| 1. |
- Allen, Ann, et al.
(författare)
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Geochemistry as a Tool for Exploration at the Renstrom Zn-Pb-Cu-Au-Ag VMS Camp, Skellefte District, Sweden
- 2015
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Ingår i: Mineral Resources in a Sustainable World. - 9782855550664 ; , s. 2047-2050
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Konferensbidrag (refereegranskat)abstract
- The Skellefte mining district in northern Sweden contains over 85 pyritic Zn-Cu-Au-Ag massive sulphide deposits. The Renstrom area, one of the most intensely mineralized parts of the Skellefte district, contains five zinc-and gold-rich deposits, three of which are confined to a specific continuous stratigraphic unit, the "Renstrom ore host unit". The great structural complexity of the area made it difficult to locate and follow the ore horizon to generate new exploration targets. A new study in the Kyrkvagen area, based on stratigraphic correlations, structural interpretations and lithogeochemical and geophysical data interpretation, revealed several NW-trending faults which separate five structural blocks. The rocks of the area could be characterized in terms of geochemistry, stratigraphy and their position in the hanging or footwall with respect to the ore horizon. Moreover, alteration patterns allowed predictions of possible extensions of the ore horizon. This increased knowledge of the Kyrkvagen area led to the identification of five new drilling targets for further exploration in one of Boliden's most important mining areas.
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| 2. |
- Bauer, Tobias, et al.
(författare)
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Crustal Scale Shear Zones Controlling Grade and Tonnage of VMS Deposits in the Skellefte District, Northern Sweden
- 2015
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Ingår i: Mineral Resources in a Sustainable World. - 9782855550664 ; , s. 45-48
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Konferensbidrag (refereegranskat)abstract
- 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.
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| 3. |
- Brethes, Anaïs, et al.
(författare)
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3D-Modelling of the Early Triassic Base-Metal Mineralized Syn-Rift Sequence in the Jameson Land Basin (East Greenland)
- 2015
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Ingår i: Mineral Resources in a Sustainable World. - 9782855550664 ; , s. 1701-1704
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Konferensbidrag (refereegranskat)abstract
- The Jameson Land Basin in central East Greenland is mineralized in Pb, Zn and Cu. Mineralization occurs in several stratigraphic horizons and along structures in Upper Permian and Triassic sediments. A good understanding of the basin architecture and evolution is therefore essential for mineral exploration in this area. 3D-Photomapping from high resolution aerial photos along with a structural interpretation of aeromagnetic data, electromagnetic data, and results from fieldwork and drilling were integrated into a 3D-structural model. This data integration allowed modelling the rift architecture in the eastern margin of the Jameson Land Basin.
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| 4. |
- Högdahl, Karin, et al.
(författare)
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Turning yesterday´s waste into tomorrow´s treasure : searching for base and critical metals in central Sweden´s ancient mine dumps
- 2015
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Ingår i: Mineral Resources In A Sustainable World. - 9782855550664 ; , s. 757-760
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Konferensbidrag (refereegranskat)abstract
- Mine dumps the abundant by-products of centuries of mining in Europe have potential to become sources of a wide range of metals and minerals. Despite their variable volumes and the geometallurgical challenges involved, they are a raw material resource to include among other, not least in the context of the present societal demand to increase recycling. Until the mid-1900s the applications and therefore the markets for many metals were limited. Additionally, many were difficult to identify, and thus often missed. In numerous mining districts this resulted in rocks hosting such metals to end up as waste, that is, on the mine dumps. The present pilot project is aimed at testing the potential for such secondary resources in the classic and ancient Bergslagen ore province in south central Sweden, with a special focus on metals presently identified as "critical" for industry. The Bergslagen province, with its 1000-year-history of mining is a suitable testing ground to find out what may actually be out there. Results so far include the detection and mineralogical characterisation of variable amounts of precious and critical as well as base metal minerals, along with the main ore commodity in many old mining fields.
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| 5. |
- Jansson, Nils, et al.
(författare)
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Oxidized Brines Inferred in the Formation of c. 1.9 Ga Stratiform Zn-Pb-Ag and Dolomite-Hosted Cu Ores, Zinkgruvan, Bergslagen, Sweden
- 2015
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Ingår i: Mineral Resources in a Sustainable World. - 9782855550664 ; , s. 1925-1928
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Zinkgruvan is an elusive Palaeoproterozoic stratiform Zn-Pb-Ag deposit which has been discussed in the context of sediment-hosted Zn-Pb (SEDEX), volcanic-hosted massive sulphide (VHMS) and Broken Hill-type (BHT) deposits. In this contribution, we address the chemistry of the ore-forming fluid, the nature of the depositional environment and the controls on ore formation based on a review of previous work complemented with new geological data from a stratigraphically underlying dolomite-hosted, zinciferous, cobaltiferous and nickeliferous Cu ore. We conclude that both deposit types can be explained as the product of a saline, oxidizing metalliferous brine which formed Cu mineralization by interaction with reduced pore waters, prior to exhalation into an anoxic brine pool, forming the stratiform Zn-Pb-Ag deposit. Our inference of fluid composition differs from many inferences on the chemistry of hydrothermal fluids involved in the formation of typical VHMS and BHT deposits, but is similar to that inferred for Proterozoic sediment-hosted Zn-Pb deposits in the McArthur basin, Australia
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| 6. |
- Jonsson, Erik, et al.
(författare)
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Apatite-iron oxide-hosted REE mineralisation at Kopslahyttan, NW Bergslagen, Sweden
- 2015
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Ingår i: Mineral Resources In A Sustainable World. - 9782855550664 ; , s. 781-784
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Konferensbidrag (refereegranskat)abstract
- Of the different types of REE mineralisation known from the Fennoscandian shield, the Palaeoproterozoic apatite-iron oxide ores of Kiruna type represent one resource type with significant potential. Here we describe an REE-rich apatite-magnetite mineralisation from the classic Bergslagen ore province in south central Sweden. Associated with moderately to weakly REE-enriched magnetite mineralisation of banded and vein types, the most apatite-rich occurrence at Kopslahyttan shows REE enrichment that is similar in both magnitude and pattern to other Kiruna type deposits. Yet, the present REE mineralogy is wholly dominated by monazite-(Ce), allanite-(Ce) and LREE-enriched epidote, the latter two often occurring as zoned crystals or aggregates. Minor xenotime-(Y) also occurs, and titanite locally hosts minor Y+HREE. The abundant fluorapatite is suggested to have been an additional, original host for REE, prior to fluid-mediated alteration leading to wholesale remobilisation of REE from the apatite. This remobilisation included dissolution-reprecipitation processes that lead to the nucleation of monazite in fluorapatite, but probably also further transport and precipitation as e.g. allanite/REE-epidote, through reactions with locally common silicates. In addition, we suggest that very coarse grained, variably Th-bearing monazite present in the mineralisation may have been a primary REE phase, in marked contrast to most other deposits of this type.
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| 7. |
- Kampmann, Tobias, et al.
(författare)
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Timing of magmatism and mineralisation at Falun, a major base metal sulphide deposit in the Fennoscandian Shield, Sweden
- 2015
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Ingår i: Mineral Resources in a Sustainable World. - 9782855550664 ; , s. 591-594
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Konferensbidrag (refereegranskat)abstract
- U-Pb (zircon) ion probe geochronology on key lithologies at the Palaeoproterozoic Falun Zn-Pb-Cu-(Au-Ag) sulphide deposit in the south-western part of the Fennoscandian Shield has been carried out. Results suggest that dominantly felsic sub-volcanic intrusion, hydrothermal alteration, ore formation and intrusion by dykes and plutons took place in a short time interval between 1894 ± 3 Ma and 1891 ± 3 Ma. Analogues to intra-arc VMS mineralisation in Peru are discussed.
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| 8. |
- Koch, Pierre-Henri, et al.
(författare)
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How to Build a Process Model in a Geometallurgical Program?
- 2015
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Ingår i: Mineral Resources in a Sustainable World. - 9782855550664 ; , s. 1419-1422
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Konferensbidrag (refereegranskat)abstract
- This work presents a literature review on ways to acquire relevant experimental data for the process model of a geometallurgical program. It identifies the needs in several unit models and proposes ideas for future developments
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| 9. |
- Lamberg, Pertti, et al.
(författare)
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Using Mineral rather than Elemental Grades in Mineral Resource Estimate : Motivation and Techniques
- 2015
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Ingår i: Mineral Resources in a Sustainable World. - 9782855550664 ; , s. 1423-1425
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Konferensbidrag (refereegranskat)abstract
- Mineral resource estimates of metallic ores use traditionally elemental grades when describing the quality of the deposit. This information is very defective as it does not take into account how much of metal is recoverable. When considering the processing properties of an ore, i.e. geometallurgy, more comprehensive picture could be received if the resource model would report mineral grades rather than elemental grades. This is because minerals define the value and possible processing options of the deposit. Techniques commonly used for an analysis of mineral composition, i.e. modal analysis, are either tedious or poor in quality. This paper shows with few examples how reliable modal analysis can be done by combining diagnostic analysis methods with element to mineral conversion.
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| 10. |
- Lishchuk, Viktor, et al.
(författare)
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Classification of Geometallurgical Programs Based on Approach and Purpose
- 2015
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Ingår i: Mineral Resources in a Sustainable World. - 9782855550664 ; , s. 1431-1434
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Konferensbidrag (refereegranskat)abstract
- Geometallurgy is a rapidly developing holistic approach for combining geological and metallurgical information for production management purposes in mining operations. The industrial application of geometallurgy is called a geometallurgical program and one of the largest challenges within geometallurgical programs is to select appropriate methods for resource characterization. Aim of such characterization is the prediction of metallurgical performance of different ore types and geometallurgical domains with the required accuracy. More than 25 geometallurgical programs from mining operations around the world were reviewed and a classification system developed with aim to clarify how geometallurgy is used and what methods are applied. The result is summarized as a two-dimensional classification which illustrates what geometallurgical approaches are used and how collected data is applied. In addition the proposed classification system gives a perspective of what are the minimum requirements for a geometallurgical program at different levels of application and who are the main participants that should be engaged in a geometallurgical program. The classification system can also be used as a reference system for benchmarking of different geometallurgical endeavours.
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