotti et al. "S6rie r6currente"is the richest of all in Mg (Xun = 1988, 1991) and with observationsmade in meta- 0.83, meanvalue). Similar trendsin chlorite compdsi- morphosedsulfide deposits(Koo & Mossman1975,

o. # o tt .F n^ lA Glinochlore field lP0. l1 o E^ o.40 I !i Chamosite field o.20

5.50 6.OO 6.50 7.OO 7,50 8 si ftc. 9. Chemicalcomposition of chlorite from tle Kipushi deposit.Symbols as in Fig. 3. Seealso Table 3 and Appendix 1.

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Nesbitt& Kelly 1980,Nesbitt 1982, 1986b). TABLE 4. F/OS D(CSANGE EQUU,IBBIIIM CON TANTS Despite the absenceof any textural evidence,the reversedpattern of the chlorite compositioncompared ABCDE to that of phlogopite may indicate that the chlorite Molar pFtprtlor associated with sphalerite is secondary in origin. xdl 0.70(0.01) 0.?0(0.02) 0.73(0.01) 0.e3(0.01) 0.s4(0.01) (1975) & 0.20(0.05) 0,02(0.014)0.07(0.03) 0.10(0.08) 0.68(0.06) However, Tewhey & Hess and Guidota,et al. xos 0.80(0.06) 0.98(0.014)0,93(0.03) 0.84(0.@) 0.42(0.$) (1975)have shown that the Mg/Fe ratio of chlorite and biotite are reversedin exfiemely Mg-enriched rocks. TsEp. log(f (sP) /f (tr) ) r! flqrd This could possibly apply to the dolomitic rocks that 2600C 7.M 8.13 ?.81 7.M 6.80 3000c 8.62 ?.60 7.08 7.08 6, host the Kipushi deposit. 3600C 6.08 ?.16 S.63 8.60 5.?6 Where coexisting, phlogopite and chlorite have 4@oc 5.?0 0.?9 a.2E 8.20 6.36 similar Xyn values, although the value of chlorite Valu6 ln lmt,hos FtrMmt om atmdatd dgvrsdo!. Iabels commonly is slightly higher by 0.02. This indicates (16tts A, it, C, D ud E) @msplal to dlfeEBt dreElumblaq{dreElumblags g (rc Ffg. it). Ai ev@ge Fgu.lt d xg sn6ly@i i BB! ! avmgs FsultNlt d B that chemical equilibrium may have been attained anatves; C: evoEgo Eult of 8 uslyEst DrD: aremgsaEpgs Fsult d 2 betweenthese minerals" which would castdoubt on the ualis; Er av€Eg€MuIt.f lSanalyss. oDfy&8fy@af F-b@!|!g DblogsFltopHo-eoFtie bavobave b€abea lnoluded lnfn th€th€-@l@ladoE. @l@ladoE. MolsD plstrpttt@plstrptd@ secondarynature of the chlorite mentionedabove. re-deterdlea ao@Daltlg to f,he foUowhg squtloE: XDhl = XBtbNft = The Si and 4'lro,6contents of chlorite are relatively eE llgltotafMd/t.hl exahednllymfrhdEllv @ldlnatsdmrdlnefed @d@iadtm! Xr'FX- F atodgatoEie @?offilapo?orfrla u!tt/4t lbE = OE @nlent trF! fomla u!tt/4. constantin all the mineral assemblages.This has also beenobserved by Guidotti et al. (L991).

F-OH ExcHaNcEEQIItr,BRIA between300 and 400"C. The biotite-chlorite isogradic reaction muscovite + dolomite + qu;artz+ water = A generalizedreaction for F-OH exchangeofbiotite biotite + chlorite + calcite + carbon dioxide, which with a fluid can be written as follows (e.g., Gunow seemsto apply to the mineral assemblagesfound in the et al. l9$O,Parry et al. L984): Kipushi deposit, was estimatedto occur at 370"C in OH(mica) + IlF(fluid) = F(mica) + HzO(fluid); the metamorphismof impure dolomite (Ferry 1976). the equilibriumconstant is Experimentaldata @awceu& Yoder 1966)indicate logK= log6tryog) mica + logffi2O)/"flI{F)l fluid. that magnesium-richchlorite is stablein a wider range Theoretical considerationsand experimental data of P-T conditions than Fe-rich chlorite. The stability (Munoz& Ludington1974, Gunow et al. l980,Yalley field of the latter is drastically limited under reducing & Essene1980, Valley et al. 1982,Munoz 1984,7h1 conditions at a temoeratureabove 350'C under a & Sve{ensky1991) on OH-F partitioningbetween a mica and a fluid phasehave establishedthat the F/OH ratio of biotite is dependenton (i) the fugacity ratio flH2OyflHF) of the fluid, (ii) temperature,and (iii) the fbmperature cation populationof the octahedralsites. Calculations of logffirOyflHF)l at temperatures oc varying from 250 to 400"C were madeusing equation logffiro)rtHF)l influid= LnQ37 | + I 100Xyn)+ A.433- log(Xy'X6s) 400 as discussedby Munoz (1992).Results are shownin Table4. Temperaturemay be inferred from observedassem- blages of metamorphicminerals: (i) dolomite, albite, 350 muscovite, quartz, phlogopite and chlorite in ores, (ii) dolomite,quartz, alAite, talc, magnesite,phlogopite in gypsum aad anhydrite-bearingdolomite, and (iii) phlogopite,chlorite, quartzin shalesof the "S6rie 300 r6currente" above the mineralization. These mineral assemblagessupport the suggestionby Lefebwe & Patterson(1982) tlat the Kipushi depositis locatedin \$ the biotite zone of the regional metamorphism. Available experimentaldata (Winkler L965, 1.967, Puhan & Johannes 1974\ and studies of meta- Los(l(H2of /f(HFlt inrluid morphosedcarbonate rocks & Smith 1975, @insent Log contoursdefining the fluid phase Ferry 1976,Rice 1977,Bowman & Essene1982) arc Ftc. 10. KI{rO)/flI{F)l coexisting with phlogopite of different fluorine cont€nts consistentwith the fust developmentof biotite, undera involved in the five mineral assemblagesdescribed in water pressure of a few kilobars, at temperature Fig. 3. Labeling as in Fig. 3.

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pressureof I kbar. SinceFe-bearing chlorite is present may be ascribedto ore-forming processesor to meta- in the reducing environmentof the Kipushi ores, it is morphic processes.The secondhypothesis is preferred reasonableto assumethat the temperaturethat affected becauseof the presenseqf similar assemblagesof the deposit during the Katangan regional meta- metamorphicminerals beyond the zone of mineraliza- morphismwas below 350"C.The amountof rvAI in the tion, occurring on a regional scalefrom the Zambian chlorite (half formula) suggests that this mineral segmentof the Copperbelt to the Kipushi area and formed at a temperaturevarying from 287 to 331'C through to the Musoshi area (kfebvre & Patterson (Cathelineau& Nieva 1985,Cathelineau 1988). This is 1982). Moreover, widespreadstructural and textural in agreementwith Cluzel's (1986) estimateof the P-T features relatable to the Katangan regional meta- conditionsof the Katanganregional metamorphismin morphismindicate that the depositis premetamorphic the area. in age (Chabu1990, Chabu & Bouldgue1992). This Given theselimiting conditions,it is assumedthat is supported by the variations h Xrr,rnvalues of F-OH exchange reactions took place at tempera- phlogopite, which can be attributedto indreasingflF) tures between 300 and 350'C. Variations of andflS) towardthe orebodyduring the metamorphism loglrtHrOyflT{F)] both within and between different ofthe deposit(Hutcheon 1979, Nesbitt t986a" b). mineral associationsare shown in Figure 10. This Investigations of metamorphic paragenesishave indicatesthat at any temperature,the relative activity of shown that the fluorine content of hydrous minerals IIF is higher in ores (curvesA and E) than in baren dependsdirectly upon the amountof fluorine presentin rocks (curves B, C and D). The variation in log the premetamorphicprotolith (Valley et al. 1982, fugacrtyratio within the oresindicates that the compo- Guidotti 1984). This fact suggeststhat fluorine in sition of the fluids with which the mica equilibrated phlogopite was inherited from the breakdown,during varied significantly. the Lufilian metamorphism,of fluorite or some other F-rich precursor present in the sulfide assemblages. CoNcLUsIoNs Variation in F contents of phlogopite reflects an inhomogeneousdistribution of fluorine-rich minerals The datapresented in this paperclearly indicatethat in the oresprior to regionalmetamorphism, resulting in the compositionof phlogopiteand chlorite is a function variableF/OH activities in the metamorphicfluids. of mineral assemblageand that chemical equilibrium The composition of the phlogopite and chlorite is has been attainedamong the different phasesof each thus a function of mineral assemblages,oxygen, sulfur association. and IIF activities. Taken in conjunction with regional Earlier, it was noted that the Xrn of phlogopite metamorphicsetting, they provide additionalevidence varies slmpathetically with Si and tfat Ti decreases that the mineralization predatedthe Lufilian foldine with increasing Si. This compositional variation is and metamorphism. obviously controlled by crystallochemicalfactors and involves a Tschermakexchange (Mg, Fe2+)+ Si = uAl ACKNOWLEDGEMENTS + rvAL and possibly also the scheme2(Mg, F&+) = rvTi + vlfl (Guidotti 1984). The manuscript has benefitted considerably from The pattern of variation h Xu" in phlogopite comments, suggestions and criticism by Drs. J.L. agreeswith a control exertedby sulfi-dationreactions, Munoz, C.V. Guidotti, R.A. Mason and R.F. Mafiin. whereasthe compositionalvariation found in chlorite, Sincere thanks are also due to the Laboratoire de althoughsimilar to that observedby Bachinski (1976) G6ochimie et M6tal1og6nie, Universit6 Paris VI, for in metamorphosedcupriferous iron deposits,is un- tectrnical, analytical and scientific assistance. expectedas far as sulfidation reactionsare concerned (Guidotti et al. 7991).The dataseem to suggestthat the RBrsnsNCEs Fe contentof chlorite dependson the concentrationof iron in the coexistingsphalerite. BAcm.rsK, D.J. (1976): Meta:norphismof cupriferous iron The relationshipbetween {0, andF concentrationin sulfide deposits,Notre Dame Bay, Newfoundland.Ecoz. phlogopiteis compatiblewith the existenceof a field of Geol.7l.M3452. Fe-F avoidancein the compositionalfield of biotite. BowrraaN,J.R. & EsseNE,E.J. (1982): P-T-X(CO) condi- Despite its very high levels, F is not at its saturation tions of contactmetamorphism in the Black Butte aureole, level in phlogopiteowing to the highXy" valuesof the Elkhom, Montona.Am. J. Sci.282,311-340. mica. That the fluorine contentsof the fluids with which Caum.nwau, M. (1988): Cation sile occupancyin chlorites phlogopiteequilibrated within the Kipushi mineralized and illites as a function of tempenfire. Clay Minerals ?3, sampleswere high is shownboth by the extremelyhigh 4',n485. concenftationsof fluorine in mica and by the corre- & Nmva, D. (1985): A chlorite solid solution spondinglylow calculatedlog fi:gacity ratios. geotherrnometer.The Los Azufres (Mexico) geothermal The generationof phlogopite and chlorite in ores syslem,Contrib. Mineral. Petrol. 91, 235-244.

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CHABU,M. (1990): Metamorphismof the Kipushi carbonate Imouar.s, M.M. (1982): lz gisemzntbt-Pb-Cu de Kipushi hosted Zn-Pb{u deposit (Shab4 Zatre). In Regional (Shaba. Tatre). Endes g6ol'ogi4w et mltallog4niquc. Metamorphismof Ore Deposic and Geneticlmplications Thdsede doctora! Univ. Catholiquede Louvain, Louvain- (P.G.Spry& L.T. Bryndzia eds.).VSP, Utrecht, Holland la-Neuve.Belgique. (n47. - & Oosrunnosctt,R. (1974): Gdologieet g6ochimie & Bour.EcuE, J. (1992): Barian feldspar and du gisementde Kipushi, 7a'ire.In Gisementsstratiformes muscovite from the Kipushi Zn-Pb-Cu deposit, Shab4 et provinces cuprifbres (P. Bartholom6, ed.). Socidtd 7ane. Can.Mineral. n, lt 43-1,152. G6ologiquede Belgique,Libge, Belgique (123-lM).

Cuzn-, D. (1986): Contributioni 1'6tudedu m6tamorphisme JAcoBs,D.C. & Pannv, W.T. (199): Geochemistryof biotite des gisements cupro-cobaltifdresstratiformes du Sud- in the SaataRita porphyry copper deposit,New Mexico. Shaba Zahe. Le district minier de Luisha. Earth "I. \fr. Econ.GeoI. 74. 860-887. Sci.5,557-574.

DnER,W.A., HowE, R.A. & ZussMAN,I. (1962): Rock- Koo, J. & MossIraaN,D.J. (1975): Origin and metamorphism Fonning Minerals.3. SheetSilicates. Longmans, London, of the Flin Flon strataboundCu-Zn sulfitle deposit" U.K. Saskatchewanand Manitoba.Econ. Geol, 70.48-62.

DB Macrt'n, I. & FRANqoIs,A. (1988): The origin of the Lmml'nq JJ. (1975):Les rochesign6es dans le Kataagiendu Kipushi (Cu, Zn, Pb) deposit in direct relation with a Shaba Zarre, le district du cuiwe. Soc, G6ol. BeIg., hoterozoic salt diapir. Copperbelt of Central Africa, Annales98.47-73. Shaba,Republic of Zanre,Ir BaseMetal Sulfide Deposits (G.H. Friedrich & P.M. Herzig, eds.). Springer Verlag, & PerrsnsoNr,L.E. (1982): Hydrotherrnalassem- Berlin, Germany(ru,-93). blage of aluminian serpentine,florencite and kyanite in the Zairian Copperbelt.Soc. Gdol. Belg,, Annales 105, Fewcrrr, I. & Yoonn, H.S. (1966): Phaserelationship of 5l-7t. chlorites in the system MgG-AI2O3-SiO"-H2O. Am. Mineral.SL, 353-380. MAsoN, R.A. (1992): Models of order and iron-fluorine avoidancein biotite. Can.MincraL 30, 343-354. FBRY, J.M. (1976): Metamorphismof calcareoussediments in the Waterville-Vassalboroarea. south central Maine: mineral reactionsand graphicalalalysis. Az. J. 9ci.776, MuNoz, J. L. (1984): F-OH and CI-OH exchangein micas 841-882. with applicarionsto hydrothermalore deposits.Ia Micas (S.W. Bailey, ed.). Rev.Mineral. 13, 469493. Guoor-n, C.V. (1984):Micas in metamorphicrocks. /n Micas (S.W. Bailey, ed.). ftey. Mineral. 13, 357467. -(1992): Calculationsof IIF and HCI fugacitiesfrom biotiG compositions:revised equations.Geol. Soc. Am", CnENEy, J.T. & CoNAroRB,P.D. (1975): Abstr.Prograns ?4, Mzl. Coexisting cordierite + biotite + chlorite from Rumford Quadrangle,Mune. Geology3, I47 -1.48. & Luonvorox, S.D. (1974): Fluoride-hydroxyl exchangein biotite. Aa J. Sci.Tl4,396413. & GuccsN'HEn4,5.(1977): Distribution of titanium betweencoexistins muscoviteand biotite in - & - (1977):Fluorine-hydroxyl exchangein pelitic schistsfrom northwesternMzine. Am. Mineral,62, synthetic muscovite and its application to 438448. muscovite-biotite assemblages.Am. Mineral. 62, 304-308. & IIsNRv,D.J. (1988):Compositional variations of biotite as a function of metamorphic Nrss[T, B.E. (1982):Metamorphic sulfide-silicate equiJibria mineral reactionsaad assemblagein the pelitic schistsof in the massivesunde depositsat Duclitown, Tennessee. westemMaine. Am, J. Sci,2EEA"fl0-292. Econ.Geol. 77,36+378.

Tuc*rerw, F. & HENRv,D.J. (1991):Chlorite- (1986a):Oxide - sulfide - silicate equilibria asso- bearing polymetamorphic metapelites in the Rangeley ciated with metamorphosedore deposits.I. Theoretical are4 Maine: evidencefor equilibrium assemblages.,{rn considerations.Econ. Geol. 81, 831-840. Mineral.76.867-879. (1986b): Oxide - sulfide - silicate equilibria asso- Gulow, A.J., Luonqcror, S.D. & Murqoz, J.L. (1980): ciated with metamorphosedore deposits.tr. Pelitic and Fluorine in micas from the Henderson molybdenite felsic volcanicterrains, Econ. Geol.81, 841-856. deposifColorado. Econ. Geol. 75, ll,n-lBl . & Ksrv, W.C. (1980): Metamorphiczonation of HLqcHBot{,I. (1979): Sulfide - oxide - silicate equilibria; sulfides,oxides and graphitein and aroundthe orebodies SnowLake. Manitoba. Azn J. Sci.2i19.643-665. at Duchown. Tennessee.Econ, Geol.75. 1010-1021.

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PARRv,W.T., Ber,urrrne, J.M. & Jacoss, D.C. (1984): Vemv, J.W.& Essu.,'r,E.J. (1980): Calc-silicate reactions in Geochemistryof hydrothermal sericite from Roosevelt Adirondackmarbles: the role offluids and solid solutions: Hot Spring and the Tintic and SantaRita porphyry copper sunmary (parts I and n). Geol. Soc. Am., Bull. 91, sysbm.Econ. Geol. 79, 72-86. tt+117,720-815.

PE{sENr,R. & SMnH,D.G.W. (1975):The developmentof Pr-rsnssN,E.U., Essnwe,E.J. & Bowuar, J.R. carbonatebearing biotite isograd assemblagesfrom Tete (1982): Fluorphlogopiteand fluorremolite in Adironclack Jaune Cache,British Colombia Canada.Can. Mineral. marbles and calculated C-O-H-F comoositions. Azz. 13,151-161. Mineral. 67,545-557.

PUHAN, D. & JouarwBs, W. (1974): Experimentelle WINIoER, H.G.F. (1965): In genbsede roches mltam.or- Undersuchungder Reaktion Dolomit + Kalifeldspat + phiques.Springer Verlag, Berlin, Allemagne. HrO = Phlogopit+ Calcit + CO2. Contrib. Mineral. Petrol. 48,23-31". - (1967): Petrogenesk of Metamorphic Rocks (secondedition). SpringerVerlag, Berlin, Germany. kce, J.M. (1977): Progressivemetamorphism of impure dolomitic limestonein the Marvsville aueole. Montana. ZAw, U.K. & Cmm, A.H. (1978):Fluoride-hydmxyl ratios Am-J. Sci.n7, L-24. of skam silicates, Cantung E-zone scheelite orebody, Tungsten, Northwest Territories. Can. Mineral. 16, Tnwrnv, J.D. & Ilrss, P.C. (1975): Continuousmetamorphic 207-221. facies charges as related to chlorite disappearancein a contact metamorphic aureole. Geol. Soc. Am., Abstr. Zil, CnEr.r& SrnnruNsrv, D.A. (1991): Partitioningof Programs7,80. F-CI-OH between minerals and hydrothermal fluids. Geochim-Cosmochim. Acta 55. 1837-1858. TsotlapsoN,A.B. (1976a):Mineral reactionsin pelitic rocks. I. hedictions of P-T-X(Fe--Mg) phaserelations. Ant J. Sci. & - (1992):F{I-OH partitioningbetween n6,401424. biotite and apatite. Geochim, Cosmochim. Acta 56, 3435-3467. (1976b): Mineral reactions in pelitic rocks. II. Calculationsof someP-T-X@e-Mg) phaserelations. Az. J. Sci.276,425454.

UNRUc,R. (1988):Mineralization controls and sourceof met- als in the Lufllian fold belt" Shaba(Zaire), aad Received August 23, 1993, revised manwcript accepted Angola.Econ. Geol. 83, 1.247-1258. October25. 1994.

APPENDIX 1. MINEBAL ASSEIOBLACSI IN TEI SAUPI,EI ANAI,YZED

SaEt)ls Bock d$orlpdoD

1160? Cebbe fE$n€ot d tlle adat zore of t!6 Ktpcbl b$da. coEtrpdtlo!: phlogoptte' alblte' tromllte' hombtrende, oblodtr, quutz' slddote sd Dho! hMttts, rutile, ahal@trt:Elts' qlcdte. Bam. 780200/2 Bam shsl6 d t-ho upp€! part of th€ nS6rls r6stt€nter. It l,E oqmd of stlotte ud finegalnedcafodteud qustz. Pods of ffigralnsdpblogoptte, quutz, dolodto ual ahlodtE @ s@tt@d ln tle gmdEasg. ODly th@ @ gnlE re earYzed. n96rle ?502351 Grsrr dolod,te f!@ ths upp€! IEt of the rr6oumte'. c@IpsitloD3 dolodta' talo, albtto, nAgh6lt6, qusts, phlogoplte, wlth leme of 54psu md anhydrlte. Bam'- S921816 oe samtrle. MheEuzed bmda soEIFs€d od fEg@ts of shals ed doloEtto. IloloElto' orlflalE foremle ud awry qwtz fom tlle mirlx. cbsf@Ityrtts ls the do4'u] eulfi.ile; rcnogryritemalglrhal*lt€ep@t. Phloggptteudchlorlte@l@-tedi!'tbo mtr.lx ed e l[torgrcm wtt! ohalaopyrlts. Pblogepite te @rrcdod by chal@pydta' dolodts ed qustz. ES Ote srple. Bscde onpqsd d debrlg of Uptrnr Kakontre oborc dolodte md fmgrs[a8 of ghsle d tbe is6ldE r€mnten, @n€nted by F€-trnr sphalstlt€' rblqh lnolualos pyrtt€, amoplElts, chal@lrydtg, galm, te@ttt€ md borit€ 8Els. Phlogofrtte ls €eb€dded ln sBhaleltts mat ts sttongly @md€d by tt. N@fomEd r|evfte ts prcot both to dololdte md 6hals fEgnets. C@-gmhsd qurytz ud dolodt€ @ also pmet la tllE @trlx, Kg 102 Mnenilfzed easple. The t!a& ls a nodlu!- to @-gBl!€d dolodts wltll s'!'{.layor of shab, arnpbSrlng a dsEfold. It t8 drenllzed botL t! tlrc gMd@ ed h flssrrB. Chal@Irydte ls tl€ dodamt guJf,alEdaml' whg@ plEtt€, mololtJElts ed borl-te e dmr. Phlogoptte l,Etot€rgm with obal@pydt€' doloElto ed quartz md fom Edlatlng flake la velu. 811S !fllsmltzod bmods. The fEgmmts re dErlyed frm a flne-gmlned 8edstm (tlle nlaEbaun, 66 tgxt) ed shale of tle n86rle r€mtsn. Th€ @trlx !s mtly @EIE8€d d Fertoh sphalerlts ud quartz. Chlorlte ed mmYlte a18o@ p@t. 8114 qF -"10!ei bmcda m fmgmts of thale that The @jo! @;sd.tudts dt thls "fnmll'ed @taln oltstsd srtcdt€. Th6 laterfrag@tal volds m fflled W blom FForlchBd strrhaler.lte; quetz, ru@yite, ahlodt€, albtt€, dolodto. 8118 Tbls eqile bq" a nodal @EtrFgldon ddlai to thet d tbe prtedlng gople (8114).

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