Western Mediterranean climate and environment since Marine Isotope Stage 3: a 50,000-year record from Lake Banyoles, Spain

Abstract

We present new stable isotope (δ 18 O calcite and δ 13 C calcite ) and diatom data from a 67-m sediment core (BAN II) from Lake Banyoles, northeastern Spain. We reassessed the chronology of the sequence by correlating stable isotope data with a shorter U-series-dated record from the lake, confirming a sedimentological offset between the two cores and demonstrating that BAN II spans Marine Isotope Stages (MIS) 3 to 1. Through comparison with previous records, the multi-proxy data are used to improve understanding of palaeolimnological dynamics and, by inference, western Mediterranean climate and environmental change during the past ca. 50,000 years. Three main zones, defined by isotope and diatom data, correspond to the MIS. The basal zone (MIS 3) is characterised by fluctuating δ 18 O calcite and benthic diatom abundance, indicating a high degree of environmental and climate variability, concomitant with large lake-level changes. During the full glacial (MIS 2), relatively constant δ 18 O calcite and a poorly preserved planktonicdominated diatom assemblage suggest stability, and intermittently, unusually high lake level.In MIS 1, δ 18 O calcite and δ 13 C calcite initially transition to lower values, recording a pattern of Late Glacial to Holocene change that is similar to other Mediterranean records. This study suggests that Lake Banyoles responds limnologically to changes in the North Atlantic oceanatmosphere system and provides an important dataset from the Iberian Peninsula, a region in need of longer-term records that can be used to correlate between marine and terrestrial archives, and between the western and eastern Mediterranean.4

The climate and vegetation of Europe, North Africa and the Middle East during the Last Glacial Maximum (21,000 years BP) based on pollen data

“…They also represent semi-quantitative data at best, with changes often described relative to the modern or other baseline. There are few lake level records available north of the Alps, but to the south, many records indicate high lake levels in areas such as Spain (Lacey et al, 2016;Moreno et al, 2012;Vegas et al, 2010), Italy (Belis et al, 1999Giraudi, 2017), Greece and Turkey (Harrison et al, 1996;Reimer et al, 2009) and the Middle East (Kolodny et al, 2005;Lev et al, 2019). These lake records are also supported by evidence of higher river levels in Morocco (El Amrani et al, 2008).…”

Absolute Chronology at the Waterlogged Site of La Draga (Lake Banyoles, Ne Iberia): Bayesian Chronological Models Integrating Tree-Ring Measurement, Radiocarbon Dates and Micro-Stratigraphical Data

“…Geomorphological and sedimentary history of Lake Banyoles has always been really very active and complex (Valero-Garcés et al 1998;Höbig et al 2012;Lacey et al 2016) and it would have affected human activites at their changing shores. The end of La Draga's First Occupation and the suggested abandonment of the site for some years can be explained by a combination of environmental changes that occurred on the shores of Lake Banyoles because of intense forest exploitation and the geomorphological evolution of the shoreline which also affected the ground near the lake.…”