When the desert was a lake: Tectonics, climate, river piracy and hominids in the Kalahari

The Okavango rift zone/delta and the Makgadikgadi paleo-megalake form a dynamic system in northern Kalahari, where tectonic activity, climate change, sedimentation, and biota have interacted in a complex pattern. Previous research suggested that the region may have been a hotspot for hominid evolution. Here we present results from the first scientific deep drilling project (OKAMAK) in the northern Kalahari, Botswana. Two drill cores, OKA (230 meters) and MAK (210 m), were drilled in the Okavango delta and Makgadikgadi paleolake. Cores recovered shallow and deep-water sands, muds and evaporitic lithologies of the Cenozoic Kalahari Group extending across the unconformity into the Cretaceous/Jurassic Karoo Group sandstones. We discuss initial stratigraphy, chronologies and paleoenvironmental information for this novel sedimentary record, present hypotheses to be tested on the complex climate of the region, history of river piracy, evolution of the delta and infilling phases of Makgadikgadi and assess the international collaborative potential of this yet to be fully understood region within a future multi- platform ICDP-IODP initiative.