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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
71

Gamification for technology-enhanced mineral value chain teaching and learning: serious gaming for geometallurgy concept

Schleret, Lilian January 2024 (has links)
The concept of gamification is being increasingly explored and applied to offer new teaching or training tools to teachers, students or employees. The field of geology and geometallurgy wasn’t particularly discussed in the topic of gamification. With the objective of creating a synthetic geometallurgical database and a game structure for a gamified simulation of a metal mine, the eastern part of the Malmberget deposit in Sweden was simplified and modelled.The geological model was obtained with assumptions of continuity and proximity, and the lack of data was reconciled using targeted randomization and regular statistics to achieve a smoother and realistic result. A rule book was created to establish the framework that a geometallurgy game should follow,using a slightly adapted version of the Desing thinking framework by the Nielsen group, which consists of elaborating ideas and concepts, implementing them and testing the results before integrating feedbacks to the creation of future elements. The accent was put on obtaining an interactive experience where the player can try various things with a reasonable difficulty, and an accessibility to feedbacks.The purpose of this project is to elaborate a mining simulation game, that could be a valuable tool in the understanding of the interdisciplinary concept of geometallurgy, as well as raising the awareness about sustainable development and how mining can be a part of it. The starting point of this project is another attempt at gamifying geometallurgy by P. Lamberg. The simulation of mineral processing was done using the HSC Sim utilizing 8 different flowsheets that were designed to offer a variety and enable strategic choices. The events occurring at a real mine and beneficiation plant were translated into simple rules. The outcome is a realistic geological and processing model, which through the addition of mining, economics and market strategy, becomes a comprehensive geometallurgy database.
72

Mineral Constraints on the Source Lithologies at Fogo, Cape Verde. / Geokemiska ledtrådar till de aktiva mantelkomponenterna på Fogo, Kap Verde.

Rydeblad, Elin January 2018 (has links)
Variations in major, minor, and trace elements compositions and ratios, as well as isotope ratios are all useful tools in studying the composition of the Earth’s mantle, and heterogeneities present therein. Since the mantle itself doesn’t easily lend itself to study, ocean island basalt (OIBs) are commonly used as a proxy due to compositional differences combined with the range of origination depth, a combination that allows them to represent the heterogeneity of the mantle, sampling everything from the core mantle boundary to the old or recent additions of recycled oceanic crust. Fogo, being one of the most active volcanoes in the world, continuously samples the interior of our planet, and as such is a prime location for studies of mantle geochemistry. This study aims to determine the origin of the mantle lithologies present at Fogo. The study is a continuation and extension of the studies conducted by Barker et al. (2014) and Magnusson (2016). This study utilises major, minor, and trace element geochemistry in clinopyroxene and olivine phenocrysts, as well as Ni-isotopes from whole rock samples. Using the relative values of Ni, Mn, and trace elements and their ratios in olivine and clinopyroxene phenocrysts we aim to further unravel the mechanics of the creation of ocean islands and provide additional constraints regarding the mechanics of the formation of heterogeneities in the Earth’s mantle. This study will focus on Ni* and Mn* in olivine phenocrysts, trace element composition and ratios of olivine phenocrysts and clinopyroxene phenocrysts, and Ni-isotope data.  This study found evidence for both pyroxenite, carbonatite, and carbonated eclogite source lithologies at Fogo. A correlation between La/Sm and δ60Ni was also found, indicating a control on the δ60Ni by source pyroxenite. This study suggests a carbonated eclogite origin for the lithologies present at Fogo, which would have hosted the majority of the olivine phenocrysts. The phenocrysts then resided within a separated carbonatite melt fraction that either contaminated or metasomatized a pyroxenite melt where the clinopyroxene phenocrysts nucleated. The melt then evolved to an alkali basalt melt through melt-rock reactions, principally via the dissolution of orthopyroxenes and concomitant precipitation of clinopyroxene and olivine (Zhang, Chen, Jackson & Hofmann 2017).
73

Characterization of Gas hydrates

Alfvén, Linda, Ignea, Sorin January 2013 (has links)
Gas hydrates are naturally occurring crystalline formations consisting of crystal structural “cages” which make up cavities where gas molecules can be trapped. Hydrates are formed under specific pressure and temperature conditions in the ground, which limits their presence to permafrost and deep sea continental margins. The interest for gas hydrates has grown bigger in the past time, mainly because of the potential as a new energy source but also because of the possibility of carbon dioxide (CO2) storage and its potential linkage to different geological hazards. Gas hydrates are still relatively poorly understood with many questions to be answered. Therefore research in this area is important. In our study we have been focusing on characterization of gas hydrate structures and their gas composition. By using the two different analytical methods X-ray powder diffraction (XRD) and gas chromatography. For this study to be successfully carried out we needed access to equipment and expertise which is only to be found in few places on Earth. Our lab work was therefore done at Pontifica Universidade Catolica do Rio Grande do Sul in Porto Alegre Brazil where a research project in gas hydrates is on going. Because of the research projects secrecy we do not know where our gas hydrate samples come from which mean we cannot link our results to any geographic area. The structural analysis shows structure I hydrate which is characterized by the presence of small gas molecules such as hydrocarbons. The results from the gas content validated that it is structure I since large concentrations of methane gas (CH4) and sulphur gas (H2S) were detected. The presence of these gases implies that the formation conditions are in a marine environment at the sulphate-methane transition zone (SMTZ).
74

Fluid inclusions and geochemistry of the Peña del Seo W-deposit, northwest Spain : Controlling mechanisms for tungsten deposition

Bergström, Sara January 2020 (has links)
The Peña del Seo tungsten deposit in northwestern Spain is situated in the tin (Sn)-tungsten (W) metallogenic province of Europe − one of the richest tin-tungsten (tantalum-lithium) mineral provinces in the world. The European Union’s current goal is to become self-sufficient of these commodities in the near future and the iTARG3T project was launched in order to improve the understanding and provide innovative exploration methods of these types of deposits. This master thesis will contribute to the iTARG3T project. The aim was to determine which physico-chemical conditions (temperature, pressure, salinity) that prevailed during the emplacement of the Peña del Seo deposit. A geochemical study was done consisting of a fluid inclusion study on the quartz veins from the deposit, and a whole-rock geochemistry analyse of the granitic rock. Homogenisation temperatures ranged between 97,6° C to 325,6° C and salinities (NaCl % equiv.) between 0,2% to 21,3%. The fluid was determined to consist of a two-component system of H2O and NaCl based on eutectic temperature. Based on its geochemical classification the granitic rock was considered to be an alkali granite, strongly peraluminous with S-type characteristics. At least two different types of fluids were present during the emplacement of the Peña del Seo deposit, one that was hot and with a moderate salinity, and one that had a lower temperature than the other fluid and a lower salinity, possibly meteoric water. The depositional mechanism of tungsten is thought to be caused by a combination between mixing between two fluids and cooling of the fluids, with the main depositional mechanism being cooling since the change in salinity was not of such magnitude that it would change the fluid chemical composition, while the decrease in temperature was. It is uncertain whether the granitic rock found at Peña del Seo is part of the granitic cupola of the greisen system. The granitic rock has similar characteristics as the leucogranites of the West Asturian-Leonese Zone and based on quartz vein morphology, which cut the D2 foliation, time of emplacement of the deposit could be linked to the syntectonic event at 320-310 Ma. If the relation between the granitic rock and the greisen system can be determined the time of emplacement would be possible.
75

Befintlig och framtida infrastruktur i Dennewitz malmkropp : Prognos och rekommendationer

Winsa, Johan January 2020 (has links)
During mining in the Malmberget mine, large amounts of information such as damage mapping, geological mapping, seismic data and stress conditions are stored. All the data that is obtained is stored in several places with different methods, which makes it problematic to use. The purpose of this work has been to compile, structure and interpret the collected data that is currently available. The aim of the compilation has been to use this information as a basis for what influence geology, structures, damage mapping and rock quality together have on the area around Dennewitz ore body.   The ore in Dennewitz consists exclusively of magnetite and the surrounding rock is characterized by hard rock in form of leptites and granite, but also the soft mineral biotite. Leptites are the predominant rock types in the area, while granite appears in lenses at the deeper levels. Historically, granite and red leptite have been the rocks that have caused the most problems in the form of rock bursts. The Dennewitz hanging wall consists of grey leptite while the foot wall is dominated by red and red-grey leptite with minor areas of granite, and in a few places also biotite.   The data compilation shows that there are flaws in the method for damage mapping, as the amount of useful data is very small compared to other areas. The compiled data on damage mapping shows that the majority of the damages is located along a large-scale geological structure that strikes in the same direction as the crosscuts. Damages are also located in the ore contact where granite and biotite lenses. The mapped damages with coordinates were used to obtain a limit angle. Using the damage coordinates, a plane representing the damages were created. The plane dips 60˚, which thus represents the limit angle for the damage zone. The plane has the same dip as the ore body and strikes 70˚ from the north over the crosscuts, and  in some cases also the local ramp.   Geologically, the drifts that runs along the orebody are the most problematic in the area. The contact between magnetite, granite and leptite creates sliding surfaces, which makes the amount of joints needed to create a potential wedge or church roof less. This problem seems to be starting at level 1034 as the granite is starting to show up and the number of joints increase. The large-scale structure that runs along the crosscuts already appears above level 1000 and is more prominent at the deeper levels. In connection with the granite also appearing in the ramp, the level entrance and crosscuts at level 1034, the number of joint sets, wedges and church roofs increases. The problems increase at the levels below when biotite also starts to show up in a few places.   The system for logging mapped damages is recommended to be revised. Damage mapping should also be performed to a greater extent at both new and old levels to increase the basis for analyes and prognoses. It is further recommended to take advantage of drilling and rock mechanical and geological analyses, as well as performing more exploration drilling, to make planning of the infrastructure more effective. Also, the method with damage zones developed by Svartsjaern (2017b), as well as further development of limit angles, should be tested in Dennewitz and other areas in the mine.
76

Extremväders påverkan på jorderosion : En GIS-modellering över Byälvens avrinningsområde

Frida, Thuresson January 2021 (has links)
When the climate change contributes to a greater amount of extreme weather that does also affect the soil erosion and the number of areas that are being affected by the soil erosion. The areas affected by the soil erosion do often suffers from economic loss because of the loss in agricultural land caused by the soil erosion. The reason being that the soil losses nutrients something that leads to less harvest and poorer quality of the water. This bachelor thesis aims to study how soil erosion gets affected by the climate change, and more specific the extreme weather, by using a RUSLE analysis.  By knowing in what extent different areas most likely get affected by soil erosion, there is great possibilities to protect those areas by protection against erosion. In this thesis three analysis have been performed over areas located in Byälvens runoff-areas to extend the knowledge about how extreme weather affect the areas and out of that get a guideline for how similar areas might be affected. As a data source for the analysis Lantmäteriet, SGU and SMHI was used.  The result shows that three analysed areas in Byälvens runoff-areas most likely will lose 93-97 percent more sediment if the precipitation increases with 50 percent compared to 2020 annual value compared to the precipitation between the years of 1961 and 1991. This could be because of the climatological factors that affect the result and the increasement in land loss due to soil erosion. The increasement in soil erosion can depend on human activities that changes the soil structure, climatological factors, but it can also be because of the coal in soil. / När klimatförändringarna bidrar till ett ökat antal extremväder så påverkar det jorderosionen och ökar andelen områden som påverkas av jorderosion. Områden som drabbas av jorderosion påverkas ofta negativt ekonomiskt eftersom resultatet av jorderosion ofta är i form av förluster av odlade områden, minskade näringsämnen vilket påverkar framtida skördar samt ger sämre vattenkvalitet. Detta kandidatarbete syftar till att studera hur jorderosion påverkas av klimatförändringarna, med fokus på extremväder, främst med hjälp av en RUSLE-analys. Genom att veta i vilken omfattning olika områden sannolikt kan bli drabbade av jorderosion så finns det goda möjligheter att förhindra en ökad jorderosion genom erosionsskydd. I det här arbetet gjordes det analyser över tre områden som är lokaliserade i Byälvens avrinningsområde för att förstå hur dessa kan bli påverkade vid en ökad andel extremväder eftersom det kan ge en riktlinje för hur andra liknande områden påverkas. Som datakälla till analysen användes Lantmäteriet, SGU och SMHI. Resultatet visar på att de tre analyserade områdena i Byälvens avrinningsområde sannolikt kommer att förlora mellan 93–97% mer sediment om nederbördsmängderna i området ökar med 50% jämfört med 2020-årsvärde i jämförelse med genomsnittsnederbörden mellan åren 1961 och 1991. Detta kan bero på de ökade klimatologiska faktorerna som påverkar och ökar jorderosionen i de undersökta områdena. Ökade jorderosioner på en plats som tidigare inte haft några omfattande jorderosions händelser kan bero på mänskliga aktiviteter som förändrar jordens struktur, klimatologiska faktorer men, även på det organiskt bundna kolet i jordarten.
77

Hydrothermal alteration and lithogeochemical marker units at the Svärdsjö Zn-Pb-Cu deposit, Bergslagen, Sweden, and their implications for exploration

Fahlvik, Anton January 2018 (has links)
In exploration, a lithogeochemical approach can be used to aid the characterisation of rocks surrounding metamorphosed and hydrothermally altered deposits. Accurate description of the geological setting of deposits is crucial for understanding the ore forming processes and identifying targets for exploration. The Svärdsjö Zn-Pb-Cu deposit is located in the heavily mineralised and metamorphosed Bergslagen ore province of south-central Sweden. The deposit and surrounding minor occurrences were actively mined for over 500 years, producing more than 1 Mt of Zn-Pb-Cu-Ag massive sulphide ore. The combination of strongly metamorphosed and hydrothermally altered rocks in Svärdsjö makes geological interpretation challenging. Therefore, an approach combining lithogeochemical and petrographic methods is used in this study. The characterisation of the rocks and hydrothermal alteration surrounding the deposit allowed for an interpretation of ore formation and its implications for further exploration in the Svärdsjö area. The results verified that the Svärdsjö mineralisations are hosted by 2–15 m thick dolomitic marble units, commonly altered to skarn. Surrounding the deposit are subvolcanic intrusions and volcanoclastic rocks of mainly dacitic composition. The combined approach also helped identifying a strong to intense hydrothermal chlorite-sericite alteration enveloping the mineralised marble units and resulted in large mass gains of Fe and Mg whereas Na was depleted. Multiple episodes of alteration and metamorphism are evident from cross-cutting relationships with less altered dykes and overprint by metamorphic minerals such as cordierite and anthophyllite. An ore formation model involving sub-seafloor volcanic-associated replacement is suggested for the Svärdsjö deposit based on (i) the presence of a zoned hydrothermal alteration system within a volcanoclastic rock sequence and (ii) the irregular stratabound sulphide lenses hosted by thin marble units in the centre of the alteration system. Additionally, it is inferred that the stratabound nature of the deposit is caused by the neutralisation of a hot acidic fluid, resulting in precipitation of the sulphides within the marble. Finally, two geochemically distinct lithological units have been identified adjacent to the mineralised zones, providing new, larger exploration targets in the area. Mass change calculations reveal that Fe and Mg enrichment and Na depletion are useful vectors towards mineralisation, with detectable changes extending for up to 100 m from the mineralised lenses. These findings showcase the usefulness of the incorporation and careful interpretation of lithogeochemical data when exploring for metamorphosed hydrothermal ore deposits in mineralised provinces of the Fennoscandian Shield or elsewhere in the world.
78

Assessing a Modeling Standard in Volcanic-Geothermal Systems: the Effects of the Lower System Boundary / Bedömning av en modellerings standard i vulkanisk geotermiska system: effekterna av den nedre systemgränsen

Faizy, Shelly Mardhia January 2021 (has links)
Geothermal energy consumption is projected to increase along with other renewable energy in the future. Therefore, it is important to have a better understanding on the evolution of geothermal systems to optimize the exploitation of such resources. Generally, numerical models are used as a fundamental tool to study a potential geothermal field. However, current modeling practices tend to focus on the shallow area around the heat source, while ignoring the deeper part below the heat source. The purpose of this project is to observe the influence of lower boundary at the bottom of intrusion towards the evolution of geothermal system, while changing the permeability and topography of host rock systematically, using a software from USGS called HYDROTHERM. Simulations differed in three main aspects: 1) having a layer below, or having the bottom boundary directly below intrusion, 2) different topographies with volcanic significance, and 3) varying permeabilities of the host rock. The study is based on a fossil geothermal system, the Cerro Bayo laccolith in Chachahuén volcanic complex (Neuquén Basin), Argentina. The input parameters were obtained in several ways. ILMAT Geothermometry analysis provide the temperature value related to the intrusion. The whole rock data is used to determined density of the intrusion by calculating partial molar volume of the oxides. The other parameters, e.g. densities of the host rock and the impermeable layer, permeability, porosity, and thermal conductivity were obtained from literature. The result from numerical modeling shows that the bottom boundary below intrusion strongly affect the entire system evolution. The added layer (with constant permeability) has strong influence on the life-span of the system. Additionally, while taking into account on the variation of topography and permeabilities, the models show two temperature anomalies: 1) A caldera volcano’s geometry “traps” heat below the caldera, whereas shield and strato-volcano geometries “push” heat away from below the volcanic edifice, and 2) a low temperature anomaly develops beneath the intrusion in all high permeability models with an added layer. Finally, this assessment could prove to be useful as prior knowledge for optimizing the extraction of heat from a given geothermal field, as well as future investigations towards geological applicability of numerical models of geothermal systems, hydrothermal alteration, and ore formation processes.
79

The Structural Architecture of the Barsele Area, Sweden : Characterising the deformation events and mineralisation

Derbyshire, Jaide January 2021 (has links)
Located at an important intersect between orogenic Au deposits in Sweden’s Gold Line and volcanicmassive sulphide (VMS) deposits in the Skellefte Mining District, the Barsele area is of high interest.Currently, the Barsele deposit consists of the Norra VMS deposit and 3 intrusive-hosted orogenic Audeposits: Avan, Central, and Skiråsen which are hosted in a 1876 ± 10 Ma early orogenic granodiorite(Thomas, et al., 2019). The aim of this thesis is to create a structural and geological model of the Barsele area whilst improvingthe understanding of the structural controls on VMS and intrusive-hosted Au mineralisation in thearea. Furthermore, this thesis aims to highlight prospective areas for future study and targeting inhopes to aid mineral exploration in the region. Geological mapping has been carried out in an area ofaround 440km2, with emphasis on structural measurements. 381 outcrop observations and more than4200 structural features were recorded using a combination of traditional and digital mappingmethods, including the use of Field Move by Petroleum Experts. The area was chosen as part of AgnicoEagle, Sweden’s mineral exploration project. The region has been affected by two dominant, syn-metamorphic cleavage forming events. The eventsdefine the main phase of the Svecofennian Orogeny which has produced ubiquitous slaty cleavage, Ndirected thrusts, and steeply inclined axial surfaces throughout the region. The region is characterisedby important N-S displacements with sinistral movement along major N-S trending transfer faults. Theabsence of strike-slip shearing in D1 structures indicates that D1 deformation was dominantly coaxialin nature and developed due to SW-NE crustal shortening. Along with this, a major ESE-WNW-strikingshear zone is identified with an inferred syn-extensional (D1) origin. D2 involved fault inversion and reactivation of syn-extensional faults as reverse shear zones. E-Wtrending lineations along more brittle SSW-NNE striking shear zones inferred to indicate an E-Worientation for crustal shortening during D2. D3 caused reactivation of the N-S-striking high-strain zones with reverse kinematics. This reactivationof trending shear zones resulted in strain partitioning into N-S zones. D3 is manifested by broad, open,N-NE trending upright folds of bedding and S2 foliation. 1st, 2nd, and 3rd order D3 structures have beencharacterised and illustrated by combining a range of data including outcrop observations, regionalStereonets, magnetic anomaly maps, and other geophysical maps.
80

How do fluids move through rocks? : High fluxes of CO2 in the Earth's crust

Kleine, Barbara January 2012 (has links)
Metamorphic hydrous, CO2-bearing fluids play a critical role in the global carbon cycle. However, how big this influence is on the global carbon cycle and therefore on global climatic processes, is unknown. The actual amount of CO2 which is released into the atmosphere due to metamorphic processes is still debated. For this purpose, fluid-driven reactions in metamorphic rocks must be studied by tracking fluid-rock interactions along pathways of ancient fluids. In the study presented in this thesis, we study fluid-rock interaction in the southeastern part of the Greek island Syros in the Cycladic Archipelago (Aegean). On Syros fluid-rock interaction is recorded by the preservation of blueschist facies assemblages at greenschist facies conditions along a normal shear zone. Blueschist preservation is caused by a combination of metasomatic addition of SiO2 and Na2O and elevated XCO2 which is maintained by high fluxes of a CO2-bearing, hydrous fluid along the shear zone. This research aims to provide a better understanding of the role of mountain building in the carbon cycle. Flux estimates for climate-forcing fluid components (e.g. carbon) require that their concentration in the fluid, fluid volumes and velocities are known. This will be the focus of future work. Further, whole rock chemistry and the availability of specific minerals will be studied to achieve knowledge about which kind of parameters influence and enhance the propagation of fluids through rocks.

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