Browsing by Author "Shifotoka, Gerhard Mekondjo Naatangwe"

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    The geology, geochemistry, and geochronology of proterozoic gneisses in the Lüderitz area, southern Namibia: insights into the evolution of the NW Namaqua Metamorphic Province
    (University of the Western Cape, 2025) Shifotoka, Gerhard Mekondjo Naatangwe
    The basement rocks of the Lüderitz area, SW Namibia are dominated by migmatitic metavolcanic and intrusive gneisses that resemble those of the Paleoproterozoic Richtersveld Magmatic Arc (~1890 Ma; RMA; of the Namaqua Natal Metamorphic Province (NNMP)). Detailed geological mapping, geochemistry, isotopic and geochronological analysis was undertaken to establish a new, modern lithostratigraphy for the area and to determine whether the Lüderitz gneisses indeed form part of the RMA. The mafic, andesitic and dacitic metavolcanic gneisses (1876 ± 9 Ma) are grouped in the Albatrosskop Formation and occur as rafts within the coeval orthogneisses (1918-1855 Ma). Six main types of orthogneiss were mapped, namely: the Kolmanskop Migmatite, Adventure Bay metagabbro-metadiorite, the Radford Bay, Kowisberg and Albatross Bay granodiorite-granite gneisses and the Elizabeth Point leucogranite gneiss. The volcanic and plutonic rocks are overlain by the Dagger Rocks Group that yielded a youngest detrital grain age of 1731 ± 46 Ma. The supracrustal and plutonic rocks were strongly deformed and metamorphosed during the polyphase Mesoproterozoic Namaqua Orogeny.