Changements hydrologiques holocènes enregistrés sur le site de la station IX du grand lac de Clairvaux (Jura, France) Reconstruction of holocène palaeohydrological changes at station IX, grand lac de Clairvaux (Jura, France)

摘要

Trenches excavated for the construction of a camping place on the south-eastern shore of the grand lac de Clairvaux have given the opportunity to observe and sample a sediment sequence documenting lake-level changes from 6300 to 1500 14C yr BP It shows an alternation of peaty layers corresponding to low lake levels at ca 63 10, 4925, 4585-3520, 3000-2885, 21 10 et 1680-1475 14C yr BP, and carbonate deposit layers recording high lake levels. These lacustrine carbonate sediments also include allochthonous detritic components suggesting, that the phases of higher lake level coincided with an increase in run-off and erosion processes on the slopes surrounding the lake. The palaeohydrological changes reconstructed at station IX agree with the regional phases of changes in lake level defined from lake sediment-sequences in the Jura mountains, the northern French Pre-Alps and in the Swiss Plateau.