Bittner, L., Bliedtner, M., Grady, D., Gil-Romera, G., Martin-Jones, C., Lemma, B., Mekonnen, B., Lamb, H. F., Yang, H., Glaser, B., Szidat, S., Salazar, G., Rose, N. L., Opgenoorth, L., Miehe, G., Zech, W., Zech, M., Heisenberg Chair of Physical Geography with Focus on Paleoenvironmental Research, Institute of Geography, Technical University of Dresden, Dresden, Germany, Department of Physical Geography, Institute of Geography, Friedrich-Schiller-University Jena, Jena, Germany, Department of Geography and Earth Sciences, Aberystwyth University, Aberystwyth, UK, Department of Geo-Environmental Processes and Global Change, CSIC, Pyrenean Institute of Ecology, Zaragoza, Spain, Limnology Unit, Department of Biology, Ghent University, Gent, Belgium, Institute of Agronomy and Nutritional Sciences, Soil Biogeochemistry, Martin-Luther-Universität Halle-Wittenberg, Halle, Germany, Environmental Change Research Centre, University College London, London, UK, Department of Chemistry and Biochemistry and Oeschger Centre for Climate Change Research, University of Bern, Bern, Switzerland, Department of Geography, University of Marburg, Marburg, Germany, Institute of Soil Science and Soil Geography, University of Bayreuth, Bayreuth, Germany, Bittner, L [0000-0003-2521-5596], Apollo - University of Cambridge Repository, and Bittner, L. [0000-0003-2521-5596]
Previous paleolimnological studies demonstrated that the sediments of Garba Guracha, situated at 3950 m asl in the afro-alpine zone of the Bale Mountains of Ethiopia, provide a complete Late Glacial and Holocene paleoclimate and environmental archive. We revisited Garba Guracha in order to retrieve new sediment cores and to apply new environmental proxies, e.g. charcoal, diatoms, biomarkers, and stable isotopes. Our chronology is established using 210Pb dating and radiocarbon dating of bulk sedimentary organic matter, bulk n-alkanes, and charcoal. Although bedrock was not reached during coring, basal ages confirm that sedimentation started at the earliest ~ 16 cal kyr BP. The absence of a systematic age offset for the n-alkanes suggests that “pre-aging” is not a prominent issue in this lake, which is characterised by a very small afro-alpine catchment. X-ray fluorescence scans and total organic carbon contents show a prominent transition from minerogenic to organic-rich sediments around 11 cal kyr BP coinciding with the Holocene onset. While an unambiguous terrestrial versus aquatic source identification seems challenging, the n-alkane-based Paq proxy, TOC/N ratios, δ13C values, and the sugar biomarker patterns suggest a predominantly autochthonous organic matter source. Supraregional climate events, such as the African Humid Period, the Younger Dryas (YD), a 6.5 cal kyr BP short drying event, and the 4.2 cal kyr BP transition to overall drier climate are recorded in our archive. The Garba Guracha record suggests that northern hemisphere forcings played a role in the Eastern African highland paleoclimate., Deutsche Forschungsgemeinschaft http://dx.doi.org/10.13039/501100001659