New insights into the climate of northern Iberia during the Younger Dryas and Holocene: The Mendukilo multi-speleothem record

Recent hydroclimate studies on the Iberian Peninsula have shown a complex regional pattern in timing and intensity of climate change spanning the Younger Dryas and the Holocene. These changes are due to multifaceted interactions between climate variability that characterizes the Atlantic Ocean region and hydroclimatic processes associated with the Mediterranean climate, thus making it difficult to recon-struct centennial-and millennial-scale variability in rainfall. In this study we present a composite and continuous isotopic record (813C and 818O) consisting of four stalagmites from Mendukilo cave (MEN composite) in the western Pyrenees covering the Younger Dryas and the entire Holocene. This record reveals millennial-scale shifts in carbon isotopes in response to changes in the hydroclimate in the northern part of Iberia. The MEN oxygen isotopes show little variation on millenial time scales but reveal centennial changes that correlate with North Atlantic events (e.g., the 8.2 kyr BP cooling event). We observe a delay in the onset of humid conditions in the early Holocene and a subsequent trend towards drier and colder conditions between 6.0 and 2.5 kyr BP. This new, high-resolution and replicated spe-leothem record denotes the complex connection that exists between the North Atlantic and Western Europe during last millennia and the strong regional heterogeneity of the hydroclimate of Iberia during this time.(c) 2023 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).

Automated summary

This study utilized stalagmite samples from Mendukilo Cave to investigate the hydroclimate changes in the northern part of Iberia. Carbon isotopes revealed millennial-scale shifts in response to hydroclimate changes, while oxygen isotopes showed variations correlated with North Atlantic events. The findings indicated a delay in the onset of humid conditions in the early Holocene and a subsequent trend towards drier and colder conditions between 6.0 and 2.5 kyr BP. This high-resolution speleothem record demonstrated the complex connection between the North Atlantic and Western Europe during the last millennia and the regional heterogeneity of Iberia's hydroclimate.