East African mid-Holocene wet–dry transition recorded in palaeo-shorelines of Lake Turkana, northern Kenya Rift

摘要: Abstract The ‘wet’ early to mid-Holocene of tropical Africa, with its enhanced monsoon, ended an abrupt shift toward drier conditions and was ultimately replaced by a climate that has persisted until the present day. forcing mechanisms, timing, spatial extent this major climatic transition are not well understood remain subject ongoing research. We have used detailed palaeo-shoreline record from Lake Turkana (Kenya) decipher characterise marked in East Africa. high-precision survey well-preserved palaeo-shorelines, new radiocarbon ages shoreline deposits, oxygen-isotope measurements on freshwater mollusk shells elucidate Holocene moisture history former lake water-levels climatically sensitive region. In combination previously published data our study shows during water-level high overflowed temporarily into White Nile drainage system. During (~ 5270 ± 300 cal. yr BP), however, fell ~ 50 m, coeval episodes aridity African continent. A comparison between palaeo-hydrological archaeological Basin suggests associated fundamental changes prehistoric cultures, highlighting significance natural variability periods protracted drought as environmental stress factors affecting human occupation Rift System.