Climate Change in Western Africa during the early evolution of modern humans

Applying high-resolution downhole logging data to decode the lake Bosumtwi (Ghana) as a climate archive

For several decades, eastern Africa was considered the cradle of anatomically modern humans. Recently, deep roots of Homo sapiens have been also confirmed for West Africa. This indicates a pan-African evolution. Especially for the western part of the African continent, we lack long, continuous and well-dated records of climate- and environmental change in high resolution. This limits our understanding of possible influences of such changes to the proposed evolution of anatomically modern humans across Africa. In this regard, the preliminary results from the ~294 m lacustrine sediment sequence of Lake Bosumtwi, encompassing the last ~1.1 Ma, clearly highlight its potential to provide the thus far missing climatic benchmark record in Western Africa. To decipher the climatic evolution during the last ~1.1 Ma in this area, we propose to use the high-resolution downhole logging data (natural gamma ray) from core logging from Lake Bosumtwi Site 5, which is situated in the centre of the lake. The robustness of this record will be underpinned by using other downhole logs and core data as reference. Finally, we will place our findings in the context of western African paleoclimate and marine reference datasets.