Late-glacial and holocene climate reconstruction as inferred from a stalagmite - grotte du Père Noël, Han-sur-Lesse, Belgium

The 64.5 cm long Pere Noel stalagmite PN-95-5 was deposited between 12.9 ka and 1.8 ka (U-series dated) with an uncertainty on the ages of the order of ca. 100 years. Besides changes in the macroscopic aspect of the stalagmite along its longitudinal section, changes in its isotopic (δ18O and δ13C) and chemical (Sr/Ca, Mg/Ca) composition are observed. These changes, combined with changes in stalagmite diameter are interpreted in terms of changes in climate in the Han-sur-Lesse region. This multi-proxy approach based on previous studies of the chemical and isotopic functioning of the cave suggests a generally wet early Holocene, important and rapid dry-wet changes around 8.5 ka, a wetter and warmer period between 7.9 ka and 6.6 ka and a dry and/or colder climate after 6.6 ka. This preliminary interpretation from the Pere Noel speleothem should be further tested against other speleothems and other archives to construct a regional climate model for the Holocene.