Abstract
This study aims to provide new insights into the lithotectonic evolution of the Buem structural unit (BSU), its relationship to the Pharusian suture zone (PSZ) as well as the significance of the BSU in the Pan-African Dahomeyide belt at the south-eastern margin of the West African Craton (WAC) and to a larger extent the West Gondwana Orogen (WGO) along the eastern margins of the WAC and Amazonian Craton. To achieve this, integrated studies, involving field mapping, detailed petrographic and structural analyses, processing of airborne geophysical data, geochemical analysis including radiogenic isotope, and geochronological studies, were done. A new lithotectonic map for the BSU was produced from field data and interpretation of regional airborne geophysical data. Rocks of the BSU include, from bottom to top: intercalated slate and metasandstone, serpentinised peridotite, gabbro, volcanic rocks, including pillow and massive lavas and pyroclastic rocks, chert, carbonate, and sandstones with shale interbeds. Integrated field mapping and interpretation of regional aeromagnetic and airborne radiometric data together with Shuttle Radar Topography Mission (SRTM 3) data reveal that the mafic-ultramafic rocks occur as tectonic slices within the BSU and mark the major thrust planes between the BSU and Togo structural unit, and BSU and Voltaian Supergroup...
D.Phil. (Geology)