Sökning: "magma plumbing systems"

Visar resultat 6 - 8 av 8 avhandlingar innehållade orden magma plumbing systems.

  1. 6. Dynamic Modelling of Physical Processes in Magmatic Systems: Dyke Emplacement and Flow-Induced Crystal Rotations

    Författare :Rémi Vachon; Christoph F. Hieronymus; Janine Kavanagh; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Numerical solutions; elasticity and anelesticity; fracturing; magmatic plumbing system; sheet-like intrusions; rheology of the crust; physics of magma; solid mechanics; fluid flow; crystal rotation;

    Sammanfattning : The main motivation for this thesis is to develop and improve numerical tools and methods that help further our comprehension of the volcanic plumbing system and its dynamics.The commonly used standard elastic model predicts solutions of dyke shape, thickness, over-pressure and fracturing criteria that do not always fit natural observations. LÄS MER

  3. 7. 3D Structure and Emplacement of the Alnö Alkaline and Carbonatite Complex, Sweden : Integrated Geophysical and Physical Property Investigations

    Författare :Magnus Andersson; Alireza Malehmir; Valentin R. Troll; Bjarne Almqvist; Odleiv Olesen; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Alnö; carbonatite; caldera; reflection seismic; anisotropy of magnetic susceptibility; gravity; magnetic; Geophysics with specialization in Solid Earth Physics; Geofysik med inriktning mot fasta jordens fysik;

    Sammanfattning : Carbonatites are carbonate-rich magmatic rocks that are rare and of great relevance for our understanding of crustal and mantle processes. Although found on all continents and in settings ranging from Archaean to present-day, their deeper plumbing system is still poorly understood. LÄS MER

  4. 8. U-Pb baddeleyite geochronology of Precambrian mafic dyke swarms and complexes in southern Africa - regional scale extensional events and the origin of the Bushveld Complex

    Författare :Johan Olsson; Berggrundsgeologi; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; U-Pb TIMS geochronology; geochemistry; baddeleyite; mafic dyke swarms; mantle plume; Bushveld Complex; Kaapvaal Craton; Zimbabwe Craton; Archean; Proterozoic;

    Sammanfattning : Dolerite dykes are formed when iron- and magnesium-rich (mafic) mantle-derived magmas ascend through the lithosphere (upper part of the mantle) and crystallize as ‘hydro-fractures’ within the crust. Dykes may exist in great numbers to form dyke swarms (linear or radiating), which can be linked to time periods of continental break-up, or attempted break-up events, associated with voluminous volcanism. LÄS MER