Towards a high-resolution speleothem fluid inclusion water isotope record for the Holocene from Milandre Cave, Switzerland

Abstract

<p>Speleothem fluid inclusions contain relics of past precipitation water, which constitute a powerful tool for studying the past hydrological cycle. Analyses of hydrogen and oxygen isotopes of the water stored in fluid inclusions allow the reconstruction of paleoclimate information such as temperature. A previous study has shown the potential of speleothems from Milandre Cave to address temperature-related issues such as the so-called “Holocene temperature conundrum”. It additionally shows the main Holocene climate feature such as the cooling occurring at the Younger Dryas or the 8.2 ka event. The mean temporal resolution achieved for the samples is relatively high, with sampling intervals ranging between 10 years for the most recent times and 50-70 years for the early Holocene. Using our new analytical line at the Department of Environmental Sciences at the University of Basel, we aim to increase the temporal resolution of the record by a factor two to four in order to provide highly-resolved water isotope and inferred temperature records for the entire Holocene. The revised Milandre Cave Fluid Inclusion temperature (MC-FIT) allows us to gain more detailed information on shorter scale events such as the 8.2 ka cooling and other prominent Holocene climatic events. The new MC-FIT record, supported by additional speleothems from neighboring caves, allows a better understanding of the central European annual temperature variability during the Holocene.</p>