Probing the edge of the West African Craton: a first seismic glimpse from Niger

摘要: Constraints on crustal and mantle structure of the Eastern part West African Craton have to date been scarce. Here we present results P receiver function SK(K)S wave splitting analyses data recorded at International Monitoring System array TORD in SW Niger. Despite lacking lateral coverage, our measurements sharply constrain thickness (∼41 km), VP∕VS ratio (1.69 ± 0.03), transition zone (MTZ) (∼247 a midlithospheric discontinuity ∼67 km depth. Splitting delay times are low with an average 0.63 0.01 s. Fast directions follow regional surface geological trend 57 1 ◦ . We suggest that is due fossil anisotropic fabrics crust lithosphere, incurred during Paleoproterozoic Eburnean Orogeny, possible contributions from later Pan-African Orogeny present-day flow. The MTZ appears be unperturbed, despite proximity sampled region deep cratonic root.