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- Kampmann, Tobias Christoph, 1987-, et al.
(author)
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Visual3D : A European network of infrastructure with focus on 3D/4D geomodelling
- 2018
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Conference paper (peer-reviewed)abstract
- While the territory of the EU in many parts shows a very high exploration potential and many EU countries remain attractive to investors (e.g. Fraser Institute, 2015), a mere 4% of global exploration expenditure is currently invested within European countries. One tool to trigger a higher degree of investment in exploration and to secure the domestic supply of both main commodities and critical raw materials (CRM) is to enhance our three-dimensional geometric understanding of the Earth’s crust.For these reasons, EIT Raw Materials decided to fund a network of infrastructure (NoI) –Visual3D – for three years (2017–2019). Visual3D involves to-date 14 partner organisations from nine EU countries. The NoI aims to integrate expertise within exploration and 3D modelling from industry, academia and research institutes, with the ambition to increase the understanding of geological bodies in 3D and 4D through improved visualisation techniques.During its first year, Visual3D has worked to identify common issues in the field of geomodelling, the solutions to which may be facilitated by a Pan-European network approach:Data compatibility. The vast majority of European mining companies are currently working with 3D solutions for mine planning, resource estimation and production, utilizing a vast variety of expert programs (e.g. Leapfrog, Vulcan, Surpac, gOcad, MOVE). This leads to a wide range in character of 3D-models, as well as various types of data and file formats. Especially the combination of models on different scales, such as the incorporation of deposit scale models into regional-scale models, often necessitates simplifications and may lead to a loss of data. Therefore, a NoI that improves the interchangeability of models and furthermore enables full data integration will increase the usability of geomodels in exploration and research.Communication of geomodels. Commonly, specific expert software in order to make different data formats readable and communicate geomodels between collaborators, clients, stakeholders and decision makers. This limits the group of possible co-workers in a modelling project and the group of people that can utilize such models to the amount of available and often expensive licenses. A network of 3D-modelling users can substantially widen the possibilities to make geomodels accessible to a wider audience.Complexity and variety of CAM software. Software packages for computer-aided modelling (CAM) for geology and for industry standard mineral resource and reserve models are rather complex. Furthermore, there is a wide variety of available CAM software, each yielding individual functions, advantages and disadvantages. Changing a software or personnel within an organisation necessitates investment in additional training and causes downtimes. Implementing work flows for data interoperability may minimize expenditures on software and training for mining and exploration companies. Hence the NoI aims to work on solutions in order to optimize the generation, interpretation and application of geomodels, and improve the time and cost efficiency of these processes.Integration and improved outward communication of the available visualisation tools at the NoI partners will support better targeting of new mineral resources at depth, and eventually reduce environmental impacts and costs by enhancing the efficiency of exploration workflows. The distribution and possible commercialization of the NoI´s outcomes among stakeholders of the extractive industry will improve the competitiveness of European exploration and mining.
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- Kampmann, Tobias Christoph, 1987-, et al.
(author)
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Syn-tectonic sulphide remobilization and trace element redistribution at the Falun pyritic Zn-Pb-Cu-(Au-Ag) sulphide deposit, Bergslagen, Sweden
- 2018
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In: Ore Geology Reviews. - : Elsevier. - 0169-1368 .- 1872-7360. ; 96, s. 48-71
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Journal article (peer-reviewed)abstract
- Mineralization types at the Palaeoproterozoic Falun base metal sulphide deposit are predominantly pyritic Zn-Pb-Cu-rich massive sulphide mineralization, disseminated to semi-massive Cu-Au mineralization, auriferous quartz veins, and mineralized shear zones of talc-chlorite-dominated schist. The massive and disseminated to semi-massive sulphide mineralization types were subject to polyphase ductile deformation (D1 and D2) and metamorphism under low-P, lower-amphibolite facies conditions, which led to the development of ore textures and paragenetic relationships indicating both mechanical and chemical remobilization of sulphides. In the massive sulphide mineralization, rare inclusion-rich pyrite occurs as relic cores inside inclusion-poor metamorphosed pyrite. Imaging and spot analysis using multielement laser ablation inductively-coupled plasma mass spectrometry (LA-ICP-MS) reveal that inclusion-poor pyrite was depleted in trace elements, which were originally present as non-stoichiometric lattice substitutions or in mineral inclusions. The inclusion-rich pyrite was shielded from depletion and, at least partly, retained its initially higher trace element concentrations, including Au.Gold is also associated with chalcopyrite in the disseminated to semi-massive Cu-Au mineralization and in the system of auriferous quartz veins hosted therein, the latter being also affected by the D2 ductile strain. It is inferred that emplacement of the vein system took place after the peak of metamorphism, which occurred between D1 and D2, but prior to and possibly even shortly after completion of the D2 deformational event. Similarities in trace element signatures in chalcopyrite are compatible with the interpretation that the quartz veins formed by local chemical remobilization of components from the Cu-Au mineralization. Transport of liberated Au from pyrite during grain growth in the massive sulphide mineralization may have upgraded the Au endowment in the quartz veins, leading to the additional formation of native gold in the veins. A strong correspondence between elements liberated from pyrite (e.g. Pb, Bi, Se and Au) and those forming discrete and characteristic mineral phases in the quartz veins (Pb-Bi sulphosalts, native gold) supports this hypothesis.Trace element signatures for the main sulphide minerals pyrite, chalcopyrite, sphalerite and galena are similar to previously published data from other metamorphosed massive sulphide deposits. The association of the Falun mineralization with elevated Bi is reflected by its occurrence in sulphide minerals (e.g. galena) and in abundant mineral inclusions of Pb-Bi sulphosalts (e.g. weibullite), especially in the disseminated to semi-massive Cu-Au mineralization. Elevated Sn concentrations in the lattice and/or as cassiterite inclusions in chalcopyrite, sphalerite and galena are compatible with a hot, acidic and reducing fluid during formation of the syn-volcanic, base metal sulphide mineralization and associated host-rock alteration.
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