The Chew Bahir Coring Project: Climate-vegetation feedbacks during the African Humid Period in the southern Ethiopian Rift

点击翻译按钮获取中文摘要

We propose to obtain up to ten replicate ca. 15-20 meter long continuous sediment cores along a north-south and an east-west transect through the Chew Bahir basin, Southern Ethiopian Rift These cores presumably include the deposits of the African Humid Period (~15 to 5 kyrs BP) providing us with information about the last dry-wet-dry cycle and associated environmental variations in East Africa. The analysis of these cores will provide the necessary information about sedimentary processes in the Chew Bahir as required for detailed planning of deeper drilling in the Southern Ethiopian Rift within the framework of the ICDP Hominid Sites and Paleolakes Drilling Project project. The first objective is to study the type and character of sediment in the basin, in particular with respect to the organic matter including pollen and biomarkers. The second objective is to determine the sedimentation rates and its variation in the Chew Bahir based on a high-resolution AMS 14C chronology on parallel carbonate and charcoal samples to estimate possible reservoir effects. The third objective is to test controversially-discussed hypotheses about the timing, magnitude and synchronicity of the African Humid Period across the continent including the possible abruptness and internal variability of this event and the influence of this important dry-wet-dry shift in the tropics on the biosphere.