Review of Paleoproterozoic tectonics in the southern West African Craton: Insights from multi-disciplinary data integration

Abstract

For over a century, research has focused on the southern West African Craton (sWAC), aiming to unravel its lithological, geochemical, geochronological, structural, metamorphic, and metallogenic record. Yet, the late Siderian to early Rhyacian (c. 2350–2265 Ma) geodynamic setting of the sWAC remains poorly constrained due to (i) the unresolved configuration of adjacent Archean blocks; (ii) limited geochronological data for the lowermost stratigraphic units; and (iii) extensive overprinting by subsequent magmatic, tectonic, and thermal events. Using a multidisciplinary data integration approach, it is however possible to conduct the analysis of tectonic processes governing the emplacement of the Paleoproterozoic granite-greenstone belts of West Africa.

In this review, we integrate all available published datasets and knowledge to provide new insights on the late Siderian to Rhyacian tectonic evolution of the sWAC. This data compilation is presented and discussed in the form of key time slices (c. 2350–2265 Ma, 2265–2200 Ma, 2200–2135 Ma, 2135–2120 Ma, 2120–2095 Ma and 2095–2060 Ma), which mark evolutionary stages in the geological history of the region. The results of our analysis support the shift from enigmatic Archean tectonic modes to plate tectonics, with the onset of subduction at c. 2265 Ma.

However, critical knowledge gaps remain, particularly regarding the tectonic significance of greenstone belts and the role of the West African Craton in potential configurations of the Eburnean–Transamazonian Orogen during the assembly of Nuna. To address these issues, future research directions are proposed to conclude this synthesis.