Publications

A number of geophysical on-shore and off-shore experiments were carried out in a profile across the southern margin of the African continental in the framework of the Inkaba yeAfrica project. Refraction seismic experiments have shown that the crustal thickness decreases rapidly from over 40 to around 30 km well inland of the present coast, before gently thinning out towards the Agulhas Falkland Fracture Zone, which marks the transition zone between continental and oceanic crust. This is consistent with a non-volcanic mode of breakup due to shear along the Agulhas-Falkland Transform Fault. In region of the abruptly decreasing Moho depth inland from the coast, lower crustal P-wave velocities up to 7.4 km/s are observed. We interpret these to represent metabasic lithologies of the Mesoproterozoic Namaqua-Natal Metamorphic Complex, or intrusions of gabbroic material added to the base of the crust by younger magmatism. This magmatism could be the result of the mid-Jurassic Karoo-Ferrar-Chon Aike event. The velocity model for the upper crust has excellent resolution, and is consistent with the known geological record.

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Stankiewicz, J.; Parsiegla, N.; Ryberg, T.; Gohl, K.; Weckmann, U.; Trumbull, R.; Weber, M. (2008): Crustal structure of Africa's southern margin from geophysical experiments. 13th International Symposium on Deep Seismic Profiling of the Contintents and Their Margins - SEISMIX 2008 (Saariselkä, Inari, Finland 2008).