Sökning: "sill"

Visar resultat 1 - 5 av 14 avhandlingar innehållade ordet sill.

  1. 1. Validating the existence of the supercraton Vaalbara in the Mesoarchaean to Palaeoproterozoic

    Författare :Ashley Gumsley; Berggrundsgeologi; []
    Nyckelord :Vaalbara; Kaapvaal Craton; Pilbara Craton; U-Pb geochronology; paleomagnetism; supercontinent; large igneous province; dyke swarm; sill province;

    Sammanfattning : In this thesis, the longevity and continuity of the Vaalbara supercraton is addressed in six papers aimed at placing new temporal and spatial constraints onthe supercraton in the Mesoarchean to Paleoproterozoic. It has been speculated since the 1960’s that the Kaapvaal Craton in southern Africa, together withthe Pilbara Craton in Western Australia existed as a single landmass during the Precambrian – the Vaalbara supercraton. LÄS MER

  3. 2. Crystallization and Differentiation Processes in the Thin Layered Alkali Gabbroic Intrusions of the Ulvö Gabbro Complex, Central Sweden

    Författare :Johan Hogmalm; Göteborgs universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; layered intrusion; fractional crystallization; modal layering; in situ crystallization; Ulvö; saucer-shaped sill; post-cumulus; LA ICP-MS;

    Sammanfattning : Fractional crystallization of magma is a commonly invoked mechanism for chemical differentiation in systems that range from volcanoes to entire planets. However, the processes that control separation of crystals and liquids in natural systems remain controversial, since the dynamics of crystallizing magma chambers cannot be studied directly. LÄS MER

  4. 3. 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

  5. 4. Stability and design of stope roofs and sill pillars in cut-and-fill and open stope mining with application to the Zinkgruvan Mine

    Författare :Jonny Sjöberg; Luleå tekniska universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Mining and Rock Engineering; Gruv- och Berganläggningsteknik;

    Sammanfattning : .... LÄS MER

  7. 5. Magnetic fabrics and paleomagnetism of the Storsjön-Edsbyn deformation zone, central Sweden

    Författare :Håkan Mattsson; Luleå tekniska universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Tillämpad geofysik; Applied Geophysics;

    Sammanfattning : Anisotropy of magnetic susceptibility (AMS) and paleomagnetic data from the Storsjön-Edsbyn Deformation Zone (SEDZ) in central Sweden are presented. The SEDZ is a regional shear zone c. 200km in length that cuts through 1.7-1. LÄS MER