The purpose of this study was to evaluate the spatial distribution of geochemistry in Swedish till and whether interpolations could predict unknown values of geochemistry between samples at a national spatial level, Sweden, and a regional, the county of Västerbotten. The information of the spatial distribution of the elements and the interpolations accurateness has several applications. For example, the establishing of infrastructure.  Which, in Sweden, is regulated by Naturvårdsverkets guidelines for sensitive land management (KM) and less sensitive land management (MKM) since elements can be harmful for the environment and health above certain levels. The guidelines for waste disposal of soil with levels of less than slight risk (MRR) does also acquire knowledge about the background levels of an area which are found in the C-horizon. The aim of the study was therefore to answer the following questions 1) Which interpolation method provides the most accurate prediction for the various elements at the national and regional level? 2) How does the calculated levels of geochemistry differ from the sampled ones for the two spatial levels? The study was conducted by studying the levels of ten elements in the C-horizon at the two spatial levels were the regional had greater sample density than the national. The interpolations that were used for these elements were the local interpolation methods kriging, inverse distance weighting (IDW), natural neighbour, thiessen polygons and triangular irregular network (TIN). Samples were gathered from Sweden’s geological Surveys (SGU) for the elements that are regulated by Naturvårdsverkets guidelines which was why these ten elements were studied: arsenic, barium, cobalt, chromium, copper, nickel, lead, antimony, vanadium, and zinc. The interpolations were done with two thirds of  the data. A validation was done with the remaining third by calculating root mean square error (RMSE). For the interpolation method with the lowest RMSE, the mean absolute square error (MAPE) was calculated for all the validation points to see how the calculated levels differed from the samples. The result showed that kriging and IDW were the most accurate interpolation methods for the data but that some of the studied elements need even greater sample density to become more correct. This can be solved by doing a cross-validation of the existing data. Furthermore, the interpolations were more accurate at the regional level for elements except antimony. The higher accuracy can be explained by the higher sample density at the regional level. At the national level the interpolations worked better in the north of Sweden than in the south which needs further studying. Overall, the interpolations were the least accurate when the levels of the elements were low, which may be the reason why antimony showed higher RMSE at the regional level. In conclusion the study showed that it is possible to use interpolations to predict values at unknown places with different accurateness.

Aluminum (Al) is a potentially toxic element for humans, animals, and plants. Al emitted from smelter plants is one source of Al that may be responsible for increased exposure to humans and the environment. In this study I investigated whether the Kubikenborg aluminum smelter (Kubal AB) emitted Al to such extent that it can be detected above regional background concentrations in soils and plants. The study was conducted by analyzing O- horizon cores and Scots’ pine (Pinus sylvestris) needles along two transects using X-ray fluorescence spectrometry (XRF). In the O-horizon cores, Al concentrations along the two transects (mean conc. 5250 mg kg-1 in T1 and 3472 mg kg-1 in T2) did not decrease with distance from the smelter. In Scots’ pine needles, Al concentrations (mean conc. 491 mg kg-1 in T1 and 590 mg kg-1 in T2) decreased significantly with distance along transect T2. Aluminum showed high negative co-variance with soil organic matter content (R2 = 0.47) and positive with silicon (Si) and titanium (Ti) in the soil (R = 0.84 and R = 0.86 respectively), suggesting that mineral dust is the main source of Al. However, the Al/Si ratio of the soil decreased with increasing distance from the smelter along T1, indicating a possible additional source of Al besides that of soil dust that may originate from smelter emission. Nevertheless, I found no strong support for detectable Al emissions in humus and Scots’ pine needles near the Kubal AB smelter.

The aim of this work is to test the proposed approach of algal scavenging as a driver of sediment mercury (Hg) on different time scales and to gain a better understanding of the mechanisms of Hg accumulation in lake sediments. A 3000-year sediment record from Nylandssjön in northern Sweden was analysed for this purpose, as well as a 20-year sediment record from the seasonal sediment traps of this lake. The diatom proxy biogenic silica (bSi) was determined by Fourier transform infrared spectroscopy (FTIRS) and chlorophyll-a (Chl-a) as a proxy for primary productivity by non-destructive visible near-infrared reflectance spectroscopy (VNIRS). Silica, normalised to minerogenic matter by aluminium (Si/Al) as an indirect diatom proxy and other geochemical parameters were analysed by the non-destructive method of X-ray fluorescence spectroscopy (XRF). The Hg content in the sediment was determined using the the thermal decomposition atomic absorption spectrophotometers (TD-AAS) method. Over the different time scales, organic matter (OM) is an important control factor for Hg, which in turn was strongly associated with primary productivity. Hg was normalised against OM by determining the Hg/LOI or Hg/C ratios. No positive correlation was found between the normalised Hg ratios and the proxies of primary productivity (bSi, Chl-a and Si/Al). Negative correlations between OM and minerogenic elements coinciding with human-induced erosion events and increasing Hg levels in the sediment were found. This is true, both for the long-term record in the sediment cores and the high-resolution data from the sediment traps. Furthermore, in the seasonal sediment record of the sediment traps, in-lake processes like lake turnover in spring and autumn could be linked to precipitation of iron oxyhydroxides (FeOOH) and increasing sedimentary Hg. This may be supported by the parallel sediment accumulation of other metals like nickel (Ni) and zinc (Zn) at the time of the lake turnover.

Primitive magmas can provide important details about the mantle from which they are derived. In this thesis, petrographic observations and new mineral chemistry analyses of the Sälskär breccia from the Alnö alkaline complex, central Sweden, are reported. The rock is a volcanic breccia in which three main constituents were identified: spheroidal melilititic lapilli, angular sövite fragments and a carbonatedominated matrix. The mineralogy of the juvenile lapilli (i.e., with olivine, phlogopite, diopside, titanomagnetite, Cr-spinel, monticellite, perovskite, apatite and calcite) are consistent with what is expected to form by small degrees of partial melting of a volatile-rich, metasomatized, mantle source (indicated by the presence of phlogopite and primary calcite). The melilititic lapilli are frequently cored by a large crystal of olivine or phlogopite with concentrically aligned lath-shaped pseudomorphs after melilitite. During ascent the melilititic magma entrained mantle debris and traveled rapidly through the crust without significant fractionation.  The pyroclast textures indicate an explosive eruption, similar to those that produce pelletal lapilli in kimberlite-type volcanism. The sövite fragments and carbonate-dominated matrix were explosively fragmented during the eruption, which also dispersed the melilite mineralogy throughout the matrix. During the eruption a diatreme formed of within the uppermost 1.5 kilometers of the crust. A mismatch between the model of diatreme formation and a previous erosional model of the area leads to the conclusion that the Sälskär diatreme is either: (i) very deep, or (ii) that the diatreme volcanism took place significantly later than the rest of the complex / Primitiva magmor kan ge viktiga detaljer om manteln som de härstammar ifrån. I denna avhandling redovisas petrografiska observationer och nya mineralkemiska analyser av Sälskärsbreccian från Alnö alkalina område, Mellansverige. Bergarten är en vulkanisk breccia där tre huvudbeståndsdelar identifierades: sfäroidala melilitiska lapilli, kantiga sövitfragment och en karbonatdominerad matrix. Mineralogin hos de juvenila lapilli (dvs med olivin, flogopit, diopsid, titanomagnetit, Cr-spinel, monticellit, perovskit, apatit och kalcit) överensstämmer med vad som förväntas att det bildas av små grader av partiell smältning av en volatilrik, metasomatiserad, mantelkälla (indikeras av närvaron av flogopit och primär kalcit). De melilitiska lapilli är ofta kärnade av en stor kristall av olivin eller flogopit med koncentriskt riktade list-formade pseudomorfer efter melilitit. Under uppstigningen tog den melilitiska magman med sig mantelfragment och färdades snabbt genom skorpan utan betydande fraktionering. Pyroklastexturer indikerar ett explosivt utbrott, liknande de som producerar pelletala lapilli i kimberlitvulkansim. Sövitfragmenten och den karbonatdominerade matrixen fragmenterades explosivt under utbrottet, vilket också spred melilit mineralogin genom matrixen. Under utbrottet bildades en diatrem i de översta 1,5 kilometerna av skorpan. Detta betyder att modellen för diatrem-bildning och den tidigare erosionsmodellen av området inte överensstämmer. Detta leder till slutsatsen att Sälskärsdiatremen är antingen: (i) mycket djup, eller (ii) att diatrem-vulkanismen ägde rum betydligt senare än den sopm bildade resten av området.

<p>This paper deals with archaeological prospection of an Iron Age farm site in Toland, Fresta parish, Uppland County in Sweden. The purpose of the paper has been to see whether the geophysical methods applied (GPR & EM-38) could produce useful results that could motivate its use in similar surveys in the future. Geochemistry has been used for the purpose of identifying possible activity areas on the site. The results have shown that it is possible with a GPR survey to identify postholes originating from the Migration Period longhouse at the site. The combining of several methods have been important for the identification and interpretation of several areas of interest.</p>

This paper deals with archaeological prospection of an Iron Age farm site in Toland, Fresta parish, Uppland County in Sweden. The purpose of the paper has been to see whether the geophysical methods applied (GPR &amp; EM-38) could produce useful results that could motivate its use in similar surveys in the future. Geochemistry has been used for the purpose of identifying possible activity areas on the site. The results have shown that it is possible with a GPR survey to identify postholes originating from the Migration Period longhouse at the site. The combining of several methods have been important for the identification and interpretation of several areas of interest.

The Scandinavian Caledonides form a mountain range comprising nappe stacks of numerous far-travelled thrust sheets. The thrust sheets consist of diverse lithologies representing pre- and synorogenic sedimentary and igneous rocks subsequently metamorphosed to various degrees, from the Late Neoproterozoic to Middle Devonian. In particular, (ultra)-high-grade metamorphic rocks have been recorded in the Seve Nappe Complex (SNC), extending &gt;1000 km along strike of the Scandinavian Caledonides. Included in the SNC of northern Sweden is the Vássačorru Igneous Complex (VIC), consisting of bimodal magmatic suites, that formed c. 845 Ma. Fieldwork was conducted in the Kebnekaise mountains of northern Sweden, focusing on the high-grade Aurek metagabbro within the VIC of the SNC. Aurek is a key locality representing both initial stages of Iapetus Ocean formation in the Ediacaran and later stage Caledonian subduction affinities, from the collision between Laurentia and Baltica. In this study, petrological description, zircon U-Pb geochronology, mineral chemistry analysis, whole rock composition, and thermodynamic modeling was performed. Zircon U-Pb geochronology yielded protolith ages of 609±2.5 Ma, and 614±2.3 Ma, suggesting the Aurek metagabbro to not be part of the VIC, as has previously been described. The age of Aurek can instead be correlated to the Kebnekaise Dyke Swarms at c. 607 Ma, in the Kebnekaise mountains. Whole rock major and trace element data of e.g., Al2O3 (15.0 – 25.0 ppm) versus SiO2 (46.0 – 53.0 ppm), Rb (2.0 – 18.0 ppm), Zr (8.0 – 58.0 ppm) versus Y (2.7 – 18.0 ppm), Th/Yb ratio 0.25 – 2.0 and Nb/Yb ratio 1.30 – 5.14, indicate assimilation of continental crust. These major and trace element signatures show that the protolith of the Aurek metagabbro probably was emplaced in a continental rift setting in the Ediacaran. Semi-quantitative thermodynamic modeling from this study present blueschist to amphibolite facies conditions for the Aurek metagabbro at 11.8 – 12.6 kbar and 480 – 565 oC, confirming the unit experienced subduction, possibly in the Late Cambrian to Early Ordovician. The metamorphic grade and protolith age show similar features to correlative rock sequences in the Tsäkkok Lens, south of Aurek, in Norrbotten. Consequently, this study concludes that subduction, exhumation and subsequent deformation for Aurek, probably was equivalent to those of the Tsäkkok Lens, extending the HP affinities of the SNC further north in the Swedish Caledonides. / Skandinaviska Kaledoniderna utgör en bergskedja bestående av olika skollor som transporterats hundratals kilometer från sin ursprungskälla. Skollorna består av varierande bergarter som representerar olika utvecklingsskeden i formationen av Kaledoniderna under senare Neoproterozoikum och mellan Devon. Utmärkande har höggradiga metamorfiska bergarter återfunnits i Seveskollan som sträcker sig &gt;1000 km längs med strykningsriktningen av de Skandinaviska Kaledoniderna. I norra Sverige inkluderar Seveskollan det magmatiska Vássačorru-komplexet, bestående av bimodal magmatism som bildats ca 845 Ma. Fältarbete utfördes kring Kebnekaisebergen i norra Sverige, med fokus på höggradig metagabbro från Aurek, ett område inom det magmatiska Vássačorru-komplexet. Aurek är ett viktigt område som representerar både initiala stadier av Iapetushavets bildande och efterföljande formationer från kollisionen mellan Laurentia och Baltica plattorna. I denna studie utfördes petrologisk beskrivning av mineral, U-Pb geokronologi av zirkon, kemisk analys av mineral och bulkkomposition av bergarter, samt termodynamisk modellering. U-Pb dateringen av zirkon resulterade i en ursprungsålder på 609±2,5 Ma och 614±2,3 Ma för metagabbro från Aurek. Detta indikerar att metagabbro i Aurek inte är en del av det magmatiska Vássačorru-komplexet, något som tidigare antagits. Åldern kan istället korreleras till Kebnekaise-gångkomplexet med en ålder på ca 607 Ma. Huvud- och spårelement i Aureks metagabbro tyder på assimilering av kontinentalskorpa, vilket föreslår att ursprungsbergarten till metagabbro i Aurek bildades i en kontinental spridningszon. Den termodynamiska modelleringen resulterade i metamorfiska förhållanden på mellan 11,8 – 12,6 kbar och 480 – 565 oC för bergarterna, vilket påvisar att den tektoniska miljön som senare präglat bergarterna förmodligen var associerad med en subduktionszon.

Förorenad mark är ett problem som kan hota ekologiska värden samt skada människors hälsa. Det finns flera åtgärder för föroreningar både ex-situ och in-situ. På senare tid har användningen av nollvärt järn som in-situ åtgärd studerats, men har inte använts tidigare i Sverige. Denna studie innefattar ett pilotförök i fält där en in-situ injektering av nollvärt järn i nanostorlek (nZVI) i Hjältevad, Eksjö kommun. Där bedrev dåvarande Televerket en impregneringsanläggning för telefonstolpar där de använde koppar, krom och arsenik (CCA) som efter ett läckage i en lagringstank förorenade grundvattnet på platsen.  Innan denna studie visade skak och kolonnförsök att tillsats av nZVI till jordprover från Hjältevad minskade koncentrationen av både total arsenik och arsenit med över 90 %. Syftet med pilotförsöket var att undersöka hur långt nZVI skulle spridas i akvifären och om arsenikhalten och grundvattenkemin påverkades på samma sätt av nZVI injekteringen som i labbförsöken.  Dynamiska grundvattenprovtagningar utfördes innan behandlingen för att kunna karakterisera grundvattnet i försöksytan. I ett inledande försök uppskattades spridningen av en 5 g/L nZVI slurry med tillsatt 0,75 g/L polyakrylsyra som injekterades med direct push teknologi. Spridningen av en nZVI injektering undersöktes genom mätning av elektrisk konduktivitet samt genom att observera färgen på grundvattnet. En spridning av nZVI mellan 0,6 och 1,5 m observerades och influensradien ökade med djupet i försöksytan samt visar på större vertikal utbredning vid grundare djup. Preferentiellt flöde kunde ses och överlappande injekteringspunkter behövs för en heltäckande utbredning. Pilotförsöket omfattade fem injekteringspunkter som borrades med 2 m avstånd vid källtermen. Sex nya grundvattenrör installerades uppströms och nedströms injektionspunkterna. Vattenprover togs under 4 månader där grundvattenkemiska parametrar som pH, EH, total As, trevärd As, och Fe koncentrationer mättes. Arsenikhalten låg runt 1700 µg/L innan behandlingen och har inte minskat 4 månader efter injektering av nZVI. I grundvattenrören närmast injekteringspunkterna fanns en tendens till ökad totalhalt och andel arsenit. Möjliga orsaker diskuteras och en hypotes är att lägre temperatur i akvifären jämfört med labbförsök förklarar lägre reaktivitet för nZVI. / Soil contamination poses ecological risks and enhances risks for human exposure to chemical in many areas of the world. Various ex-situ and in-situ soil remediation strategies have therefore been developed. The in-situ use of zero-valent iron sorbents is a relatively new strategy that has not yet been used in the field in Sweden. The current study involves a pilot study of an in-situ inejction of nano-scale zerovalent iron (nZVI) in a contaminated site in Hjältevad, Eksjö municipality. The former Swedish State-owned telephone compmnay operated a plant where telegraph poles were impregnated with chromated copper arsenate (CCA) that leaked into the groundwater following a tank rupture.   Batch and column tests done prior to the current study in the lab showed that addition of nZVI to sediment sampled from the aquifer reduced the dissolved concentrations of total arsenic as well as arsenite with more than 90 %. The aim of this pilot test was therefore firstly to investigate to investigate whether the same reduction could be obtained in the field.  Dynamic groundwater sampling was carried out before the pilot test to characterize hydrology and chemistry of the aquifer. A 5 g/L nZVI slurry was injected using direct push technology initially in one injection well to investigate spread of nZVI by measuring electrical conductivity and observing the color of the groundwater. The measured electrical conductivity and color observation showed a spread of nZVI between 0.6 and 1.5 m. The radius of influence increased with depth in the test zone and shows greater vertical spread at shallower depths. Preferential flow could be seen and overlapping injection points are thus needed for a complete coverage of the source zone. Five injection well were then drilled into the source zone at a distance of 2 m. New groundwater wells were installed downstream from the source zone where samples were taken over a period of 4 months in which chemical parameters such as pH, EH, total As, trivalent As, and Fe concentrations were measured. Arsenic concentrations were 1700 µg/L before the treatment and this concentration as well as other measured groundwater paramters did not decrease significantly during the 4 months monitoring period. In the groundwater wells closest to the injection points, the concentration of total and trivalent arsenic increased significantly. Possibly reasons are discussed and it is hypothesized that the lower aquifer temperature in the field comapred to the lab experiments may explain the lower nZVI reactivity.

One of the major challenges in earth sciences and mineral exploration has been to determine with high accuracy and at a fast rate the elemental composition as well as the general chemistry of a rock sample. Many analytical techniques e.g., scanning electron microscopy (SEM) have been employed in the past with a certain degree of success, but their analyses usually require a lengthy sample preparation and time-consuming measurements which produce results at a much slower rate than techniques whichrequire less or do not require any sample preparation at all. SEM images the surface of a sample by scanning it with a high-energy beam of electrons in a raster scan pattern, where the primary electron beam produced under very low air pressure vacuum scans across the sample by striking it, and a variation of signals produce an image of the surface, or its elemental composition together with energy dispersive X-rays. Alternatively, laser induced breakdown spectrometry (LIBS) and multi energy X-ray transmission (ME-XRT) are non-contact measurement scanning techniques, capable of producing faster results than SEM-EDS which makes them suitable for real time measurements and analyses as they do not slow down the pace of a project being carried out. LIBS is a spectroscopic technique used to characterize and detect materials where a highly energetic laser pulse is focused onto the surfaces of solids, liquids or gases resulting in atomic and molecular species to emit light at specific wavelengths which is collected with a spectrometer and analysed using a computer. Comparably, ME-XRT is a sensor-based sorting technique involving the planar projection of X-ray attenuation of a particle stream, distributed on a fast conveyor belt, where they are scanned and evaluated while passing and an image is recorded by a line scan detector.      Eleven rock samples were analysed in this study. They include four rock type samples: granite, basalt, sandstone, and gneiss, all obtained from Luleå University of Technology (LTU) sample storage and seven ore type samples which include a porphyry Cu sulphide ore, a porphyry Cu oxide ore, a porphyry Cu-Au-Ag ore, an apatite iron ore (AIO), an iron-oxide copper gold ore (IOCG), an orogenic gold ore and a volcanogenic massive sulphide ore (VMS).       The SEM results give a semi-quantitative elemental composition of the rocks, which may be usedto discriminate mineralisation. Energy dispersive X-ray spectroscopy (EDS) maps may be used to identifygeological features and secondary electron (SE) images may be used to understand the topography of the rock samples. The SEM has a low penetration depth rate but produces moderate to high accuracy resultsdepending on the settings and calibrations. It requires a lengthy sample preparation, and its analytical time is often too long for routine industrial application. LIBS results also provide rock elemental compositions similar to the SEM, which may be quantitative if the same spectrometer is used for all elements and calibrated against a standard. It also produces element maps similar to the SEM-EDS maps. LIBS analyses yield high accuracy results but at a low penetration depth. There are no standard calibrations for the LIBS measurements, which limits quantification. LIBS measurements do not require any form of sample preparation. ME-XRT analyses result in rock chemical data portraying a light material fraction (aluminium-like) and a heavy material fraction (iron-like) which may be used to distinguish different rock samples based on the closeness of their effective atomic number Zeff to that of aluminium and iron respectively. It’s analysis also produces low-resolution images of the analysed rock samples. The image resolution is too low to allow interpretation of the data in the context of the structures and textures in the rock samples. It has a higher penetration depth than LIBS and SEM-EDS producing more volumetric data but with a lower accuracy in terms of the amount of information obtained. Only two elements are used for ME-XRT calibration measurements, if many elements of varying atomic numbers could be used, it would have the ability to provide a more reliable data. Samples must have a maximum and minimum thickness; thus, sample preparation is required to regulate the rock thickness.      SEM and LIBS provide element compositions of minerals and element distribution maps required by geologist in their daily activities during exploration and mining. This information can be considered the most useful obtained from all three techniques. However, LIBS analyses are faster, and its maps are of higher quality even at the same resolution as the SEM-EDS. This makes the LIBS preferable for real time measurements and analyses. Geological activities like drill core logging, mine mapping and sampling for grade control all require fast results for project continuity and LIBS is suitable for this purpose as it can keep up with the pace of these activities. SEM analytical technique provides semi-quantitative data which is more accurate than the LIBS data and thus, preferable for usage in research institutions and universities.ME-XRT can reveal information on the internal structures or different rock sample compositions. This makes it a suitable technique in distinguishing ore from waste material especially in iron ore mining and processing where the iron needs to be separated from the siliceous waste and sorting is also required prior to beneficiation to avoid equipment destruction by abrasive quartz. LIBS and ME-XRT analytical techniques complement each other in terms of analytical capabilities as LIBS has a low penetration depthrate but high accuracy results while the ME-XRT has a high penetration depth rate but low accuracy results. They are both fast scanning techniques that can be used for real time measurements and analyses and if their analytical prowess can be improved, the combination of these two fast analytical techniques may enable us to obtain high quality data and may as well be what is needed by geologists in the future.