filter by: Publication Year
(Descending) Articles
Researches in Earth Sciences (20088299) (4)pp. 179-201
IntroductionEpithermal deposits have been studied by several researchers and their properties have been considered in various respects (Silito & Hednoquist, 2003; Hednoquist et al., 2004).One of the metamorphic magmatic zones in Iran that has always been considered by researchers, is the Urumih-Dokhtar magmatic belt (Bazin & Hubner, 1969; Amin al-Raiei et al., 2017). This belt, as part of the Tethys belt, is one of the most important metallogenic belts in Iran.Recent studies in the Shojaabad region, include Zamani studies (2013). In this research, the geochemistry and genesis of Cu-Au Index of western Shojaabad has been studied and classified as one of the porphyry deposits in relation to one of the Oligomiocene-Miocene intermediate-acidic intrusive rocks.Based on the location of the Cu-Au Index located in the middle part of the Urumieh-Dokhtar belt near to the Natanz Fault, alteration studies, geochemistry, mineralization and fluid inclusions were carried out in the area and finally genesis of the Cu-Au Shojaabad index was determined.Material and methodsDuring field investigations, 20 sample of rocks were randomly sampled from mineralization outcrops and hydrothermal alteration zones. Then, thin and polished thin sections were prepared. In order to highlight hydrothermal alteration, Aster data of study area was prepared and final map of alteration zones was drawn in ArcGIS environment.In the next step, more than 10 samples were selected for geochemical studies. The samples were analyzed by X-ray fluorescence (XRF) method at the University of Isfahan to determine the amount of major elements. Also, to obtain trace and rare earth elements, samples were examined by ICP-MS method at ACME Laboratory of Canada. Moreover, in order to evaluate the formation temperature and the nature of mineralization fluids in the region, 6 samples were selected to study the fluid inclusions. Thermometric measurements of fluid inclusions were carried out in the Department of Geology of Isfahan University.Results and discussionAccording to field surveys and microscopic studies, dominant rocks of the area include volcanic and pyroclastic rocks. The volcanic rocks are often porphyritic and exhibit a more rhyodacitic composition based on microscopic studies.According to the field surveys, processing of ASTER images, and microscopic studies, the presence of argillic alteration in the center of the region and the extension of propylitic alteration around the area is evident.The main texture observed in the ore of the area is disseminate texture. Other textures include replacement, zonal and veinlet textures.Thus, mineralization in the Shojaabad area is disseminated and often associated with quartz veins.Based on the petrographic studies of fluid inclusions, they are predominantly primary fluids and low secondary fluids.The studied fluids’ inclusions are mainly from liquid-rich type, indicating that the mineralization in this region was by hydrothermal solutions and that the mineralization temperature was not high (up to 268 ° C).The homogenization temperature for the two-phase fluid inclusions was 187 to 268 ° C and the salinity was 1.6 to 10.5 wt% NaCl. For the determination of genesis of Shojaabad index, Kesler diagram was used (2005). It is clear that the most concentrated fluid inclusions are in the seawater domain. The magmatic fluid is probably in this range due to cooling and dilution by fluids with less salinity (atmospheric waters). The most important application of fluid inclusions is to determine the characteristics, and evolution of hydrothermal fluids and ultimately the origin or genesis of the deposit. Based on the temperature results obtained from the fluids’ inclusions (homogenization temperature below 300 ° C) as well as low salinity in the region, the study area appears to be part of the epithermal reservoirs.ConclusionMineralogical studies indicate hypogene mineralization with pyrite, chalcopyrite and magnetite minerals and supergene stage with presence of chalcocite, covellite, malachite, hematite and goethite minerals.Based on the fluid inclusion studies, important factors such as the low existence of sulfide minerals in the form of fine and scattered crystals and large amounts of carbonate minerals around the ore mineralization, the Shojaabad index can be considered as low sulfidation epithermal deposits.
Journal of African Earth Sciences (1464343X) 230
The structural system related to iron mineralization in the form of skarn and hydrothermal deposits in the Shizan region, northeastern Iran, has a direct relationship with the geometry of deformations, fractures, faults, and intrusive masses, with their penetrative nature serving as the source of fluid motion. This study aims to investigate tectonic structures, analyze them, identify stress trends and mineralization phases, and illustrate the region's structure. A tectonic model related to mineralization in the Shizan region, situated at the eastern end of the intracontinental Doruneh fault, will be presented. Tectonic events in the area are attributed to the activity of this fault, with a particular focus on the Illeh fault. This fault is an important branch that influences mineralization and morphology. By surveying the faults in the region and analyzing the density of each fault series and mineral trends, two main stress trends were identified: one trending NW-SE and the other NE-SW. The change in stress trends has led to the formation of three generations of faults and mineralization. The first mineralization phase, characterized by the N080-120 trend, occurred within the first stress trend along E-W to NW-SE faults. The subsequent mineralization phase with the N350-070 trend was associated with the second stress trend along N-S to NE-SW faults. Following the N015-060 trend, the final mineralization phase occurred when the second stress trend was reactivated along NE-SW faults. The structural evolution during the initial phase of the stress trend resulted in the formation of horsts, grabens, and half-grabens. The results indicate a clear correlation between the open spaces formed in the fault zones and mineralization, facilitating solution flow and promoting iron precipitation in the first and second phases. © 2025
Ahankoub, M. ,
Shabanian, N. ,
Davoudian, A.R. ,
Bagheri, H. ,
Nasiri, M. Neues Jahrbuch fur Mineralogie, Abhandlungen (00777757) 197(3)pp. 285-301
The Hureh Au-Cu veins are located north of Shahrekord, in the central part of the Sanandaj-Sirjan Zone (SaSZ). Mineralized country rocks consist of Mesozoic volcanic, sedimentary and low-grade metamorphic rocks. Main vein minerals are quartz, adularia, carbonates, pyrite, chalcopyrite, chalcocite, covellite, malachite, azurite, hematite, magnetite and goethite. Mineralization occurs as veins, vein swarms, stockwork, and as disseminated and breccia type with quartz, adularia, illite, calcite, hematite, chlorite and sericite as gangue minerals. The analyzed vein samples show up to 1343 ppm Au and > 10000 ppm Cu. The vein minerals reflect the near neutral-pH and reduced composition of the ore fluid. Micro-thermometric analyses show that the salinity of the ore-bearing fluid was between 6.74 and 10.74 wt% NaCl equiv. Fluid inclusion microthermometry indicates mineralization temperatures between 180° and 290 °C. Minimum pressure at the time of fluid entrapment is estimated at about 50 to 100 bars, equivalent to hydrostatic depths of 110 to 150 m. The main factors that gave rise to the Hureh mineralization are an island arc tectonic setting, presence of fractures and faults, and permeabil-ity of the country rocks. The Hureh mineralization can be classified as a low sulfidation epithermal system. © 2022 E. Schweizerbart’sche Verlagsbuchhandlung, Stuttgart, Germany.
Khosravi, M. ,
Rajabzadeh, M.A. ,
Mernagh, T.P. ,
Qin, K. ,
Bagheri, H. ,
Su, S. Ore Geology Reviews (01691368) 127
The Zefreh porphyry Cu–Mo prospect is located in the central part of the NW-trending Cenozoic Urumieh–Dokhtar Metallogenic Belt, 75 km NE of Isfahan city, central Iran. Chalcopyrite and molybdenite mainly occur as disseminated sulfides in the host rocks and, to a lesser extent, in the surrounding volcanic rocks. Four types of fluid inclusions were identified in quartz-rich veins: i.e., two-phase liquid-rich, two-phase vapor-rich, simple brine, and multi-phase brine inclusions. Liquid-rich inclusions in ore-bearing, A-type quartz veins homogenized between 350° and 370 °C, suggesting that fluids trapped in these inclusions were derived from magmatic fluids at high temperatures. Simple and multi-phase brine inclusions exhibited homogenization or partial homogenization over a wide range from 350° to 1209 °C. The very high homogenization temperatures and the presence of up to six solid phases in multi-phase brine inclusions indicate heterogeneous trapping of melt, fluid, and vapor. The Zefreh porphyry prospect is thought to have formed from hypersaline liquids and vapors that exsolved from a magmatic intrusion assembled in the shallow crust. The δ34S values of sulfides from the Zefreh porphyry prospect range from +0.8‰ to +10.7‰. This indicates that the early, ore-bearing quartz veins dominated by high-δ34S pyrites may have interacted with later hydrothermal fluids, or alternatively, the pyrites are paragenetically late products of propylitic and K-feldspar-dominated potassic alteration assemblages. Another plausible explanation for significantly enriched δ34S values of sulfides may be mixing of hydrothermal fluids of magmatic origin with the Cenozoic seawater (δ34S ≈ +22‰). It is suggested that the Zefreh prospect likely would be a poor target for further exploration. © 2020 Elsevier B.V.
Petrological Journal (22285210) 10(3)pp. 1-24
In this research, the altered and non-altered zones in Marbin exploration area has been determined by VNIR and SWIR wavelengths processing of ASTER satellite images and by False Color composite and band ratio methods. The Marbin exploration area lies in the Urumieh-Dokhtar magmatic belt. The Marbin index is located in the east of the Zefreh fault within the central part of the Zefreh pull apart basin. Rhyolite to dacite are the predominant rock types of the Eocene subvolcanic and volcanic units of the area under study. The spectral of sericite, epidote, calcite and chlorite minerals in this area have been recognized using the Spectral angle mapper (SAM). Finally, with combination of spectral of index minerals in phyllic and propyllitic alteration zones with field observations, petrograghy and geochemical analysis, the alteration zones map in Marbin area have been prepared. As a result, the phyllic and the propyllitic alterations as well as the silicification are index alterations in this area. Based on litho-geochemical analyses, the high Mo/Cu contents, the occurrence of hydrothermal alterations in combination with several other evidences, we concluded that the Marbin index can be introduced as a porphyry deposit with Mo anomaly. This could be indicative of the potential of this area for the molybdenum mineralization in detailed exploration phase. © 2019, University of Isfahan.
Environmental Earth Sciences (18666299) 78(13)
Urmia Lake is one of the greatest salt lakes in the world and is located in the uppermost northwestern regions of Iran. In this study, in addition to trace elements, activity concentration of natural (238U, 232Th and 40K) and artificial (137Cs) radioisotopes are determined in soil and sediment specimens collected from the Urmia Lake shore by adopting gamma ray spectrometry method. The samples are analyzed for trace elements including heavy metals using atomic absorption and ICP-MS techniques. The activity concentration levels were determined for 238U (from 8 to 48 Bq kg−1), 232Th (from 7 to 64 Bq kg−1), 40K (from ≤ MDA to 631 Bq kg−1) and 137Cs (from ≤ MDA to 22 Bq kg−1) with the minimum detectable activity (MDA) of 5, 4, 63 and 4 Bq kg−1, respectively. It seems that except for the cadmium, all of the elements belong to uncontaminated to low contaminated soils group. The least correlation between 137Cs and other elements distribution in the area, confirms its anthropogenic man made source. Based on the cluster and factor analysis methods of data processing, 238U, 232Th and 40K belong to a similar group which in addition to their low geo-accumulation indexes can point to their geogenic sources, related to potassic volcanic rocks. Rare earth elements studies revealed that the main geochemical features of the sediment samples of the lake are affected by the intermediate to felsic Cenozoic volcano-plutonic rocks of the region. © 2019, Springer-Verlag GmbH Germany, part of Springer Nature.
Neues Jahrbuch fur Mineralogie, Abhandlungen (00777757) 195(3)pp. 247-263
The Bagher-Abad fluorite deposit is located ~20 km southeast of Mahallat city (Markazi Province), Central Iran. The vein, veinlet and open-space filling fluorite mineralization are in the Shemshak Formation of Upper Triassic-Jurassic age close to the north margin of the Sanandaj-Sirjan belt and Central Iranian microcontinent. The mineral paragenesis in the studied district includes fluorite (white, purple, and smoky), dolomite, quartz, calcite, barite, hematite, goethite, and a minor amount of pyrite. Low concentration of rare earth elements (REE) in fluorites (9.99 –16.75 ppm) reveal that REE of fluorites have likely originated from surrounding units. The chondrite-normalized REE patterns revealed slight enrichment of light rare earth elements (LREE) relative to heavy rare earth elements (HREE) in both early and late stage fluorites. Geological and geochemical relationships between fluorite mineralization, host rocks, structurally controlled open-space filings, chondrite-normalized REE patterns and the Tb/La-Tb/Ca diagram provide clues to the hydrothermal mineralization processes for the fluorites in this area. Based on the computed Eu and Ce anomaly values of early and late fluorite samples, it can be concluded that the studied fluorites were probably deposited under relatively high oxygen fugacity as a product of interaction between relatively low pH hydrothermal fluids and surrounding carbonates. Our thermometric results based on fluorite hosted fluid inclusions reveal two separate fluid populations-a low homogenization temperature (~103 °C) and higher salinity (up to 20.8 wt.% NaCl equiv.) and a high homogenization temperature (up to 152 °C) and low salinity (~11.5 wt.% NaCl equiv.). The Te (eutectic temperature) values indicate that other components such as CaCl2, KCl, and MgCl2, as well as NaCl were the main components of the mineralization fluids. The Bagher-Abad fluorite deposit is characterized by the post-orogenic event of the Shemshak Formation that is not associated with magmatic activity. The occurrence of open-space filling fluorite mineralization and lack of significant alteration of the associated host rocks are typical features of the studied deposit. These characteristic mineralization in the vicinity of orogenic belt support the idea that the Bagher-Abad fluorite deposit can be considered as a Mississippi Valley-type (MVT). © 2018 E. Schweizerbart’sche Verlagsbuchhandlung, Stuttgart, Germany.
Arabian Journal of Geosciences (discontinued) (18667538) 11(22)
The Laal-Kan fluorite deposit (west of Zanjan city, NW Iran) mainly occurred as some open-space filling and vein/veinlet in the schist of the Paleozoic age. Mineralogically, calcite, fluorite types (white, smoky, and violet), and quartz are the principal constituents accompanied by a number of minor accessory minerals such as hemimorphite, hematite, barite, and clays. Based on chemical analyses, fluorites of various colors were found to have low rare earth element (REE) concentrations (4.16–25.67 ppm). The chondrite-normalized REE patterns indicated that early fluorites were enriched in LREE, relative to HREE, whereas late fluorites were enriched in HREE relative to LREE. This study, therefore, indicated that fugacity of oxygen likely played a significant role in the occurrence of positive Ce and negative anomaly in the late fluorite. Furthermore, the Gd behavior of the fluorite samples could be attributed to the Gd-F complex in ore-forming fluids. On the other hand, low pH hydrothermal fluids under alkaline conditions were probably the main mechanism responsible for the deposition of the early fluorites in this district. Fluorite-hosted fluid inclusion analyses also indicated that fluorite-forming fluids consisted of NaCl, MgCl2, CaCl2, and LiCl with a narrow TH (118–151 °C) and high salinities (18.96–23.47 wt.% NaCl equiv.). Further, the diagram of Tb/La-Tb/Ca ratios revealed that fluorites were predominantly deposited in the hydrothermal environment and the late stage fluorites could be considered as the product of the secondary mineralization of the early fluorites due to the interaction of the fluid with the early fluorites. © 2018, Saudi Society for Geosciences.
Zare, M.R. ,
Kamali, M. ,
Fallahi kapourchali, M. ,
Bagheri, H. ,
Khoram bagheri, M. ,
Abedini, A. ,
Pakzad, H.R. Environmental Science and Pollution Research (09441344) 23(4)pp. 3285-3299
Measurements of natural radioactivity levels and heavy metals in sediment and soil samples of the Anzali international wetland were carried out by two HPGe-gamma ray spectrometry and atomic absorption spectroscopy techniques. The concentrations of 235U, 226Ra, 232Th, 40K, and 137Cs in sediment samples ranged between 1.05 ± 0.51–5.81 ± 0.61, 18.06 ± 0.63–33.36 ±.0.34, 17.57 ± 0.38–45.84 ± 6.23, 371.88 ± 6.36–652.28 ± 11.60, and 0.43 ± 0.06–63.35 ± 0.94 Bq/kg, while in the soil samples they vary between 2.36–5.97, 22.71–38.37, 29.27–42.89, 472.66–533, and 1.05–9.60 Bq/kg for 235U, 226Ra, 232Th, 40K, and 137Cs, respectively. Present results are compared with the available literature data and also with the world average values. The radium equivalent activity was well below the defined limit of 370 Bq/kg. The external hazard indices were found to be less than 1, indicating a low dose. Heavy metal concentrations were found to decrease in order as Fe > Mn > Sr > Zn > Cu > Cr > Ni > Pb > Co > Cd. These measurements will serve as background reference levels for the Anzali wetland. © 2015, Springer-Verlag Berlin Heidelberg.
Ore Geology Reviews (01691368) 66pp. 293-308
The Anarak mining area in Iran is identified as one of the best known examples of mineralization located at the intersection of two important crustal-scale lineaments, which are the E_W striking Great Kavir fault and the NW-SE trending Urumieh-Dokhtar Magmatic Belt. The objective of this research is to investigate the role of the lineaments and their subsidiaries at Anarak area in the genesis of mineral deposits. Lineaments are long-lived features which control or affect ancient as well as young crustal sequences. Lineaments are also deep-seated, because they commonly control the emplacement of deep crustal or mantle-derived magmas. Metallogenic areas of up to ~1000km2 might be observed in areas where broad structural zones intersect, because they can facilitate the localization of magmatic or hydrothermal centers. The two lineaments that intersect in the Anarak area were both very active during mineralization. Therefore, it is likely that pull-apart basins or other dilatational sites at the intersection point were not preserved for substantial lengths of time, and single large magma conduits would have been divided into smaller conduits for magma penetration and hydrothermal circulation. The presence of these small conduits in addition to a small magma input could produce conditions for the circulation of mainly meteoric waters, in which the magmatism has acted as a heat source for the mineralization system. This phenomenon has led to the generation of a metallogenic area with several similar small deposits within a circular area of radius ~30km centered at the intersection point. The two most famous deposits in this area are Talmessi and Meskani in which mineralization had occurred in two separate stages: first stage - fissure-filling copper sulfide mineralization associated with Eocene magmatism (veins, veinlets, and stockworks). The second is an overprinting stage which occurred after a fairly long interval which involves the formation of Ni-Co arsenides and U oxide minerals. © 2014 Elsevier B.V.
Hosseini-dinani, H. ,
Bagheri, H. ,
Esmaeili-vardanjani, M. Arabian Journal of Geosciences (discontinued) (18667538) 8(5)pp. 3007-3018
The Kalchouyeh copper deposit is located about 110 km east of Isfahan, in the Urumieh-Dokhtar magmatic assemblage (UDMA) arc of Iran. Mineralization is closely associated with the calc-alkaline volcanism of the UDMA arc and controlled by northwest–southeast trending strike-slip faults (Qom-Zefreh and Nain-Baft faults). A pull-apart basin along these strike-slip faults has facilitated the localization of magma and related hydrothermal systems and eventually the development of Kalchouyeh mineralization. Copper mineralization occurs mainly as veins and veinlets and is related to two distinct main stages of hypogene and supergene. Hypogene mineralization includes Cu and Pb sulfides (chalcopyrite, pyrite, galena) and Fe oxide (magnetite). Chalcocite and covellite are found in supergene mineralization. Microthermometric measurements of fluid inclusions on two mineralized veins show the presence of two different kinds of ore fluids: (1) low temperature and salinity in relation to vein A (homogenization temperature 175–252 °C, salinity 0.82–4.23 wt.% NaCl) and (2) low to moderate temperature and salinity in relation to vein B (homogenization temperature 255–324 °C, salinity 0.16–9.32 wt.% NaCl). Copper mineralization at Kalchouyeh appears to be epithermal and low-sulfidation in style, and ore deposition was the result of cooling and surface fluid dilution. © 2014, Saudi Society for Geosciences.
Journal Of Environmental Health Science And Engineering (2052336X) 12(1)
Background: The radiological quality of 226Ra, 232Th and 40K in some samples of water resources collected in Anarak-Khour a desertic area, Iran has been measured by direct gamma ray spectroscopy using high purity germanium detector in this paper. Result: The concentration ranged from ≤0.5 to 9701 mBq/L for 226Ra; =0.2 to 28215 mBq/L for 232Th and < MDA to 10332 mBq/L for 40K. The radium equivalent activity was well below the defined limit of 370Bq/L. The calculated external hazard indices were found to be less than 1 which shows a low dose. Conclusion: These results can be contributed to the database of this area because it may be used as disposal sites of nuclear waste in future. © 2014 Ehsanpour et al.; licensee BioMed Central Ltd.
Zarasvandi, A. ,
Zaheri, N. ,
Pourkaseb, H. ,
Chrachi, A. ,
Bagheri, H. Geologos (14268981) 20(3)pp. 201-214
The Permian carbonate-hosted Farsesh barite deposit is located southeast of the City of Aligudarz in the province of Lorestan, Iran. Structurally, this deposit lies in the Zagros metallogenic belt and the Sanandaj-Sirjan Zone. Barite mineralisations occur as open-space flling veins, and as massive and replacement ores along fractures, faults and shear zones of the Permian carbonate host rocks. In order to determine the structure, in addition to pe-trographic and fuid-inclusions studies, an ICP-MS analysis was carried out in order to measure the major as well as the trace and rare earth elements. The Farsesh barite deposit has a simple mineralogy, of which barite is the main mineral, followed by calcite, dolomite, quartz, and opaque minerals such as Fe-oxides. Replacement of bar-ite by calcite is common and is more frequent than space-flling mineralisation. Sulphide minerals are minor and mainly consist of chalcopyrite and pyrite, which are altered by weathering to covellite, malachite and azurite. Petrographic analysis and micro-thermometry were carried out on the two-phase liquid/vapour inclusions in ellipsoidal or irregularly shaped minerals ranging in size from 5-10 μm. The measurements were conducted on fuid inclusions during the heating and subsequent homogenisation in the liquid phase. The low homogenisation temperatures (200-125°C) and low to moderate salinity (4.2-20 eq wt% NaCl) indicate that the barite had precipitated from hydrothermal basinal water with low to moderate salinity. It appears from the major and trace elements that geochemical features such as Ba and Sr enrichment in the barite samples was accompanied by depletion of Pb, Zn, Hg, Cu and Sb. The geochemistry of the rare earth elements, such as low σREE concentrations, LREE-enrichment chondrite-normalised REE patterns, the negative Ce and positive Eu anomalies, the low Ce/La ratio and the positive La and Gd anomalies, suggest that the Farsesh barite was deposited from hydrothermally infuenced sea water. The Farsesh deposit contains low-temperature hydrothermal barite. The scatter plots of the barite (close to sea water) in different areas on the CeN/SmN versus CeN/YbN diagram support the possibility that the barite was formed from seawater-bearing hydrothermal fuids. © 2014 Alireza Zarasvandi et. al.
Kuhanestani, N.M. ,
Mohammadi, B.M. ,
Alderton d.h.m., ,
Tabatabaei s.h., S.H. ,
Bagheri, H. Arabian Journal of Geosciences (discontinued) (18667538) 7(11)pp. 4779-4791
The Ni, Co, As, and Cu deposit of Gowd-e-Morad is located 20 km northwest of Anarak in Central Iran. In this hydrothermal deposit, mineralization occurs as veins in a fault breccia zone hosted by the Chahgorbeh (schist and metabasite) complex. The main ores are made up of Ni, Co, and Cu arsenides. Petrologic studies and results obtained from geochemical analyses have indicated that the Ni, Co, As, and Cu are derived from ultramafic rocks while Pb and Zn are likely to be derived from schist. Based on the geochemical evidence, particularly the high correlation between Ni, Co, and As, it is proposed that this deposit be categorized as a “five elements” mineral deposit. Fluid inclusion studies have shown homogenization temperatures (TH) in the range 113−206 ˚C and salinity 3−13.5 % wt eq. NaCl. Therefore this “five elements” mineral deposit has been determined as a low temperature, epithermal deposit type. It is proposed that the low fluid temperatures are a result of an environment of formation which was distal to a volcanogenic source systems and the major influence of meteoric waters in the hydrothermal system. © 2013, Saudi Society for Geosciences.
Journal of Asian Earth Sciences (18785786) 29(5-6)pp. 651-665
Cu-Ni-Co-As-U mineralization in the Anarak area of central Iran occurs at the intersection of the Uroumieh-Dokhtar magmatic belt with the Great Kavir-Doruneh fault. In the area, the volcanism associated with the magmatic belt is shoshonitic in character. Chemical analyses indicate that these are subduction related magmas. Detailed investigations in the vicinity of the Talmessi mine indicate that mineralization occurred in two separate stages: a first stage of copper sulphide mineralization with a relatively simple mineralogy and associated with the Eocene magmatism, and a second stage of Cu-Ni-Co-As-U mineralization with a complex mineralogy, which probably formed during another phase of deformation in the Upper Miocene. This later deformation reactivated previously formed faults. The mineralogy, element association and isotopic composition of carbonates for the second phase of mineralization suggest a different origin to that of the first phase. The fluids are likely to be non-magmatic in origin, possibly showing an increased input from meteoric waters. The close spatial association with basic/ultrabasic igneous rocks indicates that these may be the source through alteration and remobilization. The arsenide mineralization in the Anarak area shows many features that are similar to those of the classic five-element deposits. © 2006 Elsevier Ltd. All rights reserved.
