Holocene Paleoenvironmental and Paleoclimatic Changes in North Cameroon: The Ngaoundaba Peat Record

Summary In this study, we investigate a 6-meter peat core from the NGaoundaba peatland (Northeastern Cameroon) covering almost 10 ka using bulk geochemical data and a large panel of biomarkers [Isoprenoid and branched glycerol-dialkyl-glycerol-tetraethers (isoGDGT and brGDGT respectively), n-alkanes, hopanoids and degradation products of plants]. Recent peat-specific temperature and pH calibrations based on brGDGTs ( Naafs et al., 2017 ) were applied to the NGaoundaba peatland stratigraphic record. GDGT-based temperature and pH are coherent with insolation variation ( Berger, 1981 ) and with pollen-based records from Lake MBalang ( Vincens et al., 2010 ), situated 20 km to the north of NGaoundaba. The recent peat-specific hopane-based pH calibration ( Inglis et al., 2018 ) was applied to the NGaoundaba record. Hopane and GDGT-based pH estimates present strikingly similar variations, raising new perspectives about potential brGDGT origins.