Crustal structure beneath southern Africa and its implications for the formation and evolution of the Kaapvaal and Zimbabwe cratons

The formation of Archean crust appears to in- volve processes unique to early earth history. Initial results from receiver function analysis of crustal structure beneath 81 broadband stations deployed across southern Africa re- vealsignicantdierences inthenatureof thecrustandthe crust-mantle boundary between Archean and post-Archean geologic terranes. With the notable exception of the colli- sional Limpopo belt, where the crust is thick and the Moho complex, the crust beneath undisturbed Archean craton is typically thin ( 35{40 km), unlayered, and characterized byastrongvelocitycontrastacrossarelativelysharpMoho. Thiscrustalstructurecontrastsmarkedlywiththatbeneath post-ArcheanterranesandbeneathArcheanregionsaected bylarge-scaleProterozoicevents(theBushveldcomplexand the Okwa/Magondi belts), where the crust tends to be rel- atively thick (45{50 km) and the Moho is complex.