Quantitative reconstruction of climatic variations during the Bronze and early Iron ages based on pollen and lake-level data in the NW Alps, France

Michel Magny (1) , Odile Peyron (1) , Emilie Gauthier (1) , Y. Rouèche (1) , A. Bordon (1) , Yves Billaud (2) , Emmanuel Chapron (3, 4) , A. Marguet (2) , P. Petrequin (1) , Boris Vannière (1)

1 LCE - Laboratoire Chrono-environnement (UMR 6249)
2 DRASSM - Département des Recherches Archéologiques Subaquatiques et Sous-Marines [Marseille]
3 ISTO - Institut des Sciences de la Terre d'Orléans
4 ETH Zürich - Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology [Zürich]

Vegetation and lake-level data from the archaeological site of Tresserve, on the eastern shore of Lake Le Bourget (Savoie, France), are used to provide quantitative estimates of climatic variables over the period 4000-2300 cal BP in the northern French Pre-Alps, and to examine the possible impact of climatic changes on societies of the Bronze and early Iron Ages. The results obtained indicate that phases of higher lake level at 3500-3100 and 2750-2350 cal BP coincided with major climate reversals in the North Atlantic area. In west-central Europe, they were marked by cooler and wetter conditions. These two successive events may have affected ancient agricultural communities in west-central Europe by provoking harvest failures, more particularly due to increasing precipitation during the growing season. However, archaeological data in the region of Franche-Comté (Jura Mountains, eastern France) show a general expansion of population density from the middle Bronze Age to the early Iron Age. This suggests a relative emancipation of proto-historic societies from climatic conditions, probably in relation to the spread of new modes of social and economic organisation.

Domaines: Interfaces continentales, environnement; Milieux et Changements globaux

Michel Magny, Odile Peyron, Emilie Gauthier, Y. Rouèche, A. Bordon, et al.. Quantitative reconstruction of climatic variations during the Bronze and early Iron ages based on pollen and lake-level data in the NW Alps, France. Quaternary International, 2009, 200, pp.102-110. ⟨10.1016/j.quaint.2008.03.011⟩. ⟨insu-00446344⟩