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  • 1.
    Billström, K.
    et al.
    Dep. of Geological Sciences, Swedish Museum of Natural History, Stockholm, Sweden.
    Evins, P.
    WPS Consulting Group, Stockholm, Sweden.
    Martinsson, Olof
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    Jeon, H.
    Dep. of Geological Sciences, Swedish Museum of Natural History, Stockholm, Sweden.
    Weihed, Pär
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    Conflicting zircon vs. titanite U-Pb age systematics and the deposition of the host volcanic sequence to Kiruna-type and IOCG deposits in northern Sweden, Fennoscandian shield2019Ingår i: Precambrian Research, ISSN 0301-9268, E-ISSN 1872-7433, Vol. 321, s. 123-133Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The Northern Norrbotten region, and in particular the Kiruna area, hosts a number of large apatite iron oxide deposits (e.g. the huge Kiirunavaara ore) of significant economic importance. Age data from rock lithologies hosting these ores, represented by metamorphosed rocks of the Porphyrite and Kiirunavaara Groups, are complex to interpret. This is illustrated by (LA-ICP-MS) data for titanite, and to some extent for rutile, which scatter considerably yielding ages within a span from ca. 2.1 Ga to 1.7 Ga. These analysed hydrothermal minerals, characterized by complex BSE images revealing darker and brighter zones, are located in ore zones and associated with e.g. strong scapolitisation, albitisation and actinolitisation. Previous (TIMS) zircon ages of host rocks, on the other hand, define a more narrower age interval between ca. 1900 and 1870 Ma, and this is supported by new U-Pb zircon results presented here. Furthermore, one coherent set of SIMS data for titanite from the Luossavaara ore favour that crystallization took place at ca 1.88 Ga, although laser ICP data from the same locality are much more complex. An implication arising from published pre-1.9 Ga laser ablation ages for titanites is that the emplacement of host rocks started already at around 2.1 Ga. As the depositional time of these rocks is crucial for the understanding of the overall crustal formation in northern Norrbotten, additional rocks were selected for age dating. New zircon age data (LA-ICP-MS and SIMS) give support to a scenario where host rocks to ores started to develop at around 1900 Ma and this calls for a re-evaluation of published LA-ICP-MS data of hydrothermal mineral phases.

    Here, we present four models that aim to explain how pre-1.9 Ga titanite ages, believed to have a questionable geological significance, may develop. The principal idea is that ≤2.1 Ga alteration events were not responsible for the crystallization of the hydrothermal minerals, instead it is believed that apparent old age domains carry excess radiogenic lead due to the effect of ≤1.9 Ga hydrothermal processes. Currently, the interpretation of U-Pb isotope data in the study area remains enigmatic, and further radiometric analyses are required.

  • 2.
    Alvarenga, Rodrigo A.F.
    et al.
    Ghent University, Belgium.
    Dewulf, Jo
    Ghent University, Belgium.
    Guinée, Jeroen
    Leiden University, the Netherlands.
    Schulze, Rita
    Leiden University, the Netherlands.
    Weihed, Pär
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    Bark, Glenn
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    Drielsma, Johannes
    Euromines, Belgium.
    Towards product-oriented sustainability in the (primary) metal supply sector2019Ingår i: Resources, Conservation and Recycling, ISSN 0921-3449, E-ISSN 1879-0658, Vol. 145, s. 40-48Artikel i tidskrift (Refereegranskat)
    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.

  • 3.
    Ericsson, Magnus
    et al.
    Luleå tekniska universitet, Institutionen för ekonomi, teknik och samhälle, Samhällsvetenskap.
    Drielsma, Johannes
    European Association of Mining Industries, Metal Ores and Industrial Minerals, Brussels, Belgium.
    Humphreys, David
    CEPMLP, Dundee University, Dundee, UK.
    Storm, Per
    EIT Raw Materials North AB, Luleå, Sweden.
    Weihed, Pär
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    Why current assessments of ‘future efforts’ are no basis for establishing policies on material use: a response to research on ore grades2019Ingår i: Mineral Economics, ISSN 2191-2203, E-ISSN 2191-2211, Vol. 32, nr 1, s. 111-121Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The concept of declining availability due to declining primary resource quality has been investigated for various resource categories to try to determine the effort needed in future to either extract the resource or to treat it for intended use. The concept of ‘future efforts’ due to declining primary resource quality is explored by Vieira et al. (2016, 2017). They suggest that a specific burden associated with the production of each primary material should be taken into account and that this can be done by studying the costs of production or ore requirements of the material and by projecting forward likely costs into the future. For the purpose of the analysis, they employ mine cost data for 2000–2013 and reserve data published by the US Geological Survey. We will argue below that this approach is not correct and, with this comment, we wish to make it clear that—contrary to what is suggested in much of the Life Cycle Assessment literature—the future efforts concept is not an established rule of natural resource extraction. For mineral resources, it is quite impossible to proceed with extraction in the ordered way that this approach suggests because nobody has a comprehensive view of the entire natural resource. Secondly, there is no evidence available to support the idea that extracting a mineral resource today causes a decrease in availability of that mineral tomorrow. On the contrary, the weight of evidence suggests that where declines in ore grades have been observed, they are overwhelmingly due to technology development in response to high demand and have been accompanied by increased mining efficiency and increased availability of the resource to successive generations. Grade is a rather arbitrary measure since the grade of mined ore ultimately has to do with the relationship of costs and revenues. It is not only the technology employed which matters but also how smartly this technology is applied. Thirdly, the future efforts approach entirely overlooks the potential availability of mineral materials from secondary (scrap) sources, sources which are expected to become increasingly important to mineral supply in the future. Our conclusion from the discussion is that we as humans have been able to economically access ever-increasing amounts of material from often lower and lower-grade sources. What is impossible to conclude from this is that the environment no longer contains any of the higher-grade sources. In fact, all the available evidence suggests that higher-grade deposits are still out there. We remain critical optimists.

  • 4.
    Abdelnasser, Amr
    et al.
    Geological Engineering Department, Faculty of Mines, Istanbul Technical University. Geology Department, Faculty of Science, Benha University, Benha.
    Kumral, Mustafa
    Geological Engineering Department, Faculty of Mines, Istanbul Technical University.
    Zoheir, Basem
    Geology Department, Faculty of Science, Benha University, Benaha.
    Karaman, Muhittin
    Geological Engineering Department, Faculty of Mines, Istanbul Technical University.
    Weihed, Pär
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    REE geochemical characteristics and satellite-based mapping of hydrothermal alteration in Atud gold deposit, Egypt2018Ingår i: Journal of African Earth Sciences, ISSN 0899-5362, Vol. 145, s. 317-330Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    New geochemical data of the hydrothermal alteration zones associated with gold-bearing quartz veins at Atud mine are used for better understanding the ore evolution and exploration vectoring. ASTER and Landsat 8 OLI data are used to elucidate the distribution of gold-associated alteration zones. Three alteration zones are defined; zone 1 (sericite-kaolinite-quartz-pyrite), zone 2 (quartz-sericite-albite-pyrite), and zone 3 (chlorite-carbonate-epidote ± pyrite). Sericite and hydrothermal quartz are confined to the mineralized quartz veins. Fe-OH and OH-bearing minerals are observed along NW- and NE-trending shear zones in the Main Atud mine. The association of gold-bearing quartz veins and sericite alteration is constrained by processing ASTER- and OLI-imagery data. The geochemical data of the ore-enveloping hydrothermally altered rocks are used to assess the behavior of the REEs during the mineralization process. Mild enrichment in LREE and significant enrichment in the HREE are associated with sericite in zones (1) and (2) alterations. Carbonate alteration (zone 3) is enriched in LREE and in immobile HREE. Moreover, LREE and Eu anomalies have negative correlated with the Alteration Index (A.I.) and K2O index (K.I.) in zones 1 and 2, suggesting high mobility of LREE in K-rich hydrothermal fluids. On the other hand, HREE anomalies with increasing MgO index (M.I.) in alteration zone 3 may imply low solubility of these elements in alkaline solutions. Au anomalies linked to sericite/silica alteration is a rather meaningful vector for further exploration in the area.

  • 5.
    Zeballos, Ariana
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik. Instituto de Geología y del Medio Ambiente, Universidad Mayor de San Andrés, La Paz .
    Weihed, Pär
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    Blanco, Maria
    Instituto de Geología y del Medio Ambiente, Universidad Mayor de San Andrés, La Paz.
    Machaca, Vladimir
    Instituto de Geología y del Medio Ambiente, Universidad Mayor de San Andrés, La Paz.
    Characterization of some nonmetallic resources in Bolivia: an overview of their potentiality and their application in specialized formulations2017Ingår i: Environmental Earth Sciences, ISSN 1866-6280, E-ISSN 1866-6299, Vol. 76, nr 22, artikel-id 754Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Bolivia has several nonmetallic occurrences widespread in the country. Unfortunately, they are poorly studied and slightly characterized. In the present work, several nonmetallic occurrences located in La Paz, Oruro, Potosí and Santa Cruz were studied. The results of the chemical and mineralogical characterization of the materials will be presented, in order to approach their applicability in specialized industrial formulations. A preliminary test of the final products besides an overview of their potentiality will be exposed and a current view of the commercialization as well.

  • 6.
    Kampmann, Tobias Christoph
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    Weihed, Pär
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    Debatt: Falu gruvas 1,9 miljarder år gamla geologiska processer kan säkra samhällets framtida behov av metaller2017Ingår i: Dala-Demokraten, ISSN 1103-9183, artikel-id 20 majArtikel i tidskrift (Övrig (populärvetenskap, debatt, mm))
  • 7.
    Kampmann, Tobias Christoph
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    Stephens, Michael
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    Weihed, Pär
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    3D modelling and sheath folding at the Falun Zn-Pb-Cu-(Au-Ag) massive sulphide deposit and implications for exploration in a 1.9 Ga ore district, Fennoscandian Shield, Sweden2016Ingår i: Mineralium Deposita, ISSN 0026-4598, E-ISSN 1432-1866, Vol. 51, nr 5, s. 665-680Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The Falun pyritic Zn-Pb-Cu-(Au-Ag) deposit, situated in the Palaeoproterozoic (1.9–1.8 Ga) Bergslagen lithotectonic unit in the south-western part of the Fennoscandian Shield, is one of the major base metal sulphide deposits in Sweden. Altered rocks and ore types at Falun have been metamorphosed and deformed in a heterogeneous ductile manner, strongly modifying mineral assemblages in the original hydrothermal alteration system and the geometry of the deposit. Using a combined methodological approach, including surface mapping of lithologies and structures, drill core logging and microstructural investigation, the polyphase character (D1 and D2) of the ductile deformation is demonstrated and a 3D model for the deposit created. F2 sheath folding along axes that plunge steeply to the south-south-east, parallel to a mineral stretching lineation and the dip direction of the S2 foliation, is suggested as a key deformation mechanism forming steeply plunging, rod-shaped ore bodies. This is in contrast to previous structural models involving fold interference and, in turn, has implications for near-mine exploration, the occurrence of hanging-wall components to the ore body being questioned. Typical rock-forming minerals in the Falun alteration aureole include quartz, biotite/phlogopite, cordierite, anthophyllite and minor almandine, andalusite and chlorite, as well as dolomite, tremolite and actinolite. Where observable, the silicate minerals in the alteration rocks show growth patterns during different phases of the tectonothermal evolution, considerable static grain growth occurring between D1 and D2 and even after D2. A major high-strain zone, characterized by the mineral assemblage talc-chlorite-(quartz-biotite/phlogopite) defines a boundary between northern and southern structural domains at the deposit, and is closely spatially associated with the polymetallic massive sulphide ores. A possible role as a metal-bearing fluid conduit during ore genesis is discussed.

  • 8.
    Tavakoli, Saman
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    Bauer, Tobias
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    Rasmussen, Thorkild Maack
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    Weihed, Pär
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    Elming, Sten-åke
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    Deep massive sulphide exploration using 2D and 3D geoelectrical and induced polarization data in Skellefte mining district, northern Sweden2016Ingår i: Geophysical Prospecting, ISSN 0016-8025, E-ISSN 1365-2478, Vol. 64, nr 6, s. 1602-1619Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Geoelectrical and induced polarization data from measurements along three profiles and from one 3D survey are acquired and processed in the central Skellefte District, northern Sweden. The data were collected during two field campaigns in 2009 and 2010 in order to delineate the structures related to volcanogenic massive sulphide deposits and to model lithological contacts down to a maximum depth of 1.5 km. The 2009 data were inverted previously, and their joint interpretation with potential field data indicated several anomalous zones. The 2010 data not only provide additional information from greater depths compared with the 2009 data but also cover a larger surface area. Several high-chargeability low-resistivity zones, interpreted as possible massive sulphide mineralization and associated hydrothermal alteration, are revealed. The 3D survey data provide a detailed high-resolution image of the top ∼450 m of the upper crust around the Maurliden East, North, and Central deposits. Several anomalies are interpreted as new potential prospects in the Maurliden area, which are mainly concentrated in the central conductive zone. In addition, the contact relationship between the major geological units, e.g., the contact between the Skellefte Group and the Jörn Intrusive Complex, is better understood with the help of 2010 deep-resistivity/chargeability data. The bottommost part of the Vargfors basin is imaged using the 2010 geoelectrical and induced polarization data down to ∼1-km depth.

  • 9.
    Drielsma, Johannes A
    et al.
    European Association of Mining Industries, Metal Ores and Industrial Minerals, Avenue de Broqueville/Broquevillelaan 12, 1150 Brussels.
    Russell-Vaccari, Andrea J.
    Align Consulting, 1134 Cross Creek Ct., Sheridan, WY.
    Drnek, Thomas
    RHI AG, Magnesitstrasse 30, 8614 Breitenau.
    Brady, Tom
    Newmont Mining, 6363 South Fiddler’s Green Circle Suite 800, Greenwich Village, CO 80111.
    Weihed, Pär
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    Mistry, Mark
    The Nickel Institute, Avenue des Arts/Kunstlaan, 13, 1210 Brussels.
    Simbor, Laia Perez
    European Copper Institute, Avenue de Tervueren/Tervurenlaan 168 b-10, 1150 Brussels.
    Erratum to: Mineral resources in life cycle impact assessment: defining the path forward2016Ingår i: The International Journal of Life Cycle Assessment, ISSN 0948-3349, E-ISSN 1614-7502, Vol. 21, nr 1, s. 133-Artikel i tidskrift (Refereegranskat)
  • 10.
    Zeballos, Ariana
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    Weihed, Pär
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    Blanco, Mario
    IGEMA, Universidad Mayor de San Andres, La Paz.
    Machaca, Vladimir
    IGEMA, Universidad Mayor de San Andres, La Paz.
    Geological, mineralogical and chemical characterization of Devonian kaolinite-bearing sediments for further applications in the ceramic (tiles) industry in La Paz, Bolivia2016Ingår i: Environmental Earth Sciences, ISSN 1866-6280, E-ISSN 1866-6299, Vol. 75, nr 7, artikel-id 546Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Clay minerals are widely distributed in Bolivia; among them, illitic clays are most common in the Altiplano where they are mined for use in the ceramic industry that has been growing in the last few years. In addition to illitic sediments, kaolinitic sediments have been recently discovered in sedimentary units in the Bolivian Altiplano. Residual ball clay occurrences in Devonian sedimentary units were studied as part of this work. Geological mapping and geophysical studies (ERT and GPR) were done for better understanding the origin of the deposits and were part of a preliminary study of the mineral potential to define the relationship with the host rock. Chemical and mineralogical techniques such as X-Ray Diffraction, Scanning Electron Microscopy and Inductively Coupled Plasma analyses were performed in samples from the studied area to verify the presence of kaolinite. Atterberg limits and behaviour of the raw material in ceramic specimens supported by chemical analyses show that this material is suitable for manufacturing tile ceramics. This study provides fundamental knowledge for deposit exploitation and future generation of an alternative source of employment for the inhabitants of Micaya

  • 11.
    Martinsson, Olof
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    Billström, Kjell
    Laboratory for Isotope Geology. Swedish Museum of Natural History, Stockholm, Laboratoriet för Isotopgeologi, Naturhistoriska Riksmuseet, Stockholm, Swedish Museum of Natural History, Department of Geosciences.
    Broman, Curt
    Department of Geology and Geochemistry, Stockholm University, Stockholms Universitet, Stockholm University, Department of Geological Sciences, Stockholm University.
    Weihed, Pär
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    Wanhainen, Christina
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    Metallogeny of the Northern Norrbotten Ore Province, northern Fennoscandian Shield with emphasis on IOCG and apatite-iron ore deposits2016Ingår i: Ore Geology Reviews, ISSN 0169-1368, E-ISSN 1872-7360, Vol. 78, s. 447-492Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The Northern Norrbotten Ore Province in northernmost Sweden includes the type localities for Kiruna-type apatite iron deposits and has been the focus for intense exploration and research related to Fe oxide-Cu-Au mineralisation during the last decades. Several different types of Fe-oxide and Cu-Au ± Fe oxide mineralisation occur in the region and include: stratiform Cu ± Zn ± Pb ± Fe oxide type, iron formations (including BIF's), Kiruna-type apatite iron ore, and epigenetic Cu ± Au ± Fe oxide type which may be further subdivided into different styles of mineralisation, some of them with typical IOCG (Iron Oxide-Copper-Gold) characteristics. Generally, the formation of Fe oxide ± Cu ± Au mineralisation is directly or indirectly dated between ~ 2.1 and 1.75 Ga, thus spanning about 350 m.y. of geological evolution.The current paper will present in more detail the characteristics of certain key deposits, and aims to put the global concepts of Fe-oxide Cu-Au mineralisations into a regional context. The focus will be on iron deposits and various types of deposits containing Fe-oxides and Cu-sulphides in different proportions which generally have some characteristics in common with the IOCG style. In particular, ore fluid characteristics (magmatic versus non-magmatic) and new geochronological data are used to link the ore-forming processes with the overall crustal evolution to generate a metallogenetic model.Rift bounded shallow marine basins developed at ~ 2.1–2.0 Ga following a long period of extensional tectonics within the Greenstone-dominated, 2.5–2.0 Ga Karelian craton. The ~ 1.9–1.8 Ga Svecofennian Orogen is characterised by subduction and accretion from the southwest. An initial emplacement of calc-alkaline magmas into ~ 1.9 Ga continental arcs led to the formation of the Haparanda Suite and the Porphyrite Group volcanic rocks. Following this early stage of magmatic activity, and separated from it by the earliest deformation and metamorphism, more alkali-rich magmas of the Perthite Monzonite Suite and the Kiirunavaara Group volcanic rocks were formed at ~ 1.88 Ga. Subsequently, partial melting of the middle crust produced large volumes of ~ 1.85 and 1.8 Ga S-type granites in conjunction with subduction related A −/I-type magmatism and associated deformation and metamorphismIn our metallogenetic model the ore formation is considered to relate to the geological evolution as follows. Iron formations and a few stratiform sulphide deposits were deposited in relation to exhalative processes in rift bounded marine basins. The iron formations may be sub-divided into BIF- (banded iron formations) and Mg-rich types, and at several locations these types grade into each other. There is no direct age evidence to constrain the deposition of iron formations, but stable isotope data and stratigraphic correlations suggest a formation within the 2.1–2.0 Ga age range. The major Kiruna-type ores formed from an iron-rich magma (generally with a hydrothermal over-print) and are restricted to areas occupied by volcanic rocks of the Kiirunavaara Group. It is suggested here that 1.89–1.88 Ga tholeiitic magmas underwent magma liquid immiscibility reactions during fractionation and interaction with crustal rocks, including metaevaporites, generating more felsic magmatic rocks and Kiruna-type iron deposits. A second generation of this ore type, with a minor economic importance, appears to have been formed about 100 Ma later. The epigenetic Cu-Au ± Fe oxide mineralisation formed during two stages of the Svecofennian evolution in association with magmatic and metamorphic events and crustal-scale shear zones. During the first stage of mineralisation, from 1.89–1.88 Ga, intrusion-related (porphyry-style) mineralisation and Cu-Au deposits of IOCG affinity formed from magmatic-hydrothermal systems, whereas vein-style and shear zone deposits largely formed at c. 1.78 Ga.The large range of different Fe oxide and Cu-Au ± Fe oxide deposits in Northern Norrbotten is associated with various alteration systems, involving e.g. scapolite, albite, K feldspar, biotite, carbonates, tourmaline and sericite. However, among the apatite iron ores and the epigenetic Cu-Au ± Fe oxide deposits the character of mineralisation, type of ore- and alteration minerals and metal associations are partly controlled by stratigraphic position (i.e. depth of emplacement). Highly saline, NaCl + CaCl2 dominated fluids, commonly also including a CO2-rich population, appear to be a common characteristic feature irrespective of type and age of deposits. Thus, fluids with similar characteristics appear to have been active during quite different stages of the geological evolution. Ore fluids related to epigenetic Cu-Au ± Fe oxides display a trend with decreasing salinity, which probably was caused by mixing with meteoric water. Tentatively, this can be linked to different Cusingle bondAu ore paragenesis, including an initial (magnetite)-pyrite-chalcopyrite stage, a main chalcopyrite stage, and a late bornite stage.Based on the anion composition and the Br/Cl ratio of ore related fluids bittern brines and metaevaporites (including scapolite) seem to be important sources to the high salinity hydrothermal systems generating most of the deposits in Norrbotten. Depending on local conditions and position in the crust these fluids generated a variety of Cu-Au deposits. These include typical IOCG-deposits (Fe-oxides and Cu-Au are part of the same process), IOCG of iron stone type (pre-existing Fe-oxide deposit with later addition of Cu-Au), IOCG of reduced type (lacking Fe-oxides due to local reducing conditions) and vein-style Cu-Au deposits. From a strict genetic point of view, IOCG deposits that formed from fluids of a mainly magmatic origin should be considered to be a different type than those deposits associated with mainly non-magmatic fluids. The former tend to overlap with porphyry systems, whereas those of a mainly non-magmatic origin overlap with sediment hosted Cu-deposits with respect to their origin and character of the ore fluids.

  • 12.
    Weihed, Pär
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    Mineral resources and mining2016Ingår i: Encyclopedia of the Barents Region: Vol. 1, A-M / [ed] editor-in-chef: Mats-Olov Olsson ; co-editors: Fredrick Backman ... [et al.] ; assistant and graphics editor: Lars Elenius, Oslo: Pax Forlag, 2016, s. 482-488Kapitel i bok, del av antologi (Refereegranskat)
  • 13.
    Drielsma, Johannes A
    et al.
    European Association of Mining Industries, Metal Ores and Industrial Minerals, Avenue de Broqueville/Broquevillelaan 12, 1150 Brussels.
    Russell-Vaccari, Andrea J.
    Align Consulting, 1134 Cross Creek Ct., Sheridan, WY.
    Drnek, Thomas
    RHI AG, Magnesitstrasse 30, 8614 Breitenau.
    Brady, Tom
    Newmont Mining, 6363 South Fiddler’s Green Circle Suite 800, Greenwich Village, CO 80111.
    Weihed, Pär
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    Mistry, Mark
    The Nickel Institute, Avenue des Arts/Kunstlaan, 13, 1210 Brussels.
    Simbor, Laia Perez
    European Copper Institute, Avenue de Tervueren/Tervurenlaan 168 b-10, 1150 Brussels.
    Mineral resources in life cycle impact assessment: defining the path forward2016Ingår i: The International Journal of Life Cycle Assessment, ISSN 0948-3349, E-ISSN 1614-7502, Vol. 21, nr 1, s. 85-105Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Purpose: Despite 20 years of research, there remains no robust, globally agreed upon method—or even problem statement—for assessing mineral resource inputs in life cycle impact assessment (LCIA). As a result, inclusion of commonly used methods such as abiotic depletion potential (ADP) in life cycle assessment (LCA)-related evaluation schemes could lead to incorrect decisions being made in many applications. In this paper, we explore in detail how to improve the way that life cycle thinking is applied to the acquisition of mineral resources and their metal counterparts. Methods: This paper evaluates the current body of work in LCIA with regard to “depletion potential” of mineral resources. Viewpoints from which models are developed are described and analyzed. The assumptions, data sources, and calculations that underlie currently used methods are examined. A generic metal-containing product is analyzed to demonstrate the vulnerability of results to the denominator utilized in calculating ADP. The adherence to the concept of the area of protection (AOP) is evaluated for current models. The use of ore grades, prices, and economic availability in LCIA is reviewed. Results and discussion: Results demonstrate that any work on resource depletion in a life cycle context needs to have a very clear objective or LCIA will not accurately characterize mineral resource use from any perspective and decision-making will continue to suffer. New, harmonized terminology is proposed so that LCA practitioners can build better mutual understanding with the mineral industry and recommendations regarding more promising tools for use in life cycle sustainability assessment (LCSA) are given. Conclusions: The economic issue of resource availability should be evaluated in parallel with traditional LCA, not within. LCIA developers should look to economists, the market, and society in general, for broader assessments that consider shorter-time horizons than the traditional LCIA methods. To do so, the concept of the AOP in LCA needs to be redefined for LCSA to ensure that models estimate what is intended. Finally, recommendations regarding mineral resource assessment are provided to ensure that future research has a sound basis and practitioners can incorporate the appropriate tools in their work

  • 14.
    Tavakoli, Saman
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    Dehghannejad, Mahdieh
    Department of Earth Sciences, Division of Geophysics, Uppsala University .
    de los Ángeles García Juanatey, María
    Department of Earth Sciences, Division of Geophysics, Uppsala University .
    Bauer, Tobias
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    Weihed, Pär
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    Elming, Sten-Åke
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    Potential Field, Geoelectrical and Reflection Seismic Investigations for Massive Sulphide Exploration in the Skellefte Mining District, Northern Sweden2016Ingår i: Acta Geophysica, ISSN 1895-6572, E-ISSN 1895-7455, Vol. 64, nr 6, s. 2171-2199Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Multi-scale geophysical studies were conducted in the central Skellefte district (CSD) in order to delineate the geometry of the upper crust (down to maximum ∼ 4.5 km depth) for prospecting volcanic massive sulphide (VMS) mineralization. These geophysical investigations include potential field, resistivity/induced polarization (IP), reflection seismic and magnetotelluric (MT) data which were collected between 2009 and 2010. The interpretations were divided in two scales: (i) shallow (∼ 1.5 km) and (ii) deep (∼4.5 km). Physical properties of the rocks, including density, magnetic susceptibility, resistivity and chargeability, were also used to improve interpretations. The study result delineates the geometry of the upper crust in the CSD and new models were suggested based on new and joint geophysical interpretation which can benefit VMS prospecting in the area. The result also indicates that a strongly conductive zone detected by resistivity/IP data may have been missed using other geophysical data.

  • 15.
    Weihed, Pär
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    3D, 4D and Predictive Modelling of Major Mineral Belts in Europe2015Samlingsverk (redaktörskap) (Refereegranskat)
  • 16.
    Bauer, Tobias
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    Weihed, Pär
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    Crustal Scale Shear Zones Controlling Grade and Tonnage of VMS Deposits in the Skellefte District, Northern Sweden2015Ingår i: Mineral Resources in a Sustainable World / [ed] A.S. Andre-Mayer; M. Cathelineau; P. Muchez; E. Pirard; S. Sindern, 2015, s. 45-48Konferensbidrag (Refereegranskat)
    Abstract [en]

    The Skellefte district in northern Sweden hosts abundant Paleoproterozoic, volcanic-hosted massive sulfide (VMS) deposits. The deposits formed due to pull apart basin formation in a volcanic arc setting and utilized the syn-extensional faults as fluid conduits. By comparing the structural setting in distinct structural domains with the tonnage and Cu, Au, and Ag grades a clear coupling between VMS deposits and the size of structures becomes evident. This shows how major crustal fault zones acted as fluid conduits for the ore forming hydrothermal fluids during an extensional phase. The same structures were subsequently re-activated as shear zones and possibly enhanced secondary enrichment processes.

  • 17.
    Weihed, Pär
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    Introduction2015Övrigt (Övrigt vetenskapligt)
    Abstract [en]

    This book is the result of 3- and 4-D modelling as part of the EU FP7 Promine project, which for the first time in Europe addressed the issue of pan-European 3- and 4 D geological models as a basis for mineral exploration and extraction under cover. The models that have been established cover four major mineral belts in Europe: Skellefte-Vihanti-Pyhäsalmi in Fennoscandia, Forsudetic monocline in Poland-Germany, the Iberian Pyrite Belt and the Ozza Morena zone in Spain-Portugal and the Hellenic belt of northern Greece. The basic principle for the modelling is to combine geological information from the surface, drill cores/holes, underground exposures with geophysical data, both airborne, ground and drill hole measurements. In most cases all existing and acquired data were imported and visualized in the gOcad software package. For some belts also uncertainty models are presented. 4-Dmodelling added the time aspect to the 3-Dmodels and aimed at visualizing the geological evolution of the district. 3-D predictivity maps are also presented using some different principles for the predictive models. We show in this book that it is possible to build robust 3-D models of major mineral belts in Europe and by using different approaches it is also possible to carry out 4-D modelling to help exploration industry with better targeting. The 3-D predictive models for the mineral belts clearly show the potential of undiscovered resources in various parts of Europe. The results from the modelling in the Promine project is a proof of concept, and we hope that this book serves as an inspiration for future, more full scale, projects that could be developed to contribute to a sustainable supply of metals to the society.

  • 18.
    Weihed, Pär
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    The Human Need of Metallic Raw Materials Why Exploration Matters!2015Ingår i: Mineral Resources in a Sustainable World / [ed] A.S. Andre-Mayer; M. Cathelineau; P. Muchez; E. Pirard; S. Sindern, 2015, s. 33-34Konferensbidrag (Refereegranskat)
  • 19.
    Bauer, Tobias
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    Skyttä, Pietari
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    Hermansson, Tobias
    Boliden Mineral AB.
    Allen, Rodney
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    Weihed, Pär
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    Correlation between distribution and shape of VMS deposits, and regional deformation patterns, Skellefte district, northern Sweden2014Ingår i: Mineralium Deposita, ISSN 0026-4598, E-ISSN 1432-1866, Vol. 49, nr 5, s. 555-573Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The Skellefte district in northern Sweden is host to abundant volcanogenic massive sulphide (VMS) deposits comprising pyritic, massive, semi-massive and disseminated Zn–Cu–Au ± Pb ores surrounded by disseminated pyrite and with or without stockwork mineralisation. The VMS deposits are associated with Palaeoproterozoic upper crustal extension (D1) that resulted in the development of normal faults and related transfer faults. The VMS ores formed as sub-seafloor replacement in both felsic volcaniclastic and sedimentary rocks and partly as exhalative deposits within the uppermost part of the volcanic stratigraphy. Subsequently, the district was subjected to deformation (D2) during crustal shortening. Comparing the distribution of VMS deposits with the regional fault pattern reveals a close spatial relationship of VMS deposits to the faults that formed during crustal extension (D1) utilising the syn-extensional faults as fluid conduits. Analysing the shape and orientation of VMS ore bodies shows how their deformation pattern mimics those of the hosting structures and results from the overprinting D2 deformation. Furthermore, regional structural transitions are imitated in the deformation patterns of the ore bodies. Plotting the aspect ratios of VMS ore bodies and the comparison with undeformed equivalents in the Hokuroko district, Japan allow an estimation of apparent strain and show correlation with the D2 deformation intensity of the certain structural domains. A comparison of the size of VMS deposits with their location shows that the smallest deposits are not related to known high-strain zones and the largest deposits are associated with regional-scale high-strain zones. The comparison of distribution and size with the pattern of high-strain zones provides an important tool for regional-scale mineral exploration in the Skellefte district, whereas the analysis of ore body shape and orientation can aid near-mine exploration activities.

  • 20.
    Zoheir, Basem
    et al.
    Department of Geology, Faculty of Science, Benha University.
    Weihed, Pär
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    Greenstone-hosted lode-gold mineralization at Dungash mine, Eastern Desert, Egypt2014Ingår i: Journal of African Earth Sciences, ISSN 1464-343X, Vol. 99, nr 1, s. 165-187Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The auriferous quartz±carbonate veins at Dungash mine, central Eastern Desert of Egypt, are confined to ∼E-trending dilation zones within variably foliated/sheared metavolcanic/volcaniclastic rocks. The vein morphology and internal structures demonstrate formation concurrent with a dextral shear system. The latter is attributed to flexural displacement of folded, heterogeneous rock blocks through transpression increment, late in the Neoproterozoic deformation history of the area. Geochemistry of the host metavolcanic/metavolcaniclastic rocks from the mine area suggests derivation from a low–K, calc–alkaline magma in a subduction-related, volcanic arc setting. In addition, chemistry of disseminated Cr-spinels further constrain on the back-arc basin setting and low-grade metamorphism, typical of gold-hosting greenstone belts elsewhere.Mineralogy of the mineralized veins includes an early assemblage of arsenopyrite-As-pyrite-gersdorffite±pyrrhotite, a transitional pyrite-Sb-arsenopyrite±gersdorffite assemblage, and a late tetrahedrite-chalcopyrite-sphalerite-galena-gold assemblage. Based on arsenopyrite and chlorite geothermometers, formation of gold-sulfide mineralization occurred between ∼365 and 280°C. LA-ICP-MS measurements indicate the presence of refractory Au in arsenian pyrite (up to 53 ppm) and Sb-bearing arsenopyrite (up to 974 ppm). Abundant free-milling gold associated with the late sulfide assemblage may have been mobilized and re-distributed by circulating, lower temperature ore fluids in the waning stages of the hydrothermal system.Based on the isotopic values of vein quartz and carbonate, the calculated average δ18OH2O values of the ore fluids are 5.0±1.4‰ SMOW for quartz, and 3.3±1.4‰ for vein carbonate. The measured carbonate δ13C values correspond to ore fluids with δ13CCO2= -6.7±0.7‰ PDB. These results suggest a mainly metamorphic source for ore fluids, in good agreement with the vein morphology, textures and hydrothermal alteration. The calculated δ34SH2S values for early, transitional, and late sulfide assemblages define three distinct ranges (∼1.5 to 3.6 ‰), (∼0.4 to 1.0‰), and (–3.7 to –1.9‰), respectively. The systematic evolution towards lighter δ34S values may be attributed to recrystallization, or to ore fluid buffering under variable physicochemical conditions.The shear zone-related setting, mineralogy and isotopic characteristics of gold mineralization in Dungash mine are comparable with other orogenic gold deposits in the region (e.g., Barramiya deposit), which may suggest a regional setting controlling gold metallogeny of the region. This setting should guide future exploration programs in the central Eastern Desert province.

  • 21.
    Kampmann, Tobias Christoph
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    Stephens, Michael
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    Weihed, Pär
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    Hydrothermal alteration, 3D modeling and sheath folding at the volcanic-hosted Falun Zn-Pb-Cu-(Au-Ag) deposit – implications for exploration in a 1.9 Ga ore district, Fennoscandian Shield, central Sweden2014Konferensbidrag (Refereegranskat)
    Abstract [en]

    The Paleoproterozoic (1.9 Ga), volcanic-hosted Zn-Pb-Cu-(Au-Ag) sulfide deposit at Falun is located in the Bergslagen lithotectonic unit, central Sweden, which includes one of the major ore districts in the Fennoscandian Shield, northern Europe. The Falun deposit is known mainly as one of the world’s leading copper suppliers over many centuries. During the 20th century, the mine was a major base (Zn, Pb, Cu) and precious (Ag, Au) metal producer until it closed during 1992.This study has the following four aims: (i) Identify the style and spatial distribution of hydrothermal alteration; (ii) determine the geometry of the different types of ore bodies; (iii) provide a mechanism for the structure of the deposit; and (iv) address broader implications for the Bergslagen ore district. Petrographic and structural data were collected during surface mapping and microscope work; modeling of the different ore bodies in 3D space was completed using available mine level maps and data collected during new logging of available drill cores. The Falun deposit is affected by polyphase ductile deformation and metamorphism under amphibolite facies conditions. The metamorphosed alteration rocks are dominated by distal quartz-mica-cordierite-(anthophyllite) and proximal quartz-anthophyllite assemblages, interpreted to represent Si-, Fe-, Mg-metasomatism of felsic volcanic rocks. Dolomite and calc-silicate (tremolite, actinolite, diopside)-skarn assemblages are interpreted as the equivalent alteration of carbonate rocks. Surface mapping in the open pit indicates that the ore bodies are completely enveloped by these altered rocks. Structural data suggest the presence of a reclined F2 fold that plunges steeply to the southeast, with a stretching component defined by a linear grain-shape fabric sub-parallel to the fold axis. Modeling in 3D space reveals the presence of several rod-shaped ore bodies that also plunge steeply to the southeast and thicken and merge upwards into a single ore body that is up to 270 m in diameter at the ground surface. The ore body close to this surface is zoned in a concentric pattern, from a massive, pyritic Zn-Pb-Cu-sulfide core in the inner part to a more Cu-rich sulfide zone and then a semi-massive to disseminated Cu-Au mineralization in the outer part. The cone-shaped and zoned ore bodies are interpreted as steeply-plunging megascopic sheath folds, formed in a ductile, high-strain tectonic regime. The viscosity contrast between competent, strongly silicified and metamorphosed felsic volcanic host rock and softer massive sulfide ore is suggested to have enhanced the development of these sheath folds. Steeply plunging, rod-shape geometries have commonly been reported for several volcanic-hosted sulfide and Fe oxide ore deposits in the Bergslagen lithotectonic unit and megascopic sheath folds have been identified in a high-strain belt in the northern part of this unit. If sheath fold formation can be confirmed as a key deformation mechanism for ore bodies in this mineral district, in contrast to the classical model of dome and basin fold interference structure, this will influence near-mine exploration strategies. Previous structural concepts and models for footwall/hanging wall relationships will need radical revision and areas previously considered as barren hanging wall lithologies may have a higher exploration potential.

  • 22.
    Alakangas, Lena
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    Bark, Glenn
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    Ericsson, Magnus
    Luleå tekniska universitet, Institutionen för ekonomi, teknik och samhälle, Samhällsvetenskap.
    Martinsson, Olof
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    Söderholm, Patrik
    Luleå tekniska universitet, Institutionen för ekonomi, teknik och samhälle, Samhällsvetenskap.
    Wanhainen, Christina
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    Weihed, Pär
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    Widerlund, Anders
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    Öhlander, Björn
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    Norrbottens malm- och mineralresurs och dess potentiella betydelse för innovation, samhälle och miljö2014Rapport (Övrigt vetenskapligt)
    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.

  • 23.
    Weihed, Pär
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    Greberg, Jenny
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Björkman, Bo
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Mineralteknik och metallurgi.
    Abrahamsson, Lena
    Luleå tekniska universitet, Institutionen för ekonomi, teknik och samhälle, Arbetsvetenskap.
    Andersson, Eira
    Luleå tekniska universitet, Institutionen för ekonomi, teknik och samhälle, Arbetsvetenskap.
    Fältholm, Ylva
    Luleå tekniska universitet, Institutionen för ekonomi, teknik och samhälle, Arbetsvetenskap.
    Bäckblom, Göran
    LKAB, Sverige.
    Project: Strategic Research and Innovation Agenda for the Swedish Mining and Metal Producing Industry2014Övrigt (Övrig (populärvetenskap, debatt, mm))
    Abstract [en]

    Developing the Strategic Research and Innovation Agenda for the Swedish Mining and Metal Producing Industry, for the years 2013-2030.

  • 24.
    Chmielowski, Riia
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    Jansson, Nils
    Persson, Mac Fjellerad
    Boliden Mines.
    Fagerström, Pia
    Boliden Mines.
    Weihed, Pär
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    3D geochemical modelling of hydrothermal alteration related to 1.89 Ga VHMS-type deposits, Kristineberg area, Skellefte District2013Ingår i: 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, s. 66-69Konferensbidrag (Refereegranskat)
    Abstract [en]

    A 3D geochemical model of the Kristineberg area of the Skellefte District, Sweden, is currently under construction, utilizing data from more than 1600 regionally distributed whole-rock lithogeochemical samples. The model will improve our understanding of the formation the VHMS deposits in this area. The model is built by mapping geochemical variations in 3D, and using this as a basis for modelling hydrothermal alteration in the unsampled portions of the rock column. A better understanding of the geometry, intensity, vectors of transport, and zonation of the hydrothermal zones in 3D will aid deep exploration for massive sulphide deposits in the Kristineberg area, and may potentially lead to new discoveries.

  • 25.
    Bauer, Tobias
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    Skyttä, Pietari
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    Tavakoli, Saman
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    Hermansson, Tobias
    Boliden Mineral AB.
    Dehghannejad, Mahdieh
    Uppsala University.
    Juanatey, Maria Garcia
    Uppsala University.
    Weihed, Pär
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    Allen, Rodney
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    Juhlin, Christopher
    Uppsala University.
    A regional scale 3D-model of the Skellefte mining district, northern Sweden2013Ingår i: Mineral depostits for a high-tech world: Proceedings of the 12th SGA Biennial Meeting 2013, 12-15 August 2013, Uppsala, Sweden, Uppsala: Sveriges Geologiska Undersökning , 2013, Vol. 1, s. 62-65Konferensbidrag (Refereegranskat)
  • 26.
    Skyttä, Pietari
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    Bauer, Tobias
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    Hermansson, Tobias
    Boliden Mineral AB.
    Dehghannejad, Mahdieh
    Uppsala University.
    Juhlin, Christopher
    Uppsala University.
    Hübert, Juliane
    Uppsala University.
    Weihed, Pär
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    Crustal 3-D geometry of the Kristineberg area (Sweden) with implications on VMS deposits2013Ingår i: Solid Earth, ISSN 1869-9510, E-ISSN 1869-9529, Vol. 4, s. 387-404Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Structural analysis of the Palaeoproterozoic volcanogenic massive sulfide (VMS) hosting Kristineberg area, Sweden, constrained by existing magnetotelluric (MT) and seismic reflection data, reveals that the complex geometry characterized by non-cylindrical antiformal structures is due to transpression along the termination of a major high-strain zone. Similar orientations of the host rock deformation fabrics and the VMS ore lenses indicate that the present-day geometry of the complex VMS deposits in the Kristineberg area may be attributed to tectonic transposition. The tectonic transposition was dominantly controlled by reverse shearing and related upright to overturned folding, with increasing contribution of strike-slip shearing and sub-horizontal flow towards greater crustal depths. Furthermore, the northerly dip of the previously recognized subsurface crustal reflector within the Kristineberg area is attributed to formation of crustal compartments with opposite polarities within the scale of the whole Skellefte district. The resulting structural framework of the main geological units is visualized in a 3-D model which is available as a 3-D PDF document through the publication website.

  • 27.
    Bauer, Tobias
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    Skyttä, Pietari
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    Allen, Rodney
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    Weihed, Pär
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    Fault-controlled sedimentation in a progressively opening extensional basin: the Palaeoproterozoic Vargfors basin, Skellefte mining district, Sweden.2013Ingår i: International journal of earth sciences, ISSN 1437-3254, E-ISSN 1437-3262, Vol. 102, nr 2, s. 385-400Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The Vargfors basin in the central part of the Skellefte mining district is an inverted sedimentary basin within a Palaeoproterozoic (1. 89 Ga) marine volcanic arc. The fault-segmented basin formed from upper-crustal extension and subsequent compression, following a period of intense sub-marine volcanism and VMS ore formation. New detailed mapping reveals variations in stratigraphy attributed to syn-extensional sedimentation, as well as provenance of conglomerate clasts associated with tectonic activity at the transition from extension to compression. The onset of fan delta to alluvial fan sedimentation associated with basin subsidence indicates that significant dip-slip displacement accommodating rapid uplift of the intrusive complex and/or subsidence of the adjacent volcano-sedimentary domain took place along a major fault zone at the southern margin of the intrusive complex. Subsidence of the Jörn intrusive complex and/or its burial by sedimentary units caused a break in erosion of the intrusion and favoured the deposition of a tonalite clast-barren conglomerate. Clast compositions of conglomerates show that the syn-extensional deposits become younger in the south-eastern parts of the basin, indicating that opening of the basin progressed from north-west to south-east. Subsequent basin inversion, associated with the accretion to the Karelian margin, involved reverse activation of the normal faults and development of related upright synclines. Progressive crustal shortening caused the formation of break-back faults accompanied by mafic volcanic activity that particularly affected the southern contact of the Jörn intrusive complex and the northern contact of the Vargfors basin

  • 28.
    Juanatey, Maria Garcia
    et al.
    Uppsala University.
    Hübert, Juliane
    Uppsala University.
    Tryggvason, Ari
    Uppsala University.
    Juhlin, Christopher
    Uppsala University.
    Pedersen, Laust
    Uppsala University.
    Dehghannejad, Mahdieh
    Uppsala University.
    Bauer, Tobias
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    Weihed, Pär
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    Skyttä, Pietari
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    Magnetotelluric measurements in the Skellefte ore district, northern Sweden2013Ingår i: Mineral depostits for a high-tech world: Proceedings of the 12th SGA Biennial Meeting 2013, 12-15 August 2013, Uppsala, Sweden, Uppsala, 2013, Vol. 1, s. 138-141Konferensbidrag (Refereegranskat)
  • 29.
    Zeballos, Ariana
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    Weihed, Pär
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    Blanco, Mario
    Machaca, Vladimir
    Mullite synthetization at low temperature2013Ingår i: Mineral deposit research for a high-tech world: proceedings / 12th biennial SGA meeting, 12-15 August 2013, Uppsala, Sweden / [ed] Erik Jonsson, Uppsala: Sveriges Geologiska Undersökning , 2013, s. 1784-1786Konferensbidrag (Refereegranskat)
    Abstract [en]

    The mineral nnullite (3Al(2)O(3)2SiO(2)) is frequently used by the industry in the preparation of refractory ceramics. However, it is uncommon in nature and, therefore, synthetically manufactured. The commercial mullite is synthetized from kaolinite + Al2O3 (gibbsite, bauxite), making the synthetization expensive. For that reason, naturally occurring deposits that can be utilized for the process are sought for. The Micaya deposit, located outside La Paz, Bolivia, is composed of a layer of kaolinitic shale hosted within the Vila Vila Formation composed of Devonian coarse-grained sandstones and siltstones. The shale is composed of quartz, kaolinite, muscovite and feldspar. The kaolinite can be separated from the shale by gravity separation, thus decreasing the SiO2 content and obtaining a new product with a higher Al2O3 content. The two major components (quartz and alumina) are then subjected to a calcination process at high temperatures in a suitable ceramic firing programme and results in the formation of mullite without adding extra Al2O3.

  • 30.
    Bejgarn, Therese
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    Söderlund, Ulf
    Lunds universitet.
    Weihed, Pär
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    Årebäck, Hans
    Boliden Mineral AB.
    Ernst, Richard E.
    Carleton University, Ottawa.
    Palaeoproterozoic porphyry Cu-Au, intrusion-hosted Au and ultramafic Cu-Ni deposits in the Fennoscandian Shield: temporal constraints using U-Pb geochronology2013Ingår i: Lithos, ISSN 0024-4937, E-ISSN 1872-6143, Vol. 174, s. 236-254Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The Skellefte district, northern Sweden, is known for the occurrence of 1.89 Ga Palaeoproterozoic volcanogenic massive sulphide (VMS) deposits. The deposits are hosted by the older part of a volcanosedimentary succession, which was intruded at 1.88-1.86 Ga by multiple phases of the syn-volcanic, early orogenic Jörn intrusive complex (JIC). The oldest phase of the JIC hosts different styles of mineralisation, among them porphyry Cu-Mo-Au, intrusion-related Au, and mafic-hosted Fe and Cu-Ni deposits. To discriminate between the different intrusive and ore related events, U-Pb ages of zircons have been obtained for nine intrusive phases and from Na-Ca alteration spatially related to mineralisation, while U-Pb ages of baddeleyite (ZrO2) have been used to constrain intrusive ages of three mineralised and barren mafic-ultramafic intrusive rocks.The two main JIC intrusive phases of a granodioritic-tonalitic composition in the southern study area intruded at 1887 ± 3 Ma and 1886 ± 3 Ma, respectively, and were succeeded by the intrusion of layered mafic-ultramafic intrusive rocks in the northern and southern study area at 1879 ± 1 Ma and 1884 ± 2 Ma, respectively. Emplacement of porphyry dykes took place at ca. 1877 Ma in the southern, western and northern JIC. The dykes are spatially and temporally associated with formation of porphyry style mineralisation, alteration and Au-mineralisation, as inferred from 1879 ± 5 Ma zircons in adjacent Na-Ca alteration zones. High SiO2 and Al2O3 content together with high Sr/Y ratios, mingling structures, mafic xenoliths and hornblende phenocrysts in the porphyry dykes suggest that the magma originated from hydrated partial melts, possibly from the base of the crust at a mature stage of subduction. Local extension resulted in intrusion of mafic-ultramafic rocks around 1.88 Ga prior to and after, the porphyry dykes and associated mineralisation, approximately 10 Ma after the formation of the spatially related 1.89 Ga VMS deposits in the Skellefte district. This 1.88 Ga event correlates with other 1.88 Ga mafic-ultramafic units widespread around the world, and could possibly be interpreted as a large scale response to supercontinent formation.

  • 31. Jansson, Nils
    et al.
    Chmielowski, Riia
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    Weihed, Pär
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    Hermansson, Tobias
    Boliden Mines.
    Persson, Mac Fjellerad
    Boliden Mines.
    Berglund, Alexandra
    Boliden Mines.
    Kruuna, Annika
    Boliden Mines.
    Skyttä, Pietari
    Bachmann, Kai
    TU Bergakademie Freiberg.
    Gutzmer, Jens
    TU Bergakademie Freiberg.
    Recent advances in structural geology, lithogeochemistry and exploration for VHMS deposits, Kristineberg area, Skellefte2013Ingår i: Mineral deposit research for a high-tech world: Proceedings of the 12th Biennial SGA Meeting, 12–15 August 2013, Uppsala, Sweden, 2013, s. 545-548Konferensbidrag (Refereegranskat)
  • 32.
    Dehghannejad,, Mahdieh
    et al.
    Department of Earth Sciences, Uppsala University.
    Juhlin,, Christopher
    Department of Earth Sciences, Uppsala University.
    Malehmir, Alireza
    Department of Earth Sciences, Uppsala University.
    Juanatey, Maria A. Garcia
    Department of Earth Sciences, Uppsala University.
    Skyttä, Pietari
    Department of Geosciences and Geography, University of Helsinki, FI-00014 Helsinki.
    Weihed, Pär
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    Bauer, Tobias
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    Reflection seismic imaging in the Skellefte ore district, northern Sweden2013Ingår i: Mineral depostits for a high-tech world: Proceedings of the 12th SGA Biennial Meeting 2013, 12-15 August 2013, Uppsala, Sweden, Uppsala: Sveriges Geologiska Undersökning , 2013, Vol. 1, s. 126-129Konferensbidrag (Refereegranskat)
  • 33.
    Kampmann, Tobias Christoph
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    Weihed, Pär
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    Stephens, Michael B.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    Structural investigation and 3D modelling of the Falun pyritic Zn-Pb-Cu-(Au-Ag) sulphide deposit, Bergslagen region, south-central Sweden2013Konferensbidrag (Refereegranskat)
    Abstract [en]

    One of the prominent ore deposits of the Bergslagen region in south-central Sweden is located in Falun in the northern part of this mining district. A belt of 1.91-1.89 Ga metavolcanic rocks hosts both the ores and an alteration aureole of several hundreds to thousands of metres in extent at the ground surface. Analysis of the structures in the area reveals a polyphase ductile deformational history and a major, steeply plunging F2 reclined fold. 3D modelling of the boundary surface to the pyritic Zn-Pb-Cu sulphide ore has been used to visualize the geometry of this ore body at depth, constraining its steeply plunging rod-like and NW-SE elongate shape and a geometric control by the F2 fold structure.

  • 34.
    Bejgarn, Therese
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Weihed, Pär
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    Nylander, Juhani
    Boliden Mineral AB.
    Årebäck, Hans
    Boliden Mineral AB, Earth Sciences Centre – Geology, Göteborg University.
    Söderlund, Ulf
    Lund Universitet, Department of Geology, GeoBiosphere Science Centre, Lund University.
    Ernst, Richard E.
    Geological Survey of Canada, Carleton University, Ottawa.
    Tectonomagmatic aspects of intrusive hosted Cu-Au-Mo deposits in the Skellefte District, northern Sweden2013Ingår i: Mineral deposit research for a high-tech world: proceedings / [ed] Erik Jonsson, Uppsala: Sveriges Geologiska Undersökning , 2013, s. 770-773Konferensbidrag (Refereegranskat)
    Abstract [en]

    The Algtrask gold deposit and several low grade base metal deposits, e.g. the Tallberg porphyry deposit, are hosted by the Jam intrusive complex in the northern part of the Skellefte District, northern Sweden. The intrusive complex was emplaced at 1.89-1.86 Ga in a continental margin volcanic arc setting, and the oldest 1.89 Ga phase is coeval with volcanic rocks within the Skellefte Group, a complex volcano-sedimentary succession hosting numerous VMS deposits. The intrusive hosted deposits are associated with 1.88 Ga quartz-feldspar porphyritic intrusive rocks, which formed from 1.89 Ga recycled crust. Hence, it is interpreted that the intrusive hosted deposits formed when the arc was under transpression-compression, 10 Myr after the spatially related VMS deposits, which formed when the arc was under extension.

  • 35.
    Arvanitidis, N
    et al.
    Institute of Geology and Mineral Exploration (IGME).
    Michael, C
    Institute of Geology and Mineral Exploration (IGME).
    Christidis, C
    National and Kapodistrian University of Athens.
    Weihed, Pär
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    Gaal, Gabor
    Geological Survey of Finland, P.O.Box 96, 02151 Espoo.
    Royer, J.J.
    Université de Lorraine, CNRS, Nancy.
    Perantonis, G
    Hellas Gold S.A..
    Bakalis, V
    Hellas Gold S.A..
    Ballas, D
    Hellas Gold S.A..
    Using 3D/4D modelling tools in exploration for epithermal gold potential areas in Eastern Rhodope zone (Western Thrace, NE Greece)2013Ingår i: 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, Vol. 1, s. 58-61Konferensbidrag (Refereegranskat)
  • 36.
    Arvanitidis, N
    et al.
    Institute of Geology and Mineral Exploration (IGME).
    Michael, C
    Institute of Geology and Mineral Exploration (IGME).
    Christidis, C
    National and Kapodistrian University of Athens.
    Weihed, Pär
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    Gaal, Gabor
    Geological Survey of Finland.
    Royer, J.J.
    Université de Lorraine, CNRS, Nancy.
    Perantonis, G
    Hellas Gold S.A..
    Bakalis, V
    Hellas Gold S.A..
    Ballas, D
    Hellas Gold S.A..
    Using 3D/4D modelling tools in exploration for porphyry and manto-polymetallic potential areas in Eastern Chalkidiki peninsula2013Ingår i: Mineral deposit research for a high-tech world: Proceedings of the 12th SGA Biennial Meeting 2013, 12-15 August 2013, Uppsala, Sweden, Uppsala: Sveriges Geologiska Undersökning , 2013, Vol. 1, s. 54-57Konferensbidrag (Refereegranskat)
  • 37.
    Dehghannejad, Mahdieh
    et al.
    Department of Earth Sciences, Uppsala University.
    Bauer, Tobias
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    Malehmir, Alireza
    Department of Earth Sciences, Uppsala University.
    Juhlin, Christopher
    Department of Earth Sciences, Uppsala University.
    Weihed, Pär
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    Crustal geometry of the central Skellefte district, northern Sweden: constraints from reflection seismic investigations2012Ingår i: Tectonophysics, ISSN 0040-1951, E-ISSN 1879-3266, Vol. 524-525, s. 87-99Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The Palaeoproterozoic Skellefte mining district in Sweden is one of the most important mining districts in Europe. As a part of a 4D geologic modeling project, three new sub-parallel reflection seismic profiles, with a total length of about 95 km, were acquired in the central part of the district. Processed seismic data reveal a series of gentle- to steeply- dipping reflections and a series of diffraction packages. The majority of reflections that extend to the surface can be correlated with geological features either observed in the field or interpreted from the aeromagnetic map. A set of south-dipping reflections represent inferred syn-extensional listric extensional faults that were inverted during subsequent crustal-shortening. Cross-cutting north-dipping reflections are correlated to late-compressional break-back faults. Flat-lying reflections in the central parts of the study area could represent lithological contacts within the Skellefte Group, or the contact between Skellefte Group rocks and their unknown basement. Flat-lying reflections occurring further north are inferred to originate from the top of the Jörn intrusive complex or an intrusive contact within it. So far unknown south- and north-dipping faults have been identified in the vicinity of the Maurliden deposit. Based on the seismic results, a preliminary 3D-model has been created in order to visualize the fault pattern and to provide a base for future 3D/4D modeling in the Skellefte district.

  • 38.
    Skyttä, Pietari
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    Bauer, Tobias
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    Tavakoli, Saman
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    Hermansson, Tobias
    Boliden Mineral AB.
    Andersson, Jenny
    Sveriges Geologiska Undersökning, Geological Survey of Sweden.
    Weihed, Pär
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    Evolution of early-orogenic deformation zones and their significance for the development of contrasting structural domains within the Palaeoproterozoic Skellefte District, Sweden2012Konferensbidrag (Refereegranskat)
  • 39.
    Bark, Glenn
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    Weihed, Pär
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    Geodynamic settings for Paleoproterozoic gold mineralization in the Svecofennian domain: a tectonic model for the Fäboliden orogenic gold deposit, northern Sweden2012Ingår i: Ore Geology Reviews, ISSN 0169-1368, E-ISSN 1872-7360, Vol. 48, s. 403-412Artikel i tidskrift (Refereegranskat)
    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.

  • 40.
    Bauer, Tobias
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    Skyttä, Pietari
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    Hermansson, Tobias
    Boliden Mineral AB.
    Weihed, Pär
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    Ore body shapes versus regional deformation patterns as a base for 3D prospectivity mapping in the Skellefte Mining District, Sweden2012Konferensbidrag (Refereegranskat)
  • 41.
    Gaal, Gabor
    et al.
    Geological Survey of Finland, P.O.Box 96, 02151 Espoo.
    Cassard, D.
    Bureau de Recherches Géologiques et Minières, Orléans.
    Bertrand, G.
    Bureau de Recherches Géologiques et Minières, Orléans.
    Schaeben, H.
    TU Bergakademie Freiberg.
    Royer, J.J.
    Université de Lorraine, CNRS, Nancy.
    Weihed, Pär
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    Skyttä, Pietari
    Bauer, Tobias
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    Pan-European mineral resource assessment2012Konferensbidrag (Refereegranskat)
  • 42.
    Skyttä, Pietari
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    Bauer, Tobias
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    Tavakoli, Saman
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    Hermansson, Tobias
    Boliden Mineral AB.
    Andersson, Jenny
    Geological Survey of Sweden.
    Weihed, Pär
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    Pre-1.87 Ga development of crustal domains overprinted by 1.87 Ga transpression in the Palaeoproterozoic Skellefte district, Sweden2012Ingår i: Precambrian Research, ISSN 0301-9268, E-ISSN 1872-7433, Vol. 206–207, s. 109-136Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The complex structural evolution within the VMS-hosting Skellefte district, Sweden, has been investigated to provide a solid structural framework for the known mineral deposits in the area. The area occurs in a transition zone between dominantly N-S to NNE-WSW striking structures in the north and approximately WNW-ESE oriented structural trends in the south. The presence of high-strain zones with both the above orientations in the Skellefte district allows constraining their mutual relationship, as well as their significance for the build-up of the Svecokarelian orogen at around 1.89 Ga and for the following tectonic overprint between 1.87-1.80 Ga. The methods used in this study include structural analysis complemented by potential field modelling and SIMS U-Pb geochronology on zircon. Based on the results of this study, the earliest deformation (D1) is constrained at 1.89–1.88 (1.87) Ga and tentatively attributed to crustal extension occurring synchronously with volcanism. Deposition of the Skellefte Group metavolcanic rocks is inferred to have occurred in a pull-apart basin developed due to dextral strike-slip shearing along approximately N-S striking regional-scale shear zones. Variations in the development of deformation fabric across the district indicate that the crust was divided into an upper, un-metamorphosed domain and a lower, strongly metamorphosed domain during D1. We further infer that the transition from the upper to lower crust was locally coupled with development of low-angle crustal-scale detachment zones during D1. The heterogenous crust was subsequently overprinted by transpressional deformation which may be explained by two alternative models. According to the first model, one single SSE-NNW transpressional event with distinct strain partitioning between the coaxially deformed upper crust and the non-coaxially deformed lower crust is largely responsible for the present-day structural geometry. A post-folding rhyolite dyke, here dated at 1871 ± 4 Ma, constrains the minimum age of this event (D2). The alternative model includes two separate transpressional events: a SW-NE one at (1.88-) 1.87 Ga, followed by SSE-NNW transpression at 1.86 Ga. Recognition of the early-orogenic detachment zones allow us to suggest that many of the major crustal-scale shear zones in the central Fennoscandian Shield have originated as 1.89-1.87 Ga crustal detachment zones, i.e. earlier than typically considered.

  • 43.
    Tavakoli, Saman
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    Bauer, Tobias
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    Elming, Sten-åke
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    Thunehed, Hans
    Geovista AB.
    Weihed, Pär
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    Regional-scale geometry of the central Skellefte district, northern Sweden: results from 2.5D potential field modeling along three previously acquired seismic profiles2012Ingår i: Journal of Applied Geophysics, ISSN 0926-9851, E-ISSN 1879-1859, Vol. 85, s. 43-58Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The Skellefte district in northern Sweden is one of the most important mining districts in Europe hosting approximately 80 volcanic massive sulfide (VMS) deposits. Due to its economical importance, geological and geophysical studies were carried out in order to create an image of the geometry of the upper crustal structure and integral geological elements and to evaluate their relationship to mineral deposits. Consequently, seismic reflection data along three sub-parallel profiles were acquired during 2009–2010 to map the spatial relationships between the geological structures down to a depth of ~4.5 km. Although these seismic studies helped researchers understand the regional relationship between geologic units in the central Skellefte district (CSD), the seismic reflection data did not succeed entirely in mapping the lithological contacts in the area. In this study, themodel derived fromthe seismic reflection datawas examined by using 2.5D modeling of potential field data (down to a 5 km depth) constrained by physical properties of the rocks and surface geology.Moreover, we modeled gravity and magnetic data along the non-reflective or poorly reflective parts of the seismic profiles to identify major lithological contacts and shear zones in the CSD, which could not be modeled on the basis of the seismic reflection data. Gravity and magnetic data helped reveal the spatial relationship between the Skellefte volcanic rocks, Vargfors groupmeta-sedimentary rocks and two metaintrusive complexes.Results suggest amaximum depth extent of 2.1 kmfor the tectonic contact at the southern border of the Jörn granitoid. Furthermore, this north-dipping Skellefte–Jörn contact coincides closely with magnetic lows and gravity highs, which implies that the Jörn intrusive rocks have a greater thickness than the underlying basalt. Further to the NW, gravity and magnetic data suggest a depth extent of 2 km for the Gallejaur complex, which coincides with a set of gently dipping reflectors. In addition, this study supports previous concepts of fault geometries and fault patterns as a result of upper-crustal extension and subsequent inversion during crustal shortening. In the final model interpretations of the IP data were included, thus relating indications of mineralization to the geological structures.

  • 44.
    Tavakoli, Saman
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    Bauer, Tobias
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    Skyttä, Pietari
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    Elming, Sten-åke
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    Thunehed, Hans
    Geovista AB.
    Weihed, Pär
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    Skellefte mining district in 3D: results from integrated interpretation of potential field, resistivity/IP and reflection-seismic data2012Konferensbidrag (Refereegranskat)
    Abstract [en]

    Located in northern Sweden, the Skellefte mining district has been subject to several geological and geophysical investigations, as it is hosting abundant volcanic-hosted massive sulfide deposits. The importance of mineral exploration at greater depths in the Skellefte District has been increased since most of mineralization at shallow depths are already discovered and exploited. Therefore, geophysical methods become particularly important as they can improve our knowledge about spatial relationship between geological features at the depth. In the first part (local-scale) of this study, we used resistivity/IP data to map the subsurface geometry down to 430m. Furthermore, the results of the resistivity/IP studies were constrained with potential field data down to 1.5 km depth. In the second part (Regional-scale), potential field data were used to constrain the interpretation of the reflection-seismic data down to 5 km depth. The result from the first part indicated a good correlation between the initial resistivity model and the magnetic and gravity field calculated from that model. In Part II, the gravity and magnetic data were investigated to better understand the contact between the Skellefte Group,volcanic rocks and the Bothnian Basin sedimentary rocks. Furthermore the method was used to constrain the geometry of late-orogenic gabbro-diorite and granite intrusions which occur along inferred shear zones that are only poorly indicated, or not visible at all on the reflection-seismic profiles. As the main outcome, the proposed integrated 3D model of the central Skellefte District (CSD) revealed crucial information about the spatial relationship between key lithologies which will be further used to understand the evolution of CSD in the 4th dimension, time.

  • 45.
    Bauer, Tobias
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    Skyttä, Pietari
    Hermansson, Tobias
    Boliden Mineral AB, Luleå tekniska universitet.
    Weihed, Pär
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    The comparison of ore body shapes and regional deformat patterns as a base for prospectivity mapping in the Skellefte mining district, Sweden2012Konferensbidrag (Refereegranskat)
  • 46.
    Skyttä, Pietari
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    Bauer, Tobias
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    Tavakoli, Saman
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    Weihed, Pär
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    Allen, Rodney
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    Dehghannejad, Mahdieh
    Juanatey, Maria Garcia
    Hübert, Juliane
    4-dimensional geological modelling of mineral belts2011Konferensbidrag (Övrigt vetenskapligt)
  • 47.
    Bauer, Tobias
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    Skyttä, Pietari
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    Tavakoli, Saman
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    Dehghannejad, Mahdieh
    Uppsala University, Uppsala universitet, Department of Earth Sciences, Uppsala University.
    Weihed, Pär
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    From deposit to regional scale: 4-dimensional geological modelling in the Skellefte Mining District, Sweden2011Konferensbidrag (Refereegranskat)
  • 48.
    Bauer, Tobias
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    Skyttä, Pietari
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    Dehghannejad, Mahdieh
    Uppsala University.
    Tavakoli, Saman
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    Weihed, Pär
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    Geological multi-scale modelling as a tool for modern ore exploration in the Skellefte mining district, Sweden2011Ingår i: Proceedings IAMG 2011 Salzburg: Mathematical Geosciences at the crossroads of theory and practice, 2011, s. 759-Konferensbidrag (Övrigt vetenskapligt)
    Abstract [en]

    The Palaeoproterozoic Skellefte Mining District is host to abundant ore deposits. Geological 3Dmodelling was performed using the gOcad software platform. Geological methods such as field mapping, structural analysis and facies analysis combined with geophysical techniques such as reflection seismic investigations, resistivity, magnetic, electromagnetic and gravimetric studies and analysis of potential field data provide a framework for the reconstruction of the crustal geometry and geological history of the district as a tool for modern ore exploration. Results will be furthermore utilized for kinematic 4-dimensional modelling

  • 49. Bejgarn, Therese
    et al.
    Årebäck, Hans
    Boliden Mineral AB.
    Weihed, Pär
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    Nylander, Juhani
    Boliden Mineral AB.
    Geology, petrology and alteration geochemistry of the Palaeoproterozoic intrusive hosted Ägträsk Au deposit, Northern Sweden2011Ingår i: Geological Society Special Publication, ISSN 0305-8719, E-ISSN 2041-4927, nr 350, s. 105-132Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The Ägträsk intrusive hosted Au deposit, Skellefte district, northern Sweden, is situated in the oldest, most heterogeneous part of the c. 1.89-1.86 Ga Jörn granitoid complex, which intruded a complex volcano-sedimentary succession in an island arc or continental margin arc environment. The Tallberg porphyry Cu deposit, situated only 3 km west of Ägträsk, is associated with quartz feldspar porphyritic dykes. These dykes are suggested to be genetically related to similar porphyry dykes in Älgträsk and the tonalitic host rock in Tallberg. The granodiorite hosting the Ägträsk Au-deposit does not appear to be genetically related to the tonalite or the porphyry dykes.

  • 50.
    Billström, Kjell
    et al.
    Museum of Natural History.
    Eilu, Pasi
    Geological Survey of Finland.
    Martinsson, Olof
    Niiranen, Tero
    Geological Survey of Finland.
    Broman, Curt
    Stockholm University.
    Weihed, Pär
    Wanhainen, Christina
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    Ojala, Juhani
    Geological Survey of Finland.
    IOCG and related mineral deposits of the northern Fennoscandian Shield2011Ingår i: Hydrothermal iron oxide copper-gold & related topics: a global perspective, Adelaide: PGC Publishing , 2011, s. 381-414Kapitel i bok, del av antologi (Övrigt vetenskapligt)
    Abstract [en]

    The northernmost Fennoscandian shield comprises Archaean and Palaeoproterozoic rocks. Unlike most other shield areas, economic mineral deposits are largely restricted to its Palaeoproterozoic parts. The latter are characterised by intracratonic basin evolution between ca. 2.5 and 2.0 Ga, involving recurrent mantle hotspot activity with numerous layered intrusions, komatiite and picrite eruptions, but no signs of accretionary phases or formation of major new felsic crust. Accretion and continent-continent collision followed from ca. 1.9 to 1.8 Ga, during the Svecofennian orogeny. A range of mineralisation styles are hosted by extensive ca. 2.5 to 2.0 Ga greenstone belts and younger, subduction-related 1.9 to 1.8 Ga Svecofennian intrusive and extrusive settings. These mineralisation styles partially overlap, and individual deposits may not readily be placed into genetic classification schemes. A provisional grouping of observed mineralisation styles comprises (1) stratiform-stratabound sulphide, (2) apatite-iron, (3) skarn-related iron and BIF, and (4) epigenetic(±syngenetic?) Au and Cu-Au deposits. The descriptive section of this paper also highlights features that may relate to orogenic-gold, IOCG and 'atypical metal association' categories of mineralisation. The assumption made is that the deposition of a diverse range of ore deposits was made possible by a long and complex geological evolution. This involved an initial (sowing) stage where iron, and to some extent copper and gold, were concentrated during 2.3 to 2.1 Ga (Karelian) rock-forming processes. Following this, ore elements were mobilised during two younger (Svecofennian) stages at 1.92 to 1.87 and 1.85 to 1.79 Ga, respectively. The latter were triggered by metamorphic and magmatic episodes, and fluids liberated during these stages precipitated IOCG and related deposits when fluids met structural and chemical traps in suitable host rocks. Ore fluids are generally saline, and their development probably involved incorporation of evaporates and, at least locally, also felsic magmatism may have played a role. Skarn-related mineralisation, hosted by ca. 2.1 Ga greenstones, occurs both as a BIF type in Sweden (formed at around 2.1 Ga), and as a gold-copper enriched variety (the result of Svecofennian epigenetic processes) in the Kolari region of Finland. The huge Kiirunavaara deposit is the type example of apatite iron ores, and is here considered to have formed from a magma at ca. 1.88 Ga, although it also has features best explained by a magmatic-hydrothermal overprint. A younger, less prominent, stage of apatite iron ore formation took place at approximately 1.78 Ga. Epigenetic gold and copper-gold deposits are particularly hard to classify as these show mixed ore characteristics, and to some extent this is likely to be due to multiple mineralisation stages (cf. the huge, low grade Aitik deposit in Sweden which is interpreted to be a hybrid porphyry-IOCG-type of ore). Structurally controlled, orogenic-gold mineralisation is common in the Central Lapland greenstone belt, although there are also gold deposits with enhanced contents of e.g., copper, cobalt and uranium (e.g., at Saatopoora). The latter, sometimes referred to as being of an 'atypical metal association' type, could potentially also include syngenetic mineralisation (e.g., at Juomasou). The range of epigenetic (±syngenetic) gold and copper-gold deposits could possibly be related to a vague east-west trend defined by gold-rich deposits in the east (Finland), followed by IOCG (copper±gold) and more iron-dominant ore types near the Finnish-Swedish border and further west into Sweden.

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