Sökning: "Geologi"

Visar resultat 11 - 15 av 622 avhandlingar innehållade ordet Geologi.

  1. 11. Stratigraphy and facies of Middle Silurian epicontinental carbonate platform deposits of Gotland, Sweden

    Författare :Mikael Calner; Berggrundsgeologi; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; fysisk geografi; Geologi; Geology; physical geography;

    Sammanfattning : The Silurian foreland of Scandinavia included a vast epicontinental carbonate platform system of which the island of Gotland (Sweden) is an erosional remnant. This thesis treats the Late Wenlock succession (Cyrtograptus lundgreni, Pristiograptus dubius parvus, Gothograptus nassa, Colonograptus(?) praedeubeli, and the Co(?) deubeli zones), and emphasises the sedimentology and biostratigraphy of these deposits. LÄS MER

  3. 12. Tectonic implications of ca. 1.45 Ga granitoid magmatism at the southwestern margin of the East European Craton

    Författare :Audrius Cecys; Berggrundsgeologi; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Geologi; southern Sweden; fysisk geografi; physical geography; Mesoproterozoic; geochemistry; syntectonic; petrology; structural geology; anisotropy of magnetic susceptibility; Danopolonian orogeny; Geology; granite;

    Sammanfattning : Between ca 1.53 and 1.40 Ga, the southwestern margin of the East European Craton was subjected to extensive magmatism and deformation. While various suites of anorthositic, mangeritic and charnockitic-granitic rocks were emplaced between ca. LÄS MER

  4. 13. Nanomagnetic and Micromagnetic Properties of Rocks Minerals and Sulphide Oxidation Products

    Författare :Erik Eneroth; Berggrundsgeologi; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; physical geography; Geology; multi-domain; single-domain; ilmenite; magnetite; maghemite; hematite; pyrite; marcasite; fysisk geografi; Geologi;

    Sammanfattning : Magnetic and related properties of rocks and products from oxidation of sulphide minerals have been investigated with magnetisation measurements (rocks and oxidation products), magnetic force microscopy (rocks), scanning electron microscopy (rocks and oxidation products), transmission electron microscopy (oxidation products), Mössbauer spectroscopy (oxidation products) and powder X-ray diffraction (oxidation products). The investigations have shown the following: During thermal oxidation of pyrite (cubic FeS2) and marcasite (orthorombic FeS2) in air, nano-crystals of a-Fe2O3 and g-Fe2O3 were formed. LÄS MER

  5. 14. Early Palaeozoic jawed polychaetes with focus on polychaetaspids and ramphoprionids from the Silurian of Gotland, Sweden

    Författare :Mats Eriksson; Berggrundsgeologi; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; fysisk geografi; Geologi; physical geography; Geology; chemistry; palaeobiogeography; palaeoecology; taxonomy; apparatus reconstructions; Silurian; Recent; Ordovician; early Palaeozoic; scolecodonts; Annelida; polychaeta;

    Sammanfattning : Jawed polychaete annelid worms were abundant and diverse in the early Palaeozoic seas and their jaws (scolecodonts) are common microfossils in sedimentary rocks of that age. Despite their abundance, relatively little work has been focused on these fossils. LÄS MER

  7. 15. Silurian Carbonate Platforms of Gotland, Sweden - Archives of Local, Regional and Global Environmental Changes

    Författare :Mårten Eriksson; Berggrundsgeologi; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Sedimentologi; Sedimentology; fysisk geografi; Geologi; physical geography; Geology; Gotland; Silurian; Facies; Carbonate platforms; Sequence stratigraphy; Stable isotopes; Palaeoclimate;

    Sammanfattning : This thesis treats the Silurian carbonate platforms of Gotland, Sweden, which formed close to the equator within the East Baltic Basin. Three different time intervals, all involving changes in facies composition and structure of the platforms, have been studied; Late Homerian, latest Homerian ? earliest Gorstian, and late Ludfordian, respectively. LÄS MER