Search for dissertations about: "Geologi"

Showing result 21 - 25 of 536 swedish dissertations containing the word Geologi.

  2. 21. The tectonic evolution of the western part of the Svecofennian orogen, central Sweden : Insight from U/Pb and 40Ar/39Ar geochronology at Forsmark

    Author : Tobias Hermansson; Berggrundsgeologi; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; physical geography; Geology; Svecofennian orogen; Tectonic models; Tectonic cycles; Uplift; Cooling; Ductile deformation; Geochronology; U Pb; 40Ar 39Ar; Geologi; fysisk geografi; Petrology; mineralogy; geochemistry; Petrologi; mineralogi; geokemi;

    Abstract : The Forsmark area, in the western part of the Svecofennian orogen, central Sweden, is situated between two major Palaeoproterozoic tectonic domains that show contrasting histories with respect to timing of igneous activity, ductile deformation and metamorphism. At Forsmark, WNW to NW trending, ductile deformation belts anastomose around tectonic lenses with an inferred lower degree of ductile strain. READ MORE

  4. 22. Geochemical Development of Proterozoic Granites in the SW Baltic Shield

    Author : Kirsten Holme; Berggrundsgeologi; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; principal component analysis; granite classification; magma evolution; magma genesis; granite; Eastern Segment; Western Segment; Southwestern Swedish Gneiss Complex; Sweden; Sveconorwegian Orogen; Petrology; mineralogy; geochemistry; Petrologi; mineralogi; geokemi; Geology; physical geography; Geologi; fysisk geografi;

    Abstract : The plutonic rocks in the Western Segment of the Southwestern Swedish Gneiss Complex show a distinct geochemical evolution. The 1.6 Ga Åmål granitoids and Slottsbron migmatites are a quartz dioritic to granodioritic, calc-alkaline rock suite with smooth, but somewhat fractionated, REE and other trace-element patterns. READ MORE

  5. 23. Pollen analysis, chronology and palaeomagnetism of three Late Weichselian sites in southern Sweden

    Author : Jonas Ising; Kvartärgeologi; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; southern Sweden; calendar year chronology; Late Weichselian; Pollen stratigraphy; palaeomagnetic secular variations; Geology; physical geography; Geologi; fysisk geografi;

    Abstract : Three sites, Torreberga in Skåne, Farslycke in Blekinge and Lake Bolmen in Småland, with Late Weichselian lake sediments were studied with respect to pollen analysis and palaeomagnetism. The chronologies are based on pollen stratigraphical correlations, radiocarbon dating and, for two of the sites, on a clay-varve chronology. READ MORE

  6. 24. The Ups and Downs of the Holocene: Exploring Relationships between Global CO2 and Climate Variability in the North Atlantic Region

    Author : Catherine Jessen; Kvartärgeologi; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; marklära; geomorfologi; climatology; klimatologi; rapid climate change; Holocene climate; atmospheric CO2 concentrations; geochemical proxy indicators; Paleobotanik; palynology; Geology; palynologi; fylogeni; geomorphology; fysisk geografi; Geologi; physical geography; kartografi; pedology; cartography; phylogeny; Palaeobotany; stomatal frequency; lake sediments;

    Abstract : This thesis aimed to examine the relationship between climate and atmospheric CO2 concentrations through rapid climate changes during the Holocene. Climate was reconstructed using high-resolution, radiocarbon dated, lake sediment geochemical proxies (magnetic susceptibility, loss-on-ignition, total carbon/nitrogen/sulphur determinations and biogenic silica), vegetational reconstruction (pollen analysis) and stomatal frequency based CO2 reconstructions. READ MORE

  7. 25. Assessing the reliability of detrital zircon in Early-Earth provenance studies

    Author : Ross Kielman; Martin Whitehouse; Alexander Nemchin; Victoria Pease; Marlina Elburg; Stockholms universitet; []
    Keywords : NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; Geology; geologi;

    Abstract : Our understanding of the Early Earth and the processes that have shaped its evolution have spawned predominantly from the geochemical and isotopic signatures of a small number of zircon populations around the world. Studies of trace element distributions, Hf and O isotope systematics as well as mineral inclusion chemistry in detrital zircon are combined with U-Pb chronology in order to constrain source rock characteristics. READ MORE