Palaeostress Analysis and Neotectonic Activity in the Younger Granite Province of North Central Nigeria

The Younger Granite Province of North Central Nigeria, dominated by Jurassic ring complexes of the Jos Plateau, is intersected by faults that have been reactivated during Cenozoic and potentially Quaternary tectonic episodes, raising questions about current seismotectonic activity relevant to seismic hazard assessment. This study investigates palaeostress conditions and evidence for neotectonic activity within the Younger Granite Province using fault-slip data inversion and morphotectonic analysis. Fault slip data comprising fault plane orientations and slickenside lineations were collected from forty-two outcrops distributed across five ring complex intrusions. Palaeostress tensors were computed using the direct inversion method implemented in FaultKin software, yielding principal stress orientations and their relative magnitudes for identified stress phases. Morphotectonic analysis employed digital elevation model derivatives including topographic asymmetry index, sinuosity of mountain fronts, and valley floor width-to-height ratio to identify geomorphic signatures of recent tectonic activity. Aerial photograph lineament analysis complemented field structural observations. The study applies Gutenberg-Richter analysis to the available historical earthquake catalogue for North Central Nigeria to assess whether seismicity statistics indicate active faulting at depth. Evidence for late Cenozoic fault reactivation is evaluated against crustal stress orientations derived from the World Stress Map. Results provide a foundation for seismic source characterisation in the North Central region. Keywords: palaeostress, neotectonics, Younger Granite Province, fault-slip inversion, seismotectonics.