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Publications (10 of 15) Show all publications
Warlo, M., Wanhainen, C., Bark, G., Butcher, A., McElroy, I., Brising, D. & Rollinson, G. (2019). Automated quantitative mineralogy optimized for simultaneous detection of (precious/critical) rare metals and base metals in a production-focused environment.
Open this publication in new window or tab >>Automated quantitative mineralogy optimized for simultaneous detection of (precious/critical) rare metals and base metals in a production-focused environment
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2019 (English)Manuscript (preprint) (Other academic)
Abstract [en]

Automated Scanning Electron Microscopy (ASEM) systems are widely applied in the mining industry to quantify the mineralogy of the ore feed and subsequent products generated during processing. With society pushing more and more towards sustainable mining, this quantification should be as comprehensive as possible to serve as basis for a more complete utilization of the ore. The quantification of trace minerals is of particular interest since they are often either deleterious or potential by-products which would add revenue to the operation. Systems like QEMSCAN® offer a mode specifically designed towards trace mineral analysis (TMS mode); however, it comes with inherent drawbacks. It is not comprehensive and the presence of some heavy minerals like galena can drastically increase time of analysis. For a routine application in the mining industry where major ore minerals and gangue phases require analysis this mode is unsuitable. Here, we investigate the potential of detecting micron-sized trace minerals in a comprehensive analysis using the QEMSCAN® system with analytical settings in line with the mining industry. For quality comparison, analysis was performed at a mining company and a research institution. This novel approach was done in full collaboration with the authors. Results show that the resolution of trace minerals at or below scan resolution is difficult and not always reliable due to mixed X-ray signals. However, by modification of the species identification protocol (SIP) quantification is achievable, although for optimal results verification by another analytical method (SEM-EDS) is recommended. As an add-on to routine quantitative mineralogical analysis focused on major ore minerals, this method can produce quantitative data and information on mineral association for trace minerals of precious and critical metals which may be potential by-products in a mining operation.

Keywords
automated scanning electron microscopy, QEMSCAN®, trace minerals, gold
National Category
Natural Sciences
Research subject
Ore Geology
Identifiers
urn:nbn:se:ltu:diva-73862 (URN)
Available from: 2019-05-07 Created: 2019-05-07 Last updated: 2019-05-14
Alvarenga, R. A. .., Dewulf, J., Guinée, J., Schulze, R., Weihed, P., Bark, G. & Drielsma, J. (2019). Towards product-oriented sustainability in the (primary) metal supply sector. Resources, Conservation and Recycling, 145, 40-48
Open this publication in new window or tab >>Towards product-oriented sustainability in the (primary) metal supply sector
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2019 (English)In: Resources, Conservation and Recycling, ISSN 0921-3449, E-ISSN 1879-0658, Vol. 145, p. 40-48Article in journal (Refereed) Published
Abstract [en]

Consideration of sustainable supply of (primary) metals is increasingly influencing the policy agenda of western societies. Environmental sustainability can be managed from different perspectives, including a site-oriented one (strongly used by the mining sector) and a product-oriented one (as with life cycle assessment). The objectives of this article are to analyse and discuss the differences in these perspectives; to discuss potential benefits to the metal/mining sector of also considering the product-oriented perspective; and to propose ways for a smooth implementation. We made use of literature and expert knowledge, on top of interviews with different stakeholders, to identify why and how these perspectives are (not) used in the metal/mining sector. Moreover, we identified three key concerns related to the implementation of a product-oriented perspective in the sector (e.g., use of unrepresentative life cycle inventory (LCI) datasets for metal-based products) and proposed three corrective actions for all of them (e.g., increase the quantity and quality of LCI). Finally, we discuss how the corrective actions could be implemented in the sector in a smooth way and some potential benefits from its implementation.

Place, publisher, year, edition, pages
Elsevier, 2019
Keywords
Raw materials, Mining, Metal, Life cycle, Sustainability
National Category
Geology
Research subject
Ore Geology
Identifiers
urn:nbn:se:ltu:diva-73134 (URN)10.1016/j.resconrec.2019.02.018 (DOI)000466251200005 ()2-s2.0-85061805826 (Scopus ID)
Note

Validerad;2019;Nivå 2;2019-03-07 (johcin)

Available from: 2019-03-07 Created: 2019-03-07 Last updated: 2019-06-18Bibliographically approved
Yousefi, F., Sadeghian, M., Wanhainen, C., Ghasemi, H., Lambrini, P., Bark, G., . . . Koroneos, A. (2017). Mineral chemistry and P-T conditions of the adakitic rocks from Torud–Ahmad Abad magmatic belt, S-SE Shahrood, NE Iran. Journal of Geochemical Exploration, 182(A), 110-120
Open this publication in new window or tab >>Mineral chemistry and P-T conditions of the adakitic rocks from Torud–Ahmad Abad magmatic belt, S-SE Shahrood, NE Iran
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2017 (English)In: Journal of Geochemical Exploration, ISSN 0375-6742, E-ISSN 1879-1689, Vol. 182, no A, p. 110-120Article in journal (Refereed) Published
Abstract [en]

Torud-Ahmad Abad magmatic belt is located 175 km east and southeast of Shahrood in the northern part of the Central Iran Structural Zone and includes a thick sequence of Paleocene to middle Eocene volcanic and volcanosedimentary rocks. This magmatic belt was formed by numerous hypabyssal igneous adakitic domes constituting basaltic andesite, andesite, trachyandesite, dacite, trachydacite, and dacite. The investigated rocks are mainly composed of pyroxene, amphibole, and plagioclase, with minor biotite and opaque minerals. Mineral chemical analysis reveals that plagioclase composition varies from albite to labradorite, clinopyroxene varies from diopside to augite, and amphibole varies from Mg-hastingsite to Mg-hornblende.

Amphibole geothermobarometry suggests crystallization temperatures of 850–1050 °C, at 2–6 kbar and the temperature of 920–970 °C, at a pressure of 3–4.5 kbar, which are conditions in agreement with andesite and dacite formation. Clinopyroxene crystallized at temperatures of 1020–1170 °C, at 2–10 kbar, indicating crystallization at crustal depths of maximum 30 km for the studied intrusive rocks in the Torud-Ahmad Abad magmatic belt.

Place, publisher, year, edition, pages
Elsevier, 2017
National Category
Geology
Research subject
Ore Geology
Identifiers
urn:nbn:se:ltu:diva-65725 (URN)10.1016/j.gexplo.2017.09.006 (DOI)000414886000009 ()2-s2.0-85030482210 (Scopus ID)
Note

Validerad;2017;Nivå 2;2017-10-04 (andbra)

Available from: 2017-09-19 Created: 2017-09-19 Last updated: 2018-03-15Bibliographically approved
Fettweis, R. & Bark, G. (2017). The new Vindelgransele gold ore domain, northern Sweden: preliminary results from the Fabodtjarn lode gold deposit. In: Mercier Langevin, P; Dube, B; Bardoux, M; Ross, PS; Dion, C (Ed.), Mineral Resources to Discover: . Paper presented at 14th SGA Biennial Meeting on Mineral Resources to Discover, Quebec City, Canada, AUG 20-23, 2017 (pp. 139-142). Society for Geology Applied to Mineral Deposits
Open this publication in new window or tab >>The new Vindelgransele gold ore domain, northern Sweden: preliminary results from the Fabodtjarn lode gold deposit
2017 (English)In: Mineral Resources to Discover / [ed] Mercier Langevin, P; Dube, B; Bardoux, M; Ross, PS; Dion, C, Society for Geology Applied to Mineral Deposits , 2017, p. 139-142Conference paper, Published paper (Refereed)
Abstract [en]

The Fabodtjarn lode gold deposit is located in the Vindelgransele area, in the Skellefte District, in northern Sweden. The mineralization consists of a quartz vein system hosted in a sequence of turbiditic greywackes and pelitic sedimentary rocks, situated 20-30 meters above the contact with a granodiorite sill. The aim of the study is to better understand the genesis and controls on ore at Fabodtjarn and improve exploration guides for the area. Gold deposits have been known in the Skellefte District for over a century. However, there is an ongoing debate whether some of these deposits are intrusion-related or orogenic gold. Several gold deposits in the Vindelgransele area are spatially associated with intrusive rocks. There might thus be a genetic link between the Fabodtjarn deposit and the intrusion, or the intrusive rocks have simply acted as structural traps during compressional stress conditions.

Place, publisher, year, edition, pages
Society for Geology Applied to Mineral Deposits, 2017
National Category
Geology
Research subject
Ore Geology; Ore Geology
Identifiers
urn:nbn:se:ltu:diva-70283 (URN)000439764100035 ()978-2-9816898-0-1 (ISBN)
Conference
14th SGA Biennial Meeting on Mineral Resources to Discover, Quebec City, Canada, AUG 20-23, 2017
Available from: 2018-08-09 Created: 2018-08-09 Last updated: 2018-08-09Bibliographically approved
Hamberg, R., Bark, G., Maurice, C. & Alakangas, L. (2016). Release of arsenic from cyanidation tailings (ed.). Paper presented at . Minerals Engineering, 93, 57-64
Open this publication in new window or tab >>Release of arsenic from cyanidation tailings
2016 (English)In: Minerals Engineering, ISSN 0892-6875, E-ISSN 1872-9444, Vol. 93, p. 57-64Article in journal (Refereed) Published
Abstract [en]

At a gold mine in northern Sweden, gold occurring as inclusions in pyrrhotite and arsenopyrite is leached by cyanidation of the ore. The main sulphide minerals in the ore are pyrrhotite and arsenopyrite. Effluents from the cyanidation process are treated with Fe2(SO4)3 to form Fe-precipitates suitable for the co-precipitation of As. The aim of this study was to perform static and kinetic leaching tests on the ore and tailings to define geochemical processes governing As mobility. Sequential leaching tests suggested that the majority of dissolved As deriving from the sulphide fraction in the ore was incorporated in newly formed Fe-precipitates in the tailings. The mobility of As in the tailings was therefore mainly dependent on the stability of these As-bearing Fe-precipitates. Weathering cell tests (WCT) involving 31 weekly cycles of wetting and air exposure were conducted to assess the stability of the As in the tailings under accelerated weathering conditions. The first stage of the WCT was characterized by a pH ≈ 5 and low As leaching, probably driven by the dissolution of amorphous Fe-As species. In the second stage of the WCT, leaching of Fe, S and As increased and the pH decreased to <3.5. An increase of the leachate’s molar Fe/S-ratio suggested that pyrrhotite oxidation was occurring. The falling pH destabilized As-bearing Fe-precipitates, causing further As release. The total As release during the WCT corresponded to only a small proportion of the tailings’ total As content. The accelerated As-leaching observed towards the end of the WCT could thus indicate that its release could increase progressively over time.

National Category
Geochemistry Geology
Research subject
Tillämpad geokemi; Ore Geology
Identifiers
urn:nbn:se:ltu:diva-5851 (URN)10.1016/j.mineng.2016.04.013 (DOI)000377313900008 ()2-s2.0-84964596057 (Scopus ID)409d1fb8-7260-414b-88b4-4904aadd11f9 (Local ID)409d1fb8-7260-414b-88b4-4904aadd11f9 (Archive number)409d1fb8-7260-414b-88b4-4904aadd11f9 (OAI)
Note
Validerad; 2016; Nivå 2; 20160502 (andbra)Available from: 2016-09-29 Created: 2016-09-29 Last updated: 2018-07-10Bibliographically approved
Alakangas, L., Bark, G., Ericsson, M., Martinsson, O., Söderholm, P., Wanhainen, C., . . . Öhlander, B. (2014). Norrbottens malm- och mineralresurs och dess potentiella betydelse för innovation, samhälle och miljö (ed.). Paper presented at . Luleå: Luleå tekniska universitet
Open this publication in new window or tab >>Norrbottens malm- och mineralresurs och dess potentiella betydelse för innovation, samhälle och miljö
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2014 (Swedish)Report (Other academic)
Abstract [sv]

Gruvindustrins betydelse för samhällsutveckling och infrastruktur i Sverige och inte minst i Norrbottens län är mycket stor. De geologiska förutsättningarna att hitta nya brytvärda förekomster i Norrbotten är goda. Länet är tillsammans med Västerbotten en av Europas viktigaste regioner för utvinning av metaller. Det syns också i den nyligen framtagna regionala mineralstrategin för Norrbotten och Västerbotten. Visionen för den regionala mineralstrategin: ”Genom långsiktigt hållbart nyttjande av Norrbottens och Västerbottens läns mineralresurser har ytterligare tillväxt skapats i regionen och hela Sverige. Vi har utvecklat och stärkt vår ställning som ledande gruv- och mineralnation.”Eftersom framtidspotentialen för gruvnäringen är mycket god men okunnigheten hos både allmänhet och beslutsfattare om näringens betydelse för innovation och samhällsutveckling är stor, kopplat med en utbredd oro för miljöpåverkan, måste dessa viktiga framtidsfrågor belysas. Med finansiering från Länsstyrelsen i Norrbotten bedrevs därför under första hälften av 2014 en förstudie som syftade till att sammanfatta kunskapsläget om framtidens gruvindustri i Norrbotten. Resultaten av förstudien redovisas i den här rapporten. En viktig slutsats är att det under nästa strukturfondsperiod (med start 2015) behövs ett framtidsinriktat forskningsprogram för att belysa de möjligheter som finns. Denna förstudie utgör grund för en kommande ansökan till strukturfonderna. Kompetensen som finns vid Luleå tekniska universitet, Sveriges centrum för gruvrelaterad forskning och utbildning, bör användas för att studera troliga framtidsmöjligheter och hur de ska kunna användas för att få en så positiv utveckling som möjligt för länet. Projektet bör innehålla följande tre huvudinriktningar, som naturligtvis hör ihop:Vilka malm- och mineralresurser finns det potential för i Norrbotten, och vilka kommer sannolikt att exploateras i framtiden?Vad kommer den exploateringen att ha för betydelse för innovation och samhällsutveckling?Vad kommer den exploateringen att få för miljöeffekter och hur ska man göra för att minska miljöbelastningen?En annan slutsats är att nedlagda gruvområden inte måste ses som förstörd natur. Betydande mervärden som gruvturism skulle kunna skapas om vilja, kreativitet och beslutsamhet finns. Detta är ett givet utvecklingsområde där småföretag och entreprenörer kan göra stor insats om de politiska och myndighetsmässiga förutsättningarna finns. Dessa aspekter skulle också kunna belysas i det föreslagna forskningsprogrammet eller i ett eget projekt.

Place, publisher, year, edition, pages
Luleå: Luleå tekniska universitet, 2014. p. 43
National Category
Geology Geochemistry Economics
Research subject
Ore Geology; Tillämpad geokemi; Economics
Identifiers
urn:nbn:se:ltu:diva-24390 (URN)ac38cfe2-8d54-49fe-9485-7ebfae93dad8 (Local ID)ac38cfe2-8d54-49fe-9485-7ebfae93dad8 (Archive number)ac38cfe2-8d54-49fe-9485-7ebfae93dad8 (OAI)
Note
Godkänd; 2014; 20160411 (bark)Available from: 2016-09-29 Created: 2016-09-29 Last updated: 2018-03-26Bibliographically approved
Bark, G., Wanhainen, C. & Pålsson, B. (2013). Textural setting of gold and its implications on mineral processing: preliminary results from three gold deposits in northern Sweden (ed.). In: (Ed.), (Ed.), Mineral deposit research for a high-tech world: Proceedings of the 12th Biennial SGA Meeting, 12–15 August 2013, Uppsala, Sweden. Paper presented at Biennial SGA Meeting : Mineral deposit research for a high-tech world 12/08/2013 - 15/08/2013 (pp. 302-305). Uppsala: Sveriges Geologiska Undersökning
Open this publication in new window or tab >>Textural setting of gold and its implications on mineral processing: preliminary results from three gold deposits in northern Sweden
2013 (English)In: Mineral deposit research for a high-tech world: Proceedings of the 12th Biennial SGA Meeting, 12–15 August 2013, Uppsala, Sweden, Uppsala: Sveriges Geologiska Undersökning , 2013, p. 302-305Conference paper, Meeting abstract (Refereed)
Abstract [en]

Within the European Union (EU27) the two most important gold producers are Finland and Sweden, covering more than two thirds of the European market. Due to the high gold prize mining companies are looking to extract more of the metal by improving recovery. We have done textural analysis on three gold-bearing deposits to better understand how the gold-textures seen in drill cores might affect the processing of different gold-ore types. In the Nautanen IOCG deposit, gold deportment is different whether gold is associated with pyrite or magnetite, and this must be considered when optimising the future mine and process planning. In the VMS-type Kristineberg deposit, the gold is associated with pyrite, sphalerite, and galena. Low gold recoveries from flotation could be explained by the occurrence of gold-inclusions in the pyrite. In the epigenetic Svartliden lode gold deposit, the gold is rather coarse-grained and associated with arsenopyrite-löllingite, and silicates. The relatively large grain size of gold can result in incomplete breakdown of the largest gold grains in the cyanide leaching process. To properly understand gold deportment in ores and to be able to improve mine planning and predict metal recoveries a comprehensive textural analysis of gold in drill core-samples is essential.

Place, publisher, year, edition, pages
Uppsala: Sveriges Geologiska Undersökning, 2013
Keywords
Earth sciences - Endogenous eartn sciences, Gold, ore texture, northern Sweden, process mineralogy, in-situ analysis, Geovetenskap - Endogen geovetenskap
National Category
Geology Metallurgy and Metallic Materials
Research subject
Ore Geology; Mineral Processing
Identifiers
urn:nbn:se:ltu:diva-29702 (URN)34114906-4747-4988-859a-ec6c7a9b81dd (Local ID)978-91-7403-207-9 (ISBN)34114906-4747-4988-859a-ec6c7a9b81dd (Archive number)34114906-4747-4988-859a-ec6c7a9b81dd (OAI)
Conference
Biennial SGA Meeting : Mineral deposit research for a high-tech world 12/08/2013 - 15/08/2013
Note
Godkänd; 2013; 20130819 (bark)Available from: 2016-09-30 Created: 2016-09-30 Last updated: 2018-03-15Bibliographically approved
Bark, G. & Weihed, P. (2012). Geodynamic settings for Paleoproterozoic gold mineralization in the Svecofennian domain: a tectonic model for the Fäboliden orogenic gold deposit, northern Sweden (ed.). Paper presented at . Ore Geology Reviews, 48, 403-412
Open this publication in new window or tab >>Geodynamic settings for Paleoproterozoic gold mineralization in the Svecofennian domain: a tectonic model for the Fäboliden orogenic gold deposit, northern Sweden
2012 (English)In: Ore Geology Reviews, ISSN 0169-1368, E-ISSN 1872-7360, Vol. 48, p. 403-412Article in journal (Refereed) Published
Abstract [en]

Northern Sweden is currently experiencing active exploration within a new gold ore province, the so called Gold Line, situated southwest of the well-known Skellefte VMS District. The largest known deposit in the Gold Line is the hypozonal Fäboliden orogenic gold deposit. Mineralization at Fäboliden is hosted by arsenopyrite-rich quartz veins, in a reverse, mainly dip-slip, high-angle shear zone, in amphibolite facies supracrustal host rocks. The timing of mineralization is estimated, from field relationships, at ca. 1.8 Ga.The gold mineralization is hosted by two sets of mineralized quartz veins, one steep fault-fill vein set and one relatively flat-lying extensional vein set. Ore shoots occur at the intersections between the two vein sets, and both sets could have been generated from the same stress field, during the late stages of the Svecofennian orogen.The tectonic evolution during the 1.9–1.8 Ga Svecofennian orogen is complex, as features typical of both internal and external orogens are indicated. The similarity in geodynamic setting between the contemporary Svecofennian and Trans-Hudson orogens indicate a potential for world-class orogenic gold provinces also in the Svecofennian domain.The Swedish deposits discussed in this paper are all structurally associated with roughly N-S striking shear zones that were active at around 1.8 Ga, when gold-bearing fluids infiltrated structures related to conditions of E-W shortening.

National Category
Geology
Research subject
Ore Geology
Identifiers
urn:nbn:se:ltu:diva-11854 (URN)10.1016/j.oregeorev.2012.05.007 (DOI)000310401600021 ()2-s2.0-84866335586 (Scopus ID)ae0e4a50-7e42-4e0e-aecf-fa1c385cff44 (Local ID)ae0e4a50-7e42-4e0e-aecf-fa1c385cff44 (Archive number)ae0e4a50-7e42-4e0e-aecf-fa1c385cff44 (OAI)
Note
Validerad; 2012; 20120515 (andbra)Available from: 2016-09-29 Created: 2016-09-29 Last updated: 2018-07-10Bibliographically approved
Bark, G. (2008). On the origin of the Fäboliden orogenic gold deposit, northern Sweden (ed.). (Doctoral dissertation). Paper presented at . Luleå: Luleå tekniska universitet
Open this publication in new window or tab >>On the origin of the Fäboliden orogenic gold deposit, northern Sweden
2008 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

A new promising ore province, the Gold Line, southwest of the well- known Skellefte District, northern Sweden, is currently under exploration. This province hosts, so far, one operating mine, the Svartliden Au mine, and the recently closed Blaiken Zn-Pb-Au-Ag mine. The largest known gold deposit, the hypozonal Fäboliden orogenic gold deposit, in the area was recently granted mining permits. The deposit holds c. 54 Mt at 1.2 g/t Au, with a planned production of 4.6 Mt of ore/year. The mineralization at Fäboliden is commonly hosted in arsenopyrite-bearing quartz-veins, within a roughly N-S striking, steeply dipping shear zone in amphibolite facies volcano- sedimentary host rocks. The narrow belt of supracrustal rocks is surrounded by late- to post-orogenic Revsund granite. The gold is fine-grained (2-40 µm) and closely associated with arsenopyrite- löllingite and stibnite. Gold is found in fractures and as inclusions in the arsenopyrite-löllingite. Gold is also seen as free grains in the silicate matrix of the host rock. The hydrothermal mineral assemblage in the proximal alteration zone is diopside, calcic amphibole, biotite, and minor andalusite and tourmaline. This type of assemblage is commonly recognized in hypozonal orogenic gold deposits worldwide. The lateral extent of the proximal alteration zone is estimated to 30-50 meters, and there is a good agreement between diopside- amphibole-biotite alteration, quartz veining, and gold mineralization. The mineral assemblage in the distal alteration zone is characterised by the presence of Ca- and Fe-Mg amphiboles, hedenbergite, biotite, and quartz. The transition from the distal alteration into the regional metamorphic assemblage is diffuse, and the only discernable feature appears to be a gradual decrease of amphibole away from the mineralization. The ductile gold-hosting fabric progresses laterally across the Revsund granite contact and then disappears after a few meters inside the granite, suggesting that at least the final stages of mineralization syn- to postdate the emplacement of the c. 1.81-1.77 Ga Revsund granite. Relationships between garnet-biotite and graphite geothermometry, together with these field relationships, indicate that the late stages of mineralization at Fäboliden post-date regional peak-metamorphism in the area, which is estimated at c. 1.80 Ga. The Fäboliden gold mineralization is hosted by a reverse, mainly dip-slip, high-angle shear zone with a relatively small horizontal shear movement. The mineralization constitutes two sets of mineralized quartz veins, one steep fault-fill vein system that is parallel to the regional foliation and one flat-lying extensional vein system. Both vein sets are suggested to have been generated from the same stress field, during E-W shortening at c. 1.80 Ga. At least two types of ore shoot are present at Fäboliden, intersections between the fault-fill vein set and the extensional vein set and bends in the shear zone system both show elevated gold content, similar to many gold- quartz vein deposits globally. The fluids involved in the precipitation of gold at Fäboliden shows characteristics similar to other hypozonal orogenic gold deposits, such as a CO2-CH4-H2S fluid composition and pressure-temperature conditions of c. 4 kbar and 520-560°C. Sulphur isotope data ranges between -1.5 and +3.6‰. Oxygen and hydrogen isotope data ranges between +10.6 and 13.1‰, and -120 to -67‰, respectively. The hydrothermal fluids at Fäboliden are interpreted to have originate from a crustally contaminated magmatic source. The potential for future orogenic gold discovery in the Fennoscandian Shield is considered good. From this PhD study it is suggested that interesting targets, concerning exploration for orogenic gold in at least the Gold Line, would be areas associated with roughly N-S striking tectonic zones that were active at around 1.80 Ga.

Place, publisher, year, edition, pages
Luleå: Luleå tekniska universitet, 2008. p. 20
Series
Doctoral thesis / Luleå University of Technology 1 jan 1997 → …, ISSN 1402-1544 ; 2008:72
National Category
Geology
Research subject
Ore Geology
Identifiers
urn:nbn:se:ltu:diva-17548 (URN)3e73a150-bd33-11dd-a7c4-000ea68e967b (Local ID)3e73a150-bd33-11dd-a7c4-000ea68e967b (Archive number)3e73a150-bd33-11dd-a7c4-000ea68e967b (OAI)
Note
Godkänd; 2008; 20081128 (ysko)Available from: 2016-09-29 Created: 2016-09-29 Last updated: 2018-03-15Bibliographically approved
Bark, G., Broman, C. & Weihed, P. (2007). Fluid chemistry of the Palaeoproterozoic Fäboliden hypozonal orogenic gold deposit, northern Sweden: evidence from fluid inclusions (ed.). Paper presented at . GFF, 129(3), 197-210
Open this publication in new window or tab >>Fluid chemistry of the Palaeoproterozoic Fäboliden hypozonal orogenic gold deposit, northern Sweden: evidence from fluid inclusions
2007 (English)In: GFF, ISSN 1103-5897, E-ISSN 2000-0863, Vol. 129, no 3, p. 197-210Article in journal (Refereed) Published
Abstract [en]

A new ore province, the Gold Line, southwest of the Skellefte District, northern Sweden, is currently under exploration. The largest known deposit in the Gold Line is the hypozonal Fäboliden orogenic gold deposit. The mineralization is hosted by arsenopyrite-bearing quartz veins, within a steep shear zone in amphibolite facies metagreywacke host rocks. Gold occur in fractures and as intergrowths in arsenopyrite-löllingite, and as free grains in the silicate matrix of the host rock. The hydrothermal mineral assemblage in the proximal alteration zone is diopside, calcic amphibole, biotite, and minor andalusite and tourmaline. Primary fluid inclusions in the Fäboliden quartz veins show a CO2-CH4 or a H2S (±CH4) composition (the latter recognized for the first time in a Swedish ore deposit). The primary fluid inclusions are associated with arsenopyrite-löllingite (+gold) and the CO2-CH4 fluid was also involved in precipitation of graphite. A prevalence of carbonic over aqueous fluid inclusions is characteristic for a number of hypozonal high-temperature orogenic gold deposits. The Fäboliden deposit, thus, shows fluid compositions similar to other hypozonal orogenic gold deposits. The proposed main mechanism for precipitation of gold from the fluids, is a mixing between H2S-rich and H2O?-CO2±CH4 fluids. Fluid inclusion data indicate arsenopyrite-löllingite and graphite deposition at a pressure condition of about 4 kbar. Graphite thermometry indicates maximum temperatures of 520-560°C for the hydrothermal alteration at Fäboliden, suggesting that at least the late stages of the mineralizing event took place shortly after peak-metamorphism in the area, i.e. at c. 1.80 Ga.

National Category
Geology
Research subject
Ore Geology
Identifiers
urn:nbn:se:ltu:diva-13111 (URN)10.1080/11035890701293197 (DOI)2-s2.0-35848940683 (Scopus ID)c498b040-82d8-11dc-896e-000ea68e967b (Local ID)c498b040-82d8-11dc-896e-000ea68e967b (Archive number)c498b040-82d8-11dc-896e-000ea68e967b (OAI)
Note
Validerad; 2007; 20071025 (bark)Available from: 2016-09-29 Created: 2016-09-29 Last updated: 2018-07-10Bibliographically approved
Organisations
Identifiers
ORCID iD: ORCID iD iconorcid.org/0000-0001-9846-1793

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