Canadion Minerologist Yol. 29, pp. 207-215(1991)

ROOUESITE.BEARINGTIN ORESFROM THE OMODANI. AKENOBE,FUKOKU, AND IKUNOPOLYMETALLIC VEIN-TYPE DEPOSITS IN THEINNER ZONE OF SOUTHWESTERNJAPAN

MASAAKI SHIMIZU UniversityMuseum, University of Tokyo, Tokyo 113,Jopan

AKIRA KATO National ScienceMuseum, Tokyo 169,Japan

ABSTRAc"I Mots-dAs.roquesite, gisements polym6talliques en fissu- res,isotopes de soufre, activitd du soufre,temperature, Indium- mineralization is observedin the Omodani, Omodani,Akenobe, Fukoku, Ikuno, Japon. Akenobe, Fukoku, and Ikuno deposits,which are Cu- dominant polymetallic veins of late Cretaceous to early Tertiary agein the Inner Zone of southwesternJapan. The INrnooucrIoN indium-tin-bearing oresare commonly composedof roque- site (CuInS2), , , - Sincethe first report of the occurrenceof roque- tetrahedrite, and quartz, with local , site in Japan, from the Eisei vein of the Akenobe mawsonite, and arsenopyrite.The content of deposit (Kato & Shinohara 1968), no additional the sphaleritethat coexistswith roquesite,stannoidite and roquesitehas beendescribed. This report documents tennantite-tetrahedrite is very low. Temperatures of for- new occurrencesof roquesitein tin ores from the mation based on fluid-inclusion quartz data on from the Omodani Pref.), Akenobe(Hyogo Pref.), Omodani and Akenobe depositsare in range @ukui the the from 285o (Kyoto to 3looc. The 6:+5values ofthe roquesite-b-earingtin ores the Fukoku Pref.), and the Ikuno deposits are virtually constant (-0.8 to +0.3y65). Basedon these (Hyogo Pref.), in the Inner Zone of southwestern descriptions, possible ranges in activity during for- Japan. These deposits are subvolcanic-type(e.g., mation of the roquesite-bearing tin ores are estimated to Schneiderhdhn 1955) Cu-dominant polymetallic be approximately l0-8 to l0{ atm., and the temperature veins.The indium-bearingtin oresare characteristi was greater than 285oC. cally composedof roquesite, stannoidite, sphalerite, membersof the tennantite-tetrahedriteseries, bor- Keywords: roquesite, polymetallic vein-type deposits, sul- nite and chalcopyrite. Stanniteand kesteritehave not fur isotopes, activity of sulfur, temperature, Omodani, been found. Information possible of Akenobe, Fukoku, Ikuno, Japan. on activiry sul- fur and temperatureof formation of the roquesite- bearing ores can be estimated on the basis of SoMMAIRE electron-microprobeand thermochemicaldata, and fluid-inclusion data obtained on the coexisting Une min€ralisationi indium-dtain a &6 documentdedarrs quartz. les gisementsde Omodani, Akenobe, Fukoku et lkuno, tous des systbmesde fissures polym6talliques d dominance de Cu, d'6ge cr€tac6tardif d tertiaire pr6coce, situ6s dans la DnsczuprronoN Tm DEPosrrs zone interne du Sud-Ouestdu Japon. Le minerai i In-Sn contient couramment roquesite (CuInS), stannoidite, AND ORE MTNTNANOCY sphaldrite, tennantile*t6tra6drite, chalcopyrite et quartz, ainsi que bornite, mawsonite, gal&neet ars6nopyriteacces- The Omodani, Akenobe, Fukoku, and Ikuno soires. La teneur en fer de la sphaldrite en coexistenceavec deposits are located in a former tectonically active roqucite, stannoiditeet tennantite-tetra€driteest trb faible. zone called the Maizuru belt or the Hida marginal D'apr0s les donndessur les inclusions fluides du quartz des tectonic belt, betweenmetamorphic and nonmeta- gisementsd'Omodani et d'Akenobe, la temp€raturede for- morphic belts (Fig. 1). The Maizuru belt probably mation du minerai aurait 6te entre 285 et 3l0oC. Ls valeurs was a convergent plate margin during the late de FaS du minerai d'6tain contenant de la roquesite sont Paleozoic.Granitic batholiths, ultramafic rocks, and i peu prds constantes(-0.8 e + 0.3700).L'activit€ en sou- pelitic fre au cours de la formation du minerai aurait €t6 d'envi- rocks with lignite exist in the vicinity of each ron l0-8 i 10-6 atm., et la tempdrature, sup6rieurei deposit. The specimensare describedbelow, and 2850C. have beendeposited at the University Museum of the University of Tokyo and National Scienc€Museum. (Traduit par la R6daction) Some were collectedby the presentauthors. 207

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of 56.9 t 2.8 Ma and 51.9 x. 2.6Ma, respectively (Ministry of International Trade and Industry of Japan 1980). Total productionof the depositfrom 1888to 1966 was4.4 x 105tonnes of ore with averagegrades of 1-5 7o Cu, 3-20 oloZn,4-6 {o Pb, and 85 grams per tonne of Ag. Ore specimensstudied are largely composedof bornite, sphalerite,tennantite, stannoi- dite, chalcopyrite,and small amountsof ldllingite, HIDA BELT mawsonite,galena, and nativesilver (Table l). Gan- gue minerals are quartz, chlorite, fluorite, K- feldspar of the adularia habit and calcite. Roque- site is associatedwith bornite, sphalerite,stannoi- dite, mawsonite, galena,and arsenopyrite(Fig. 2A).

Akenobe Cu-Zn-Sn-Ag deposit

The geologyof the Akenobemining district, Oya- cho, Yabu-gun,Hyogo Prefecture,has been studied by Kato (1920),Saigusa (1958), Muraoka & Ikeda (1968),Kojima & Asada (1973),Sato e/ al. (1977), RYOKEBELT I and Shiozawa(1984). It is located in the Maizuru 136'0 , 5o rookm belt betweenthe Sangunmetamorphic belt to the north and the unmetamorphosedMino-Tamba belt Frc. l. Locationsoftlte Omodani,Akenobe, Fukoku, and to the south. The products of mineralization are Ikunodeposits in theInner Zone of southwestJapan. hosted in sedimentaryand volcanic rocks of the Maizuru Group, of Permian age. K-Ar agesof dikes from the district indicate that the post-ore felsite Omodani Cu-Zn-Pb-Ag deposit (granophyre)is 57.8 + 2.9 Ma and 52.6 t 2.1 Ma, and the pre-orerhyolite is 72.8 r 2.9 Ma (Ishihara Omodani is located at Izumi-mura, Ono-gun, & shibata 1972). Fukui Prefecture, in the Hida marginal tectonic belt Total productionfrom 1935to 1986is 1.7 x 107 betweenthe Hida metamorphiccomplex (Hida belt) tonnesof ore, and averagegrades are I . I 9o Cu,2.00/o and the nonmetamorphicrocks to the south (Mino- Zn,0.4VoSn, and 20 g/t of Ag. Roquesitewas dis- Tamba belt). The veinslie within the Omodani rhyo- coveredin the N 2l stope, -8th level of the Eisei vein lite (Kawai 1956),correlated with the Nohi rhyolite of this deposit, where it occurswith chalcopyrite, (Makiyama et al. 1975), which covers Mesozoic quartz and siderite (Kato & Shinohara 1968).The sedimentaryrocks. The Omodani rhyolite is mainly roquesite-bearingores used in this study wererecently composedof weldedtuff (70-75 wt. 9o SiO), tuff collectedfrom the l4th level of the ChiemonNo. 4 breccia,tuff (71-75 wt.9o SiO), and granite por- vein, and are principally composedof sphalerite, phyry (ca. 77 wL.tloof SiO2).The K-feldspar from tetrahedrite,stannoidite, bornite, chalcopyrite,and the weldedtuff and granite porphyry givesK-Ar ages lesseramounts of mawsonite,galena, ferberite, cas-

TABLE1. FIINEMLASSEI'tsLAGE OBSERVED IN SPECII'1ENS STUDIED AND MNGE OF FE".NN(ATOilIC)

Ore DelpElt Sp Tn-Td Rq Sd cp Others OBodEni ++ ++ ++ + ++ Lo,Ap,Mw,Gn,Ag Fez- /Zn o.ool" o.2a-o.37 0.07-0,32 lffi. wt..8 In (.) 0.83 (16) 0.07 (19) 0.02 162) (8) 0,09 (10) 0.09 (13) Alenebe ++ ++ i + ++ + Msrcn Fez' / zn 0. 003-0.005 0 . 03-0. 12 0. 05-0. 38 w. sL.$ In (*) 0.48 (e) 0.05 (19) 0.03 (e) (10) 0.11 (11) 0.08 (8) Fukoku a+i + ++ + Mw,l'ld Fez' / zn 0.004-0.015 0.88-1.25 o.45-O.72 nax. rf.8 In (r) 0.08 (20) 0.98 (12) (6) o.30 (14) 0.21 (33) Ikune. *+ + ++ + Aprcn gez* / Zn 0.016-0.036 1.65-2.00 0.97-1.49 &ax. $t..9 h (*) 1.61 (7) 0.09 (10) (15) 0.13 (23) 0.31 (35)

tbbr€viatlong: Ag nativ€ ailver, Ap areenopyrlte, Bn bornlt€, cp chaLcopyrite, cn galena, I- loLlingite, ltd mtlldlte, Ms nausonite, Rq roqueglte, Sd Btmoidite, gp sphalerite, Tn-Td temiltite- t€trahedrite ++ comon, + lesa comn. .) nuober of enalysis aa) sphalerl-te tmr€st Ln Cui there are &any tiny chalcopyrite inclusions in gphalerite.

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siterite, scheelite, and an undetermined Ni-Co sul- l.l VoCu,2.2t/oZn,0.4t/0Pb,0.3 Vo Sn, 58.3e/t (Table fide 1, Fig. 2B). Gangueminerals are quafiz, Ag, and A3 g/t Au. The ore specimensused in this fluorite, and siderite. study are composed of roquesite, stannoidite, sphalerite, tennantite, chalcopyrite, and small Fukoku Cu-Zn-Ag deposit amounts of arsenopyrite, galena and quartz (Table I, Fig. 2D). Fukoku also is situated in the Maizuru belt, ar Miyagai, Fukuchiyama City, Kyoto prefecture. The Cnslttcar CovpostrtoN oF CoExIsrINc SuLrrle mining district is geologicallycomposed of sandstone MTNSRALSrN In-Sn Onr with subordinate shales of the Triassic yakuno Group. The Kumohara granite, of probable late Cre- The chemical composition of coexisting minerals taceousage, and severalmasses ofultramafic rocks in the roquesite-bearingore was determinedusing occur near the deposit. a JEOL 733II electronmicroprobe analyzerat the The ore specimensstudied consist of roquesite, GeologicalInstitute, Faculty of Science,Universfuy sphalerite, stannoidite, tennantite, chalcopyrite, and of Tokyo, using the methodsof Shimizu et sl. (1986), small amounts of mawsonite, selenium-bearing matildite (up to 4.7 wt.9o Se), and quartz (Table l, Roquesite and chalcopyrite Fig. 2C). Cosalite,boulangerite, and nativebismuth have been reported in the deposit (Shimizu et al. Representativechemical compositionsand atomic 1966). proportions of theseminerals are given in Tables2 and 3, respectively.All the grains examinedaxe com- Ikuno Cu-Zn-Pb-Sn-Ag deposit positionallyhomogeneous. Slight substitutionof Fe for In in roquesiteis suggested,whereas that of In The Ikuno mining district, locatedat Ikuno-cho, for Fe is very limited in the associatedchalcopyrite. Asako-gun, Hyogo Prefecture, 17 km southeastof the Akenobedeposit, occurs in Cretaceousrhyolitic Stqnnoidite and andesiticvolcanic and pyroclasticrocks of the Ikuno Group. The geologyand mineralizationwere Stannoidite is essentiallyhomogeneous in most describedby Maruyama (1957). K-Ar ages from cases,but the F€* /Zn ratio varies significantly adularia from the deposit are 63.3 t 1.9 Ma, 65.6 (Table 4), indicating the presenceof material with x. 2.0Ma, and 70.5 a 2.1 Ma (Ministry of Interna- the id_ealformula Cur(Zn,Fe)Fe]+Sn2S12,where Zn tional Trade and Industry of Japan, 1984). > Fe4*, inferred following referenceto the method Total production ofthe depositduring 1940-1973 of calculationof the F&+ /Zn ratio in this mineral was 6.9 x 106tonnes of ore with averagegrades of by Shimizu & Shikazono (1987).

TABLE2. REPRESEI,ITATIVECHEI.IICAL COI{POSITION OF ROOUESITE

NErC&r FEBCBNT ATOUIC - Oao f,lED. PROPORTIoN (IOTAL ArOt{S 4) 9g Ag !E zD cd u! Io g Total Cu Ag Fo OEod.ad z\ Cd !4! In S 25.44 0.03 0.34 0.30 0.03 o.o1 46,2! 25.OO SS.35 1.014 0.001 0.015 25.s9 0.00 0.32 0.32 qa,zs gg.iz 0.011 0.001 o.ooo 0.981 1.976 0.07 o.o0 za.t) 1.016 0.000 0.016 0.012 0.001 o.ooo o.s7a !.9.1., 26.54 0.00 0.48 0.25 0.04 o.02 as.az za.8 sg.18 1.018 0.000 Aterob€ 26.24 0.021 0.009 0.001 o.o01 0.972 r.s7a o.Lt 0.30 0.34 0.06 o.o1 aa.$ z6.is gg.za 1.000 0.002 0.013 0.013 25.92 0.08 0.30 0.45 o.03 0.001 o.ooo 0.973 1.99? o.01 ea.sa za.si ta.Bs 0.986 0.002 0.013 0.017 o.OO1 o.O0o 0.980 2.001 26.r7 0.0r 0.41 0.40 0.05 o.o1 es.ta za.ii ,;:0; ' 24.9 - - 1.003 0.000 0.018 0.015 0.001 o.ooo 0.9?o 1.993 1.8 0.1 o.2 46.3 as.i ,r:o- 0.96 - 0.08 0.00 - Fu*oLu 25.2t 0.73 0.46 0.10 0.04 o.02 o.oo 0.99 1.96 ao.e: :o.ez r0o.ao 0.992 0.003 0.020 0.004 0.001 0.001 0.981 2.OOO 25.08 0.08 0.sl 0.05 0.0s o.03 ae.zs za.tt ioit.ii 25.52 0.15 0.86 0.94? 0.002 0,022 0.002 0.001 o.oot o.9ao 2.005 0.05 0.05 o.03 as.z: zs-os inn'ii-i6 1.012 0.003 0.037 0.002 Xkuao 26.30 0.09 0.46 0.31 0.os o.04 as.ae zs-rz iA 0.00r o.o01 0.974 1.969 26.4s o.os 0.54 1.007 0.002 0.020 0.011 0.001 0.002 0.972 1.985 0.3s 0.06 o.04 a5.Bo 25.14 ,6.fi r.005 0.001 0.024 0.013 26.3s 0.33 0.90 0.19 0.05 o.02 es.ge 0.001 0.002 0.9?1 1.983 zo.:g ro6.ii 0.999 0.007 0.039 0.00? o.oo1 0.001 0.964 1,.sA2 a' Aato & ALbohala (1968)

IABT"E]. REPRESEIITATTVECHHI1ICAL COMPOSITIOT{ OF CHALCOPYRITE pBoponuon ole cu Ag pe ,ft"To*"T"* Aroulc (m!At -!,To!ts € 4) oedsl-f,bp. s rn rotar sAgF6z^cdt{nsIu 34.76 o;06 29.e5 o.o1 o.oo il,oa le.to 6]o1 34.7e 0.03 99.65 1.009 0.001 0.9a9 0.000 0.001 0.001 1.998 0.OOO 29.82 o.o3 o.o: o.oi :,i.ie o.io ss.75 r..007 0.001 34.?3 0.06 2e.61 o.r4 o.oe 0.982 0.001 0.001 0.001 2. oo5 o. oo1 AkenotE o.oi i.i.ii o.dz ee.38 1.009 0.001 0.981 0.004 0.001 o.oo1 1.99? 34.43 O.0o 30.46 0.01 o.Oe o.Oi :i.gi o.de O.OO1 34.6e 0.07 30.4e 99.99 0.994 0.000 1.001 0.000 0.001 o.oo1 2.ooo o.oo1 o. 04 o. os o. or ii. gi 6. dr roo.31 1.000 0.001 34.47 0.00 30.0e o.04 o.04 1.000 0.001 0.ool, o.ool 1.995 o.OOO Fukoku o.02 ,i.i; 6:i7 ee.4s 1.002 0.000 0.995 0.001 0.001 0.001 2.ooo o.oo1 34.30 o.02 30.31 o.s2 a:0d 0.oo iil6i 6li: 34.3s 0.00 1oo,04 0.991 0.000 0.997 0.015 0.000 0.001 1.995 o.OOO 30.24 o.os o.03 o.03 :i.at o:04 ee.6e 0.996 0.000 0.996 34.68 o.os 2e.97 o.oe. o.o2 0.002 0. o0o o. oo1 2.002 o. o0o rkuo-. o.oz li.si i.is ee.51 1.007 0.001 0.991 0.002 0.000 0.000 I.992 o.oo2 34.59 0.16 30.29 0.06 o.oz o.oi :,i.so o.ig 34.50 0.02 r00.21 0,998 0.003 0.994 0.002 0.000 o.ooo 1.996 o.OO3 30.06 0.03 o.oe o.o: ri.oe o.ig 99.5? 1.002 0.000 0.993 34.51 0.02 2e,92 o.o4 o.o2 0.001 o.oo1 o.ool 1.997 0.003 o,o2 ii.ir 6.io es.40 1.003 0.000 0.989 0.001 0.000 o.oo1 1,999 o.OO3

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TABLE4. REPRESENTATMCHEI.IICAL C0MPOSITION 0F STANNOIDITE

VIEIGBT ?ERCENT Ore Dsp. Cu Ag I'e Zn Cd Mn Sn S In Total Onodani 39.2L 0.02 9.63 4.35 0.06 0.01 LA.25 2A.7A 0.00 100.32 39.16 0.01 9.50 4.23 0.09 0.02 18.51 2A.79 0.09 100.40 39.02 0.01 9.53 4.18 0.09 0.04 18.39 24.73 0.07 100.05 Akenobe 38.46 0.01 9,25 4.13 0.09 0.01 18.16 29.04 0.06 99.2I 38.84 0.06 9.27 4.43 0.06 0.01 18.13 29.4L 0.00 100.20 38.90 0.05 9.76 3,74 0.09 0.01 LA.44 29.37 0.03 100.39 Fukoku 38.56 0.03 10.25 3.05 0.03 0.01 LA.26 29.29 0.10 99.56 38.81 0.06 10.25 2.9L 0.01 0.06 18.56 29.5A 0.17 100.41 3A.47 0.02 10.3? 2.92 0.04 0.03 18.58 28.35 0.09 99.92 Ikuno 38.83 0.O2 11.00 2.20 0.05 0.03 18.52 29,40 0.07 100.13 38,77 0.00 11.13 2.L0 0.03 0.02 18.44 29.46 0.00 99.95 38.65 0.06 1r..0? 2.08 0.07 o.02 18.21 29.L3 0.00 99.29

AIO!,IIC PBOPOBTIONS(TCXTAL AIIOMS ' 2s) cu Ag Fe ZD, Ctl 1{! g! g In Fa'', lzn 8.082 0.002 2.259 0.a72 0.00? 0.002 2.0t4 11.758 0.000 0.20 8.074 0.OOt 2.230 0.84? 0.010 0.004 2,044 11.765 0.009 0.2L 8.070 0.001 2.243 0.841 0.011 0.008 2.036 11.776 0.008 0.22 7.9a6 0.001 2.185 0.834 0.010 0.003 2.o20 11.952 0.007 0.2r 7.974 o.O0? 2.1t6 0.884 0.006 0.002 1.993 11.966 0.000 0.24 ?.980 0.006 2.278 0.745 0.011 0.011 2.O25 1t.942 0.O04 0.35 7.956 0.004 2.406 0.612 0.004 0.002 2.0r7 11.973 0.011 0.64 7.945 0.007 2.387 0.579 0.001 0.014 2.O34 11.997 0.019 0.?1 7.920 0.002 2.422 0.584 0.005 0.007 2.o44 11.972 0.019 0,72 7.968 0.002 2.567 0.438 0.006 0.008 2.035 11.954 0.008 L.29 7.956 0.000 2.599 0.419 0.004 0.005 2.026 11.978 0.000 1.40 7.994 0.007 2.605 0.418 0.008 0.005 2.016 11.937 0.000 1.41

TABLE5. REPRESENTATIVECHB'IICAL COMPOSITION OFTENNANTITE-TETMHEDRITE-SERIES PHASE

WEIGET PERCEMT ore Dep. cu Ag Fe zn cd Mn sn As sbBis se In lrotal Onodani 42.98 0.06 1.83 6.29 O.24 0.09 0.04 10.01 L.92 0.00 27.70 0.L2 0.01 99.75 43.47 0.06 1.90 6.74 0.25 0.03 0.00 L8.46 1.36 0.00 28.03 0.02 0.04 l-00.35 4?.L6 0.06 2.04 6.75 0.19 0.03 0.01 L7.69 2.45 0.00 2?.82 0.07 0. 04 100. 30 Akenobe 39.09 0.33 0.20 8.16 0.0? 0.02 0.10 7.A7 18.48 0.00 25.7L 0.08 0.00 99.30 39.65 0.25 0.42 7.97 0.09 0.01 0.03 8. 11 17.06 0.00 2s.78 0.07 0.00 99.44 39.06 0.36 0.39 7.99 0.10 0.02 0.06 5.52 2I.3L 0.00 25.56 0.07 0.01 100.45 trukoku 34.86 7.46 3.22 3.52 0.15 0.04 0.03 9.50 9.91 4.89 24.95 0.02 0.78 99.33 35.43 6.66 3.25 3.41 0.L2 0.06 0.04 10.01 9.00 5.58 25.18 0.04 0.72 99.50 32.s8 9.51 3.30 3.10 0.16 0.09 0.03 7,37 11.33 6.97 24.74 0.00 0.82 100.00 Ikuno 39.91 1.16 4.5L 3.2O 0.06 0.01 0.00 L2.73 1-0.46 0.98 26.A2 0.03 0.05 99.92 4L.23 0.82 4.66 3.L2 0.05 0.01 0.03 13.?0 8.80 0.00 26.7A 0.06 0.07 99.31 40.06 1.16 4.77 2.78 0.06 0.03 0.00 13.91 7 .7r 2.37 26.79 0 . 03 0 . 08 99.75.

AToMIC PROPORTIONS(TOTAL ATOMS= 29) cu Ag l'€ z\ cd Mn sn A6 sb Bi s se In Ee/zrt 10.119 0.008 0.491 1.554 0.032 0.013 0.00s 3.59s 0.237 0.000 L2.923 0.022 0.002 0.32 10.138 0.008 0.505 1.s2? 0.033 0.007 0.000 3.651 0.166 0.000 L2.957 0.004 0.005 0.33 10.117 0.009 0.544 1.53? 0.026 0.007 0.001 3.5t7 0.300 0.000 L2.926 0.014 0.005 0.35 9.925 0.049 0.059 2.014 0.011 0.005 0.014 r.s22 2.449 0.000 L2.936 0.015 0.000 0.03 9.996 0.036 0.120 1.952 0.012 0.003 0.005 1.735 2.244 0.000 12.881 0.014 0.000 0.06 9.927 0.054 0.114 1.9?3 0.015 0.006 0.009 1.191 2.A26 0.000 L2.A7L 0.014 0.002 0.06 9.098 L.L47 0.957 0.894 0.023 0.012 0.004 2.103 1.350 0.388 12.908 0.003 0.113 1.07 9.X96 1.018 0.9s9 0.859 0.018 0.018 0.006 2.204 L.2I9 0.440 12.950 0.009 0.103 L.L2 8.673 L.49L 1.000 0.802 0.024 0.029 0.004 1.664 1.575 0.564 X3.053 0.001 0.121 L.25 9.757 0.167 1.254 0.760 0.008 0.003 0.000 2.640 1.334 0.073 12.99L 0.006 0.00? 1.65 10.009 0.117 L.247 0.736 0.00? 0.003 0.003 2.A20 1.115 0.000 12.883 0.010 0.009 L.75 9.793 0.16? 1.327 0.661 0.008 0.009 0.000 2.AA4 0.983 0.176 L2.976 0.006 0.011 2.00

Tennant i te - te t r qh e d r i t e materialsstudied. The total of As + Sb + Bi + In is very closeto 4, which suggeststhat the In3*, though The grains examinedare generallyheterogeneous, low in content, can lodge in a trigonal prism. although the general formula (Cu,Ag)16@e,Zn)2 (As,Sb,Bi,In)aSt3is applicableto all of them (Iable Sphalerite 5). Tennantitefrom the Fukoku deposit showsthe highest silver, bismuth and indium contents of the Compositional homogeneity is confirmed in the

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TABI.T6. REPRESEJTATIVECHS'UCAL COMPOSITION OF SPHALERITE

I{EI@I' PERCEIII AToMIc PRoPoRTIoNS (TOTAI AToMs = 2) Or€ Dep. Cu Fe Z\ Cd !4n g X! lotal Cu Fe Zn Cd l{n g In ?elZD OBodml- 0.82 0.39 64.45 0.65 0.02 32.14 0.12 99.21 0.013 0.00? 0.975 0.006 0.000 0.991 0.006 0.00? 0.s4 0.44 55.22 0.56 0.01 32.36 0.?S 100.31 0.013 0.008 0.9?7 0.005 0.000 0.989 0.00? 0.008 0.59 0.65 65.41 0.67 0.03 32.45 0.21 100.11 0.011 0.01r 0.979 0.005 0.001 0.991 0.002 0.011 !Ielobe 0.30 0.19 55.23 0.58 0.03 33.0S 0.30 99.74 0.005 0.003 0.975 0.005 0.001 1.008 0.003 0.004 0.38 0.29 65,63 0,67 0.03 33.04 0.36 100.41. 0.006 0.005 0.977 0.006 0.001 1.002 0.003 0.005 0.39 0.30 64.74 0.59 0.03 32.71 0.48 99.24 o.006 0.005 0.974 0.005 0.001 1.004 0.004 0.005 nrtoku 0.47 0.44 66.40 0.20 0.14 32.62 0.08 100.35 0.00? 0.007 0.989 0.001 0.002 0.991 0.001 0.007 0.46 0.44 6s.93 0.25 0.09 33.01 0.02 100.20 0.007 0.008 0.979 0.002 0.002 1.000 0.000 0.004 1.28 0.87 64.78 0.25 0.07 32.37 0.05 99.64 0.020 0.015 0.971 0.002 0.001 0.990 0.000 0.015 0.4s 0.91 65.5S 0.41 0.05 32.49 0.04 99.96 0.007 0.016 0.981 0.004 0.001 0.991 0.000 0.016 0.5? 0.9? 65.01 0.49 0.04 32.62 0.05 99.75 0.009 0.0t7 0.9?3 0.004 0.001 0.996 0.000 0.017 0.49 1.05 55.17 0.51 0.05 32.70 0.04 100.01. 0.008 0.018 0.973 0.004 0.001. 0.996 0.000 0.018

IABLE7. REPRESENTATIVECHB.IICAL CfiPOSITIONS OF BORNITE

NBI@T PERN AToUIC PBOPOBTINS (TOas Arouil - X0) Ole &p. As re s s6 TotaL cuAsF€g9e hodani 45.46 20.19 10.1A 23.41 0.06 99.10 3.961" !.O27 1.000 4.007 0.004 41.t2 18.46 1,0.25 23.5? 0.01 99.1r 4.064 0.932 0.999 4.004 0.00r. 49.38 16.04 10.30 23.69 0.06 99.47 4.201 0.804 0.997 3.993 0.004 ,rksob€ 62.01 o.27 Lt.24 25.47 0.03 99.01 4.936 0,013 1.019 4.018 0,002 62.54 0.27 1r.62 25.59 0.12 100.15 4.931 0.013 1.042 3.998 0.008 0.27 1r..39 25.45 0.13 99.4A 4.939 0.013 1.028 4.002 0.008

tn! rKUNo c -T-I N +i NI LL FUKOKU -l- L AKENOBE F*.-OMODANI 12340 1 (Fe/ Zn)sp x 102 (Fe/Zn)rn-to Frc. 3. Atomic Fe2+/Zn ratio of sphalerite (A) and of tennantite-tetrahedrite (B) as a function of Fe?+/Zn in stannoidite.Symbols: Sp sphalerite,Sd stannoidite, Tn-Td tennantite-tetrahedrite.

gains examined.As shown in Table 6, the iron con- bornite, but it may be a discretespecies from bor- tents are very low in all of them. Note that the iron nite, if it is found to be compositionallydiscontinu- content of sphaleriteassociated viith is quite ous with bornite, or structurally different from it. high (Shimizu & Shikazono 1985, 1987). DISCUSSIoN Bornite Mineral assemblagesof the specimensstudied and Bornite is common in the roquesite-bearingores ranges of atomic F€+ /Zn ratios are summarizedin from the Omodani and Akenobe deposits(Table l), Table l. There is a wide range of Fd*-for-Zn sub- although it is not found in the ores studied by Kato stitution in coexisting stannoidite, sphalerite, and & Shinohara (1968). The material from the latter tennantite-tetrahedrite (Figs. 3A., B). The F** /Zn deposit fits the ideal formula, but that from the ratio of stannoidite is positively correlated with that former has an unusually high Ag content, giving an of sphalerite and tennantite-tetrahedrite. No ideal formula AgCuoFeSn(Table 7). It is accompa- experimental data bearing on the influence of tem- nied by native silver. It iii tentatively handled as bor- perature on iron and zinc partitioning among these nite here in favor of its optical similarity to ordinary minerals have beenobtained yet, but could be of use

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C.' c o f, 200 B8- L l! Akenobe Deo

Roquesite-beoring

200 300 3s0c Temperoture Frc. 4. Histogramsof filling temperaturesof fluid inclusionsin quartz associated witl roquesitefrom &e Omodani (A) and Chiemon No. 4 vein, Akenobe deposits (B).

Xp"s=0O01

N Stonnoiditefietd o (Shimizu 1987) o & Strikozono :0.005 0.01 eOl I ite fietd

Stonnite fietd (Shimizu& Shikozono1985) B'yr ..'

Temperoture 20 200 250 300 350"C Fro. 5. Temperature - log a(S) diagram for roquesite-bearing ores. Curves A and B correspond to a($) - temperature relationships for the assemblageof stannoi dite - chalcopyrite - borpite - mawsonile - SzGas)for a@e) = I and a(Fe) : 0.1 a(Fe) is defined as the activity of the CqFel+F*+Sn2Sl2 component in tle stannoidite solid solution. Symbols: Mw mawsonite, Sd stannoidite, Bn bor- nite, Cp chalcopyrite.

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TABI..E8. SULFURISOTOPIC COI{POSITIONS NNE of Busan, and is related to the emplacement OFROOUESITE-BEARING BULKORES of the Bulgugsagranite. We believethat the indium mineralization there is of the same age as that in ore Delpsit 534s lper nlt; onodsl -0.8 Japan, on the other side of the Sea of Japan. Ak'sobe -0.9 (average' n-32)i n*.oku -0.5 lkuo +0. 3 ACKNOWLEDGEMENTS r) ghiozara,s mpublished data We are grateful to Professor Akio Tsusue of Kumamoto University for the organization of this as a geothermometer.The comparison of estimated project, Mr. Takuya Shiozawa,whose previous work temperaturesof formation of roquesite-bearingores stimulated this study, and Professor R.F. Martin, from the geological standpoint enablesthe group- Drs. Chris Stanley,M. Gunneschand anonymous ing of four depositsinto two pairs, Ikuno-Fukoku refereesfor their comments,which servedto improve and Akenobe-Omodani:the estimatedtemperature the manuscript. This work was partly supported by of formation of the former is higherthan the latter. Grant-in-Aid for Scientific Research(Nos. 623030 The indium contents of sphalerite, tennantite- ard 01740471)from the Ministry of Education, tetrahedrite,stannoidite, and chalcopyritefrom the Science,and Culture of Japan,and by the Fujiwara Ikuno and Fukoku depositsgenerally tend to be Foundation of Natural History. higher than those from the Omodani and Akenobe deposits(Table l). The high indium contentsof these REFERENcES minerals are probably favored by higher tempera- turesof formation, providedthat the degreeof con- Iuer, N. & Cnor, S. (1984):The first Koreanoccur- centrationof indium in all the depositswas approx- renceof roquesite.Mineral. J. 12, 162-172. imately equal. Filling temperaturesof fluid inclusions in the coexisting quartz from the Omodani and Isrunene,S., Sero,K. & Tsurruune,K. (1981):Some Akenobe deposits give a temperature ranging from aspectson the tin-polymetallic veinsin the Akenobe mine area, 285 to 310'C (Frg.4). southwest Japan. Mining Geol. 3L, 147-156(in Japanesewith Englishabstr.). Shimizu & Shikazono(1985, 1987)estimated the probable physicochemicalenvironment of formation & Snrnere,K. (1972)zRe-examination of the ofstannoidite- and stannite-bearingtin ores in Japan metallogenicepoch of the lkuno-Akenobe province (Fig. 5). In this figure, the log a(S, - temperature in Japan.Mining Geol. 22, 67-73. field of the roquesite-bearingtin ores from the Omodani and Akenobedeposits can be estimatedto Kero, A. & Snnonane,K. (1968):The occurrenceof be approximatelyl0-8 atm. at 285oCto l0{ atm. at roquesitefrom the Akenobemine, Hyogo Prefec- 3l0oc, based on the thermochemicaldata on the ture, Japan.Mineral. J. 5,276-284. mineral assemblage,FeS contents of sphalerite, and Karo, T. (1920):A contributionto the knowledgeof fluid-inclusion data. The approach referred to here the cassiteriteveins of pneumato-hydatogeneticor is the same as that used by Shimizu & Shikazons hydrothermalorigin. A studyof the -tinveins (1987).The field ofthe roquesite-bearingores falls of the Akenobedistrict in the provinceof Tajima, within that of the stannoidite-bearingores. Japan."/. Coll. Sci,,Tokyo Imperial Univ.43, Art, The isotopic compositions of sulfur in the 5, l-60. Akenobeand Ikuno depositshave been reported by Yamamoto (1974\, Sasaki & Ishihara (1980), and Kawer,M. (1956):On the late Mesozoicmovement in Ishihara et ol. (198L),but those of the roquesite- the westernpart of the Hida plateau.I. Geological study in the bearing ores are reported here for the first time. It southern mountainland of Arashimadake, Fukui Prefecture. Geol. preliminary J. Soc. is worthy of note that sulfur isotope Iapan 62, 559-573(in Japanese). study on the roquesite-bearingores indicates a very narrow range of 63aSvalues, from -0.9 to +0.3%0 Kotrraa, Y. & Asaoe, I. (1973):The Akenobe ore (Iable 8). This could indicate a magmatic origin, and deposits:their geologicstructure and fracturepat- suggsts either that the physicochemicalenvironment terns.Mining Geol. 23, 137-l5l (in Japanesewith of the deposits did not change during the indium Englishabstr.). mineralization, or that the metaVsulfur ratios in the ore fluids responsiblefor the indium mineralization Marttaua, J., MonrsHtre,A. & Irorcewe, J. (1975): RegionalGeologlt of Jopan, (revised were too small to changethe isotopic compositions Chubu-chihou edition).Asakura Shoten, Tokyo (in Japanese). in the fluids sienificantly. Roquesite also occurs in the Ulsan Fe-W-As MAnunuMa,S. (1957):The relationsbetween ore veins skarn-typedeposit in the Republic of Korea (Imai andigreous intrusives. Mining Geol.7,28l-284Qn & Choi 1984).The deposit is located about 80 km Japanesewith Englishabstr.).

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MINISTRY OF INTERNATIONAL TRADE AND Sttrrvrrzu,M., KATo, A. & Surozawa, T. (1986): INDUSTRY OF JAPAN (1980):Report on Regional Sakuraiite:chemical composition and extent of GeologicalSumey in the Hida District. Part I (in (Zn,Fe)In-for-CuSnsubstitution. Can. Mineral. A, Japanese). 405-409.

MINISTRY OF INTERNATIONAL TRADE AND & SHmezoNo,N. (1985):Iron and zinc parti- INDUSTRY OF JAPAN (1984):Report on Regional tioning betweencoexisting stannite and sphalerite: Geological Sumey in the Bantan District (ln a possibleindicator oftemperatureand sulfur fuga- Japanese). city, Miner. Deposila20,314-320,

Muneore, N. & kme, S. (1968):Recent geologic & - (1987):Stannoidite-bearing tin ore: exploraiionand developmentof the Akenobemine. mineralogy,:ralogy, texture and physicochemical environ- Mining Geol, Lt,79-91 (in Japanesewith English ment of formation. Can. Mineral. 25,229-236. abstr.). Sunrazu,T., Kano,A. & Mersuo, G. (1966):Minerals Sarcusa,M. (1958):Geology and mineralizationof the from the Fukoku mine, Kyoto Prefecture,with spe- Akenobemine, Hyogo Prefecture,Japan. Mining cial referenceto cosalite,boulangerite, hexastannite Geol.t,218-238 (in Japanesewith Englishabstr.). and some secondary arsenic minerals. Chigaku Kenkyu 17,201-209 (in Japanesewith English Sesarr, A. & Issrrnre, S. (1980):Sulphur isotope abstr.). characteristicsof granitoids and related rnineral depositsin Japan.Proc. 5th Quort.IAGOD Symp. SHrozawe,T. (1984):Mineralization of the Akenobe l, 325-335. Tin - PolymetallicDeposits, Hyogo Prefecture,Cen- tral Japan.M.S. thesis, Univ. Tokyo, Tokyo, Japan. Sano,N., AseoanI. & Kesaversu, S. (1977):Geo- logicalstructure and ore depositsof the Akenobe Yevarvoro,M. (1974):Distribution of sulfur isotopes mine, Hyogo Prefecture,Japan, Mining Geol.21, in the Ryuseivein of the Akenobemine, Hyogo 245-262(in Japanesewith Englishabstr.). Prefecture,Japan. Geochem. J. 8, 75-76. ScHNnrnrnsdsN,H. (1955): Erzlagerstiitten,Kurz- vorlesungzur Einfuhrung und zur lAiederholung. ReceivedApril 4, 1990, revised manuscript accepted GustavFischer Verlag, Stuttgart,Germany. October 12, 1990.

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