Essays about: "Birimian"

Found 4 essays containing the word Birimian.

  1. 1. Understanding igneous processes through zircon trace element systematics : prospects and pitfalls

    University essay from Lunds universitet/Geologiska institutionen

    Author : Marín Ósk Hafnadóttir; [2014]
    Keywords : plagioclase fractionation. zirkon; hydrothermal alteration; precambrian; zircon; Ghana; hydrotermal-omvandling; plagioklasfraktionering; Earth and Environmental Sciences;

    Abstract : Zirkon från magmatiska bergarter extraherades från fem granitoider i Birimianterrängen i Ghana., och detritala zirkoner provtogs från sex platser i centrala Västgrönland. Av dessa härrör en population från palaeoproterozoikum i Prøvens magmatiska komplex. READ MORE

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

    University essay from Lunds universitet/Geologiska institutionen

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

    Abstract : 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. READ MORE

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

    University essay from Lunds universitet/Geologiska institutionen

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

    Abstract : 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. READ MORE

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

    University essay from Lunds universitet/Geologiska institutionen

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

    Abstract : 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. READ MORE