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  • 1551. Wikström, A.
    et al.
    Skiöld, T.
    Öhlander, Björn
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    A 1.88 Ga old dyke swarm in northern Sweden and its possible importance as a new terrane indicator1994In: Vol. 6, no Suppl. 2, p. 22-23Article in journal (Other academic)
  • 1552.
    Wikström, A.
    et al.
    Museum of Natural History, Stockholm.
    Skiöld, T.
    Museum of Natural History, Stockholm.
    Öhlander, Björn
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    The relationship between 1.88 Ga old magmatism and the Baltic-Bothnian shear zone in northern Sweden1996In: Precambrian crustal evolution in the North Atlantic region, American Association of Petroleum Geologists (AAPG), 1996, p. 249-259Chapter in book (Other academic)
  • 1553. Wikström, Anders
    et al.
    Skiöld, Torbjörn
    Öhlander, Björn
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    The Bläsberget and Siknäs dikes in northern Sweden: their chemistry, age and relationship to the Bothnian-Baltic shear zone1993In: Abstracts of lectures and posters: 21:a Nordiska geologiska vintermötet 10-13 Januari 1994 Luleå / [ed] Jan-Anders Perdahl, Luleå: Högskolan i Luleå , 1993, p. 228-Conference paper (Other academic)
  • 1554. Wikström, Anders
    et al.
    Öhlander, Björn
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    A shear-zone related, albite porphyritic mafic breccia in northern Sweden1999In: Vol. 4, no 1, p. 793-Article in journal (Other academic)
  • 1555.
    Wikström, Tommy
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Nordmark, Desiree
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Pelkonen, Markku
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Lagerkvist, Anders
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Fluorescent in situ hybridization technique in anaerobic process studies2012In: Abstract proceedings of 7th Intercontinental Landfill Research Symposium :: Södra Sunderbyn, June 25th to 27th, 2012 / [ed] Anders Lagerkvist, Luleå: Luleå tekniska universitet, 2012, p. 130-131Conference paper (Refereed)
  • 1556. Williams, P.
    et al.
    Guoyi, D.
    Pollard, P.
    Broman, C.
    Martinsson, Olof
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Wanhainen, Christina
    Mark, G.
    Ryan, C.
    Mernagh, T.
    The nature of iron oxide-copper-gold ore fluids: fluid inclusion evidence from Norrbotten (Sweden) and the Cloncurry district (Australia)2003In: Mineral Exploration and Sustainable Development: Proceedings of the Seventh Biennial SGA Meeting on Mineral Exploration and Sustainable Development / [ed] D.G. Eliopoulos, Rotterdam: Millpress , 2003, p. 1127-1130Conference paper (Other academic)
  • 1557. Wilson, M.R.
    et al.
    Öhlander, Björn
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Cuney, M.
    Hamilton, P.J.
    Geodynamic significance of contrasting granitoid types in northern Sweden1985In: Abstracts: Helsinki Symposium on the Baltic Shield, Helsingfors, March 4-6, 1985, 1985Conference paper (Other academic)
  • 1558.
    Wilson, M.R.
    et al.
    Swedish Geological Co..
    Öhlander, Björn
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Cuney, M.
    Uranium Geology International Centre.
    Hamilton, P.J.
    Scottish Universities Research and Reactor Centre.
    Geodynamic significance of contrasting granitoid types in northern Sweden1987In: Proterozoic lithospheric evolution / [ed] Alfred Kröner, 1987, p. 161-173Conference paper (Refereed)
  • 1559.
    Windt, L. De
    et al.
    Ecole des Mines de Paris.
    Dabo, D.
    Ecole des Mines de Paris.
    Lidelöw, Sofia
    Badreddine, R.
    INERIS, Wastes and Contaminated Sites Unit.
    Lagerkvist, Anders
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Reactive transport modeling of leachate evolution of MSWI bottom ash used as road basement: Hérouville (France) and Dåva (Sweden) sites2009Conference paper (Other academic)
    Abstract [en]

    The recycling of municipal solid waste of incineration (MSWI) bottom ash as aggregates for road basement requires a better characterization of the evolution of leachate chemistry over a timescale of many decades. In this paper, a common reactive transport model is applied to the Hérouville (France) and Dåva (Sweden) pilot roads whose leachate emissions have been sampled during 10 and 6 years, respectively. The model considers simultaneously the hydrodynamic processes (rain water infiltration, advective and diffusive transport), pH-buffering and solubility-controlled processes by secondary minerals, ageing by atmospheric carbonation, and the leachate chemistry (major elements and trace metals such as Al, Cu, Pb). The evolution of pH is fairly well simulated with the following pH-buffering sequence: portlandite, calcium silicate hydrate (CSH), ettringite and, finally, calcite. The quantity of CO2 dissolved in the percolating rain water is generally not sufficient to explain the pH evolution and carbonation processes, requiring atmospheric gaseous inputs. The relation between pH evolution and element release is discussed for both sites. Calculated Pb release is overestimated when based on solubility-controlled mechanisms only. Edge effects are shown to be important at both sites with an emphasis of carbonation and release of non reactive elements. Temperature has no significant effect on the calculated leachate chemistry in the range of 5 - 30° C, except at high pH.

  • 1560.
    Windt, Laurent De
    et al.
    Ecole des Mines de Paris.
    Dabo, David
    Ecole des Mines de Paris.
    Lidelöw, Sofia
    Badreddine, Rabia
    INERIS, Wastes and Contaminated Sites Unit.
    Lagerkvist, Anders
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    MSWI bottom ash used as basement at two pilot-scale roads: comparison of leachate chemistry and reactive transport modeling2011In: Waste Management, ISSN 0956-053X, E-ISSN 1879-2456, Vol. 31, no 2, p. 267-280Article in journal (Refereed)
    Abstract [en]

    The recycling of municipal solid waste incineration bottom ash as aggregates for road basement requires assessing the long-term evolution of leachate chemistry. The Dåva (Sweden) and Hérouville (France) pilot-scale roads were monitored during 6 and 10 years, respectively. Calculated saturation indices were combined to batch test modeling to set a simplified geochemical model of the bottom ash materials. A common reactive transport model was then applied to both sites. At Hérouville, pH and the concentration of most elements quickly drop during the first two years to reach a set of minimum values over 10 years. The decrease is less pronounced at Dåva. The evolutions of pH and major element concentrations are fairly well related to the following pH-buffering sequence: portlandite, C-S-H phases or pseudo-wollastonite and, finally, calcite in equilibrium with atmospheric CO2. Al(OH)3, barite, ettringite and monohydrocalcite may also control leachate chemistry. Cu release is correctly modeled by DOM complexation and tenorite equilibrium. Temperature has no significant effect on the modeling of leachate chemistry in the range 5-30 °C, except at high pH. Effects at road edges and roadside slopes are important for the release of the less reactive elements and, possibly, for carbonation processes.

  • 1561.
    Wortberg, Katharina
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Conrad, Sarah
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Andersson, Per S.
    Department of Geosciences, Swedish Museum of Natural History.
    Ingri, Johan
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Strontium isotopes: A tracer for river suspended iron aggregates2017In: Applied Geochemistry, ISSN 0883-2927, E-ISSN 1872-9134, Vol. 79, p. 85-90Article in journal (Refereed)
    Abstract [en]

    The Kalix River shows distinct temporal variations in the Sr-isotope ratio in filtered water (0.726–0.732). During base flow in winter the 87Sr/86Sr ratio is on average 0.730. When discharge increases and peaks during spring flood the 87Sr/86Sr ratio shows the most radiogenic (0.732) values. The temporal variations in the 87Sr/86Sr ratio in the Kalix River can be explained by mixing of water from the woodlands and the mountain areas.

    During high water discharge in May the 87Sr/86Sr ratios are more radiogenic in the suspended phase (1 kDa - 70 μm) compared to the truly dissolved phase (<1 kDa). The difference in 87Sr/86Sr ratio between the two phases (Δ 87Sr/86Sr) is linearly correlated with the suspended iron concentration. During spring flood Sr and Fe derived from an additional source, reach the river. Deep groundwater has a more radiogenic 87Sr/86Sr isotope ratio than the Kalix River during spring flood and thus, represents a possible source for the suspended Fe and the associated Sr. Strontium can be coprecipitated with and adsorbed to different types of Fe aggregates. We propose that the Sr-isotope ratio in the suspended phase reflects the isotopic composition of the water at the interface between anoxic groundwater and oxic stream water in the riparian zone, where the Fe aggregates are formed. These particles dominate the suspended phase in the river and the mixing with mountain waters, poor in Fe, produces the difference in the isotopic signature.

    The different signatures in suspended and truly dissolved fraction indicate that these aggregates are relatively stable during stream-river transport. As such the 87Sr/86Sr can be used to trace the origin of the non-detrital suspended phase.

  • 1562.
    Xiao, Gang
    et al.
    State Key Laboratory of Clean Energy Utilization, Zhejiang University.
    Jin, Baosheng
    Thermo-Energy Engineering Research Institute, School of Energy and Environment, Southeast University, Nanjing.
    Ni, Mingjiang
    State Key Laboratory of Clean Energy Utilization, Zhejiang University.
    Cen, Kefa
    State Key Laboratory of Clean Energy Utilization, Zhejiang University.
    Tan, Zhongxin
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    A steam dried municipal solid waste gasification and melting process2011In: Frontiers of Environmental Science & Engineering in China, ISSN 1673-7415, E-ISSN 1673-7520, Vol. 5, no 2, p. 193-204Article in journal (Refereed)
    Abstract [en]

    Considering high-moisture municipal solid waste (MSW) of China, a steam dried MSW gasification and melting process was proposed, the feasibility was tested, and the mass and energy balance was analyzed. Preliminary experiments were conducted using a fixed-bed drying apparatus, a 200 kg per day fluidized-bed gasifier, and a swirl melting furnace. Moisture percentage was reduced from 50% to 20% roughly when MSW was dried by slightly superheated steam of 150A degrees C-350A degrees C within 40 min. When the temperature was less than 250A degrees C, no incondensable gas was produced during the drying process. The gasifier ran at 550A degrees C-700A degrees Cwith an air equivalence ratio (ER) of 0.2-0.4. The temperature of the swirl melting furnace reached about 1240A degrees C when the gasification ER was 0.3 and the total ER was 1.1. At these conditions, the fly ash concentration in the flue gas was 1.7 g center dot(Nm(3))(-1), which meant over 95% fly ash was trapped in the furnace and discharged as slag. 85% of Ni and Cr were bound in the slag, as well as 60% of Cu. The mass and energy balance analysis indicates that the boiler heat efficiency of an industrial MSW incineration plant reaches 86.97% when MSW is dried by steam of 200A degrees C. The boiler heat efficiency is sensitive to three important parameters, including the temperature of preheated MSW, the moisture percentage of dried MS Wand the fly ash percentage in the total ash.

  • 1563.
    Xu, Jingying
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Feasibility study of soil washing to remediate mercury contaminated soil2013Licentiate thesis, comprehensive summary (Other academic)
    Abstract [en]

    Mercury (Hg) cannot be degraded. Therefore only two principal processes are available for the treatment of Hg-contaminated soil: (1) the separation of Hg from the soil or (2) the stabilisation of Hg within the soil. Prior to selecting a suitable treatment technique, it is necessary to have an understanding of Hg behaviour in contaminated soil, i.e., distribution in particle size fractions, dissolution at different pH and in the presence of chlorides, and mobilisation using various extractants. The thesis aims to evaluate the potential for applying soil washing to decontaminate the Hg-contaminated soil. The Hg contamination originated from inappropriate waste disposal, chlor-alkali process and harbour activities, and the soil was also polluted by other trace elements, i.e., Zn, Cu and Pb, etc. The soil was fractionated from fine to coarse particles to study the effectiveness of physical separation. A pH-static titration ranging from pH 3 to 11 was performed to assess the mobility of Hg in response to pH changes. The chloride influence on Hg mobilisation was studied using an HCl solution of different concentrations as the leachant. Batch leaching tests were used to evaluate Hg solubility in water, and extraction efficiency by various extractants. The extractants derived from wastes were acidogenic leachates generated from biodegradable wastes, and alkaline leachates produced from fly/bottom ashes. The studied soil consisted of dominant coarse-grained fractions, which is usually suitable for particle size separation. However, dry sieving has been shown to be insufficient to separate clean from contaminated soil fractions although the Hg concentrations decreased with increasing particle sizes. The reasons are likely to be: (i) the physical attachment of fines to coarse particles; (ii) the strong chemical bond of soil organic matter (OM) and minerals for Hg. Distilled water could barely mobilise the Hg from the soil, most likely due to firm chemical bonding between the soil and Hg. Despite the fact that enhanced Hg dissolution was observed at pH 5 and 11 in this study, soil washing by pH adjustment was insufficient for Hg removal. The introduction of chlorides did not facilitate the Hg mobilisation either. Retention of Hg in the soil by OM seemed to be predominant over Hg mobilisation by chlorides. Chemical extraction by leachates from wastes as well as EDTA solution and NaOH solutions showed that neither alkaline nor acidic leachates could facilitate Hg removal from the soil. Mercury was firmly bound in the soil matrix and no more than 1.5% of the total Hg could be removed by any of the tested extractants. Future research should therefore focus on the development of Hg immobilisation techniques.

  • 1564.
    Xu, Jingying
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Bravo, Andrea Garcia
    Department of Ecology and Genetics, Limnology, University of Uppsala.
    Lagerkvist, Anders
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Bertilsson, Stefan
    Department of Ecology and Genetics, Limnology, University of Uppsala.
    Sjöblom, Rolf
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Kumpiene, Jurate
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Sources and remediation techniques for mercury contaminated soil2015In: Environment International, ISSN 0160-4120, E-ISSN 1873-6750, Vol. 74, p. 42-53Article in journal (Refereed)
    Abstract [en]

    Mercury (Hg) in soils has increased by a factor of 3 to 10 in recent times mainly due to combustion of fossil fuels combined with long-range atmospheric transport processes. Other sources as chlor-alkali plants, gold mining and cement production can also be significant, at least locally. This paper summarizes the natural and anthropogenic sources that have contributed to the increase of Hg concentration in soil and reviews major remediation techniques and their applications to control soil Hg contamination. The focus is on soil washing, stabilisation/solidification, thermal treatment and biological techniques; but also the factors that influence Hg mobilisation in soil and therefore are crucial for evaluating and optimizing remediation techniques are discussed. Further research on bioremediation is encouraged and future study should focus on the implementation of different remediation techniques under field conditions.

  • 1565.
    Xu, Jingying
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering.
    Kleja, Dan B
    Swedish Geotechnical Institute.
    Biester, Harald
    Department of Environmental Geochemistry, Institute of Geoecology, University of Braunschweig.
    Lagerkvist, Anders
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Kumpiene, Jurate
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Influence of particle size distribution, organic carbon, pH and chlorides on washing of mercury contaminated soil2014In: Chemosphere, ISSN 0045-6535, E-ISSN 1879-1298, Vol. 109, p. 99-105Article in journal (Refereed)
    Abstract [en]

    Feasibility of soil washing to remediate Hg contaminated soil was studied. Dry sieving was performed to evaluate Hg distribution in soil particle size fractions. The influence of dissolved organic matter and chlorides on Hg dissolution was assessed by batch leaching tests. Mercury mobilization in the pH range of 3–11 was studied by pH-static titration. Results showed infeasibility of physical separation via dry sieving, as the least contaminated fraction exceeded the Swedish generic guideline value for Hg in soils. Soluble Hg did not correlate with dissolved organic carbon in the water leachate. The highest Hg dissolution was achieved at pH 5 and 11, reaching up to 0.3% of the total Hg. The pH adjustment was therefore not sufficient for the Hg removal to acceptable levels. Chlorides did not facilitate Hg mobilization under acidic pH either. Mercury was firmly bound in the studied soil thus soil washing might be insufficient method to treat the studied soil.

  • 1566.
    Xu, Jingying
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Kleja, Dan Berggren
    Department of Environmental Engineering, Swedish Geotechnical Institute.
    Lagerkvist, Anders
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Kumpiene, Jurate
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Influence of soil particle size, organic carbon and pH on mercury distribution and dissolution in contaminated soil2013In: Influence of soil particle size, organic carbon and pH on mercury distribution and dissolution in contaminated soil, 2013, p. 45-Conference paper (Refereed)
    Abstract [en]

    Mercury (Hg) cannot be destroyed therefore only two principal processes are available for the treatment of Hg-contaminated soil: 1) separation of Hg from soil (through wet-sieving and/or chemical extraction), or 2) stabilization of Hg within the soil (through chemical immobilisation or stabilisation/solidification). If Hg separation is used, soil can be cleaned while Hg recovered. A complex matrix may, however, cause low treatment efficiency. Therefore, prior to selecting the suitable treatment technique, an understanding of Hg solubility and distribution in particle size fractions of the contaminated soil is necessary. The aim of this study was to evaluate the potential for applying soil washing technology to clean Hg contaminated soil based on Hg distribution in soil particle size fractions, Hg solubility in water and pH-dependant Hg dissolution. Soil contaminated by different industrial processes (e.g. waste dump, chlor–alkali process, harbour activities) was collected from Tidermans padding area upstream of Göta River, Sweden during the site remediation. The soil was dry sieved into particle-size fractions of <0.063 mm, 0.063–0.125 mm, 0.125–0.25 mm, 0.25–0.5 mm, 0.5–1 mm, 1–2 mm and 2–4 mm and along with the bulk soil were analysed for total Hg and total organic carbon (TOC). A batch leaching test at liquid-to-solid ratio (L/S) 10 was performed to determine water soluble Hg and dissolved organic carbon (DOC). A pH-static leaching test was performed to determine Hg solubility in the pH range of 3-11. All particle size fractions contained Hg above the Swedish guideline value for contaminated soil (2.5 mg/kg for less sensitive land use). Total Hg concentrations decreased with increasing particle size (except fraction 1-2 mm), ranging from 48.70 mg/kg to 10.29 mg/kg. The TOC contents were similar in all size fractions from 8.72 to 10.88 and had no correlation with the total Hg. Water soluble Hg was low in all size fractions, making up for 0.04% to 0.12% of the total Hg. Contents of DOC declined from fine to large fractions, however, no correlation between Hg solubility and DOC content has been observed. Mercury desorption was affected by pH and fluctuated throughout the tested pH range. The least Hg dissolution was achieved at pH=3 and pH 9 in all fractions and the bulk soil, while the dissolution peaks were observed at pH=5 and pH=11. The results show that the soil washing applying wet-sieving and particle separation method would be unfeasible since elevated Hg concentrations are distributed in all tested soil particle fractions and water solubility of Hg is very low. Chemical extraction focusing on pH 5 or pH 11 might improve the Hg removal. Geochemical modelling is being performed to understand this Hg behaviour in the studied soil.

  • 1567.
    Xue, K.
    et al.
    Institute for Environmental Genomics and Department of Microbiology and Plant Biology, University of Oklahoma, Norman.
    Nostrand, J.D. van
    Institute for Environmental Genomics and Department of Microbiology and Plant Biology, University of Oklahoma, Norman.
    Vangronsveld, Jaco
    Hasselt University, Centre for Environmental Sciences, Agoralaan Building D, B-3590 Diepenbeek.
    Witters, N.
    Hasselt University, Centre for Environmental Sciences, Agoralaan Building D, B-3590 Diepenbeek.
    Janssen, Jolien
    Hasselt University, Centre for Environmental Sciences, Agoralaan Building D, B-3590 Diepenbeek.
    Kumpiene, Jurate
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Siebielec, Grzegorz
    Institute of Soil Science and Plant Cultivation - State Research Institute.
    Galazka, Rafal
    Institute of Soil Science and Plant Cultivation - State Research Institute.
    Giagnoni, L.
    University of Florence, Department of Agrifood Production and Environmental Sciences, P.le delle Cascine 28, I-50144 Florence.
    Arenella, Mariarita
    Department of Plant, Soil and Environmental Sciences, University of Florence.
    Zhou, J-Z
    Institute for Environmental Genomics and Department of Microbiology and Plant Biology, University of Oklahoma, Norman.
    Renella, Giancarlo
    University of Florence, Department of Agrifood Production and Environmental Sciences, P.le delle Cascine 28, I-50144 Florence, Department of Plant, Soil and Environmental Sciences, University of Florence, University of Florence.
    Management with willow short rotation coppice increase the functional gene diversity and functional activity of a heavy metal polluted soil2015In: Chemosphere, ISSN 0045-6535, E-ISSN 1879-1298, Vol. 138, p. 469-477Article in journal (Refereed)
    Abstract [en]

    We studied the microbial functional diversity, biochemical activity, heavy metals (HM) availability and soil toxicity of Cd, Pb and Zn contaminated soils, kept under grassland or short rotation coppice (SRC) to attenuate the risks associated with HM contamination and restore the soil ecological functions. Soil microbial functional diversity was analyzed by the GeoChip, a functional gene microarray containing probes for genes involved in nutrient cycling, metal resistance and stress response. Soil under SRC showed a higher abundance of microbial genes involved in C, N, P and S cycles and resistance to various HM, higher microbial biomass, respiration and enzyme activity rates, and lower HM availability than the grassland soil. The linkages between functional genes of soil microbial communities and soil chemical properties, HM availability and biochemical activity were also investigated. Soil toxicity and N, P and Pb availability were important factors in shaping the microbial functional diversity, as determined by CCA. We concluded that in HM contaminated soils the microbial functional diversity was positively influenced by SRC management through the reduction of HM availability and soil toxicity increase of nutrient cycling. The presented results can be important in predicting the long term environmental sustainability of plant-based soil remediation.

  • 1568.
    Yousefi, Fazilat
    et al.
    Department of Petrology and Economic Geology, Faculty of Earth Sciences, Shahrood University of Technology.
    Sadeghian, Mahmoud
    Department of Petrology and Economic Geology, Faculty of Earth Sciences, Shahrood University of Technology.
    Wanhainen, Christina
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Ghasemi, Habibollah
    Department of Petrology and Economic Geology, Faculty of Earth Sciences, Shahrood University of Technology.
    Frei, Dirk
    Department of Earth Science, Faculty of Natural Science, University of the Western Cape.
    Geochemistry, petrogenesis and tectonic setting of middle Eocene hypabyssal rocks of the Torud–Ahmad Abad magmatic belt: An implication for evolution of the northern branch of Neo-Tethys Ocean in Iran2017In: Journal of Geochemical Exploration, ISSN 0375-6742, E-ISSN 1879-1689, Vol. 178, p. 1-15Article in journal (Refereed)
    Abstract [en]

    The Torud–Ahmad Abad magmatic belt is located in the south-southeast of Shahrood (East of Semnan Province, NE Iran) and lies in the northern part of the Central Iran Structural Zone (CISZ), where a thick sequence of Paleocene to middle Eocene volcanic and volcanosedimentary rocks cropped out. This sequence was intruded by numerous dikes, hypabyssal igneous domes and one small gabbrodioritic intrusion, with compositions ranging from trachybasaltic andesite, trachyandesite, dacite, trachyte, gabbro, diorite and syenite. Various enclaves (cogentic and noncogenetic) with different composition, size and shape have been found in these domes and dikes. These enclaves are evidence of magma mixing and crustal contamination. Geochemically, the studied rocks exhibit a calc-alkaline to high potassium calc-alkaline affinity, and are enriched in LREE and LILE and depleted in HREE and HSFE. Other geochemical characteristics, such as a silica content varying between 59–63 wt% and 51–59 wt%, a Na2O content > 3 wt%, Al2O3 content > 16 wt%, Yb < 1.8 ppm, and Y < 18 ppm, make it possible to classify these rocks as high silica adakite in the Ahmad Abad region and low silica adakite in the Sahl-Razzeh region or at least, adakitic like rocks. Also, depletion of Nb and Ti, and high enrichment in Rb, Ba, K and Th, imply crustal contamination of the mentioned adakitic domes. The petrographical and geochemical evidence show that the magma forming of the high silica adakites has been originated from partial melting of the subducted oceanic slab of Neo-Tethys (Sabzevar–Darouneh branch) in amphibolite to eclogite facies and the low silica adakites formed by partial melting of the metasomatized or modified mantle wedge, above the subduction zone. Gabbroic to syenitic rocks are the products of fractional crystallization of basic magma which originated from a nearly non-modified mantle wedge above the subducted oceanic slab. U-Pb dating of the dacitic and andesitic rocks belong to hypabyssal rocks yielded age of 41.4 ± 0.3 Ma, and 35.5 ± 0.2 Ma respectively and consistent to Middle to Late Eocene.

  • 1569.
    Yousefi, Fazilat
    et al.
    Faculty of Earth Sciences, Shahrood University of Technology.
    Sadeghian, Mahmoud
    Faculty of Earth Sciences, Shahrood University of Technology.
    Wanhainen, Christina
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Ghasemi, Habibollah
    Department of Petrology and Economic Geology, Faculty of Earth Sciences, Shahrood University of Technology.
    Lambrini, Papadopoulou
    Department of Mineralogy-Petrology-Economic Geology, Aristotle University of Thessaloniki.
    Bark, Glenn
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Rezaei-Kahkhaei, Mehdi
    Department of Petrology and Economic Geology, Faculty of Earth Sciences, Shahrood University of Technology.
    Koroneos, Antonis
    Department of Mineralogy-Petrology-Economic Geology, Aristotle University of Thessaloniki.
    Mineral chemistry and P-T conditions of the adakitic rocks from Torud–Ahmad Abad magmatic belt, S-SE Shahrood, NE Iran2017In: Journal of Geochemical Exploration, ISSN 0375-6742, E-ISSN 1879-1689, Vol. 182, no A, p. 110-120Article in journal (Refereed)
    Abstract [en]

    Torud-Ahmad Abad magmatic belt is located 175 km east and southeast of Shahrood in the northern part of the Central Iran Structural Zone and includes a thick sequence of Paleocene to middle Eocene volcanic and volcanosedimentary rocks. This magmatic belt was formed by numerous hypabyssal igneous adakitic domes constituting basaltic andesite, andesite, trachyandesite, dacite, trachydacite, and dacite. The investigated rocks are mainly composed of pyroxene, amphibole, and plagioclase, with minor biotite and opaque minerals. Mineral chemical analysis reveals that plagioclase composition varies from albite to labradorite, clinopyroxene varies from diopside to augite, and amphibole varies from Mg-hastingsite to Mg-hornblende.

    Amphibole geothermobarometry suggests crystallization temperatures of 850–1050 °C, at 2–6 kbar and the temperature of 920–970 °C, at a pressure of 3–4.5 kbar, which are conditions in agreement with andesite and dacite formation. Clinopyroxene crystallized at temperatures of 1020–1170 °C, at 2–10 kbar, indicating crystallization at crustal depths of maximum 30 km for the studied intrusive rocks in the Torud-Ahmad Abad magmatic belt.

  • 1570.
    Zaher, Mohamed Abdel
    et al.
    National Research Institute of Astronomy and Geophysics (NRIAG), University of Oulu.
    Pirttijärvi, Markku
    Department of Physics, University of Oulu.
    Korja, Toivo
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering. Oulu Mining School, University of Oulu.
    Geophysical Studies of the Raahe-Ladoga Shear Complex in the Iisalmi Area of Finland2017In: Geophysica, ISSN 0367-4231, E-ISSN 2324-0741, Vol. 52, no 2, p. 43-67Article in journal (Refereed)
    Abstract [en]

    We have studied geophysical properties of the Raahe-Ladoga Shear Complex, a major NW-SE trending strike-slip shear zone in Central Finland. Aeromagnetic and airborne electromagnetic data from the Raahe-Ladoga Shear Complex, provided by the Geological Survey of Finland, were processed and interpreted in combination with the regional gravity data of the Finnish Geodetic Institute and the Geological Survey of Finland. Filtering techniques such as the first vertical derivative, horizontal and tilt gradients, and pseudo-gravity were applied for the visual interpretation and analyses of the shear complex in the Iisalmi area. The gravity data emphasized a NW-SE trend along a transition zone between the Archaean Karelian Province and the Palaeoproterozoic Svecofennian Province. This is consistent with the anomalies in the magnetic field intensity. Geophysical properties were also studied with gravity, magnetic and magnetotelluric ground surveys that were conducted across a narrow dominant segment of the entire shear complex near Iisalmi. The data indicated that weak negative gravity anomalies and strong magnetic anomalies are associated with the shear zone. Gravity modelling suggests that anomalies of small wavelength are related to shear zones and fractures, but the depth extent and dip cannot be resolved. Magnetic interpretation revealed that the shear zone can be modelled with near-vertical (82º eastward dip) sheet-like bodies with a depth extent over 2 km. The 2-D inversion of magnetotelluric data shows that the upper crust in the Iisalmi area is very resistive. High resistivity of the strongly sheared crust suggests the old shear complexes are not necessarily conductive opposite to many active shear complexes worldwide.

  • 1571.
    Zainy, Maher
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering. Geosurve.
    Geological Report about the Field Work in western part of the Zagros Fold and Thrust Belt, NE Iraq2017Report (Other academic)
    Abstract [en]

    The studied area is located in the Western part of Zagros Fold and Thrust Belt, northeastern part of Iraq, along the border between Iraq and Iran. It covers an area of about 1600 Km2. It is rugged area, the relief difference ranges from 2526 to 440 m. The high terrain is mainly of structural origin, which is represented by Avroman Range and Qulqula Imbricate structure. The studied area includes twelve geological units of sedimentary rocks, which are ranging in age from Triassic to Late Cretaceous, besides different types of Quaternary sediments. The work, which performed in the area, was field work, which carried out to identify the structural characteristics, via get structural data of the major and minor structures in the area. The field work performed during two periods (Summer-2016 and spring-2017). Performed six geological traverses and studied the structural elements of forty one minor folds during the field work in additional to other minor structures. The goals are build 3D-model for study area using Move and Arc GIS softwares. Moreover, to obtained better understanding of the tectonic history and how many tectonic phases effected the area and explain the relationship between the major and minor structures in the area. The studied area contains a numbers of minor structures that come in different forms, sizes and directions, which indicate their effect in many tectonic phases. Furthermore all most all the structures in the studied area are related with thrusting, which due to the collision between Arabian and Iranian Plates since Miocene till now.

  • 1572.
    Zainy, Maher
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Al-Ansari, Nadhir
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Mining and Geotechnical Engineering.
    Bauer, Tobias
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Ask, Maria
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    The Tectonic and Structural Classifications of the Western Part of the Zagros Fold and Thrust Belt, North Iraq, Review and Discussion2017In: Journal of Earth Sciences and Geotechnical Engineering, ISSN 1792-9040, Vol. 7, no 2, p. 71-89Article in journal (Refereed)
    Abstract [en]

    The Zagros fold and thrust belt represents a tectonically significant area, and one

    of the richest areas in oil and gas reservoirs in the world. The Zagros fold and

    thrust belt is the deformational product of the Cretaceous-present day convergence

    of the Arabian and Iranian (Eurasian) plates (subduction and collision). The belt

    extends more than 2000 km from southern Turkey through the north and

    northeastern Iraq to the Strait of Hormuz in southwestern Iran. The Zagros fold

    and thrust belt is divided into two parts which are; Western part within Iraqi

    region and Eastern part within Iranian region. The western part of the Zagros fold

    and thrust belt has been traditionally subdivided into several structural zones that

    are generally striking parallel to the plate boundary. This is characterized by

    exposure of Late Ordovician to Pliocene - Pliestocene formations with different

    types of Quaternary Sediments. This research will concentrate on Western part of

    Zagros fold and thrust belt and the styles of structural classifications, which will

    aid to clarify and better understand the tectonic and structural history and

    evolution of the region. We have considered the last version of structural

    classification as the most relevant one to the reality, especially within outer

    platform (Unstable shelf). Where it divides the region into four structural zones,

    which are: Low Folded zone, High Folded Zone, Imbricate Zone, and Zagros

    Suture Zone and these zones were further divided to several subzones. This

    classification is based on the structural style and intensity of deformation,

    stratigraphy, mechanicalstratigraphy and tectono-stratigraphy of the deformed

    sequences, Age of deformation, surface physiography and morphology. The data

    used in the classification is more reliable, up to date and relevant.

  • 1573.
    Zainy, Maher T.
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Al-Ansari, Nadhir
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Mining and Geotechnical Engineering.
    Bauer, Tobias
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Ask, Maria
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    The Tectonic and Structural Classifications of the Western Part of the Zagros Fold and Thrust Belt, North Iraq, Review and Discussion2017In: Journal of Earth Sciences and Geotechnical Engineering, ISSN 1792-9040, E-ISSN 1792-9660, Vol. 7, no 2, p. 71-89Article in journal (Refereed)
    Abstract [en]

    The Zagros fold and thrust belt represents a tectonically significant area, and one of the richest areas in oil and gas reservoirs in the world. The Zagros fold and thrust belt is the deformational product of the Cretaceous-present day convergence of the Arabian and Iranian (Eurasian) plates (subduction and collision). The belt extends more than 2000 km from southern Turkey through the north and northeastern Iraq to the Strait of Hormuz in southwestern Iran. The Zagros fold and thrust belt is divided into two parts which are; Western part within Iraqi region and Eastern part within Iranian region. The western part of the Zagros fold and thrust belt has been traditionally subdivided into several structural zones that are generally striking parallel to the plate boundary. This is characterized by exposure of Late Ordovician to Pliocene - Pliestocene formations with different types of Quaternary Sediments. This research will concentrate on Western part of Zagros fold and thrust belt and the styles of structural classifications, which will aid to clarify and better understand the tectonic and structural history and evolution of the region. We have considered the last version of structural classification as the most relevant one to the reality, especially within outer platform (Unstable shelf). Where it divides the region into four structural zones, which are: Low Folded zone, High Folded Zone, Imbricate Zone, and Zagros Suture Zone and these zones were further divided to several subzones. This classification is based on the structural style and intensity of deformation, stratigraphy, mechanicalstratigraphy and tectono-stratigraphy of the deformed sequences, Age of deformation, surface physiography and morphology. The data used in the classification is more reliable, up to date and relevant.

  • 1574.
    Zeballos, Ariana
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Geological, geochemical and mineralogical characterization of non-metallic mineral deposits in the La Paz region, Bolivia2018Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Industrial mineral resources are a promising source of economic development in Bolivia where the mining industry’s main focus is on metalliferous deposits. The industrial mineral resources in Bolivia are of large quantity, even though they remain only locally known, as well as understudied to a large degree.

    This thesis aims to show the industrial mineral mining potential of La Paz and Bolivia as a whole. Bolivia’s resources of industrial minerals can potentially be used for numerous industrial applications. Three deposits have been geologically and mineralogically characterized. In addition, the potential applications of the mined products are addressed.

    Firstly, the Micaya deposit, located at the Micaya village south-west of La Paz city, comprising two whitish kaolinite-bearing occurrences, was investigated. The material is currently used in tableware production. The Micaya deposit is situated in a Palaeozoic sequence in the Altiplano basin. The general mineral composition of the occurrences is 56 vol.% quartz, 21 vol.% muscovite, 18 vol.% kaolinite and <5 vol.% feldspar. The kaolinite-bearing sediments were formed through enhanced weathering of the muscovite-rich siltstones aided by groundwater remobilization along permeable fault zones. Micaya kaolinite is suggested to be suitable for industrial applications.

    Secondly, the Choquetanga deposit, located south-east of La Paz city and currently mined for Sn and W, is associated with a coarse-grained granitic batholith that was studied for its feldspar characteristics in this work. Geologically, the Choquetanga area is dominated by a Palaeozoic sedimentary sequence intruded by the porphyritic granite from the Quimsa Cruz batholith in the south-east of the Eastern Cordillera. The Quimsa Cruz batholith is composed of megacrystalline granite with 5–10 cm long orthoclase, albite and oligoclase crystals that contain a considerable alkali content of YK2O,Na2O=7.84–10.25 wt.%.

    Thirdly, the La Fabulosa deposit, located north-west of the Eastern Cordillera, was studied for its feldspar occurrences hosted in granites and pegmatites. The deposit is composed of a metasedimentary sequence of Palaeozoic age intruded by the Sorata batholith, which comprises two-mica granites, granodiorites and pegmatites with an alkali content of YK2O,Na2O=7.41–14.25 wt.%, hosted in the minerals microcline, orthoclase and oligoclase.

    The potential raw materials from the three studied industrial mineral deposits were evaluated for use in ceramic applications. In addition, nine non-metallic occurrences, most of them currently mined and located at Oruro (one zeolite occurrence), Potosí (one diatomite and one montmorillonite occurrence), La Paz (three clay deposits and one diatomite occurrence) and Santa Cruz (two kaolin deposits) have been sampled. Mineralogical and lithogeochemical characterization of the materials have been performed to address higher-value applications for the deposits.

    X-ray diffraction (XRD) and inductively coupled plasma mass spectrometry (ICP-MS) were used to identify the mineralogical and lithogeochemical composition of the host rocks to the deposits. Scanning electron microscopy (SEM) were performed on the kaolinite-bearing materials to characterize the microstructure in the rocks. This indicates mineral paragenesis and has therefore implications for mineral deposit formation. Physical tests on the ceramic specimens, such as drying shrinkage (Choquetanga 0.20 vol.%, La Fabulosa 0.31 vol.%), firing shrinkage (Choquetanga 1.66 vol.%, La Fabulosa 1.59 vol.%), bending strength (Choquetanga 69.55 N/mm2, La Fabulosa 70.20 N/mm2), water absorption (Choquetanga 2.13 vol.%, La Fabulosa 0.58 vol.%) and Mohs hardness value of 7, demonstrate the potential application of the studied industrial minerals in the production of floor tile ceramics.

    The results of this work show the geological potential for industrial mineral exploitation in Bolivia. It is expected that these investigations will serve as a starting point and encouragement for future geological research and mineral exploration with important implications for the supply of industrial minerals for the growing industrial sector of Bolivia.

  • 1575.
    Zeballos, Ariana
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering. Instituto de Geología y del Medio Ambiente, Universidad Mayor de San Andrés, La Paz .
    Weihed, Pär
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    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 formulations2017In: Environmental Earth Sciences, ISSN 1866-6280, E-ISSN 1866-6299, Vol. 76, no 22, article id 754Article in journal (Refereed)
    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.

  • 1576.
    Zeballos, Ariana
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Weihed, Pär
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    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, Bolivia2016In: Environmental Earth Sciences, ISSN 1866-6280, E-ISSN 1866-6299, Vol. 75, no 7, article id 546Article in journal (Refereed)
    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

  • 1577.
    Zeballos, Ariana
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Weihed, Pär
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Blanco, Mario
    Machaca, Vladimir
    Mullite synthetization at low temperature2013In: 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, p. 1784-1786Conference paper (Refereed)
    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.

  • 1578.
    Zhang, Wei
    et al.
    College of Land and Environment, Shenyang Agricultural University.
    Alakangas, Lena
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Wei, Zhongyi
    College of Land and Environment, Shenyang Agricultural University.
    Long, Jinghua
    Research Institute of Land Reclamation and Ecological Restoration, China University of Mining and Technology (Beijing).
    Geochemical evaluation of heavy metal migration in Pb-Zn tailings covered by different topsoils2016In: Journal of Geochemical Exploration, ISSN 0375-6742, E-ISSN 1879-1689, Vol. 165, p. 134-142Article in journal (Refereed)
    Abstract [en]

    Heavy metal migration was evaluated in Pb-Zn tailings covered by different topsoil constructions. The four topsoil constructions each had different interlayers: one with direct topsoiling above the tailings (CT); the second had a limestone interlayer between the tailings and topsoil with two geotextile layers set above and below the interlayer (SLS); the third had a lime interlayer, also with two geotextile layers (SL); and the fourth had a clay interlayer with two geotextile layers (SC). The topsoils were evaluated in a 210-day laboratory column leaching experiments and in a 3-year field cover application at an abandoned Pb-Zn tailings pond (northeastern China). The contents of Pb, Zn and Cd in the soils, leachates, interlayers and leaves of Amorpha fruticosa L. were analysed by inductively coupled plasma optical emission spectroscopy (ICP-OES).Results showed that the pH values of the leachates from the columns increased with time, from 6.5 to the range of 7.5 to 8.03, and the maximum in pH in C1 (tailings), C2 (CT), C3 (SLS), C4 (SL) and C5 (SC) appeared after the 180th day, at 7.85, 7.89, 7.78, 8.03, and 7.89, respectively. The topsoil effectively reduced the concentrations of Pb, Zn and Cd in the leachate, and the addition of a limestone or lime interlayer enhanced the efficiency, especially for Zn and Cd. The Pb, Zn and Cd concentrations in the topsoil that directly cover the tailings were appreciably less than the initial concentrations, resulting from the eluviation. The presence of a limestone or lime interlayer reduced the mobility of Zn and Cd, and a clay interlayer was effective in preventing the migration of Pb and Zn but had less impact on Cd.During the 3-year field experiment, the pH values of the topsoil increased slightly with time, from 7.15 to the range of 7.67 to 8.20. At the end of the experiment, Pb, Zn and Cd concentrations in the topsoil at the SLS, SL and SC plots showed little change compared with the initial value in 2012. Acid-soluble Pb, Zn and Cd concentrations of the upper soil (0–0.1 m) at CT increased from 0.19, 1.95 and 0.11 mg kg− 1 in 2012 to 1.82, 32.87 and 0.56 mg kg− 1 in 2015, indicating that acid-soluble heavy metals migrated from tailings to topsoil. Acid-soluble Cd in topsoil and in the interlayer showed a small increase at plot SC, indicating that Cd may migrate through the clay layer to topsoil with pore water. The Pb contents in leaves at SLS and SL were 2.38 and 3.04 mg kg− 1, which were appreciably lower than at CT and SC, and the Zn and Cd contents in leaves at CT were 45.78 and 0.26 mg kg− 1, which were higher than at SLS, SL and SC. Topsoiling with an interlayer could be a reliable technique for preventing toxic elements from moving downward or upward during ecological restoration of tailings ponds.

  • 1579.
    Zhang, Wei
    et al.
    College of Land and Environment, Shenyang Agricultural University, Shenyang.
    Long, Jinghua
    Research Institute of Land Reclamation and Ecological Restoration, China University of Mining and Technology (Beijing).
    Wei, Zhongyi
    College of Land and Environment, Shenyang Agricultural University, Shenyang.
    Alakangas, Lena
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Vertical distribution and historical loss estimation of heavy metals in an abandoned tailings pond at HTM copper mine, northeastern China2016In: Environmental Earth Sciences, ISSN 1866-6280, E-ISSN 1866-6299, Vol. 75, no 22, article id 1462Article in journal (Refereed)
    Abstract [en]

    In the tailings pond of the Hongtou Mountain (HTM) copper mine in northeastern China, four sampling points were set at intervals of 80 m along the discharge direction of the tailings slurry to investigate the vertical distribution characteristics of heavy metals in shallow layer (0–5 m) tailings. In addition, 18 sampling points were set by a grid method (50 m × 50 m) to estimate the historical loss amount of contaminants from the surface layer (0–1.2 m) of the HTM tailings pond. Tailings samples were taken at every 0.2 m, and the pH value, the total content and acid-soluble fraction of heavy metals and chemical compositions were determined following the standard methods. The results showed that the pH values of tailings ranged from 3.01 to 8.11, which increased with depths from 0 to 2.2 m, and varied between pH values of 7.0 and 7.5 in 2.2–5 m. Cu, Zn, Cd and S were the major contaminants in the tailings. The total Cu content was higher at the downstream sampling points near the dam. Zn and Cd were higher at the upstream sampling points near the discharge. Three distinct zones (oxidised zone, cemented layer and unoxidised zone) were found in the HTM tailings pond. The depth of the oxidised zone was 0.4 m, and the elements in the oxidised tailings were obviously lower due to the sulphides oxidation and acid mine drainage. Cu was enriched in the cemented layer, and the Cu content reached values between 1200 and 3000 mg/kg, which were 1.5–3 times higher than the average value. Zn, Cd, Ni and Fe were also slightly elevated in the cemented layer. Below the groundwater table, the acid-soluble fraction of Cu, Zn and Cd was relatively stable at a lower level and showed insignificant variations, as the cemented layer and groundwater could efficiently prevent the oxidation process. The amount of Cu, Zn and Cd leaving the tailings pond with drainage water was 8.08, 21.60 and 72.93%, respectively, of the amount released from oxidation. Most of the Cu released from oxidation was retained in the cemented layer. The total mass of S, Zn and Cd released from the tailings to surrounding ecosystems was estimated approximately 762.75 t, 6997.5 and 86.06 kg, respectively, in the last 20 years.

  • 1580.
    Zocher, Anna-Lena
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Self-organizing maps: a tool to study element distribution in headwater streams2018Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Headwater streams are ubiquitous in watercourse systems and their importance for water quality in streams of higher orders is well-known. Yet, element compositions of headwaters are seldom systematically investigated. This study reports data from 104 headwaters in forested catchments in southeastern Sweden sampled at three occasions. Multielement analyses are common practice nowadays, however, vast amounts of data points cannot easily be grasped by the human eye. Therefore, Kohonen’s self-organizing map (SOM) technique, i.e. an unsupervised neural network technique, served as visualization tool to simplify and interpret the large data set here (> 10,000 data points). Similarity index plots were used to reveal that the partially high seasonal variations in total element concentrations were caused by a shift in redox conditions in the overall system. The plots further showed that the included parameters (elements, background parameters, catchment parameters) had different associations to each other under oxic and anoxic conditions. This study clearly demonstrates that SOMs allow to quickly gain a general impression of system properties, which bears a great potential to facilitate decisions about further detailed studies when dealing with multivariate data sets in stream water research.

  • 1581.
    Zoheir, Basem
    et al.
    Department of Geology, Faculty of Science, Benha University.
    Weihed, Pär
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Greenstone-hosted lode-gold mineralization at Dungash mine, Eastern Desert, Egypt2014In: Journal of African Earth Sciences, ISSN 1464-343X, Vol. 99, no 1, p. 165-187Article in journal (Refereed)
    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.

  • 1582. Zuber, J.A.
    et al.
    Öhlander, Björn
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Origin of the Transscandinavian Igneous Belt: evidence from gravity measurements and geochemistry1993In: Abstratcts Volume: 19th Noftig Meeting, 1993Conference paper (Other academic)
  • 1583.
    Zuber, Josef A.
    et al.
    Luleå University of Technology.
    Öhlander, Björn
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Geophysical and geochemical evidence of Proterozoic collision in the western marginal zone of the Baltic Shield1990In: Geologische Rundschau, ISSN 0016-7835, E-ISSN 1432-1149, Vol. 79, no 1, p. 1-11Article in journal (Refereed)
    Abstract [en]

    New continental crust was formed in the Svecofennian domain of the Baltic Shield c. 1.9 Ga ago. Approximately 0.1-0.15 Ga later, new crust accreted to the SW part of the Shield. In this paper an attempt is made, on the basis of gravity measurements and lithogeochemistry, to describe the tectonic processes responsible for the continental growth c. 1.75-1.8 Ga ago. The Transscandinavian Granite Porphyry Belt (TGPB) separates the Svecofennian domain from the polymetamorphic terrain of the SW Swedish gneiss region. Red orthogneisses occurring immediately west of the TGPB are the deformed equivalents of the TGPB type granitoids, while grey orthogneisses, displaying a tonalitic-granodioritic trend and situated further west, were generated in a »volcanic arc« environment. The TGPB granitoids and the red SW Swedish gneisses represent a transition from this volcanic arc type rock to contemporaneous »within-plate« type granites intruded in the Svecofennian crust. The volcanic arc was forced against the Svecofennian crust in which large tensional fracture zones ensued with strike directions normal to the collision front. In such tensional environments the »withinplate« type granites were generated. In the collision zone the crust was down-warped, and huge amounts of granitic melts were generated at the base of the crust. This TGPB Magma rose upwards utilizing the fracture zone between the arc rocks, generated slightly earlier, and the Svecofennian crust. A relatively thin upper part of the TGPB that spread laterally westwards became strongly deformed during the collision (i.e. the red SW Swedish gneisses), while the major deep-reaching TGPB root zone that was not completely solidified yet, acted as a buffer against the foliation front.

  • 1584. Zuber, Josef A.
    et al.
    Öhlander, Björn
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Gravimetrical and geochemical studies of 1.8 Ga old granites in the Strängnäs-Enköping area, south central Sweden1991In: Geologiska föreningens i Stockholm förhandlingar, ISSN 0016-786X, Vol. 113, no 4, p. 309-318Article in journal (Refereed)
    Abstract [en]

    The Central Swedish Gravity Low is a distinct belt of gravity lows striking west-east from the Transscandinavian Igneous Belt to the Baltic Sea. Large homogeneous intrusions of c. 1.8 Ga old potassium rich granites with high contents of elements such as Y, HREE, and Nb, typical of granites generated in tensional environments, coincide with the gravity lows in the Fellingsbro-Lisjö area in the west and the Vallentuna area in the east. Between these areas only smaller and more heterogeneous granites of this age are exposed. The gravity measurements in the Strängnäs-Enköping area, however, clearly show the existence of large granite bodies beneath the present surface. The present and previous gravimetrical and lithogeochemical investigations suggest that c. 1.8 Ga ago, a tensional zone, now striking west-east, existed in the older crust. As a result of fusion of the lower crust in the tensional zone, a huge granitic ridge was formed along what is now the Central Swedish Gravity Low. The ridge was a heterogeneous mixture of granitic melts and solid residues. The Fellingsbro-type granites rose from this heterogeneous ridge through tensional fractures, and homogeneous intrusions were formed. The structural pattern of the tensional zone has a geometry remarkably similar to a modern oceanic ridge.

  • 1585.
    Åberg, Annika
    et al.
    Luleå tekniska universitet.
    Kumpiene, Jurate
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Ecke, Holger
    Evaluation and prediction of emissions from a road built with bottom ash from municipal solid waste incineration (MSWI)2006In: Science of the Total Environment, ISSN 0048-9697, E-ISSN 1879-1026, Vol. 355, no 1-3, p. 1-12Article in journal (Refereed)
    Abstract [en]

    In autumn 2001, a full-scale test road was built with municipal solid waste incineration (MSWI) bottom ash at the Dåvamyran landfill, Umeå, Northern Sweden. Leachates were collected from asphalted sections with either bottom ash or gravel as filling material. In this research, 12 months of ash leachate sampling were evaluated with respect to emissions of contaminants such as trace metals and chlorides (Cl). The usefulness of regression models describing trace metal mobility from bottom ash was also tested as predictive tools for reusability applications of MSWI bottom ash. Cl, Cu, and Cr had the highest mobility (considering leachate concentrations) in the ash leachate, though concentrations of Cl and Cu decreased during the sampling period (Cl from 10,000 to 600 mg l- 1; Cu from 1600 to 500 μg l- 1). An increased mobility of Cr during the autumns (about 3-4 times higher compared to the summer) was noted with a maximum value of nearly 70 μg l- 1 during autum 2001. Pb showed a very low mobility over the entire year with leachate concentrations of around 3-4 μg l- 1. Chemical equilibrium calculations using Minteq indicated that several Cu minerals were oversaturated in the leachate, thus mineral precipitation could be responsible for declining amounts of Cu in the leachate. Adsorption to iron oxides was found to be a probable explanation for the low mobility of Pb. A reasonably good agreement between regression models and field values were achieved for Ni, Pb, Zn, and Cu, while the models for Cd and Cr were less promising. Even though a large part of the variation (R2 = 61-97%) in the leaching experiment could be explained by only pH and L / S, field data were much more scattered than expected from field pH.

  • 1586. Åberg, J. A.
    et al.
    Weihed, Pär
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Geochemical alteration associated with Au-bearing quartz veins at the Björkdal gold deposit, Skellefte district, northern Sweden1999In: Gold '99 Trondheim: bPrecambrian gold in the Fennoscandian and Ukrainian shields and related areas : abstract volume / [ed] Nigel J. Cook; Krister Sundblad, Trondheim: American Speech-Language-Hearing Association, 1999, p. 173-175Conference paper (Other academic)
  • 1587. Åberg, J. A.
    et al.
    Weihed, Pär
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Petrographic- and chemical characteristics of alteration associated with Au-bearing quartz veins at the Bjorkdal gold deposit, Skellefte District, northern Sweden1999In: Mineral deposits; processes to processing: proceedings of the Fifth biennial SGA meeting and the Tenth quadrennial IAGOD symposium / [ed] C.J. Stanley, Rotterdam: Balkema Publishers, A.A. / Taylor & Francis The Netherlands , 1999, p. 1005-1008Conference paper (Refereed)
  • 1588.
    Åström, Mats E.
    et al.
    Linnaeus University, School of Natural Sciences.
    Österholm, Peter
    Abo Akademi University, Department of Geology.
    Gustafsson, Jon Petter
    Royal Institute of Technology, Department of Land and Water Resources Engineering.
    Nystrand, Miriam
    Abo Akademi University, Department of Geology.
    Peltola, Pasi
    Linnaeus University, School of Natural Sciences.
    Nordmyr, Linda
    Linnaeus University, School of Natural Sciences.
    Boman, Anton
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Attenuation of rare earth elements in a boreal estuary2012In: Geochimica et Cosmochimica Acta, ISSN 0016-7037, E-ISSN 1872-9533, Vol. 96, p. 105-119Article in journal (Refereed)
    Abstract [en]

    This study focuses on attenuation of rare earth elements (REE) when a boreal creek, acidified and loaded with REE and other metals as a result of wetland drainage, empties into a brackish-water estuary (salinity < 6 ‰). Surface water was collected in a transect from the creek mouth to the outer estuary, and settling (particulate) material in sediment traps moored at selected locations in the estuary. Ultrafiltration, high-resolution ICP-MS and modeling were applied on the waters, and a variety of chemical reagents were used to extract metals from the settling material. Aluminium, Fe and REE transported by the acidic creek were extensively removed in the inner/central estuary where the acidic water was neutralised, whereas Mn was relatively persistent in solution and thus redistributed to particles and deposited further down the estuary. The REE removal was caused by several contemporary mechanisms: co-precipitation with oxyhydroxides (mainly Al but also Fe), complexation with flocculating humic substances and sorption to suspended particles. Down estuary the dissolved REE pool, remaining after removal, was fractionated: the <1kDa pool became depleted in the middle REE and the colloidal (0.45 μm (1kDa) pool depleted in the middle and heavy REE. This fractionation was controlled by the removal process, such that those REE with highest affinity for the settling particles became most depleted in the remaining dissolved pool. Modeling, based on Visual MINTEQ version 3.0 and the Stockholm Humic Model after revision and updating, predicted that the dissolved (<0.45 μm) REE pool in the estuary is bound almost entirely to humic substances. Acid sulphate soils, the source of the REE and other metals in the creek water, are widespread on coastal plains worldwide and therefore the REE attenuation patterns and mechanisms identified in the studied estuary are relevant for recognition of similar geochemical processes and conditions in a variety of coastal locations.

  • 1589.
    Åström, M.E.
    et al.
    Kalmar University, School of Natural Sciences.
    Boman, Anton
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Fröjdö, S.
    Abo Akademi University, Department of Geology.
    Fast iron sulfide oxidation in a region of land uplift and artificial drainage2011Conference paper (Other academic)
  • 1590.
    Ödman, Fredrik
    et al.
    Luleå tekniska universitet.
    Ruth, Thomas
    Analytica AB, Box 511, SE-183 25 Täby.
    Rodushkin, Ilya
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Ponter, Christer
    Analytica AB.
    Validation of a field filtration technique for characterization of suspended particulate matter from freshwater: Part II. Minor, trace and ultra trace elements2006In: Applied Geochemistry, ISSN 0883-2927, E-ISSN 1872-9134, Vol. 21, no 12, p. 2112-2134Article in journal (Refereed)
    Abstract [en]

    A field filtration method for the concentration and separation of suspended particulate matter (SPM) from freshwater systems and the subsequent determination of minor, trace and ultra trace elements (As, Ba, Be, Cd, Co, Cr, Cs, Cu, Ga, Hf, Mo, Nb, Ni, Pb, Rb, Sb, Sc, Sn, Sr, Ta, Th, Tl, U, V, W, Zn and Zr) is validated with respect to detection limits, precision and bias. The validation comprises the whole procedure including filtration, sample digestion and instrumental analysis. The method includes two digestion procedures (microwave acid digestion and alkali fusion) in combination with inductively coupled plasma atomic emission spectrometry (ICP-AES) and inductively coupled plasma quadrupole mass spectrometry (ICP-QMS). Total concentrations of these 27 trace and minor elements have been determined in suspended particulate matter (SPM) from lake and river water with low levels of suspended solids (

  • 1591.
    Öhlander, Björn
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    A molybdenite province in Norrbotten and Västerbotten, northern Sweden1983In: Geologiska föreningens i Stockholm förhandlingar, ISSN 0016-786X, Vol. 105, no 3, p. 229-234Article in journal (Refereed)
    Abstract [en]

    During the period 1967-1980 private prospectors recovered 122 molybdenite mineralized samples from Norrbotten and Vsterbotten, northern Sweden, representing acid igneous rocks of intrusive character, including quartz veins, supracrustal rocks of predominantly acid volcanic origin and skarns. The molybdenite occurrences are generally confined to the Proterozoic continental domain north of the Skellefte district. Fifty-six of the molybdenite samples from different rock types were analysed for major elements and 13 trace elements. Tin is, besides molybdenum, the only element enriched in all rock types. The molybdenite mineralized samples are poor in Nb, not enriched in Rb, and show occasionally high concentrations of F and Cu.

  • 1592.
    Öhlander, Björn
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Geochemical analyses of rocks of the Haparanda suite, northern Sweden1984In: Geologiska föreningens i Stockholm förhandlingar, ISSN 0016-786X, Vol. 105, no 2, p. 167-169Article in journal (Refereed)
    Abstract [en]

    Thirteen samples of the primorogenic Haparanda suite (gabbro to granodiorite) in northernmost Sweden were analysed for major elements and the trace elements Rb, Sr, Ba, Cu, Zn, Mo, Sn, Be, Nb, Y, Zr, Cr, Ni, V, F, Cl and S. The results accord with the view that the Haparanda suite is an I-type rock suite generated in a compressional environment. The Sn-content is higher than expected, but Sn, Mo and Be are not enriched in the most silicic samples. The F-content is higher in gabbros and Mo is correlated with Cu. -B.L.

  • 1593.
    Öhlander, Björn
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Geochemical characteristics of granites associated with molybdenite mineralization in northern Sweden1984In: Abstracts / 16e Nordiska geologiska vintermötet, Stockholm 9-13 januari 1984, Stockholm: Stockholm: Institutionen för musik- och teatervetenskap, Stockholms universitet, 1984, p. 251-Conference paper (Other academic)
  • 1594.
    Öhlander, Björn
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Geochemical characteristics of granites associated with Proterozoic molybdenite mineralization in northern Sweden1985In: Chemical Geology, ISSN 0009-2541, E-ISSN 1872-6836, Vol. 51, no 3-4, p. 247-263Article in journal (Refereed)
    Abstract [en]

    Proterozoic molybdenite occurrences in northern Sweden are associated with small plutons of intrusive character located in supracrustal belts whereas large granite areas are barren. In this study, 152 samples of granites associated with molybdenite mineralization, mineralized aplites, granites not known to be associated with molybdenite occurrences but located in supracrustal belts and granites from the large granite areas have been analysed for major elements and the selected trace elements Mo, Sn, Be, Ba, Rb, Sr, Cu, Zn, Zr, V, Y, Nb, F, Cl and S. The study showed that major-element geochemistry and modal composition are not useful for distinguishing between potentially molybdenite-mineralizing and barren granites in northern Sweden. Enriched contents of Sn, Be, Y, Rb and F are most useful for identifying ore-associated granites in the supracrustal belts. The granites from the large granite areas have very low contents of Sn, Mo, Be, Nb, Y, F, Cl and S. It is proposed that the granites associated with molybdenite occurrences were probably generated by partial melting of earlier igneous rocks, or they may be of subcrustal origin, the large granite bodies originated by partial melting of Archean continental crust.

  • 1595.
    Öhlander, Björn
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Geochemistry of Proterozoic molybdenite - mineralized aplites in Northern Sweden1985In: Mineralium Deposita, ISSN 0026-4598, E-ISSN 1432-1866, Vol. 20, no 4, p. 241-248Article in journal (Refereed)
    Abstract [en]

    The largest known Precambrian molybdenite occurrences in Sweden are of the aplitic type. In order to improve the understanding of their genesis, 67 samples of aplites, aplitic granites and associated granites were analyzed for major elements, Mo, Sn, Be, Ba, Rb, Sr, Cu, Zn, Zr, V, Cr, Ni, Y, Nb, F, Cl and S. Five samples were analyzed for rare earth elements. The following genetic model can be proposed: In the upper parts of granitic intrusions the magma is enriched in lithophile elements and elements such as F and Mo. The aplites represent direct differentiation products of the granites and have solidified without the development of a second mobile aqueous phase, except locally, where small pegmatite segregations have formed. As crystallization proceeds, the concentration of Mo in the magma increases, and when the aplites solidify, the Mo that cannot be incorporated in the rock-forming minerals is precipitated as molybdenite. Biotite seems to be the major Mo-carrier among the rock-forming minerals in the aplites.

  • 1596.
    Öhlander, Björn
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Geochemistry of the Fellingsbro type granites, Sweden1987In: Proterozoic geochemistry: abstracts, Lund June 3-6 1987, IGCP , 1987, p. 67-68Conference paper (Other academic)
  • 1597.
    Öhlander, Björn
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Geological setting, tectonic control and REE geochemistry of Proterozoic Mo and W occurrences in northern Sweden1987In: Vol. 17, no 4, p. 643-Article in journal (Other academic)
  • 1598.
    Öhlander, Björn
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Geological setting, tectonic control and REE geochemistry of Proterozoic W occurrences in northern Sweden1987In: Vol. 17, no 4, p. 643-Article in journal (Other academic)
  • 1599.
    Öhlander, Björn
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Lantanoidmönstret i några Mo-och W-förekomster i norra Sverige1986In: Abstracts: 17e Nordiska geologmötet, Helsingfors universitet, 12-15.5. 1986, 1986, p. 286-Conference paper (Other academic)
  • 1600.
    Öhlander, Björn
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Proterozoic molybdenite mineralization in northern Sweden1983Doctoral thesis, comprehensive summary (Other academic)
293031323334 1551 - 1600 of 1660
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