ABSTRACT
Togo is dominated by S-N and SSW-NNE (north of 9°N) striking tectonic structures of Late Proterozoic age (Togo Mountains, in Benin: Atacora chain). This zone is interpreted as a collision event by continental plate convergence and overthrusting with a western and north-western direction affiliated with the West African Craton (Panafrican Orogeny, ~610-550 Ma). For many years the crossing of the predominately quarzitic escarpments (600-800 m asl) between the south and the north of Togo caused severe infrastructure problems. Due to long and narrow, steep and winding mountain roads many heavy-duty trucks accidents occured at the Alédjo fault and the Défalé Pass. As Togo became in recent years a transit country to the landlocked Hinterland (‘Gateway to the Sahel’ for Burkina Faso, Niger, Mali), connecting the deep water port in the capital Lomé with the international border into Burkina Faso, the National Road 1 is an important international link that has sustainably been developed. Between 2012-2015 two bypass roads were built by the China Road and Bridge Cooperation (CRBC) to ease the ’bottleneck’ at the Aledjo fault and the Défalé Pass. The bypass roads were surveyed in detail and routing was critically discussed. Due to large openings and road cuts, new insights into the geology and geomorphology of the Atacora structural unit in Togo became possible. Aspects of marine morphodynamics (coastal erosion) due to the port extension in Lomé, and also perspectives of the reconstruction of railway infrastructure instead of road traffic are discussed.
