Sökning: "plagioclase"

Visar resultat 1 - 5 av 17 avhandlingar innehållade ordet plagioclase.

  1. 1. Deformation behaviour and chemical signatures of anorthosites: : Examples from southern West Greenland and south-central Sweden

    Författare :Henrik Svahnberg; Sandra Piazolo; Anders Scherstén; Holger Stünitz; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; anorthosite; plagioclase; deformation; strain localisation; fluid-rock interaction; electron backscatter diffraction EBSD ; Solid earth geology and petrology; Berggrundsgeologi och petrologi; Mineralogy; Petrology and Geochemistry; mineralogi; petrologi och geokemi;

    Sammanfattning : Plagioclase is the most abundant mineral in the lower crust and it is thus important to constrain the behaviour of plagioclase during deformation. Anorthosites, which are plagioclase-rich rocks, are common in Archaean cratons but their origin and rheological importance is still debated. LÄS MER

  3. 2. Magma plumbing architecture in Indonesia and the North Atlantic Igneous Province

    Författare :Börje Dahrén; Valentin R Troll; Abigail K. Barker; Steffi Burchardt; Ben Ellis; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; magma plumbing; geothermobarometry; plagioclase; clinopyroxene; magma-crust interaction; hazard mitigation; Geovetenskap med inriktning mot mineralogi; petrologi och tektonik; Earth Science with specialization in Mineral Chemistry; Petrology and Tectonics;

    Sammanfattning : Magma plumbing systems represent the physical framework of magma transport and storage from the source region in the mantle, through the crust, until reaching the surface in a volcanic eruption. Characterising the different aspects of magma plumbing, in particular the distribution of magma storage zones throughout the crust, is of key importance to better understand the behaviour of individual volcanoes. LÄS MER

  4. 3. Crystal chemistry of Fe-Ti oxides in mafic rocks and metabasites: A study aimed at refinement of geological tools and interpretations

    Författare :Benyam Estifanos; Berggrundsgeologi; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Fe-Ti oxide; hercynite; siderite; stilpnomelane; olivine corona; Swedish Caledonides; hysteresis; PIXE; synchrotron XRD; Rietveld; microprobe; red corundum; palaeomagnetism; eclogite; plagioclase clouding; dolerite; pyroxene gneiss; Geology; physical geography; Geologi; fysisk geografi;

    Sammanfattning : This thesis consists of four subprojects: (A) ‘Clouding of plagioclase by Fe-Ti oxides’, (B) ‘Fe-Ti oxides during high-pressure metamorphism of mafic rocks’, (C) ‘Magnetic study of Fe-Ti oxides in mafic rocks and metabasites’, and (D) ‘Topotactic phase transitions in oxide minerals’. A) In southern Sweden dolerite dikes and gabbros with clouded plagioclase are common. LÄS MER

  5. 4. Vaikijaur, a palaeoproteroic Cu-Au porphyry style mineralization in the Jokkmokk granitoid at the archaean-proterozoic boundary in northern Sweden

    Författare :Christina Lundmark; Luleå tekniska universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Malmgeologi; Ore Geology;

    Sammanfattning : The Jokkmokk granitoid is exposed in a plutonic massif northwest of Jokkmokk in northern Norrbotten. It is light grey to white, fine-grained, with megacrysts of feldspar and glomeroporphyritic hornblende and biotite. Small enclaves of mafic rocks and synplutonic mafic dykes are products of mingling with a coeval and possibly cogenetic mafic magma. LÄS MER

  7. 5. Berggrundsmorfologiska studier över kustslätten och Norrlandsterrängen inom delar av Umeå kommun, norra Norrland

    Författare :Karel Miškovský; Umeå universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Precambrian bedrock; Fennoscandia; morphology; Umeå; weathering processes;

    Sammanfattning : The aim of this studv is to investigate interrelationships betweenbedrock relief and geological material. The area of investigation covers ca 350 km and is located in the Precambrian bedrock in the central part of Umeå commune, in northern Norrland. LÄS MER