Sökning: "BALTIC SHIELD"

Visar resultat 11 - 15 av 20 avhandlingar innehållade orden BALTIC SHIELD.

  1. 11. Sveconorwegian orogenesis in the southwestern Baltic Shield - Zircon geochronology and tectonothermal setting of orthogneisses in SW Sweden

    Författare :Jenny Andersson; Berggrundsgeologi; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Petrology; Geologi; fysisk geografi; physical geography; Geology; structural markers; augen gneiss; orthogneiss; migmatite; ion microprobe; Pb-Pb evaporation; U-Pb; geochronology; zircon; Sweden; Mylonite Zone; Western Segment; Sveconorwegian orogen; Eastern Segment; mineralogy; geochemistry; Petrologi; mineralogi; geokemi;

    Sammanfattning : The Mylonite zone (MZ) is a prominent late-Sveconorwegian lithological terrane boundary in the SW Baltic Shield along which large-scale crustal block movements took place during the Sveconorwegian orogeny. The southern section of the MZ also defines a conspicuous metamorphic break separating upper amphibolite and high-pressure granulite facies rocks in the parautochthonous Eastern Segment (ES), from middle amphibolite facies rocks in the overlying Western Segment (WS). LÄS MER

  3. 12. Seismic structure of the central Svecofennian lithosphere

    Författare :Sebastian Buntin; Alireza Malehmir; Christopher Juhlin; Michał Malinowski; Raymond Durrheim; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Wide-angle reflection refraction seismic; near-vertical incidence seismic; Moho; crust-mantle boundary; saucer-shaped sill; BABEL; FENNOLORA; UPPLAND; Fennoscandian Shield; Bergslagen; Uppland Batholith; Geofysik med inriktning mot fasta jordens fysik; Geophysics with specialization in Solid Earth Physics;

    Sammanfattning : Lithospheric structures in the Fennoscandian Shield in Sweden have been studied by a number of large-scale wide-angle seismic reflection/refraction (WARR) and normal-incidence reflection profiles since the 1960s. Among these were the over 2000 km long Fennoscandian Long Range (FENNOLORA) project in 1979 and the Baltic and Bothnian Echoes from the Lithosphere (BABEL) in 1989, which provided valuable images of the subsurface down to over 60 km depth including the Moho. LÄS MER

  4. 13. Dynamic Source Models of Icelandic Earthquakes and Teleseismic Tomograhy along the TOR array

    Författare :Z. Hossein Shomali; Göran Ekström; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Earth sciences; Geovetenskap; Earth sciences; Geovetenskap; Geofysik med inriktning mot seismologi; Geophysics with specialization in Seismology;

    Sammanfattning : This thesis describes new inversion-oriented methodological developments and their seismological applications. In the first study presented the dynamic source parameters of some local Icelandic earthquakes are studied by employing a time domain moment tensor inversion method. LÄS MER

  5. 14. Seismic tomography : Inversion for P- and S-wave velocities

    Författare :Ari Tryggvason; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Earth sciences; Geovetenskap; Earth sciences; Geovetenskap; Geofysik med inriktning mot seismologi; Geophysics with specialization in Seismology;

    Sammanfattning : Seismology is undoubtedly the most powerful method for determining the structure of the Earth below the deepest borehole. This thesis describes the, use of seismic signals from both man-made and earthquake sources to model seismic velocities within a volume of the Earth. LÄS MER

  7. 15. U-Pb geochronology of tectonothermal events related to the Rodinia and Gondwana supercontinents -observations from Antarctica and Baltica

    Författare :Oskar Paulsson; Berggrundsgeologi; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; klimatologi; pedology; climatology; Fysisk geografi; geomorfologi; marklära; kartografi; geomorphology; Physical geography; Gondwana; Rodinia; Antarctica; Baltica; Dronning Maud Land; cartography;

    Sammanfattning : This thesis presents data from two areas, Dronning Maud Land, Antarctica, and the Scandinavian Caledonides, Baltica. In addition, a comparative geochronological study is presented. The bedrock of Dronning Maud Land (DML) is dominated by migmatitic gneisses and post-tectonic intrusions. LÄS MER