Temporal patterns in lacustrine stable isotopes as evidence for climate change during the late glacial in the Southern European Alps

• Published in: Journal of Paleolimnology
• Main Authors: Finsinger, Walter, Belis, Claudio, Blockley, Simon, Eicher, Ueli, Leuenberger, Markus, Lotter, André, Ammann, Brigitta
• Other Authors: Laboratory of Palaeobotany and Palynology, Utrecht University Utrecht, Research Laboratory for Archaeology and the History of Art Oxford, University of Oxford Oxford, Climate and Environmental Physics Bern (CEP), Physikalisches Institut Bern, Universität Bern Bern -Universität Bern Bern, Institute of Plant Sciences, University of Bern
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2008
• Subjects: Stable isotopes; Ostracods; Climate; Pollen analysis; Lateglacial; vegetation dynamics; Laacher See Tephra; Italy; Alps; Europe; geo; envir; North Atlantic
• Online Access: https://doi.org/10.1007/s10933-008-9205-7; https://hal.archives-ouvertes.fr/hal-01845846

International audience We investigated oxygen and carbon isotopes of bulk carbonate and of benthic freshwater ostracods (Candona candida) in a sediment core of Lago Piccolo di Avigliana that was previously analyzed for pollen and loss-on-ignition, in order to reconstruct environmental changes during the late glacial and early Holocene. The depth–age relationship of the sediment core was established using 14 AMS 14C dates and the Laacher See Tephra. While stable isotopes of bulk carbonates may have been affected by detrital input and, therefore, only indirectly reflect climatic changes, isotopes measured on ostracod shells provide unambiguous evidence for major environmental changes. Oxygen isotope ratios of ostracod shells (δ18OC) increased by ∼6‰ at the onset of the Bølling (∼14,650 cal BP) and were ∼2‰ lower during the Younger Dryas (∼12,850 to 11,650 cal BP), indicating a temporal pattern of climate changes similar to the North Atlantic region. However, in contrast to records in that region, δ18OC gradually decreased during the early Holocene, suggesting that compared to the Younger Dryas more humid conditions occurred and that the lake received gradually increasing input of 18O-depleted groundwater or river water.