La séquence sédimentaire des Gravanches / Gerzat : enregistrement d’événements « catastrophiques » à valeur chronologique en Limagne d’Auvergne (Massif Central, France)

A sedimentary sequence from the Gravanches/Gerzat area in the Limagne d'Auvergne, France, reveals a series of catastrophic events that provide precise chronological markers for the region. These include seven volcanic ash layers (téphras) linked to the Chaîne des Puys, seismic deposits, and evidence of a potential cosmic event ('Niveau Rouge'). The sequence spans from the Late Glacial to the Subatlantic period, with key dates such as 13,500 cal. BP for CF1a/CF1b, 12,064 ± 316 cal. BP for CF3, and 7,741 ± 74 cal. BP for the 'Niveau Rouge'. Additionally, dark humic deposits ('terres noires de Limagne') are dated between the Boreal period (CF7 téphra) and the 4th/5th century CE, marking a regional humid crisis. This study combines archaeological data with tephrochronology to establish a robust chronological framework for palustrine sequences in Grande Limagne.

Vernet, G. (2013). La séquence sédimentaire des Gravanches / Gerzat : enregistrement d’événements « catastrophiques » à valeur chronologique en Limagne d’Auvergne (Massif Central, France). Quaternaire, vol. 24/2, 99–107. https://doi.org/10.4000/quaternaire.6519