Sökning: "West African Craton"

Hittade 4 uppsatser innehållade orden West African Craton.

  1. 1. Internal geology and emplacement processes of Kimberlites, Case Study from the Tsabong Kimberlite Field, Botswana

    Master-uppsats, Luleå tekniska universitet/Geovetenskap och miljöteknik

    Författare :Mpho Ndebele; [2020]
    Nyckelord :Kimberlites; Geology; Emplacement Processes; Botswana;

    Sammanfattning : The Crateceous (85 Ma) MK1 pipe is part of the Tsabong kimberlite cluster located approximately550km south west of Gaborone and geologically found within the Kapvaal Craton. The Tsabongkimberlite field consists of 86 known kimberlites. The MK1 pipe is the largest of this cluster at 140ha,1. LÄS MER

  3. 2. The Birimian event in the Baoulé Mossi domain (West African Craton) : regional and global context

    Master-uppsats, Lunds universitet/Geologiska institutionen

    Författare :Mikael Grenholm; [2014]
    Nyckelord :accretionary orogen; Atlantica; Birimian event; supercontinent cycle; Lomagundi-Jatuli event; Earth and Environmental Sciences;

    Sammanfattning : The crystalline basement of the West African Craton (WAC) was established during the Siderian to Orosirian (circa 2.35-1.95 Ga) Birimian event through accretion of extensive tracts of juvenile crust that was tectonically juxtaposed with Archean cratons. LÄS MER

  4. 3. U-Pb, O and Lu-Hf isotope ratios of detrital zircon from Ghana, West-African Craton : formation of juvenile, Palaeoproterozoic crust

    Master-uppsats, Lunds universitet/Geologiska institutionen

    Författare :Bára Dröfn Kristinsdóttir; [2013]
    Nyckelord :Hf-Model ages; West African Craton; detrital zircon; Ghana; crustal growth; Earth and Environmental Sciences;

    Sammanfattning : Detrital zircon were sampled from five rivers in Ghana and they were analysed in situ for U-Th-Pb, O and Lu-Hf isotopes. Based on the analyses, their U-Pb crystallisation ages, δ18O isotope ratio, εHf and Hf-model ages were determined. This provides information about the origin and crustal evolution of the Palaeoproterozoic bedrock in Ghana. LÄS MER

  5. 4. Petrology of Birimian granitoids in southern Ghana : petrography and petrogenesis

    Kandidat-uppsats, Lunds universitet/Geologiska institutionen

    Författare :Mikael Grenholm; [2011]
    Nyckelord :Ghana; Birimian; granitoids; subduction; TTG; water-saturated melting; transcurrent deformation; Earth and Environmental Sciences;

    Sammanfattning : Den Paleoproterozoiska Birimiska terrinen består av vulkaniska och sedimentära bergarter i grönstensbälten och metasedimentära bassänger som har blivit intruderade av två generationer granitoider. Den Birimiska terrinen utgör en stor del av den västafrikanska kratonen. LÄS MER