Unified Mapping of the African Rift System: Lithospheric Strength and Magmatic Evolution

The interaction between mantle plumes and continental lithosphere results in a complex spectrum of rifting outcomes, ranging from magma-rich breakups to failed rifts. Current research in the Turkana Depression posits a "Refractory Paradox," suggesting that failed rifts like the Anza Graben remain "dead zones" because prior melting events extracted volatiles, leaving behind a mechanically strong, dried-out lithosphere resistant to modification. However, it remains unclear if this "baked-dry" signature is a global requirement for rift failure or a local anomaly. We investigate this hypothesis by mapping the subtle architectural differences—specifically Moho sharpness and seismic lid preservation—that distinguish magma-poor regions from their magma-rich counterparts. To overcome the limitations of standard receiver function (RF) analysis, which is often degraded by noise and reverberations, we apply a rigorous, high-resolution workflow. We first denoise seismic data using the CRISP-RF algorithm, employing sparsity-promoting Radon transforms to suppress incoherent noise while preserving full-wavefield phases. These clean data are then inverted alongside surface wave dispersion measurements using a transdimensional probabilistic Bayesian  framework. This approach allows us to quantify non-uniqueness and robustly constrain multi-layered crustal properties (Vp/Vs ratios) and lithospheric velocity structure without placing limiting assumptions on elastic properties. By integrating these refined seismic constraints with common-conversion-point (CCP) stacking, we resolve the trade-off between magmatic underplating (gradational Moho, Vp/Vs > 1.8) and tectonic thinning (sharp Moho, Vp/Vs ~1.74). Finally, we pair these structural observations with thermo-chemical modeling (WINTERC-G/PerPleX) to convert velocities into temperature and composition. This study aims to determine if the lithospheric strength beneath the African Rift is governed by volatile depletion or alternative weakening mechanisms, such as anisotropy or eclogitization.