Tectonic evolution of the Central Steep Zone, Axum area, northern Ethiopia: inferences from magnetic and geochemical data

Northern Ethiopia's Central Steep Zone (CSZ) reveals critical insights into the tectonic evolution of the Arabian–Nubian Shield during Gondwana assembly. This 10 km-wide, high-strain belt exhibits NE-trending foliations and vertical lineations, indicative of transpressive kinematics and a positive flower structure. Magnetic fabric analysis and geochemical data highlight mafic rock assemblages with ocean-floor characteristics, including amphibolite and serpentinite, subjected to metamorphic conditions (680 °C, 3.4 kbar). A post-deformation monzonite intrusion suggests partial melting of these mafic rocks. The CSZ extends over 200 km into Eritrea's Nafka terrane, forming a major structure during the closure of the Mozambique Ocean. This study deciphers the complex strain and deformation patterns, offering new perspectives on the collision tectonics shaping this UNESCO World Heritage Site.

De Wall, H., Dietl, C., Jungmann, O., Tegene, A. T., & Pandit, M. K. (2011). Tectonic evolution of the Central Steep Zone, Axum area, northern Ethiopia: inferences from magnetic and geochemical data. Geological Society, London, Special Publications, 357(1), 85–106. https://doi.org/10.1144/sp357.6