Geological, Geochemical, and Fluid Inclusion Evidences for the Origin of the Ravanj Pb–Ba–Ag Deposit, North of Delijan City, Markazi Province, Iran

Home , Galena

Turkish Journal of Earth Sciences Turkish J Earth Sci (2016) 25: 179-200 http://journals.tubitak.gov.tr/earth/ © TÜBİTAK Research Article doi:10.3906/yer-1501-26

Geological, geochemical, and fluid inclusion evidences for the origin of the Ravanj Pb–Ba–Ag deposit, north of Delijan city, Markazi Province, Iran

Mostafa NEJADHADAD1, Batoul TAGHIPOUR1,*, Alireza ZARASVANDI2, Alireza KARIMZADEH SOMARIN3 1Department of Earth Sciences, Faculty of Sciences, Shiraz University, Shiraz, Iran 2Department of Geology, Faculty of Earth Sciences, Shahid Chamran University (SCU), Ahvaz, Iran 3Department of Geology, Faculty of Sciences, Brandon University, Manitoba, Canada

Received: 27.01.2015 Accepted/Published Online: 28.09.2015 Final Version: 08.02.2015

Abstract: The Lower Cretaceous sequences of the Ravanj anticline in Iran host the Ravanj Pb–Ba–Ag mineralization. Economic orebodies are restricted to the thrust zone within the brecciated massive limestone and immediately above the Jurassic shale and/or shale–limestone intercalations of the Lower Cretaceous. Paragenetic sequence and distinct zoning of mineral assemblages indicate that ore-forming fluid migrated through thrust zones along the NE-trending faults. The REE pattern of mineralized host rock is characterized by HREE-enrichment ((La/Lu)PAAS = 0.24). The Ce/Ce* ratio of mineralized host samples shows negative Ce anomalies, which is most 34 likely inherited from seawater. The positive Eu/Eu* anomaly suggests high ƒO2 during ore deposition. Negative δ S values of the Ravanj sulfide minerals (–27‰ to –11‰) suggest bacteriogenic sulfate reduction, whereas positive δ34S values of barite (+20‰) fall in the range of Tertiary marine sulfates. Multiple isotopic sulfur sources of sulfides and sulfate minerals support mixing of a reduced negative isotopic sulfur-bearing fluid and a positive isotopic sulfate-bearing fluid. The average of homogenization temperatures of fluid inclusions from the early and late-stage mineralization calcites are 165 and 160 °C, respectively. The salinity of fluid inclusions varies between 0.66 and 18 wt% NaCl equivalent with an outlier at 22.2. Wide variation in the salinity of fluid inclusions can be explained by fluid mixing between a higher salinity group with 14–18 wt% NaCl equivalent and a lower salinity group with 0.66–8 wt% NaCl equivalent. In the Ravanj, fine grained sulfide minerals are consistent with a sulfur supersaturated fluid. High concentrations of Pb can be present in oxidized, chlorine-bearing fluids if the concentration of total H2S is very low. Therefore, mixing of two geochemically different fluids could precipitate both galena and barite. These data show that the Ravanj Pb–Ba–Ag deposit is comparable with Pb-rich Mississippi Valley-type deposits such as the Viburnum Trend district in the USA.

Key words: Ravanj Pb–Ba–Ag deposit, rare earth elements, multiple isotopic sulfur sources, microthermometry, fluid mixing

1. Introduction poor (or sulfate-rich) brine with another less saline, H2S- Sandstone and carbonate hosted Pb-rich deposits, with Zn/ rich fluid (or organic and methane bearing) better explains (Zn+Pb) < 1, are an unusual end member of MVT deposits Pb mineralization in this area (Rowan and Leach, 1989; (Sverjensky, 1984a; Leach et al., 2005). Correlation of metal Anderson, 1991; Plumlee et al., 1994). An anomalous ratio with lithology is reported by Gustafson and Williams Pb-rich fluid reported by Appold and Wenz, (2011) in (1981). Sverjensky (1984a) has proposed that different sphalerite hosted fluid inclusions showed that one of the rates of water–rock interaction in sandstone and carbonate aforementioned fluids was enriched in Pb. aquifers could form galena- and sphalerite-rich deposits The well-known episode of Pb–Zn mineralization from single basinal brine. In this model, low Zn/Pb ratio in Iran took place in the Cretaceous carbonate rocks, deposits are associated with sandstone aquifer, while including well-known world-class MVT deposits such as high Zn/Pb ratio deposits occur in carbonate aquifers. Emarat, Mehdi Abad, and Irankuh (Rajabi et al., 2012). The basinal brine model (Sverjensky, 1984a) specifically Dixon and Pereira (1974) suggested that these deposits explains mineral paragenesis and the Zn/Pb ratio of MVT range from sedimentary exhalative (SEDEX) to MVT, but deposits. Some investigations on the Viburnum Trend most of these deposits are characterized by carbonate host deposits, USA, show that Pb-rich ores were deposited as rock and are classified as MVT (Lisenbee and Uzunlar, a result of fluid mixing. Mixing of a metal-rich and H2S- 1988; Ghazban et al., 1994; Ehya et al., 2010). The Ravanj * Correspondence: [email protected] 179 NEJADHADAD et al. / Turkish J Earth Sci

Pb–Ba–Ag deposit is located 20 km north of Delijan units start with disconformable terrigenous sediments (Figure 1a) in the Urumieh–Dokhtar magmatic belt consisting of a basal conglomerate, upper quartzose (Figure 1b). Ore mineralization is found in 7 separated sandstone, and bedded cream sandy dolomite. These strata and/or partially attached pockets and lens-like orebodies (Cd strata in Figure 1c) show maximum thickness of about (Figure 1c). The Ravanj deposit has been in operation for 50 m. The Lower Cretaceous strata overlays the Jurassic 40 years and total extracted ore is estimated to be about 4 strata of the Shemshak formation (J.Sh). The latter consists million metric tons (Mt) at 2.5% Pb cutoff grade (Samani of dark gray laminated shales with interbeds of quartz- et al., 2010). There are two hypotheses regarding the origin rich sandstone. Shale layers are composed of clay, sericite, of the Ravanj deposit: and quartz. These types of progradation from Jurassic • Based on geology, semiconcordant to concordant to Lower Cretaceous rocks are also reported in other morphology of orebodies, mineralogy, and ore textures, deposits in the region such as Emarat (Ehya et al., 2010) Modabberi (1995) suggested an early diagenetic origin and Anjireh-Vejin (Lisenbee and Uzunlar, 1988). Bedded for the Ravanj deposit. In his model, the economic Orbitolina limestone with minor shale and mudstone metals were probably derived from continental overlays conformably the progressive Cd strata. The weathering or distal volcanism and then deposited shale content of bedded Orbitolina limestone increases due to reaction with bacterial reduced sulfur in the upwards and grades into shale. The thickness of the shale- progressive carbonate facies of tidal flats. bearing limestone sequence (Ksb) is about 250 m. Minor • In another study, based on host rock type, ore textures, Pb–Ba mineralization locally occurs in the Ksb strata. and ore mineralogy, Aliabadi (2000) suggested that The economic ore zone (5 – 30 m thick) is hosted by a deposition of low-grade metal-bearing sediment massive to thick-bedded Rudist-bearing limestone (Km2), was followed by subsequent remobilization and up to 130 m thick. The orebodies occur above the thrust concentration of the metals by circulation of connate contact of the Jurassic shale/shale-limestone and massive and meteoric waters (MVT model). limestone. There is a sharp contact between mineralized Although general geology and ore mineralogy of the and unmineralized zones in the NW part of the deposit Ravanj Pb–Ba–Ag deposit have been studied and generally whereas mineralization splays towards the SE region. It are known, the source of metals and fluids and mechanism appears that mineralization was controlled by NE–SW of the mineralization are controversial. This study covers trend faults. These normal faults dip ~60° to the SE and rare earth elements geochemistry of country shale, host crosscut the host rock and thrust faults. The host rock rock, and ore samples to gain a better understanding of carbonates alternate with two shale-bearing strata. The the source of metals. In addition, sulfur isotope data Km2 is conformably overlain by Albian shale (U.Sh). The and microthermometric investigations are carried out Lower Cretaceous units are unconformably superimposed in order to understand the source of sulfur and possible by a succession of Eocene conglomerate, shale, marl, tuff mechanisms of ore precipitation. (E.5), volcaniclastic rocks (E.6), Oligocene conglomerate, shale, sandstone and gypsum (Lower Red Formation, 2. Geological setting L.R), and the Oligo-Miocene marl and limestone of the The Ravanj Pb–Ba–Ag deposit is located in the Zagros Qom formation (Qm). Post-lower Miocene granodiorite orogenic belt in western Iran. From northeast to southwest (Gd) stocks and dykes (Dy) intrude along NW–SE normal of Iran, this belt is subdivided into three parallel belts faults and also cut all strata from the Jurassic shale to the including the Urumieh–Dokhtar magmatic arc (UDMA), Qom formation. These post-mineralization younger dykes the Sanandaj–Sirjan metamorphosed zone (SSZ), and the (Figure 1c) also cut orebodies. Pyrite is the only opaque Zagros folded-thrust belt (Alavi, 1994; Golonka, 2004). mineral in these dykes. Post-Cretaceous rocks do not The southern boundary of SSZ with the Zagros folded- show any evidence of Pb mineralization; however, an Fe thrust belt is clearly visible but the northern boundary deposit (e.g., Sarvian magnetite deposit in northeast part with the UDMA is not obvious in Central Iran due to the of Ravanj Anticline) occurs in the Eocene volcanic rocks. extensive coverage of Tertiary rocks, lateral facies changes, Cross cutting relationships indicate that these post-lower and complex deformation. The main differences between Miocene granodiorite (Gd) stocks and dykes were injected the SSZ and UDMA are age and intensity of the magmatic after Pb–Ba mineralization and seemingly played no events; the SSZ and UDMA are characterized by intense distinct role in the Ravanj Pb–Ba mineralization. magmatic events of Mesozoic and Cenozoic, respectively (Berberian and King, 1981). 3. Methodology The Ravanj Pb–Ba–Ag deposit is hosted by the Lower Representative samples were collected from the open pit Cretaceous strata that are exposed in the core of the Ravanj parts of A, Bw, Cn, and Cs, and from A and Bs tunnels anticline in the UDMA (Emami, 1996). The Cretaceous (Figure 1c). Detailed mineralogical studies were performed

180 NEJADHADAD et al. / Turkish J Earth Sci

1a 1b 49 00 Tehran 53 00 Caspian

Hamadanan Central Iran 35 00

Tehran Arak Ravanj Ravanj Emarat Delijan Dare Noghre Iran Dare Noghre

SSZ UMDA Anjire-V Isfahan ZFB ejin Persian Gulf Irankuh UDMA Mine ZFB SSZ N

3 City

0 0 50 00 475000 1c Gd 476000 E.6 Km2 Km2 E.5 Sh 3782500 3782500 Km2 U.sh A Cd Ksb Ksb

Km2 Km2 Cn Cd Ksb Km2 Ksb Bn U.sh D Bw Sh Cs Bs Km2

Ksb L.R E.5 Al 3781500

Qm 3781500 E.6 475000 Km2 476000

L.Miocene Qm Limestone and Marl (Qom F) Al Alluvium Dyke (mainly acidic) Oligocene L.R Conglomerate, Sandstone, Gypsum (L.Red F) Dy Granodiorite, Diorite (Post L. Miocene) E.6 Volcanic rocks Gd Normal Fault Conglomerate, Shale, Tuff, Sandstone

Eocene E.5 Thrust U.sh Shale with Limestone intercalations Anticline axe Km2 Massive Limestone, bedded in upper part Ksb Bedded Limestone, Shale with thin bedded limestone Cs Orebody Conglomerate, Sandstone,Dolomite L. Cretaceous L. Cd sampling location N Jurassic Sh Dark gray Shale with sandsone intercalation 0 125 250 Figure 1. a) Simplified map showing location of the Ravanj deposit in Iran. b) Other Pb–Zn deposits in region (modified after Alavi, 1997). c) Geological map of the Ravanj anticline (modified after Modabberi, 1995). UDMA: Urumieh-Dokhtar magmatic arc, SSZ: Sanandaj-Sirjan zone, ZFB: Zagros Folded belt.

181 NEJADHADAD et al. / Turkish J Earth Sci 0.24 32025 390.2 10.01 1 0.57 174 5 192.69 0.3 5.64 44.7 576.1 0.23 30 BST-78 0.03 1712 36.6 6.07 21 4.2 424 15 11.36 0.59 5.28 167.1 21.9 0.15 30.7 BST-63 0.06 1242 56.5 1.81 9 1.81 544 12 11.47 0.35 1.83 161.9 9.1 0.37 36.4 BST-58 0.01 1484 121 12.24 10 1.98 710 10 14.93 0.37 6.12 131.6 63.7 0.15 29.8 BST-201 0.05 1906 23.6 3.47 1 1.06 161 9 8.59 0.35 12.73 36.6 13.4 0.3 35.7 BST-124 0.04 3738 358 9.8 2 0.55 139 6 38.98 0.27 14 51.2 408.6 0.27 26.7 BST-85 0.04 4416 46 9.93 1 0.47 117 6 30.14 0.21 3.64 9.9 51.6 0.19 32.9 BST-17 0.04 4204 63.5 10.09 7 0.36 252 12 9.06 0.45 10.04 104.7 113.9 0.15 27.8 BST-22 0.02 1591 150.9 9.72 1 0.88 165 7 31.08 0.29 10.58 40.4 175.5 0.2 30.2 BST-73 0.06 6374 178.7 10.6 3 0.95 222 7 40.63 0.32 2.33 35.1 229.5 0.65 29.8 BST-110 0.01 340 41.8 3.74 4 0.83 351 9 0.55 0.42 1.8 21.9 31.41 1.38 36.4 AT -28 AT 0.18 13205 61.5 6.1 1 0.87 157 8 68.25 0.35 13.5 35.8 59.8 0.51 34.6 BST-72 0.06 679 19.5 1.02 2 0.76 68 8 6.6 0.35 3.41 24.1 1.79 0.27 33.9 BST-121 0.04 3686 48.1 8.85 1 0.22 120 6 30.13 0.3 15.24 7.7 44.7 0.32 24.5 BST-46 0.08 9368 72.5 10.1 20 5.47 199 16 41.32 0.52 9.38 146.9 71.3 0.43 23.3 BST-204 Zn/(Zn + Pb) Zn Sb Pb % Ni Fe % Cu Co Cd Bi Ba % As Ag Mg % Ca % Element Chemical composition of mineralized whole rock of the Ravanj deposit. Ca, Mg, Ba, Fe, and Pb are in % and other elements are in ppm. Samples with numbers starting starting numbers with Samples in ppm. are elements other in % and Pb are and Ca, deposit. Mg, Ba, Fe, the Ravanj of mineralized rock whole of 1. Chemical composition Table n = 30. respectively. A tunnel, BS and from are AT and BST with

182 NEJADHADAD et al. / Turkish J Earth Sci 0.04 3319 91.84 6.29 7.9 1.38 9.2 19.45 0.38 14 64.75 80.83 31.5 Avg. 0.61 660.77 0.03 3480 118.7 10.34 7 1.63 8 10.25 0.42 2.94 47.3 90.3 23.9 BST-06 1.33 389 0.01 260 43.1 4.76 16 2.98 17 3.2 0.3 1.67 270 41.3 31.2 BST-37 0.14 645 0.01 543 51.26 7.36 10 0.95 10 1.17 0.46 1.48 29.7 37.14 36.3 AT-27 0.3 686 0.01 174 1.23 1.76 5 0.93 9 1.09 0.37 7.03 35.2 7.4 34.8 BST-153 0.57 187 0.01 521 73.27 6.43 11 0.76 10 0.82 0.42 4.37 42.2 80.2 34.6 AT-7 0.25 1304 0.01 506 52.35 6.25 13 1.66 13 0.53 0.44 1.53 53.6 42.49 37.4 AT-8 0.21 341 0.01 216 64.82 1.59 16 1.83 8 0.42 0.43 1.15 55.7 12.59 25.4 AT-22 1.21 1740 0.07 2213 69.3 2.98 23 1.84 10 3.02 0.46 0.87 49.8 52.43 18.8 AT-9 2.83 665 0.01 100 85.76 1.73 8 1.01 7 0.33 0.43 4.17 32.4 24.85 30.1 AT-38 1.85 1250 0 116 20.46 5.456 5 0.58 8 0.35 0.43 14.54 27.7 14.91 38.9 AT-12 0.39 168 0.02 1147 25.6 6.67 4 1.18 8 6.56 0.29 1.25 77.2 27.4 34.4 BST-3 0.49 88 0.03 2367 52 7.82 2 1.29 8 13.25 0.35 4.86 46.3 46.1 33.1 BST-21 0.18 283 0.02 1509 25.8 6.49 18 2.84 13 6.03 0.41 9.22 100.2 19.5 35 BST-60 0.24 205 0 153 118.98 3.08 8 0.61 6 0.33 0.44 6.27 36.2 33.56 33 AT-19 1.81 784 0.01 295 71.84 2.39 7 0.24 5 0.38 0.41 2.11 19.3 17.31 33.1 AT-17 0.87 896 Zn/(Zn + Pb) Zn Sb Pb % Ni Fe % Cu Co Cd Bi Ba % As Ag Mg % Ca % Element Table 1. (Continued). Table

183 NEJADHADAD et al. / Turkish J Earth Sci

Table 2. REE concentrations (in ppm) of the Jurassic shale (S1, wt.% and 0.02–1 ppm, respectively (Table 1). Six samples S2), mineralized (S3–S5), and unmineralized rock (S6). of Jurassic shale and unmineralized and mineralized limestone were analyzed for REE content. Samples were Element S-1 S-2 S-3 S-4 S-5 S-6 dried at 110 °C, crushed to less than 2 mm, and pulverized La 1.11 1.04 0.05 0.08 0.04 0.01 to –75 µm and analyzed using ICP-MS following multi- Ce 1.07 1.10 0.05 0.05 0.04 0.01 acid digestion of a 0.25 g split giving total to near total Pr 1.11 1.09 0.06 0.06 0.04 0.01 values for rare earth elements at LabWest (Table 2). The Nd 1.09 1.11 0.07 0.07 0.04 0.01 REE detection limit varies between 0.1 and 0.01 ppm. Five sulfide samples of main stage (2 samples) and late- Sm 1.25 1.30 0.14 0.11 0.06 0.01 stage galena (1 sample), colloform (1 sample), and main Eu 1.25 1.27 1.80 3.17 1.02 0.06 stage pyrite (1 sample), and three barite samples from Cs Gd 1.30 1.27 1.45 2.53 0.88 0.04 orebody were handpicked under a binocular microscope Tb 0.97 1.11 0.21 0.18 0.08 - and analyzed for their isotope sulfur composition. Dy 0.77 0.96 0.20 0.17 0.08 0.02 Analyses were carried out at Washington State University Ho 0.70 0.93 0.21 0.19 0.08 - in the US, using a continuous flow isotope ratio mass spectrometer (IRMS). Sulfur isotopic ratio is reported Er 0.60 0.84 0.18 0.16 0.08 0.02 in ‰ relative to Vienna Canon Diablo Troilite (VCDT) Tm 0.59 0.91 0.20 0.20 - - by assigning a value of –0.3‰ to IAEA S1 silver sulfide Yb 0.57 0.83 0.49 0.79 0.14 0.02 (Table 3). Homogenizations, first and last ice melting Lu 0.48 0.69 0.23 0.30 - - temperatures, and clathrate temperature of 101 fluid ∑REE 197.3 200.6 21.45 29.68 13.23 2.39 inclusions were measured using a Linkam THMS600 Eu/Eu* 1.04 1.06 2.37 2.44 2.21 2.11 Heating and Freezing Stage with a temperature range of –196 to +600 °C, at the University of Lorestan, Iran. La/Sm 0.89 0.80 0.37 0.68 0.73 1.04 Final ice melting temperatures and homogenization Gd/Lu 2.69 1.84 6.26 8.43 - - temperatures, respectively, were measured with a precision Ce/Ce* 0.96 1.03 0.87 0.73 0.90 0.88 of ±0.2 °C and ±0.1 °C (Table 4). La/Lu* 2.29 1.50 0.22 0.25 - - Lu/Ho 0.69 0.74 1.11 1.61 - - 4. Results 4.1. Ore and gangue zoning At Ravanj, galena and barite show zoning from lower on 67 polished thin sections. Thirty samples were selected to upper parts of all orebodies. Sphalerite and pyrite are from the A and Bs orebodies for geochemical studies of also found in the Cs (southern part of C) orebody. The major and minor elements of host rocks. These samples southwestern part of the Cs orebody is highly pyritized were analyzed by inductively coupled plasma-mass and is characterized by a Zn/(Zn+Pb) ratio greater spectrometer (ICP-MS) method under high temperature, than 0.3. Toward the outside of the orebody, galena and hydrofluoric acid digestion of a 0.25 g split giving total to barite increase. Gradually towards the southeast part, near total values for all elements at LabWest in Australia. barite increases, Zn decreases, and the Zn/(Zn+Pb) ratio Detection limits of major and trace elements are 0.01 reaches lower than 0.1 (Figure 2). Similar metal zoning in carbonate hosted MVT deposits has been described Table 3. Sulfur isotope data from galena, pyrite, and barite of the in other districts such as Pine Point, Southeast Missouri, Cs orebody. and Irish Midland deposits (Leach et al., 2005). From bottom to top of the orebodies, ore grade decreases δ34S ‰ Sample Mineral UTM (X,Y) Description (Figure 3), whereas barite and calcite content increase. (CDT) Minor dolomite mineralization occurs outward from the S1 Barite 474722, 3781530 20.67 Main stage barite orebodies where ore grade is low. S2 Galena 474773, 3781540 –23.38 Late-stage galena This type of mineralization could be consistent with S3 Barite 475043, 3781491 20.92 Main stage barite the direction of the fluid flow path. Metal zoning in the Ravanj Pb–Ba–Ag deposit provides the opportunity to S4 Galena 474911, 3781463 –27.32 Main stage galena correlate the mineral paragenesis with metal zoning. S5 Barite 474978, 3781619 20.35 Main stage barite S6 Galena 475041, 3781398 –25.56 Main stage galena 4.2. Mineralization Stratabound and lens-shape orebodies occur S7 Pyrite 474830, 3781507 –11.88 Main stage pyrite semiconcordant to concordant at the stratigraphic base of S8 Pyrite 474980, 3781800 –14.21 Colloform pyrite the massive limestone (Km2) at the tectonic contact with

184 NEJADHADAD et al. / Turkish J Earth Sci

Table 4. Summary of the microthermometric data of the Ravanj deposit (n = 101).

Host mineral Inclusion type Tm, carb Tm, clath (°C) Te (°C) Tm, ice (°C) Th (°C) Salinity (wt% NaCl equiv.) N Stage 2 calcite L+V - - – –3.3/–13.8 123.7–204.8 5.2–17.9 55 Stage 3 calcite L+V - - –37.2/–52.8 –0.4/–19.8 120.7–220.4 0.66–22.2 21 Barite L+V - - – –1.8/11.9 141–200.8 2.95–15.95 17 Stage 2 calcite L1+L2+V –56.7/–58.1 4.2 /7.3 – – 173–194.6 5.2–10.2 5 Stage 3 calcite L1+L2+V –56.7/–57.8 1.9/6.3 – – 177.1–202 6.87–13.2 3

Tm, carb: first CO2 melting; Tm, clath: last clathrate melting; Th, CO2: melting temperature of CO2 phase; Te: first ice melting; mT , ice: last ice melting; Th, total: total homogenization; Th: homogenization to liquid; Ts, NaCl: halite dissolution; N: number of measurements. shale. The breccias and replacement ore are localized by as massive aggregates of anhedral grains as well as thrust and normal faulting (Figure 4a). Minor ore is also replacement and disseminated grains. Both hydrothermal deposited in the lower shale and in thin carbonate layers. (Figure 4d) and fault breccias (Figure 4e) exist, but the Sulfide textures are mostly consistent with open-space carbonate host solution is more important. Ore-matrix filling (Figure 4b) of breccias (Figure 4c) and fractures breccia include fragments of the host carbonate rocks

474650 475450 3781830 3781830

0.0 200m

Csw-09 pond

Zn/(Zn+Pb)>0.3

Csw-03 Post M ocene ntermed ate dyke Lower Cretaceous upper shale Zn/(Zn+Pb)<0.1 Lower Cretaceous mass ve l mestone Lower Cretaceous th n bedded l mestone and shale Pond M neral zed l mestone Other faults than thrust Thrust M neral zed dr ll ng(from old to recent) Unm neral zed dr ll ng(from old to recent) 3781230 3781230 474650 475450 Figure 2. Geological map of the Cs and Bw orebodies.

185 NEJADHADAD et al. / Turkish J Earth Sci

DDH–Csw09 DDH–Csw03 m –1 m –1 –3 –3 –5 –5 –7 –7 –9 –9 –11 –11 –13 –13 –15 –15 Mass ve l mestone –17 –17 Mass ve l mestone –19 –19 –21 –21 –23 –23 –25 –25 –27 –27 –29 –29 Low grade ore –31 –31 –33 –33 –35 –35 –37 Low grade ore –37 –39 –39 –41 –41 –43 –43 –4545 –4545 Med um grade ore –47 –47 –49 –49 H gh grade ore –51 –51.7 Shale –53 1 2 3 4 5 %Pb –55 –57 Shale 1 2 3 4 5 %Pb Figure 3. Strip logs of two drill holes (Csw03 and Csw09). Locations of drillholes are shown in Figure 2. supported by a matrix of host rock fragments, calcite, pyrite type III and stage 1 sphalerite mineralization that barite, and fine sulfide grained minerals (Figure 4f). In occurred after the early stage of galena and shows a hiatus veins and open spaces galena and barite are deposited between galena mineralization stages. A similar hiatus contemporaneously (Figure 4g). Calcite (Figure 4h) and between galena mineralization stages during which bladed pyrite (Figure 4i) veins are abundant. marcasite was precipitated is reported in the Viburnum There is no evidence of syngenetic ore deposition. The Trend in SE Missouri (Mavrogenes et al., 1992). Finally, ore has simple mineralogy. The following primary ore during the late stage, rare inclusion-free galena, up to 5 minerals were identified: galena and pyrite as major ore mm in size, was deposited with calcite and dolomite in minerals, and sphalerite, tetrahedrite, and chalcopyrite open spaces (Figure 5c). as accessory ore minerals. Calcite, barite, dolomite, and Pyrite: Four types of pyrite are distinguished. Type I: quartz are gangue minerals. Supergene minerals include Spherules and framboidal fine-grained pyrite. This type cerussite, Fe-oxides, smithsonite, covellite, malachite, and occurs as inclusions and partially engulfed aggregates in azurite. Galena: Galena is the main ore mineral. It occurs as galena, unmineralized limestone, and in the lower organic- anhedral disseminated grains (0.1–0.6 mm) and open rich shale layers. Framboidal pyrites associated with the space filling (1–5 mm). It seems that galena was deposited ore are considered to be indicators of biogenic activity in the early, main, and late stages of mineralization. (Love, 1962; Mavrogenes et al., 1992; Kucha et al., 2010). Early stage galena is paragenetically associated with Type II: Colloform pyrite, 0.2 to 2 mm in size (Figure 5d), tetrahedrite and shows intergrowth texture. Galena at the formed after framboidal pyrite. It is found with minor main stage contains inclusions of sphalerite (Figure 5a), barite in host rocks. Carbonate and barite relicts are found tetrahedrite (Figure 5b), and pyrite. These two stages of within colloform pyrite. Colloform texture of pyrite is a galena mineralization were separated from each other by function of the saturation rate of iron and sulfur in fluid,

186 NEJADHADAD et al. / Turkish J Earth Sci

a b c Ba Km2

J.sh

d e f H Gn C3 Gn Py H Ca C2 Gn C3 H Do

g h I

Ca C3 C2

Figure 4. a) Cretaceous massive limestone (Km2) thrusted over the Jurassic shale (J.sh). b) Mineralized brecciated massive limestone. c) Galena (Gn) and barite (Ba) deposited as open space filling of the breccia zone. d) Open space filling ore and gangue minerals. Rhythmic mineral deposition includes galena, pyrite, and calcite. e) Rhythmic fracture-filling galena (Gn) and calcite (Ca). f) Late-stage disseminated galena in the brecciated host rock cemented by dolomite (Do) and late-stage calcite (C3). g) Barite and galena intergrowth in the Cn orebody. h) Late-stage calcite (C3) crosscutting pre-main stage calcite (C2) in a low grade ore sample. i) Vein type pyrite (Py) in black massive limestone. and indicates rapid crystallization from a supersaturated Sphalerite: Paragenetically, sphalerite formed earlier ore fluid (Anderson, 2008; Anderson and Thom, than main-stage galena. Dark green to black sphalerite 2008). Colloform pyrite was deposited after host rock occurs as fine disseminated anhedral grains and rarely sparitization and minor barite deposition, but framboidal intergrowth with galena (Figure 5f). pyrite was deposited as early diagenetic mineral. Type III: Fahlore group: Fahlore minerals are distributed Most of pyrite at Ravanj is type III. It occurs as euhedral randomly and usually occur as inclusions in galena. They or aggregates, veins, and veinlets (Figure 5e). These rarely show intergrowth textures with galena or engulfed veins are composed of pyrite with or without galena and sphalerite. barite. Pyrite veins crosscut type I and II pyrite, stage 1 Chalcopyrite: Rare chalcopyrite occurs as anhedral galena, barite, and main-stage calcite. Type IV: Anhedral blebs in galena. It is deposited before and during galena to subhedral disseminated pyrite associated with open deposition. space filling calcite. This uncommon pyrite accompanies Calcite: Calcite precipitation has taken place in 3 late-stage galena and represents the final stage of sulfide stages. First, calcitization occurred as micrite replacement mineralization. Absence of marcasite suggests that the ore- by sparite, which predated sulfide mineralization. Large forming solution had a pH of higher than 5 (Stanton and calcite crystals (up to 1 cm, Figure 5g) and veinlets formed Goldhaber, 1991). during the second stage. This calcite occurred before

187 NEJADHADAD et al. / Turkish J Earth Sci

Sph2 a Py b c

Tt Gn Sph Ca Gn1 Gn Cv Gn2 Sph1 200um 100um 300um

d Py e f

Py Gn

Gn Py Ca Sph

Ca Ca Ca B Ba Do

300um 1mm

Ca g h Ca I Do

150um 200um 200um

Figure 5. a) Rhythmic deposition of sphalerite and galena. Stage 2 sphalerite (Sph2) coated stage 1 galena (Gn1) containing sphalerite inclusion. Main stage galena engulfed the whole set. b) Sphalerite engulfed by tetrahedrite hosted by galena. c) Late- stage galena without sulfide mineral inclusion. d) Colloform pyrite associated with calcite and barite. Note the replacement of calcite and barite by colloform pyrite. e) Pyrite engulfed by galena and both are in bitumen matrix between calcite grains. f) Sphalerite intergrowth with galena engulfed pyrite. g) Stained thin section with alizarin red-S from mineralized host rock of the Cs orebody, h) Galena filling space between calcite grains in mineralized rock. Note the dissolution and replacement of calcite. i) Fan-like texture of barite. H: Host rock, Ca: Calcite, Ba: Barite, B: Bitumen, Do: Dolomite, Py: Pyrite, Gn: Galena, Sp: Sphalerite, T: Tetrahedrite. b–h under the PPL and the rest under CPL. the main stage galena because they show evidence of grained quartz (smaller than 50 microns) are found in dissolution and replacement by main-stage galena (Figure dolomite as well as open spaces. It is generally surrounded 5h). Finally, fractures and dissolution cavities were filled by galena. with post-mineralization stage calcite. Secondary minerals: At Ravanj, oxidation processes Barite: Dispersed platy and prismatic crystals, caused formation of Fe-oxyhydroxides, cerussite, bundles, and stellate aggregates of barite, as a few mm to smithsonite, covellite, malachite, and azurite. Oxidation of cm in length, are ubiquitous in open spaces and vugs of sulfide minerals in near-surface condition in most Iranian host rocks. Where barite is a main gangue mineral, ore Pb–Zn deposits could be due to the arid climate and a minerals are generally disseminated among barite grains. low water table (Reichert and Borg, 2008). A summary of Most barite mineralization occurred during and after mineralization paragenesis in the Ravanj deposit is shown main-stage galena mineralization (Figure 5i). in Figure 6. Dolomite: Dolomite occurs as a minor gangue mineral 4.3. Geochemistry formed during pre-main and late-stage mineralization. The Zn/(Zn+Pb) ratios in the Ravanj deposit is low (0.01– Quartz: Trace amount of anhedral to euhedral fine- 0.24 with mean of 0.08). The Mg value is also very low

188 NEJADHADAD et al. / Turkish J Earth Sci

Pre m neral zat on S. M neral zat on Stage Surpegene Calc te C2 C3 Dolom te Pyr te Chalcopyr te Sphaler te Tetrahedr te Galena M Bar te Quartz B tumen Covell te Malach te, Azur te Cerruc te, Goet te

Figure 6. Summary of mineralization paragenesis in the Ravanj deposit, C2: pre-main stage calcite, C3: late-stage calcite, M, main-stage galena.

(average 0.6%), suggesting that extensive dolomitization δ34S values of galena, pyrite, and barite samples from did not take place. The Ag content of whole rock samples the Cs orebody in the Ravanj deposit show a wide range ranges from <2 ppm to 576 ppm, with an average of 80 (Figure 9). This value in sulfide minerals ranges from ppm. Ag shows a moderate positive correlation with Pb –27.32‰ to –11.88‰ and in barite samples from 20.35‰ (r = 0.52) and a strong positive correlation with Sb (r = to 20.92‰. The 34δ S values in galena vary between 0.95) in all samples (Table 5a; Figure 7a). Ag in low grade –27.32‰ and –23.38‰; these values in pyrite range from samples (Ag <53 ppm) shows a higher correlation with Pb –14.21‰ to –11.88‰. (r = 0.66) and a lower correlation with Sb (r = 0.36) (Table 5b; Figure 7c). It is notable that in high grade samples (Ag 4.4. Microthermometry >53 ppm), Ag–Pb correlation decreases to 0.22 and Sb–Ag Fluid inclusion samples were collected from calcite and correlation increases to 0.97 (Table 5c; Figure 7d). barite of the Cs orebodies. Sphalerite was not suitable Total rare earth elements concentration (∑REE) of for microthermometric studies due to its small grain the Jurassic shale ranges from 197.3 to 200.6 ppm. It is size and dark color. Suitable fluid inclusions are found comparable with the ∑REE content of the PAAS (Post in three types of gangue minerals: 1) stage 2 calcite (C2, Archean Australian Shale, 184.69 ppm; McLennan, 1989). Figure 10a) that was deposited before main-stage galena. ∑REE values of unmineralized carbonate host rock are Microthermometric measurements were done on two very low and fall within the narrow range of 2.49 to 2.95 (Figure 10b) and three phase inclusions (Figure 10c) ppm. ∑REE in mineralized samples (13.03–29.68 ppm) of this type of calcite. 2) late-stage calcite (C3) that was is higher than that in the unmineralized host rocks (2.39 deposited after main-stage galena (Figure 10d). 3) barite ppm). The PAAS-normalized REE pattern of the studied that was deposited during and after main-stage galena samples is shown in Figure 8. REE patterns of the Jurassic (Figures 10e and 10f). shale samples show a fractionation of the MREEs [negative Double polished sections were prepared using the (Lu/Ho)PAAS = 0.69–0.74]. Moreover, the Jurassic shale procedure of Shepherd et al. (1985) with a maximum exhibits a positive (La/Lu)PAAS anomaly [(La/Lu)PAAS = thickness of about 100 um. The studied fluid inclusions 1.5–2.3]. Mineralized samples have a negative (La/Lu) consist of a liquid and vapor phase (2–25 µm in size); these PAAS anomaly [(La/Lu)PAAS = 0.22–0.25] (Figure 8a). A are the most common group of inclusions. The liquid/vapor positive Eu anomaly (Eu/Eu* = 2.01–2.40) is seen in ratio (0.75–90) is almost constant in these inclusions. Less both mineralized and unmineralized carbonate samples common monophase liquid (L) and three phase (H2OL (Figure 8b). Mineralized samples display a low negative + CO2L+ CO2V) types were also found. It appears that Ce anomaly (Ce/Ce* = 0.73–0.9), while unmineralized monophase inclusions are secondary in origin. The criteria samples (Ce/Ce* = 0.98) do not show such a negative of Roedder (1984) are used to determine the primary anomaly (Figure 8c). Another notable characteristic of the origin of the fluid inclusions. REE patterns includes (La/Sm)PAAS values <1, except for The first melting temperature of two phase inclusions unmineralized host rock samples. (Te) varies from –59.8 to –37.2 °C, indicating the

189 NEJADHADAD et al. / Turkish J Earth Sci

Table 5. a) Correlation coefficient(r) between some of the major and trace elements in selected samples of the Ravanj deposit.

Ca Mg Ag As Ba Bi Cd Co Cu Fe Ni Pb Sb Zn Ca 1.00 Mg –0.41 1.00 Ag –0.26 –0.17 1.00 As –0.11 –0.26 –0.10 1.00 Ba –0.03 –0.32 0.18 –0.14 1.00 Bi –0.10 0.31 –0.36 0.19 –0.14 1.00 Cd –0.16 –0.22 0.83 –0.08 0.20 –0.34 1.00 Co 0.00 –0.23 –0.33 0.82 –0.13 0.49 –0.28 1.00 Cu –0.14 0.43 –0.24 0.06 –0.40 0.36 –0.31 0.01 1.00 Fe –0.27 –0.07 –0.20 0.72 –0.12 0.51 –0.08 0.80 0.04 1.00 Ni –0.32 0.28 –0.31 0.57 –0.32 0.70 –0.32 0.73 0.43 0.76 1.00 Pb –0.30 –0.43 0.52 0.06 0.28 –0.23 0.42 –0.01 –0.40 0.07 –0.18 1.00 Sb –0.32 –0.03 0.95 –0.10 0.14 –0.32 0.73 –0.40 –0.08 –0.19 –0.26 0.46 1.00 Zn –0.19 –0.16 0.76 –0.06 0.17 –0.22 0.98 –0.20 –0.29 –0.02 –0.23 0.40 0.65 1.00 Values in bold are statistically significant at 99% confidence level (for n = 30)

Table 5. b) Correlation coefficient (r) between some of the major and trace elements in samples with Ag content < 53 ppm.

Ca Mg Ag As Ba Bi Cd Co Cu Fe Ni Pb Sb Zn Ca 1.00 Mg –0.57 1.00 Ag –0.37 0.18 1.00 As –0.01 –0.26 –0.03 1.00 Ba 0.10 –0.27 –0.16 –0.25 1.00 Bi –0.07 0.33 –0.18 0.06 –0.09 1.00 Cd –0.22 –0.39 0.37 –0.08 0.33 –0.56 1.00 Co 0.10 –0.30 0.02 0.85 –0.21 0.28 –0.18 1.00 Cu –0.41 0.53 –0.07 0.08 –0.42 0.38 –0.44 –0.08 1.00 Fe –0.14 –0.15 –0.02 0.80 –0.21 0.43 –0.11 0.87 0.11 1.00 Ni –0.42 0.31 0.11 0.55 –0.35 0.62 –0.36 0.65 0.43 0.79 1.00 Pb 0.08 –0.48 0.66 –0.04 0.24 –0.29 0.64 0.05 –0.48 0.02 –0.15 1.00 Sb –0.36 0.61 0.36 –0.09 –0.30 0.24 –0.14 –0.28 0.66 –0.14 0.21 –0.16 1.00 Zn –0.34 –0.21 0.51 –0.15 0.27 –0.46 0.93 –0.16 –0.44 –0.05 –0.20 0.66 –0.10 1.00 Values in bold are statistically significant at 99% confidence level (for n = 21)

Table 5. c) Correlation coefficient (r) between some of the major and trace elements in samples with Ag content > 53 ppm.

Ca Mg Ag As Ba Bi Cd Co Cu Fe Ni Pb Sb Zn Ca 1.00 Mg 0.06 1.00 Ag –0.16 –0.10 1.00 As –0.65 –0.28 –0.42 1.00 Ba –0.19 –0.15 –0.05 0.03 1.00 Bi –0.31 0.00 –0.63 0.72 –0.10 1.00 Cd 0.03 0.07 0.77 –0.29 –0.08 –0.37 1.00 Co –0.45 –0.02 –0.69 0.81 0.02 0.96 –0.48 1.00 Cu 0.48 –0.29 –0.38 0.04 –0.49 0.29 –0.42 0.20 1.00 Fe –0.61 0.22 –0.37 0.73 0.00 0.67 –0.12 0.77 –0.07 1.00 Ni –0.45 –0.04 –0.53 0.79 –0.19 0.89 –0.39 0.92 0.39 0.83 1.00 Pb –0.66 –0.24 0.22 0.53 –0.24 –0.07 0.02 0.06 –0.29 0.23 0.13 1.00 Sb –0.19 –0.13 0.97 –0.37 0.01 –0.70 0.67 –0.71 –0.35 –0.33 –0.51 0.29 1.00 Zn 0.01 0.12 0.66 –0.19 –0.09 –0.19 0.97 –0.33 –0.40 –0.04 –0.27 –0.04 0.53 1.00 Values in bold are statistically significant at 99% confidence level (for n = 9)

190 NEJADHADAD et al. / Turkish J Earth Sci

450 B 14 y = 0,6776x + 30,112 A y = 0,0139x + 5,1625 400 R² = 0,9094 12 R² = 0,266 350 10 300 8 250 Pb (%)

Sb (ppm) 200 6 150 4 100 2 50 0 0 0 50 100 150 200 250 300 350 400 450 500 550 600 650 0 100 200 300 400 500 600 700 Ag (ppm) Ag (ppm) 300 450 D y = 35,632x + 15,681 C R² = 0,5147 400 250 350 200 300 250 y = -0,1132x + 200,82 As (ppm) 150 Sb (ppm) 200 R² = 0,1214 150 100 100 50 50 0 0 0 200 400 600 800 1000 1200 1400 0 1 2 3 4 5 6 Cu (ppm) Fe (%) Figure 7. Binary diagrams showing correlation between selected elements in the Ravanj deposit, A) Pb vs. Ag in all samples. B) Sb and Ag in all samples. C) Ag vs. Cu in high content Ag samples. D) Fe vs. As in all samples.

1.20 10.00

1.03 1.00 1.00 0.96 0.98 0.90 0.10 0.87 Ce/Ce* 0.80 PAAS normal zed 0.01 0.73 Jurass c Shale1 Jurass c Shale2 h gh grade ore host1 H gh grade ore host2 Low grade ore host Unm neral zed host 0.00 0.60 La Ce Pr Nd Sm Eu Gd Tb Dy Ho Er Tm Yb Lu Sh1 Sh2 Unm n. Host L. ore host H. ore Host1 H. ore Host2 3.00

2.50 2.40 2.00 2.16 2.27 2.01 1.50 0.98 Eu/Eu* 0.98 1.00

0.50

0.00 Sh1 Sh2 Unm n. Host L. ore host H. ore Host1 H. ore Host2 Figure 8. a) PAAS-Normalized REE (McLennan, 1989) patterns of the Jurassic shale (Sh1, 2), mineralized and unmineralized host rock. b and c) Eu/Eu* and Ce/Ce* variation.

191 NEJADHADAD et al. / Turkish J Earth Sci

4 to 22.2 wt% NaCl equiv.), respectively (Figure 11a). Homogenization temperatures range from 141 to 208 °C

3 Bar te for inclusions in barite and 122 to 220.4 °C for inclusions in the late-stage calcite (C3) (Figure 11b). First melting

ma n stage galena temperatures (T ) for CO -bearing inclusions of both 2 e 2 C2 and C3 calcite grains are similar and vary between Frequency colloform pyr te ma n stage pyr te late stage galena –56.7 and –58.1 °C and Tmclat ranges from +1.9 to +7.3 1 °C corresponding to salinities between 5.15 and 13.2 wt% NaCl equivalent (Figure 11c). It seems that salinity of this 0 30 23 18 13 8 3 –2 –7 –12 –17 –22 –27 –30 type of inclusions is low to medium. The homogenization δ34 S temperature of carbonic inclusion range is in the range of Figure 9. Frequency histogram values of δ34S in the Ravanj aqueous inclusions (Figure 11d). Less than 10 mole% CH4 sulfide and sulfate minerals. has been proposed for CO2-rich inclusions (Goldstein and Reynolds, 1994). Inclusions in the pre-main stage calcite (Figure 11e) show a wider range of salinity compared to presence of CaCl2 in addition to NaCl (e.g., Roedder, those in the late-stage calcite and barite (Figure 11f). 1984; Goldstein and Reynolds, 1994). The last ice melting temperature for inclusions hosted by main-stage calcite 5. Discussion ranges from –3.2 to –13.8 °C (5.2–17.6 wt% NaCl equiv.). 5.1. Syngenetic or epigenetic? Microthermometry results for fluid inclusions hosted by Semi-concordant to concordant orebodies in the lower part barite and post-mineralization calcite show the last ice of massive limestone (Km2) in contact with shale without melting temperature ranges from –2.2 to –11.9 °C (3.6 clear relationship with NW-trending normal faults, as to 15.9 wt% NaCl equiv.), and –0.4 to –19.8 °C (0.66 well as mineralized stylolite, fine-grained ore, regional

a b c V L2 C2 L V V L1 L1 V L1

0 250 um 500um 0 15 um 30um 0 15 um 30um d f V e V

V L Ba

0 10 um 20um 0 100 um 200um 0 10 um 20um

Figure 10. Fluid inclusion types in calcite of the Ravanj deposit. a) Primary fluid inclusions in pre-main stage calcite engulfed and dissolved by main stage galena. Location of b and d photomicrographs are shown. b) Two-phase liquid and gas fluid inclusion and three-phase aqueous-carbonic inclusion (L1+L2+V) trapped in the pre-main-stage calcite. c) Two-phase liquid and gas fluid inclusion trapped in the post-main-stage calcite. d) Two-phase liquid and gas fluid inclusion trapped in the pre-main-stage calcite. e) Distribution of primary fluid inclusions in a barite crystal in the ore zone. f) Enlargement of (e). Two-phase liquid and gas fluid inclusion trapped in barite.

192 NEJADHADAD et al. / Turkish J Earth Sci

20 16 A 18 B 14 16 Bar te 12 Ba 14 C2 10 C2 12 C3 8 C3 10 Frequency

Frequency 8 6 6 4 4 2 2 0 0

Sal n ty (wt% NaCl) Th (°C)

3 3 C3 carbon c C3 carbon c C D C2 carbon c C2 carbon c 2 2 Frequency Frequency 1 1

0 0

T (°C) Sal n ty (wt% NaCl) h 400 400 F 350 350 E 300 300 C3 250

250 (°C) Bar te h

C2 T

(°C) 200

h 200 Carb. T Carb. 150 150 100 100 50 50 0 0 0 5 10 15 20 25 30 0 5 10 15 20 25 30 Sal n ty (wt% NaCl Equ v.) Sal n ty (wt% NaCl) Figure 11. Homogenization temperature (a) and salinity (b) histograms of aqueous inclusions. Homogenization temperature (c) and salinity (d) histograms of carbonic inclusions. Salinity–homogenization temperature plots (e and f) for fluid inclusions from the Ravanj. scale disseminated galena mineralization, diagenetic Tire-Vejin district (Figure 12b), and the Goushfil deposit crystallization rhythmites (DCRs), and association of ore (Figure 12c), occur in contact of shale and limestone with framboidal pyrite are structural and textural features (Lisenbee and Uzunlar, 1988; Ghazban et al., 1994; Ehya that suggest mineralization resulted from syn-sedimentary et al., 2010). In the Ravanj deposit, orebodies occur as to syn-diagenetic processes at Ravanj (e.g., Modabberi, concordant to semiconcordant masses where a Km2 1995). member thrusts over the shale or shale-carbonate layers It is notable that most carbonate hosted MVT deposits (Figure 12d). in the Esfahan-Malayer belt in Iran, such as the Emarat Tabular masses occur in many MVT deposits. deposit (Figure 12a), the Vejin-e-Balla orebody in the Anderson (2008) proposed that tabular mineralization

193 NEJADHADAD et al. / Turkish J Earth Sci NW csw6 L mestone csw2 Shale Shale csw1 csw5 csw15 csw4 csw14 F L mestone D B cs4 cs3 S 50m SE S Shale . 50m A Dolom te Irankuh F L mestone 50m Dolom t zed mass ve l mestone Cretaceous upper Shale Cretaceous shale w th th n bedded l mestone ntercalat on Cretaceous mass ve l mestone Ore zone C Shale N N

Figure 12. Cross sections of Lower Cretaceous carbonate hosted deposits in the Esfahan-Malayer Pb–Zn belt. a) N–S cross section of the Emarat deposit (Ehya et al., 2010). b) Unscaled cross section of the Vejin-e-Balla orebody (Lisenbee and Uzunlar, 1988). c) N–S cross section of the Goushfil deposit (Ghazban et al., 1994). d) SE–NW cross section of the Cs orebody of the Ravanj deposit. shows a gas phase control. Sheet-like and tabular bodies bearing gas cap with metals in the ore solution will form form when ore forming solutions flow under a methane fine-grained orebody. However, reaction of sulfate with a gas cap (±H2S, ±CO2). More supersaturated fluid with mainly CH4 gas cap will be slow in the ore forming solution respect to sulfide minerals results in rapid growth and and because of the low rate of sulfate reduction ore would fine-grained deposition of galena and colloform pyrite. be coarse-grained. In the Ravanj deposit, colloform pyrite Anderson (2008) suggested that reaction of the H2S- is consistent with a supersaturated fluid model. Fine-

194 NEJADHADAD et al. / Turkish J Earth Sci grained galena of the main stage and coarse-grained late- Cu stage galena may be evidence of continuous consuming and decreasing of H S in the ore forming fluids. 2 Carbonate Pb-Zn In the Ravanj deposit, ore grade decreases from the 30 SE M ssour (Pb-r ch) 30 lower part to the upper part of orebodies. Due to the Sandstone(Pb-r ch) disseminated Pb mineralization in the Km2 unit, Pb Ravanj(Pb-r ch) background (200 ppm) in the Ravanj area (Samani et 10 10 al., 2010) is much higher than Pb average in limestone (8 ppm). Similar regional trace mineralization has been Pb Zn reported in the Ozark region (Viets and Leach, 1990). Figure 13. Triangular diagram of Pb, Zn, and Cu contents of carbonate and sandstone-hosted ore deposits (after Gustafson Erickson et al. (1988) attributed such mineralization to the and Williams, 1981). The data point of the Ravanj deposit fall passage of a regional scale metal bearing fluid through the in the Pb-rich corner. Ozark MVT province. Rhythmically banded ore is usually developed by cycles of dissolution and open-space filling. The DCRs (Dill et al., 2011). The low content of Ag in the Ravanj ore result from the interaction of hot brines within the host deposit correlates with low temperature mineralization rocks in an open system, long after the lithification (Leach by sedimentary source fluids. The average content of Ag and Sangster, 1993). Sulfide-bearing stylolite is commonly is 80 ppm, which corresponds to the 75th percentile of found with MVT (Leach et al., 2005). statistical values of MVT deposits (Leach et al., 2005). At The fact that mineralization occurs in the hanging wall Ravanj, other trace elements such as Cu, As, Sb, and Au of the thrust faults and other lines of evidence, such as are very low, which is similar to the MVT deposits and epigenetic fault breccia mineralization, replacement ore, dissimilar to magmatic related Pb–Zn deposits (Sagiroglu regional disseminated galena in the Cretaceous carbonate and Sasmaz, 2004; Leach et al., 2005). rock, and absence of exhalative sedimentary rocks in Comparisons between interelement relationships the district, support an epigenetic origin for the Ravanj indicate positive correlation between Pb, Sb, and Ag over mineralization in the best way possible. a wide range of values. High correlation is seen between Pb and Ag in low values of Ag (<53 ppm). A similar 5.2. Geochemistry correlation is found between Sb and Ag at high values of Hydrothermal alteration in the Ravanj deposit manifests Ag (>53 ppm). Silver occurs mainly in galena as inclusions as host rock replacement by sulfide minerals and barite of Ag-bearing minerals such as tetrahedrite (Klein and as well as minor dolomitization. In the MVT deposits, Harbburt, 1993). A positive correlation between Sb and dolomitization is due to the low Ca/Mg ratio of mineralized Cu (r = 0.66) and no distinct correlation between Ag and fluids, high pH, and high rate of reaction between ore Cu (r = –0.07) in low grade Ag (<53 ppm) ore corresponds fluid and host rock (Moore, 1989; Plumlee et al., 1994). to low Ag content of tetrahedrite. The positive correlation The reaction of a dolomite-saturated fluid with a lower between Ag and Sb (r = 0.97) in high grade Ag samples (Ag temperature limestone results in extensive replacement of > 53 ppm) corresponds to high Ag content in tetrahedrite. limestone by dolomite (Plumlee et al., 1994). Mg content ΣREE values of the Ravanj Jurassic shale (197–201 of the Ravanj mineralized host rock is low; however, minor ppm) are more than PAAS (185 ppm, McLennan, 1989). dolomite formed locally. In the Ravanj deposit, calcite The PAAS-normalized REE patterns show differences was dissolved during the main stage of mineralization. between the altered and unaltered wall rock and Jurassic This process consumed +H and increased pH. Low shale. Mineralized rock contains higher ∑REE (with an dolomitization, in contrast to high calcitization, may be average of 13–30 ppm) than unmineralized host rock (2 attributed to the low Mg content of hydrothermal fluids ppm). Mineralized host rocks show HREE fractionation or mixing of two fluids with equal Mg/Ca ratio (Plumlee [(La/Lu) = 0.22–0.25], negative Ce anomaly, and et al., 1994). PAAS positive Eu anomaly. This may be indicative of a different The Ravanj deposit is enriched in Pb compared to Zn, REE source in the mineralized rocks and the Jurassic shale. and has a Zn/(Zn+Pb) ratio lower than 0.1 (Figure 13). In REEs are lithophile elements and their abundances in magmatic related Pb–Zn deposits, the Ag content of galena sulfide minerals (mainly galena) are very low (Morgan is high (generally >1000 ppm, up to 5000 ppm; Qian, and Wandless, 1980). Most barite samples show LREE- 1987). Low Ag values (generally <500 ppm) are reported enriched patterns due to the crystallographic limitations in sedimentary deposits (Qian, 1987). Silver content of the for HREE substitution in barite lattice (Guichard et al., Ravanj deposit is low (2–550 ppm, average 80 ppm). Ag 1979). Barite content in the selected mineralized samples content of <100 ppm is considered to be an indicator of was very low. This may suggest that most features of the low-temperature hydrothermal solutions at shallow depth

195 NEJADHADAD et al. / Turkish J Earth Sci

REE pattern in the Ravanj ore resulted from hydrothermal The inherent weakness of calcite and barite causes calcite rather than barite. High contribution of seawater some inclusions of these minerals stretched before in the hydrothermal fluid causes a typical LREE-depleted homogenization. If partial re-equilibration in soft minerals pattern and results in negative Ce/Ce* values (Lottermoser, occurred, plotting of inclusion size against homogenization 1992; Davies et al., 1998; Ehya, 2012). However, high ƒO2 temperature would show a positive correlation (Bodnar et of hydrothermal fluids during initial weathering in the al., 1989; Wilkinson, 2001). Such a positive correlation is near-surface environment could result in oxidation of seen in the Ravanj barite inclusion (Figure 14a); however, +3 +4 Ce and immobilization as Ce (Chesley et al., 1994). their Th overlapped with other fluid inclusion data (Figure Moreover, a positive Eu anomaly indicates an oxidizing 14b). Barite-hosted inclusions possibly show evidence of depositional environment near the magnetite–hematite very low (+10 °C) partial re-equilibration. or sulfide–sulfate redox equilibria (Sverjensky, 1984b) In a basinal brine model, the brine is saturated with and probably near-surface depositional conditions (Bau, respect to their aquifer constituents (Sverjensky, 1984a). 1991). The Eu associated with hydrothermal solutions was Jurassic shale and Lower Cretaceous strata (terrigenous probably derived from the alteration of feldspathic source Cd member and Ksb shale-carbonate member) at Ravanj rocks (Jebrak et al., 1984). are composed of silicate minerals. Therefore, these fluids The δ34S values of MVT deposits show a wide range have reached saturation with respect to silica. A decreasing from –30‰ to +30‰ and are more negative in their values temperature of ore forming fluid about 10 °C will precipitate than those in SEDEX deposits (–5‰ to +30‰). MVT silica approximately equal to or exceeding the amount of deposits commonly have one or more possible sources precipitated galena (Rowan and Leach, 1989). Therefore, of sulfur (Leach et al., 2005). The temperature of sulfide narrow change in homogenization temperatures of fluid mineralization in the MVT deposits generally exceeds inclusions (+10 °C) in the Ravanj deposit is consistent with conditions of sustaining efficient bacterial processes, low silica precipitation. and therefore bacteriogenic sulfate reduction occurs at Salinity of fluid inclusions ranges widely from 0.66 to a different place and/or time relative to sulfide mineral 18 (with an outlier 22.2) wt% NaCl equivalent (average 8.4 34 deposition (Leach et al., 2005; Wilkinson, 2011). The δ S wt% NaCl equivalent). Variations in the salinity content of values of the Ravanj deposit show at least two sources of fluids can be explained in terms of multiple fluid sources sulfur. Sulfide minerals are enriched in light sulfur (–27‰ and fluid mixing. These fluid inclusions can be subdivided to –23‰ in galena and –14‰ to –11‰ in pyrite) and their into two groups: a higher salinity group with 14 to 18 formation is probably related to bacterial reduction. The (average 15.7) wt% NaCl equivalent and a lower salinity 34 δ S values in barite (20.35‰ to 20.92‰) suggest that group with 0.66 to 8 (average 5.6) wt% NaCl equivalent. the sulfur in barite was derived from upper Cretaceous These two groups are separated from each other by a or Tertiary seawater sulfates. Therefore, a characteristic small group of intermediate salinity inclusions probably fractionation of about 35‰ to 45‰ away from sulfate resulting from fluid mixing between low and high salinity can be suggested for the observed range of δ34S in the fluids (Figure 15). Both fluid types show similar Th, Ravanj deposit. The multiple sulfur sources suggest suggesting isothermal mixing. The higher salinity brine is mixing of reduced light sulfur-bearing fluid with heavy typical of MVT fluids (10–30 wt% NaCl equivalent; Leach sulfate-bearing solution, which caused galena and barite et al., 2005) and lower salinity fluid is similar to seawater mineralization. Various generations of pyrite and galena (5.6 wt% NaCl equivalent; Leach et al., 2005). Densities of have different ranges of isotopic sulfur composition. Early these two fluids are higher than 1 g/cm3 and lower than 1 deposited sulfide minerals have isotopically heavier sulfur 3 34 g/cm , respectively. than later minerals. For example, the δ S values of main- Most fluid inclusions of the pre-main stage stage galena samples (ranging from –23‰ to –25‰) are mineralization calcites show higher salinity than in the heavier than those in the late-stage galena (–27‰). This late-stage calcite. Aqueous–carbonic inclusions of pre- suggests a change in the sulfur isotopic composition of main stage mineralization calcite show lower salinity (5.7 hydrothermal fluid. wt% NaCl equivalent) than post-stage mineralization 5.3. Microthermometry calcite (10.2 wt% NaCl equivalent). These two distinct The homogenization temperatures of fluid inclusions salinity groups support fluid mixing of a lower salinity from the two phase (L+V) and three phase (L1+L2+V) CO2-bearing fluid and a higher salinity brine. Presence inclusions of the pre-main stage calcite, post-main stage of CO2-bearing inclusions with low to medium salinity calcite, and barite range from 122 to 220 °C. Average Th (5.2–13.2 wt% NaCl equivalent) and Th (170–200 °C) values in fluid inclusions of the pre- and post-main stage close to Th of the aqueous inclusions (average 165 °C), calcite are similar (165 and 160 °C, respectively), while Th absence of correlation between temperature and salinity, is slightly higher (175 °C) in barite-hosted inclusions. and absence of gas-rich fluid inclusions that homogenize

196 NEJADHADAD et al. / Turkish J Earth Sci

13 14 12 a b 11 12

10 10 9 8 8 6 7 4 Flu d Inclus on S ze (µm) 6 Flu d Inclus on S ze (µm) 2 C2 5 Bar te C3 4 0 120 140 160 180 200 220 100 150 200 250 T (°C) h Th (°C) Figure 14. Plots of homogenization temperature vs. inclusions size. a) Barite. b) C2 (stage 2 calcite) and C3 (post mineralization calcite). Only inclusions in barite show positive correlation.

C2 C3 bar te as a result of carbonate dissolution provides the ingredients 400 0.6 0.7 0.8 0.9 for later precipitation of calcite. Marcasite forms at low pH (less than about 5) and low 350 1.0 temperatures (below 240 °C; Murowchick and Barnes, 300 1986; St Marie and Kesler, 2000). In the Ravanj deposit,

250 absence of marcasite may indicate that the fluid during ore (°C)

h 1.1 deposition had a pH of >5. The below-neutral pH of the

T 200 fluid is demonstrated by the dissolution of carbonate host

150 rock. At 160 °C, in near-surface (1–5 km) basinal brines, the neutral pH is about 5.8 (Gumez-Fernandez et al., 2000). 100 This suggests that pH values were likely between 5 and 6 50 1.2 during sulfide deposition and dissolution of calcite in the Ravanj deposit. The presence of two fluids with different 0 0 5 10 15 20 25 30 salinity but similar temperature may indicate that near- Sal n ty (wt% NaCl) isothermal mixing of these fluids (possibly having different H2S and metal content) had a role in ore precipitation. Figure 15. Th-salinity diagram of the Ravanj fluid inclusions. The dashed lines show densities (g/cm3) of fluid inclusions (after Association of galena and barite may indicate that one Wilkinson, 2001). of these fluids was oxidized and the other one was sulfur- rich. Total sulfate content of fluid controls precipitation of barite (Hanor, 2001). A CO2-bearing, low salinity fluid to vapor phase are evidences for lack of CO2 effervescence is more reducing than the hematite–magnetite buffer. In (Shepherd et al., 1985; Wilkinson, 2001). such fluid, sulfur is predominantly formed as reduced Precipitation of sulfides and dissolution or precipitation state (Philips and Evans, 2004) and such a condition is of calcite depend on the extent of mixing between two appropriate for barium solubility. Barite has precipitated geochemically distinct fluids (Corbella et al., 2004). either due to mixing of reduced high barium water with Dissolution of calcite shows fluid might have originally oxidized sulfate-rich water (Hanor, 2000) or due to been acidic in nature, or hydrogen ions were produced by oxidation of a reduced sulfur and Ba-rich fluid (Plummer, precipitation of metal sulfides according to the following 1971). Since barite is an insoluble mineral in oxidized reaction: systems, its precipitation defines the mixing zone of 2+ + reduced fluid containing Ba with an oxidized or sulfate- 2H2S +2 Zn = 2ZnS + 4H Hydrothermal dissolution of carbonate requires acidic bearing fluid. fluids and occurred by this reaction: 5.4. Genetic model + 2+ 2CaCO3 + 4H = 2Ca + 2H2O + 2CO2 Textural evidences of the Ravanj ore minerals are 2+ The production of additional Ca and CO2 in the fluid compatible with epigenetic mineralization. Simple

197 NEJADHADAD et al. / Turkish J Earth Sci mineralogy and low Ag, Sb, and Cu content are consistent The Ravanj ore deposit shows similarities with and with MVT deposits (Dill et al., 2011). It appears that differences fom some of the known MVT deposits. Ore deposition of ore at Ravanj is more compatible with mineralization in the Ravanj deposit is similar to that in carbonate-hosted MVT deposits than syngenetic SEDEX the Viburnum Trend deposits; both deposits have Zn/ shale-hosted deposits (Leach et al., 2005) or magmatic (Zn+Pb) < 1, indicating their enrichment in Pb compared Pb–Zn deposits that have complex mineralogy and high to Zn. Stratigraphically, in the Ravanj and Viburnum Trend content of Ag, Sb, Cu, and/or Au (Sagiroglu and Sasmaz, deposits, a sandstone member lies unconformably over 2004; Paiement et al., 2012). the basement and it is overlain by carbonate sequences. In the Ravanj deposit, barite accompanies galena; The best mechanism for ore deposition in the Viburnum however, barite and galena were deposited under different Trend and the Ravanj deposits is fluid mixing (Rowan and geochemical conditions (Hanor, 2000; Kharaka and Hanor, Leach, 1989; Appold and Wenz, 2011). Salinity and Th of 2007). Colloform pyrite and fine-grained galena are Ravanj ore fluids (14–18 wt % NaCl equivalent, 165 °C) is consistent with a sulfur-supersaturated fluid (Anderson, in the lower part of salinity and upper part of Th ranges 2008; Anderson and Thom, 2008) in the Ravanj ore. Fluid of MVT ore fluids (10–30 wt % NaCl equivalent, 90–200 inclusion studies in barite and pre-main-stage and post- °C). Salinity and Th of the Ravanj ore fluids are more main-stage calcite show that two fluids with different comparable with the salinity and Th of Irish Midlands basin salinity but similar Th mixed during mineralization. One ore fluids (8–19 wt % NaCl equivalent). Other features of the fluids had high salinity, probably oxidized, metal- such as epigenetic mineralization, lack of dolomitization, rich with heavy sulfur isotope (~20‰), and the other and Pb-rich characteristic of the Ravanj ore are in contrast one had low salinity, enriched in CO2, and probably light to the early diagenetic, high dolomitization, and Zn-rich isotopic sulfur (–27‰ to –11‰). These two different feature of ore from the Irish Midlands basin deposits. fluids required two distinct aquifers. These aquifers could be basal terrigenous strata (conglomerate, sandstone, and Acknowledgments sandy dolomite; Cd) with a maximum thickness of 50 m, Authors acknowledge the financial support from the and a crushed thrust zone of massive limestone above the Research Committee of Shiraz University. The CEO of organic-rich shale. Minor remnants of framboidal pyrite Ravanj mine, H Slami Ghane, is thanked for providing in the massive limestone of the Ravanj mineralized host unlimited access to the Ravanj deposit and M Hosseini for rock show microbial activity under reduced conditions help during field work. Fluid inclusion microthermometry (Kucha et al., 2010). These aquifers were separated and was carried in the laboratory of the Lorestan University restricted by aquitard shales. Fluids from lower aquifer in Lorestan, Iran. Contributions of Mr Ahmadnejad, migrated along the northeast trending fault conduit to laboratory president of the fluid inclusion lab, are kindly thrust zone where fluid mixing caused co-precipitation of acknowledged. The authors are also grateful to the galena and barite. anonymous reviewers of the Turkish Journal of Earth Sciences for their constructive comments.

References

Alavi M (1994). Tectonics of Zagros Orogenic belt of Iran, new data Anderson GM, Thom J (2008). The role of thermochemical sulfate and interpretation. Tectonophysics 229: 211–238. reduction in the origin of Mississipi Valley-type deposits. II. Carbonate-sulfide relationships. Geofluids 8: 27–34. Alavi M, Vaziri H, Seyed-Emami K, Lasemi Y (1997). The Triassic and associated rocks of the Nakhlak and Aghdarband areas Appold MS, Wenz ZJ (2011). Composition of ore fluid inclusions in central and northeastern Iran as remnants of the southern from the Viburnum Trend, Southeast Missouri District, Turonian active continental margin. Geol Soc Am Bull 109: United States: implications for transport and precipitation 1563–1575. mechanisms. Econ Geol 106: 55–78. Ali Abadi MA (2000). Geochemical and mineralogical studies and Bau M (1991). Rare-earth element mobility during hydrothermal geneses of Ravandje Pb-Ag deposit, Delijan, Central Iran. MSc, and metamorphic fluid-rock interaction and the significance Shiraz University, Shiraz, Iran. of the oxidation state of europium. Chem Geol 93: 219–230. Anderson GM (1975). Precipitation of Mississippi Valley-type ore. Berberian M, King GCP (1981). Towards a paleogeography and Econ Geol 70: 937–942. tectonic evolution of Iran. Can J Earth Sci 18: 210–265. Anderson GM (1991). Organic maturation and ore precipitation in Bodnar RJ, Binns PR, Hall, DL (1989). Synthetic fluid inclusions. VI. Southeast Missouri. Econ Geol 86: 909–926. Quantitative evaluation of the decrepitation behavior of fluid inclusions in quartz at one atmosphere confining pressure. J Anderson GM (2008). The mixing hypothesis and the origin of Metamorp Geol 7: 229–242. Mississippi Valley-type ore deposits. Econ Geol 103: 1683– 1690. 198 NEJADHADAD et al. / Turkish J Earth Sci

Chesley JT, Halliday AN, Kyser TK, Spry PG (1994). Direct dating Klein C, Hurlbut CS (1993). Manual of Mineralogy. New York, NY, of Mississippi Valley-type mineralization: use of Sm-Nd in USA: Wiley. fluorite. Econ Geol 89: 1192–1199. Leach DL, Sangster DF (1993). Mississippi Valley-type lead-zinc Corbella M, Ayora C, Cardellach E (2004). Hydrothermal mixing, deposits. Geolo Assoc Canada 40: 289–314. carbonate dissolution and sulfide precipitation in Mississippi Leach DL, Sangster DF, Kelley KD, Large RR, Garven G, Allen Valley-Type deposits. Miner Deposita 39: 344–357. CR, Gutzmer J, Walters S (2005). Sediment-hosted lead–zinc Davies JF, Prevec SA, Whitehead RE, Jackson SE (1998). Variations in deposits: a global perspective. Econ Geol 100th Anniversary: REE and Sr-isotope chemistry of carbonate gangue, Castellanos 561–608. Zn–Pb deposit, Cuba. Chem Geol 144: 99–119. Lisenbee AL, Uzunlar N (1988). Pb-Zn mineralization at Anjireh- Dill HG, Weiss W, Botz R, Dohrmann R (2011). Paleontological, Vejin mines, Sanandaj-Sirjan zone, Iran. In: Kisvarsanyi G, mineralogical and chemical studies of syngenetic and Grant SK, Pratt WP, Koenig JW, editors. Proceedings Volume epigenetic Pb–Zn–Ba–P mineralizations at the stratotype of of the International Conference on Mississippi Valley type the K/P boundary (El Kef area, Tunisia). Int J Earth Sci 100: lead-zinc deposits: Missouri, University of Missouri-Rolla, pp. 805–846. 180–187. Dixon CJ, Pereira J (1974). Plate tectonics and mineralization in the Lottermoser BG (1992). Rare earth elements and hydrothermal ore Tethyan Region. Miner Deposita 9: 185–198. formation processes. Ore Geol Rev 7: 25–41. Ehya F (2012). Variation of mineralizing fluids and fractionation of Love LG (1962). Biogenic primary sulfide of the Permian REE during the emplacement of the vein-type fluorite deposit Kupferschiefer and marl slate. Econ Geol 57: 350–366. at Bozijan, Markazi Province, Iran. J Geochem Explor 112: Mavrogenes JA, Hagni RD, Dingess PR (1992). Mineralogy, 93–106. paragenesis, and mineral zoning of the West Fork mine, Ehya F, Lotfi MI (2010). Emarat carbonate-hosted Zn–Pb deposit, Viburnum Trend, Southeast Missouri. Econ Geol 87: 113–124. Markazi Province, Iran: A geological, mineralogical and Modabberi S (1995). Geology, facies analysis, mineralogy, isotopic (S, Pb) study. J Asian Earth Sc 37: 186–194. geochemistry and genesis of Ravandje Pb-Ag deposit, Central Emami MH (1996). Kahak map 1:100,000. Geological Survey and Iran. MSc, Tarbiat Modarres University, Tehran, Iran. Mineral Exploration of Iran. Moore CH (1989). Carbonate Diagenesis and Porosity. Amsterdam, Erickson RL, Chazin B, Erickson MS, Mosier EL, Whitney H (1988). the Netherlands: Elsevier. Tectonic and stratigraphic control of regional subsurface Morgan JW, Wandless GA (1980). Rare earth elements in some geochemical patterns, midcontinent, U.S.A. In: Kisvarsanyi hydrothermal minerals: evidence of crystallographic control. G, Grant SK, editors. North American conference on tectonic Geochim Cosmochim Ac 44: 973–980. control of ore deposits and the vertical and horizontal extent of ore systems Proceedings pp. 435–446. Murowchick JB, Barnes HL (1986). Marcasite precipitation from hydrothermal solutions. Geochim Cosmochim Ac 50: 2615– Ghazban F, McNutt H, Schwarcz HP (1994). Genesis of sediment- 2629. hosted Zn–Pb–Ba deposits in the Irankuh district, Esfahan area, west-central Iran. Econ Geol 89: 1262–1278. Philips GN, Evans R (2004). Role of CO2 in the formation of gold deposits. Nature 429: 860–863. Goldstein RH, Reynolds, TJ (1994). Systematics of fluid inclusions in diagenetic minerals. Society of Economic Geologists and Plumlee CS, Leach DL, Hofstra AH, Landis GP, Rowan EL, Viets JC Paleontologists 31: 199 p. (1994). Chemical reaction path modeling of ore deposition in Mississippi Valley type Pb-Zn deposits of the Ozark region, Golonka J (2004). Plate tectonic evolution of the southern margin U.S. midcontinent. Econ Geol 89: 1361–1383. of Eurasia in the Mesozoic and Cenozoic. Tectonophysics 381: 235–273. Qian Zh (1987). Trace elements in galena and sphalerite and their geochemical significant in distinguishing the genetic types of Guichard F, Church TM, Treuil M, Jaffrezic H (1979). Rare earths Pb-Zn deposits. Geochemistry 26: 177–190. in barites: distribution and effects on aqueous partitioning. Geochim Cosmochim Ac 49: 983–997. Rajabi A, Rastad E, Canet C (2012). Metallogeny of Cretaceous carbonate-hosted Zn–Pb deposits of Iran: geotectonic setting Hanor JS (2000). Barite-celestine geochemistry and environments of and data integration for future mineral exploration. Int Geol formation. Rev Mineral Geochem 40: 193–275. Rev 56: 1–24. Hanor JS (2001). Reactive transport involving rock buffered fluids Reichert J, Borg G (2008). Numerical simulation and a geochemical of varying salinity. Geochim Cosmochim Ac 65: 3721–3732. model of supergene carbonate-hosted non-sulfide zinc Jebrak M, Debbah B, Touray JC (1984). Saumures associées aux deposits. Ore Geol Rev 33: 134–151. fluorines filoniennes du Maroc central dans le district d’El Roedder E (1984). Fluid inclusions. In: Ribbe RH, editor. Review in Hammam. Bulletin de Minéralogie 107: 233–240 (in French). Mineralogy, 12. Mineralogical Society of America.

199 NEJADHADAD et al. / Turkish J Earth Sci

Rowan EL, Leach DL (1989). Constraints from fluid inclusions on marcasite (FeS2) from 0° to 200°C and summary of results. U.S. sulfide precipitation mechanisms and ore fluid migration in Geological Survey Open-File Report: 91-310, 27. the Viburnum Trend lead district, Missouri. Econ Geol 84: Sverjensky DA (1984a). Oil field brines as ore-forming solutions. 1948–1965. Econ Geol 79: 23–37. Sagiroglu S, Sasmaz S (2004). Mineralogy and geochemistry of the Sverjensky DA (1984b). Europium redox equilibria in aqueos argentiferous Pb–Zn and Cu veins of the Colaklí area, Elazig, solution. Earth Planet S Lett 67: 70–78. Eastern Turkey. J Asian Earth Sci 23: 37–45. Viets JG, Leach DL (1990). Genetic implications regional and Samani B, Hoseyni M, Shahandeh R, Nejadhadad M (2010). temporal trends in ore fluid geochemistry of Mississippi Lithogeochemical exploration in the Ravanj Mine area, 46p. Valley-type deposits in Ozark region. Econ Geol 85: 842–861. Shelton KL, Gregg JM, Johnson AW (2009). Replacement dolomites Wilkinson JJ (2001). Fluid inclusions in hydrothermal ore deposit. and ore sulfides as recorders of multiple fluids and fluid sources Lithos 55: 229–272. in the southeast Missouri Mississippi Valley-type district: Halogen- 87Sr/86Sr-δ18O-δ34S systematic in the Bonneterre Wilkinson JJ (2010). A review of fluid inclusion constraints on Dolomite. Econ Geol 104: 733–748. mineralization in the Irish ore field and implications for the genesis of sediment-hosted Zn-Pb deposits. Econ Geol 105: Shepherd TJ, Rankin AH, Alderton AH (1985). A Practical Guide to 417–442. Fluid Inclusion Studies. 1st ed. Leeds, UK: Blackie. St. Marie J, Kesler SE (2000). Iron-rich and iron-poor Mississippi Valley-Type mineralization, Metaline district, Washington. Econ Geol 95: 1091–1106. Stanton MR, Goldhaber MB (1991). Experimental studies of the synthesis of f pyrite and

200