Millennial-scale climate variability during the Last Interglacial recorded in a speleothem from south-western France

A stalagmite (BDinf) recovered from an archaeological cave (Bourgeois–Delaunay, La Chaise de Vouthon) in SW France provides a rare, high-resolution, precisely dated continental palaeoclimate record covering the warmest part of the Last Interglacial (128 ± 1–121 ± 1 ka). The growth interval spans the pluvial period recorded in Soreq and Peqiin Cave speleothems (during sapropel event S5), suggesting that the eastern Mediterranean and western Europe experienced relatively wet conditions simultaneously during this part of the Last Interglacial. Stable oxygen and carbon isotope ratios from BDinf show prominent millennial-scale variations, which are interpreted respectively in terms of changes in the amount of rainfall reaching the cave and soil biological activity. The timing of the oxygen isotope changes agrees with similar excursions recorded in speleothems from Corchia Cave (Italy), where close coupling between rainfall amount and regional sea surface temperatures has been demonstrated. Three “warmer–wetter” periods are interspersed with four “cooler–drier” periods. The first “warmer–wetter” period is the most prominent, as is the case at Corchia, and coincides with the SST optimum off western Europe. This is followed by a prominent “cooler–drier” excursion (centred on ∼126 ka), which can be linked to a period of increased loess deposition recorded in annually laminated lake sediments from Eifel, Germany. Although there is already ample evidence for Last Interglacial climate instability, we show for the first time that specific climatic events occurred more or less synchronously between southwestern Europe, central Mediterranean (Italy) and northern Europe (Germany).