Abstract Orogenic gold deposits from the Reefton goldfield in New Zealand hosted in Ordovician metasediments of the Greenland group have produce 67 tons of gold before 1951. The Blackwater mine in Waiuta account for about 1/3 of the gold production at Reefton prior 1951. The ore system at Blackwater consist of NE trending steeply dipping gold-bearing quartz veins (Birthday reef) occurring in faulted, sheared and folded alternating sequence of sandstone-mudstone metamorphosed to low greenschist facies and hydrothermally altered proximal to distal from the quartz vein. Host rock and ore forming fluids interaction resulted in a systematic change in the mineralogy and geochemistry of the wallrock developing a distinctive footprint of the ore system. The mineral assemblage subsequent to hydrothermal alteration is formed by quartz veining, chlorite, carbonates (minor calcite-dolomite-ankerite-siderite), albite, K-Mica and composite quartz-carbonate veining, carbonates spotting, pyrite, arsenopyrite, chalcopyrite, cobaltite, galena and in a lesser extent ullmannite, gersdorffite, pentlandite, millerite and sphalerite. Mass balance calculation based on geochemical data obtained by ultra-low detection analysis with a detection limit in part per trillion of Au, As and Sb provide new insight in the geochemical footprint of the ore system at Blackwater. A clear zone of roughly 40 meters (20 meters above and below the birthday reef) is enriched in Au, As and Sb up to respectively 6806%, 605% and 891% compared to the un-mineralised protolith. Furthermore, mass changes in K2O and Na2O indicate a consistent decrease in Na and increase in K in the vicinity of the Birthday reef reflecting the replacement of albite by K-mica. This is corroborated by pattern of alkali alteration index Na/Al for albite and 3K/Al for K-Mica showing similar trend. Carbonation and de/-hydration index also exhibits peaks in samples adjacent to the Birthday reef, though carbonation index is also influenced by carbonates content in the protolith or late carbonation that may not related to gold mineralisation. Using the indicators above-mentioned it is possible to define the mineralogical and geochemical “footprint” for the ore system in the host rock allowing to use this footprint as a tool for mineral exploration for orogenic gold deposits similar to Blackwater. Given that the geochemical footprint of orogenic gold deposit such as Blackwater is significantly wider than the economically viable part of the deposit defining the footprint of the ore system offers the potential for vectoring from sub-economic mineralisation towards higher-grade ore that is economically viable.

The Fäboliden gold deposit is an ore body in northern Sweden’s Bothnian Basin and has been the subject of studies and test mining since the early 2000s when the Gold Line, an area of anomalously high-Au glacial till in Northern Sweden, became a center of economic interest. The deposit is a hypozonal orogenic gold deposit that displays many characteristic features of ore bodies of this type, including the presence of compound sulfide grains composed of a core of löllingite surrounded by a rim of arsenopyrite, and an abundance of pyrrhotite throughout the deposit and surrounding alteration zone. Laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) was used to first map the distribution of trace elements in several of the arsenpyrite-löllingite grains, then to perform spot analyses of pyrrhotite grains in samples from across the distal and proximal alteration zones of the deposit. The maps of the trace elements in the compound löllingite-arsenopyrite grains show that: As and Au are found in greater abundance in the löllingite than in the arsenopyrite; Cu, Fe, S, and Ti are found in greater abundance in the arsenopyrite than in the löllingite; and Ag, Au, Bi, La, Mn, Pb, Sr, Ti and Tl are found in zones of secondary enrichment along fractures within the grains. Uranium and V may also be enriched along fractures, although this isn’t clear on all of the maps. Gold is an element of particular interest, because its distribution throughout the sulfide phases can be used to constrain the mechanism and relative timing of mineralization within the deposit. The presence of invisible gold within the löllingite, but not within the arsenopyrite, shows that gold is not incorporated into arsenopyrite at high temperatures and will instead be concentrated in the löllingite core of the composite grain and at the margin between the two sulfide phases as the löllingite is altered to arsenopyrite. Previous research on the Fäboliden gold deposit, including geothermometric analysis of vein-hosted graphite within fluid inclusions and garnet-biotite geothermometry as well as structural evidence provided by regional deformation, indicate that mineralization occurred post-peak metamorphism. The textures seen are therefore not conclusive of mineralization occurring syn- or pre-peak metamorphism, as has previously been proposed based on research of orogenic gold deposits in Western Australia. The spot analysis of pyrrhotite samples from across the deposit shows a distinct decrease in Ni and Co content in the proximal alteration zone, suggesting uptake of these elements by other minerals such as the löllingite and arsenopyrite. Multiple analyses performed on single grains show local variation, but are insufficient to establish the presence or determine the character of growth zonation within pyrrhotite.

Quartz and pyrite samples from Pliocene-recent, sub-economic orogenic gold mineralisation in the Southern Alps and Mesozoic economic deposits in the Otago Schist Belt have been analysed for noble gases and halogens. Palaeo-hydrothermal fluids preserved in fluid inclusions were released by crushing and analysed by mass spectrometry. Helium isotope measurements confirm the absence of a mantle-derived fluid component in gold-bearing veins from the Southern Alps and at the large gold deposit at Macraes in Otago. A possible minor mantle helium component is observed in veins within 10km of the Alpine Fault that do not contain gold. Halogen ratios support the absence of mantle-derived fluid and support the presence of a crustal fluid derived from sediments, indicated by high I/Cl ratios. Mixing trends between 40Ar/36Ar and Cl/36Ar indicate mixing between a meteoric-derived fluid or air and crust-derived fluid in all sample types. A correlation between 40Ar/36Ar and 132Xe/36Ar shows that xenon is also sourced from the crustal fluid. Despite a strong crustal-radiogenic Ar signal in some samples, measured neon isotope ratios are atmosphere like. Noble gas elemental ratios show strongly fractionated 20Ne/36Ar away from air-saturated water and air values in deeper formed veins, suggesting air contamination is not dominant. Evidence for the presence of a significant trapped vapour phase is provided by calculated noble gas concentrations in water. Formation of this vapour phase using a two-stage model of de-gassing of meteoric water, and subsequent partial re-dissolution by a Rayleigh fractionation process could account for fractionated 20Ne/36Ar and atmospheric neon isotope ratios. In the Southern Alps, three main types of mineralisation can be identified by noble gas and halogen properties. Deep forming veins contain the most gold and are characterised by 20Ne/36Ar greater than air, 132Xe/36Ar ratios up to 75 times the air value, indicating metamorphic and meteoric fluid components. Some deep ankeritic type veins that display evidence of a CO2-rich component fluid show the highest 20Ne/36Ar ratios. Shallow, late veins have 20Ne/36Ar between air-saturated water and air values, and lower xenon and iodine contents. These veins formed from a boiling rock-exchanged meteoric fluid with a minor metamorphic fluid component and contain less gold. The characteristics of the Nenthorn deposit in Otago are similar to those of the shallow Alpine veins. The economically significant Macraes deposit possibly formed from a meteoric component and a strong metamorphic fluid component derived from the original sediments. This is indicated by the highest levels of excess xenon (relative to air) determined in this study. There is some potential for xenon to be used to fingerprint gold bearing fluids sourced from similar metasedimentary piles in orogenic belts.

PALEOFLUID CHEMISTRY OF OROGENIC GOLD DEPOSITS: NOVEL ANALYTICAL METHODS AND CASE STUDIES FROM THE BOHEMIAN MASSIF Tomáš Hrstka1 1 Charles University in Prague, Faculty of Science, Institute of Geochemistry, Mineralogy and Mineral Resources, Albertov 6, Praha 2, CZ-128 43 Abstract of the Ph.D. Thesis Fluid inclusions represent a unique tool for understanding the processes leading to the formation of mineral deposits and fluid-rock interactions in general. Orogenic gold deposits in the central part of the Bohemian Massif (Libčice and Kasejovice deposits) were studied in order to provide a better understanding of their genesis. A multifaceted approach was adopted including a broad spectrum of micro-analytical methods. While traditional methods were used as the basis of this study (e.g., microthermometry, SEM and optical microscopy), the application and improvement/development of modern analytical methods (e.g., LA-ICP- MS and Raman spectroscopy) or introduction of alternative innovative techniques (CLSM, Nano- tomography, QEMSCAN) constituted a significant part of this study. This study reveals the importance of the HCO3 - species in hydrothermal fluids (i.e., >100 řC to ~350 řC). Previously, the prevalence of Cl- and other anions was reported for hydrothermal paleofluids and the majority of studies suggested...

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No. of bitstreams: 1 Dissertação - Andrés H Z Riveros.pdf: 7865960 bytes, checksum: 0f87630d48c333d2901830046a8e84e1 (MD5) Previous issue date: 2014-10-07 / CNPq - Conselho Nacional de Desenvolvimento Científico e Tecnológico / In the Pitangui region, extreme NW in the Quadrilátero Ferrífero-MG, meta-volcano-sedimentary rocks outcrop, characteristics of a greenstone belt sequence type contained in the Group Nova Lima (Rio das Velhas Supergroup), which host the auriferous deposit Satinoco. Conventional petrographic and SEM analysis, of the host rock, of hydrothermal alteration zones, and of mineralized rock as well as specific chemical analysis in pyroxene, garnet, amphibole, feldspar, chlorite and sulphides were performed to characterize the metallogenic evolution of the mineralizing processes in Satinoco and determine the equilibrium conditions during prograde metamorphism, of the metamorphic peak and retro-metamorphism. The metamorphic peak paragenesis is marked by mineral associations almandine ± biotite ± hornblende ± grunerita-cummingtonite, hornblende ± plagioclase and by pyroxene recrystallization. The mineral association combined with mineral chemistry revealed evidence of metamorphism in conditions of facies amphibolite with temperature of 663 oC to 717 oC (geothermometer plagioclase - amphibole), as well as pressure on roughly 9 Kbares (Al-Amphibole). The tectonometamorphic events may have occurred during the Neo-Archean to the Proterozoic generating two dominant Sn foliation and Sn+1 of crenulation and transpressive transcurrent structures activation. To these structures, hydrothermal processes and polymetallic mining of orogenic type were linked which generated deposition the auriferous ore of Satinoco. The ore mineral is docked as discontinuous bodies arranged in transpressive shear zone with orientation of 306°-315°/45°-60°E. The mineralization in Satinoco is arranged stratigraphically within the basal sequences of the Nova Lima Group, structurally controlled in the direction NW-SE, hosted on metapiroxenite at the base and mica-amphibole schist at the top, and associated with areas of hydrothermal alteration. Minerals derived from fluid - host rocks interactions were associated with processes of silicification, sulfidation, chloritization, epidotization, carbonation, sericitization, and uralitization. Such effects are spatially distributed according to the shear zone deformation. The auriferous ore geneses is related to two pulses of mineralizing fluids: i) sulphides of Fe, As, Cu, Zn, Pb, and ii) a second generation of sulfides of Fe, As, Au, Cu. According to the chlorite composition characteristics, it was formed in a temperature between 390 oC and 457 oC. These temperatures would be indicative of chemical equilibrium conditions during retrograde metamorphism that reached greenschist facies metamorphic, and of the conditions under which acted hydrothermal processes derived from the fluids percolation during ore genesis, reaching greenschist metamorphic facies. We postulate that the auriferous deposit in Satinoco has metallogenetic features of epigenetic type, similar to the deposits of orogenic gold type, comparable to the metallogenetic features of other exploited deposits in the Quadrilátero Ferrífero, which are considered largest deposits. / Na região de Pitangui extremo NW do Quadrilátero Ferrífero (MG), afloram rochas metavulcanossedimentares, características de uma sequência tipo greenstone belt contidas no Grupo Nova Lima (Supergrupo Rio das Velhas), as quais hospedam a jazida aurífera Satinoco. Análises de petrografia convencional e MEV, da rocha encaixante, de zonas de alteração hidrotermal, da rocha mineralizada, assim como, análises químicas pontuais em piroxênio, granada, anfibólios, feldspatos, clorita e sulfetos foram realizadas para caracterizar a evolução metalogenética dos processos mineralizantes em Satinoco e determinar as condições de equilíbrio durante o pico metamórfico e do retrometamorfismo. A paragênese do pico metamórfico está marcada pelas associações minerais almandina ± biotita ± grunerita-cummingtonita ± hornblenda, hornblenda ± plagioclásio. A associação mineral revelou evidências de metamorfismo em condições de fácies anfibolito, com temperatura do pico metamórfico de 663 oC até 717oC (Geotermômetro plagioclásio – anfibólio) e pressão em aproximadamente 9 Kbares (Al-Anfibólio). Eventos tectonometamórficos geraram duas foliações: Sn dominante e Sn+1 de crenulação e ativação de estruturas transcorrentes transpressivas. A estas estruturas, foram vinculados processos hidrotermais e de mineração polimetálica de tipo orogenético que gerou a deposição do minério aurífero Satinoco. O minério forma corpos descontínuos dispostos em zona de cisalhamento transpressiva com atitude 306°-315° / 45°-60°NE. A mineralização em Satinoco se dispõe estratigraficamente dentro das sequências basais do Grupo Nova Lima, estruturalmente controlada na direção NW-SE, hospedado em metamáficas-ultramáficas na base e mica-anfibólio xisto no topo, e associada a zonas de alteração hidrotermal. Minerais derivados da interação fluido - rocha encaixante foram associados a processos de silicificação, sulfetação e cloritização, epidotização, carbonatação, sericitização e uralitização. Tais efeitos se distribuem espacialmente paralelos à deformação vinculada à zona de cisalhamento. A gênese do minério aurífero se relaciona a dois pulsos de fluidos mineralizantes: i) sulfetos de Fe, As, Cu, Zn, Pb, e ii) uma segunda geração de sulfetos de Fe, As, Au, Cu. Segundo as características de composição da clorita, está se formou em temperatura variando entre 390 oC e 457 oC. Estas temperaturas seriam indicativas das condições de equilíbrio químico durante o metamorfismo retrógrado que atingiu a fácies metamórfica xisto verde, e das condições nas que atuaram os processos hidrotermais derivados da percolação de fluidos durante a gênese do minério. Postulamos que a jazida aurífera em Satinoco tem características metalogenéticas de tipo epigenética, similares às dos depósitos tipo orogenic gold, comparáveis às feições metalogenéticas de outros depósitos explorados no Quadrilátero Ferrífero, de grande porte.

Cette thèse correspond à une étude comparative détaillée de trois gisements aurifères birimiens (~ 2 Ga) du craton ouest africain (Syama, Tabakoroni et Tellem), situés sur la ceinture de Bagoé au Mali. La minéralisation se concentre dans les roches où les structures de déformation fragile sont les plus développées (basaltes et métasédiments bréchifiés, microgranite à Tellem) et se développe préférentiellement en bordure des veines. Les sulfures majeurs (pyrite à Syama et pyrite + arsénopyrite à Tabakoroni et Tellem) sont zonés avec : i) un cœur arsénifère riche en inclusions d'albite, d'ankérite et de rutile (accessoirement pyrrhotite); ii) une bordure limpide, globalement moins arsénifère que le coeur mais présentant une fine zonation avec des alternances de zones riches en As et de zones pauvres en As. L'or se présente sous forme d'or invisible inclus dans le réseau cristallin des sulfures, de petits grains individualisés en inclusion dans les sulfures, souvent accompagnés de sulfoantimoniures, notamment la tétraédrite et la chalcostibite, et d'or libre associé au quartz. Les pyrites arsénifères et les arsénopyrites des gisements de la ceinture de Bagoé sont parmi les plus riches en or invisible de tous les gisements d'or de l'Afrique de l'Ouest et tout à fait comparables à ceux de la ceinture d'Ashanti au Ghana. / This thesis presents a comparative study of the Syama, Tabakoroni and Tellem gold deposits, located in the N-S trending Bagoé greenstone belt of Mali. Mineralization is found preferentially along the edges of millimetre- to centimetre-sized quartz, quartz-albite, quartz-ankerite, dolomite-quartz veins developed in tension gaps that formed during brittle deformation. Gold mineralization is mostly associated with pyrite in the three deposits, and also with arsenopyrite at Tabakoroni and Tellem. These sulphides are zoned with (i) an arsenic-rich core containing several albite, ankerite and rutile inclusions (less commonly, pyrrhotite) and (ii) a clear border of finely alternating As-rich and As-poor bands. Gold occurs in the form of i) invisible gold included in their crystal lattices, ii) small individual grains bound to these sulphides, frequently accompanied by sulphoantimonides, mainly tetrahedrite and chalcostibite and iii) free gold associated with quartz. The arseniferous pyrites and arsenopyrites of the Bagoé belt deposits are among the richest in invisible gold in all gold deposits in West Africa and are quite comparable to those of the Ashanti Belt in Ghana.

[Formulae and special characters can only be approximated here. Please see the pdf version of the abstract for an accurate reproduction.] The formation of world-class Archean orogenic gold deposits in the Eastern Goldfields Province of Western Australia was the result of a critical combination of physical and chemical processes that modified a single and widespread ore-fluid along fluid pathways and at the sites of gold deposition. Increased gold endowment in these deposits is associated with efficient regional-scale fluid focusing mechanisms and the influence of multiple ore-depositional processes at the deposit-scale. Measurement of the complexity of geologic features, as displayed in high-quality geologic maps of uniform data density, can be used to highlight areas that influence regional-scale hydrothermal fluid flow. Useful measurements of geological complexity include fractal dimensions of map patterns, density and orientation of faults and lithologic contacts, and proportions of rock types. Fractal dimensions of map patterns of lithologic contacts and faults highlight complexity gradients. Steep complexity gradients, between domains of high and low fractal dimensions within a greenstone belt, correspond to district-scale regions that have the potential to focus the flow of large volumes of hydrothermal fluid, which is critical for the formation of significant orogenic gold mineralization. Steep complexity gradients commonly occur in greenstone belts where thick sedimentary units overly more complex patterns of lithologic contacts, associated with mafic intrusive and mafic volcanic units. The sedimentary units in these areas potentially acted as seals to the hydrothermal Mineral Systems, which resulted in fluid-pressure gradients and increased fluid flow. The largest gold deposits in the Kalgoorlie Terrane and the Laverton Tectonic Zone occur at steep complexity gradients adjacent to thick sedimentary units, indicating the significance of these structural settings to gold endowment. Complexity gradients, as displayed in surface map patterns, are an indication of three-dimensional connectivity along fluid pathways, between fluid source areas and deposit locations. Systematic changes in the orientation of crustal-scale shear zones are also significant and measurable map features. The largest gold deposits along the Bardoc Tectonic Zone and Boulder-Lefroy Shear Zone, in the Eastern Goldfields Province, occur where there are counter-clockwise changes in shear zone orientation, compared to the average orientation of the shear zone along its entire length. Sinistral movement along these shear zones resulted in the formation of district-scale dilational jogs and focused hydrothermal fluid-flow at the Golden Mile, New Celebration and Victory-Defiance deposits. Faults and lithologic contacts are the dominant fluid pathways in orogenic gold Mineral Systems, and measurements of the density of faults and contacts are also a method of quantifying the complexity of geologic map patterns on high-quality maps. Significantly higher densities of pathways in areas surrounding larger gold deposits are measurable within 20- and 5-kilometer search radii around them. Large variations in the sulfur isotopic composition of ore-related pyrites in orogenic gold deposits in the Eastern Goldfields Province are the result of different golddepositional mechanisms and the in-situ oxidation of a primary ore fluid in specific structural settings. Phase separation and wall-rock carbonation are potentially the most common mechanisms of ore-fluid oxidation and gold precipitation. The influence of multiple gold-depositional mechanisms increases the potential for significant ore-fluid oxidation, and more importantly, provides an effective means of increasing gold endowment. This explains the occurrence of negative δ34S values in ore-related pyrites in some world-class orogenic gold deposits. Sulfur isotopic compositions alone cannot uniquely define potential gold endowment. However, in combination with structural, hydrothermal alteration and fluid inclusion studies that also seek to identify multiple ore-forming processes, they can be a useful indicator. The structural setting of a deposit is also a potentially important factor controlling ore-fluid oxidation and the distribution of δ34S values in ore-related pyrites. At Victory-Defiance, the occurrence of negative δ34S(py) values in gently-dipping dilational structures, compared to more positive δ34S(py) values in steeply-dipping compressional structures, is potentially associated with different gold-depositional mechanisms that developed as a result of fluid-pressure fluctuations during different stages of the fault-valve cycle. During the pre-failure stage, when fluids are discharging from faults, fluid-rock interaction is the dominant gold-depositional mechanism. Phase separation and back-mixing of modified ore-fluid components are dominant during and immediately after faulting. Under appropriate conditions, any, or all, of these three mechanisms can oxidize orogenic gold fluids and cause gold deposition. The influence of multiple gold-depositional mechanisms during fault-valve cycles at dilational jogs, where fluid pressure fluctuations are interpreted to be most severe, can potentially explain both the large gold endowment of the giant to world-class Golden Mile, New Celebration and Victory-Defiance deposits along the Boulder-Lefroy Shear Zone, and the presence of gold-related pyrites with negative δ34S values in these deposits. This study highlights the interplay that exists between physical and chemical processes in orogenic gold Mineral Systems, during the transport of ore fluids in pathways from original fluid reservoirs to deposit sites. Potentially, a single and widespread orogenic ore-fluid could become oxidized, and lead to the formation of ore-related sulfides with variable sulfur isotopic compositions, depending on the nature and orientation of major fluid pathways, the nature of wall-rocks through which it circulates, and the precise ore-depositional processes that develop during fault-valve cycles.

Cette thèse visait à mieux définir les méthodes de ciblage et apporter des éléments de réponse sur la genèse des gisements d’or de type orogénique en périphérie des grands couloirs de déformation archéens. Cette thèse est présentée sous forme de trois articles. Le premier article traite de la distribution mathématique des gisements aurifères de type orogénique le long des grands couloirs de déformation. Une approche permettant de d’établir que la localisation des gisements se situant le long de structure de premier ordre n’est pas indépendante de la localisation de ses voisins a été développée. Cette approche permet de donner des éléments de réponse sur la formation de ces gisements et de générer des probabilités de découvertes à l’échelle régionale. La deuxième partie de cette présente une méthode l’évaluation du potentiel minéral sous couverture sédimentaire en 3D. Les teneurs aurifères compilées dans le secteur ont permis d’évaluer et de quantifier les relations spatiales existantes entre certaines entités géologiques et les emplacements minéralisés afin de cibler les endroits à haut potentiel. Enfin, les travaux présentés dans le dernier chapitre visent à délimiter les zones possédant une perméabilité structurale accrue lors de l’épisode de déformation contemporain à la mise en place de gisements aurifères de type orogénique. Une modélisation géomécanique 3D qui tient compte des propriétés physiques des roches a été effectuée sur un segment de faille choisi en utilisant un code d’élément fini. La déformation s’effectue en attribuant sur chaque discontinuité structurale des vecteurs ou des champs de déplacement en fonction des observations de terrain / This thesis had the objective to define targeting methods adapted to orogenic gold deposits hosted in greenstone belts and to better understand the formation mechanism of these deposits. The work accomplished is presented in three distinct articles. The first article aimed to determine if a mathematical relation can characterize the spatial distribution of orogenic gold deposits along a crustal scale fault zone within or if the localization of a deposit is independent of the position of each other. A uniform law was fitted between the frequency and the curvilinear inter-distance between successive orogenic gold occurrences along the CLLF for distances ranging from 315 to 5600 m. This approach gave insights on the formation mechanism and allowed the generation of a probability map for undiscovered deposits at a regional scale. The second chapter of this thesis focuses on a sector of the Cadillac Larder Lake Fault that was considered as having a high potential for discovery using the methodology presented in the last chapter. Compiled assays allowed the evaluation of the spatial association of certain geological features with orogenic gold mineralizations to allow targeting high potential areas. Finally, the work presented in the last chapter aimed at identifying dilatant zones during the deformation that is contemporaneous to the orogenic gold deposit formation. A 3D geomechanical modelling which takes rock properties into account was performed on a chosen segment of a fault zone using a finite element code. The deformation was induced using displacement vectors or fields interpreted from field data

Ädelfors is situated ca 17 km east of Vetlanda, Jönköping County, in the N-S striking Trans-scandinavian igneous belt and is a part of the NE-SW striking 1.83-1.82 Ga Oskarshamn-Jönköping belt emplaced during a continental subduction towards the Svecofennian continental margin. The continental arc hosts the 1.83 Ga metasedimentary Vetlanda supergroup composed of foliated metagreywacke, metasandstone and metaconglomerate. The sequence is intercalated by mafic and felsic volcanites and hosts the Cu-Au-Fe-mines at Ädelfors. Ädelfors mining field consists of ca 330 mineralized quartz veins hosting both copper, gold and iron. The iron mines Nilsson’s iron mine (NFE) and Fe-mine (FE), the copper mine Kamelen (KM) and the gold mines Brånad’s mine (BR), Adolf Fredrik’s mine (AF), Old Kron mine (GKR), Old Kolhag’s mine (GKO), Thörn mine (TH), New Galon mine (NG), Stenborg’s mine (ST), Tysk mine (TG), Hällaskallen (HS) and Fridhem (FR) have been investigated to deduce a possible genetic relation between the veins and their origin. Sulfur isotope ratios have also been conducted on pyrite from KM, AF and FE. The veins can stucturally be divided into several groups. AF, GKR, ST, NG, TH and possibly NFE are striking 10-70° with a dip of 55-70°. BR, GKO and KM are striking 110-140° with a dip of 80-90° whereas TG and HS strike 90-110° dipping 85°. Fridhem, being distal to the other mines, strikes 70° and dips 80°. A chlorite-quartz-biotite-sericite-rich metapelite hosts the veins in all localities except; FR where a layered, beresitizised felsic volcanite rich in plagioclase, sericite, biotite and quartz hosts disseminated pyrite; and NFE, HS and NG which are hosted by a mafic tuffite. Quartz veins are mainly milky and equigranular, exceptions are FE with black pyrite-bearing quartz veins, cutting through the banded magnetite-metapelite and KM with its dynamically recrystallized quartz. Chlorite-, zeolite-, carbonate-, hematite-, amphibole-, kalifeldspar-, sericite-, biotite- and epidote alteration has been observed among the localities. The ore minerals are dominated by: fractured sub- to euhedral pyrite in cataclastic aggregates or selvage bands, interstitial chalcopyrite in pyrite, marcasite, pyrrhotite, gold and sporadic chalcopyrite diseased sphalerite and arsenopyrite. Previously not reported tetradymite, staurolite, galena and Ce-monazite have also been observed. Bismuthinite and tetradymite as inclusions in pyrite were observed in AF, GKR, FR and TG. Gold was observed in AF, BR, GKR and TG as inclusions in pyrite or quartz with a Au/Ag median of 78.41. HS distinguishes itself with Au/Ag ratios of 4.66-5.25. The trace element ratios in pyrite reveal two major types of pyrite. 1) found in FE and KM (pyrite type 1) with Co/Ni ratio of 10.94, Bi/Au of 1.79, Bi/S of 0.037, Au/Ag of 11.13, S/Se of 235.96 and As/S of 0.006. 2) found in NG, GKO, ST, TH, AF, NFE, HS, GKR, BR, FR, TG and as stringers in KM4 py1 pyrite type 2) with an average Co/Ni ratio of 5.26, Bi/Au of 1.95, Bi/S of 0.031, Au/Ag of 4.19, S/Se of 0 and As/S of 0. δ34S values strengthens this grouping as KM and FE has 1,3-2,6 ‰ and AF 3,6-3,8 ‰. The following geological interpretation has been concluded: The banded iron formation in FE is the earliest mineralization and was later fractured, emplacing quartz veins with pyrite of type 1. During this event, the Cu-vein in KM was also formed. A second generation of fractures, emplaced after the Småland granitoids formed, were filled with quartz and pyrite of type 2 at mesozonal depth. This is the main stage of gold mineralization and includes NG, GKO, ST, TH, AF, NFE, GKR, BR, FR and TG. During this event, pyrite of type 2 was added to KM, causing recrystallizing of the quartz. HS is possibly emplaced last or altered as it is more enriched in silver. Morphology, mineralogy, alterations, mineral chemistry and sulfur isotope signatures indicates an orogenic origin of the gold-rich quartz veins at Ädelfors as well as the copper-rich vein in KM. / Ädelfors ligger ca 17 km öster om Vetlanda, Jönköpings län, i det N-S strykande Transskandinaviska granit och porfyrbältet och är en del av det NÖ-SV strykande 1,83-1,82 Ga Oskarshamn-Jönköpingsbältet (OJB) bildad i en kontinental subduktionszon i kanten av den Svecofenniska kontinentalplattan. I denna kontinentalbåge ligger Vetlanda supergruppen som är en metasedimentär del av OJB bestående av starkt folierad 1,83 Ga metagråvacka, metasandsten och metakonglomerat med inlagringar av mafiska och felsiska vulkaniter. Ädelfors gruvfält består utav ca. 330 kvartsgångar förande mestadels guld men också koppar. Järnmineraliseringar i form av bandad järnmalm finns också i området. Geologin, mineralogin och pyritens kemiska sammansättning från järngruvorna Nilssons järngruva (NFE) och Fe-gruvan (FE), koppargruvan Kamelen (KM) och guldgruvorna Brånadsgruvan (BR), Adolf Fredriks gruva (AF), Gamla Krongruvan (GKR), Gamla Kolhagsgruvan (GKO), Thörngruvan (TH), Nya Galongruvan (NG), Stenborgs gruva (ST), Tyskgruvan (TG), Hällaskallen (HS) och Fridhem (FR) har undersökts för att finna eventuella genetiska likheter. Svavelisotopförhållande har fastställts för pyrit från AF, FE och KM. Strukturellt kan gångarna delas in i ett antal grupper. AF, GKR, ST, NG, TH och möjligtvis NFE stryker 10-70° och stupar 55-70°. BR, GKO och KM stryker 110-140° och stupar 80-90° medan TG och HS stryker 90-110° och stupar 85°. Fridhem stryker 70° och stupar 80°. En klorit-kvarts-sericit-biotitrik metapelit utgör värdbergarten i alla gruvor förutom; FR där den utgörs av en beresitiserad felsisk vulkanit rik på plagioklas, sericit, biotit och kvarts med disseminerad pyrit; och NFE, HS, NG vilka har en mafisk tuffitisk moderbergart. Kvartsgångarna är mjölkvita med undantag för FE:s svarta, pyritförande kvarts vilket uppträder som sprickfyllnad i den bandade järnmalmen och är senare bildad. Kvartsen i KM är starkt dynamiskt omkristalliserad. Svag till måttlig foliation är vanlig i sidoberget med undantag av stark foliation i TG och NFE, vilka är lokaliserade i förkastningssprickor med stark kloritförskiffring av värdbergarten. Klorit-, zeolit-, karbonat-, hematit-, amfibol-, kalifältspat-, sericit-, biotit- och epidotomvandling förekommer i majoriteten av lokalerna. Malmmineralen är dominerande sprött deformerad subhedral till euhedral pyrit som kataklastiska aggregat eller band, interstitiell kopparkis i pyrit, markasit, magnetkis, guld och sporadiskt kopparkissjuk zinkblände och arsenikkis. I det här arbetet har även tetradymit, staurolit, blyglans och Ce-monazit observerats. Bismutinit och tetradymit i form av inneslutningar i pyrit observerades i AF, GKR, FR och TG. Guld observerades i AF, BR, GKR och TG som inneslutningar i pyrit eller fritt i kvarts med Au/Ag medianvärde på 78,41, avvikande är HS med värden mellan 4,66-5,25.    Förhållanden mellan spårelement i pyrit indikerar två typer av pyrit. Typ 1 funnen i FE och KM har följande värden: Co/Ni = 10,94, Bi/Au = 1,79, Bi/S = 0,037, Au/Ag = 11,13, S/Se = 235,96 och As/S = 0,006. Typ 2 funnen i NG, GKO, ST, TH, AF, NFE, HS, GKR, BR, FR, TG och som sliror i KM4 py1 har följande värden Co/Ni = 5,26, Bi/Au = 1,95, Bi/S = 0,031, Au/Ag = 4,19, S/Se = 0 and As/S = 0. δ34S värden styrker denna uppdelning där KM och FE har värdena 1,3-2,6 ‰ och AF 3,6-3,8 ‰. Den geologiska utvecklingen av fältet har tolkats som följande: FE-gruvans bandade järnmalm är den tidigaste mineraliseringen vilket följs utav uppsprickning och läkning av kvarts med pyrit typ 1 som också bildar kopparmineraliseringen KM. Senare sprickzoner efter Smålandsgraniternas intrusion läks av kvarts med pyrit typ 2 på mesozonalt djup vilket bildar NG, GKO, ST, TH, AF, NFE, GKR, BR, FR, TG och omkristalliserar och introducerar nya pyritsliror i kvartsen i KM. HS bildas möjligtvis sist eller har blivit omvandlad eftersom den är anrikad på silver. Morfologi, omvandlingar och svavelisotop-signaturer tyder på ett orogent ursprung för Ädelfors guldrika kvartsådror samt den kopparrika kvartsådern i KM.