O01_01

Holocene glacier chronologies from various cosmogenic nuclides combined with radiocarbon dating

Schimmelpfennig I¹, Charton J¹, Jomelli V¹, Schaefer J², Lamp J², Godard V¹, Bard E¹

¹Aix Marseille Univ, CNRS, IRD, INRAE, CEREGE, Aix En Provence, France, ²LDEO, Columbia University, Palisades, USA

This presentation deals with the reconstruction of Holocene glacier advances and retreats using cosmogenic nuclide dating of glacial landforms in combination with radiocarbon-dates in various glacier forefields. One site is Steingletscher (Central European Alps, Northern mid-latitudes), where we applied the emerging approach of paired ¹⁰Be-¹⁴C dating of recently deglaciated bedrock to constrain the duration of Holocene glacier recession. Combining the results with the ¹⁰Be moraine chronology and existing radiocarbon dates of organic material from the same site allowed reconstructing the glacier’s Holocene retreat and advance history (Schimmelpfennig et al., Clim. Past 18, 23-44, 2022). Large glacier extents prevailed in the Earliest and the Late Holocene, while in between significant retreat occurred during several millennia, which is in agreement with existing glacier chronologies in the Alps and other parts of the North-Atlantic region as well as in the Tropics (Jomelli et al., Nat. Comm. 13, 1419, 2022).

Another site is Ampere glacier on the basaltic Kerguelen archipelago in the Southern mid-latitudes. We reconstructed the Holocene behavior of this glacier, using ³⁶Cl dating of moraines and paired bedrock and erratic boulder surfaces (Charton et al., QSR 283, 107461, 2022). The results, combined with earlier published radiocarbon-dates of peat, imply that glaciers had significantly retracted extents throughout the Holocene, while Holocene maximum extents occurred only in the last millennium. This pattern is quasi-unique and highlights the non-uniformity of Holocene glacier behavior throughout southern mid-latitudes.