Contrasted Late Glacial and Holocene hydrology of Sarliève paleolake (France) from sediment geometry and detrital versus biochemical composition - Archive ouverte HAL Access content directly
Journal Articles Journal of Paleolimnology Year : 2009

Contrasted Late Glacial and Holocene hydrology of Sarliève paleolake (France) from sediment geometry and detrital versus biochemical composition

(1) , (1) , (1)
1

Abstract

Since the end of the Last Glacial Maximum, hydrology in Europe has been influenced by both climate changes, and since Neolithic times, an increase in human activity. Paleohydrological reconstructions, especially from lake studies, can help identify the respective impact of these two factors. The present work focuses on a lacustrine geosystem, the Sarlie`ve paleolake in the Massif Central (France), in an unusually dry, temperate area. The lake sediment geometry (core drillings, geotechnical methods), and the geochemical and mineralogical characterization of the catchment rocks and soils, and of the lacustrine deposits, indicate major variations in paleohydrology during the last 12,000 years as dated by 14C, palynology and tephrochronology. In addition, a model quantifying detrital versus biochemical lacustrine components was developed to identify hydrological trends. The data show that the Sarlie`ve area was characterized mainly by remarkably dry conditions, hence sharpening the climatic trends at middle latitudes in Western Europe. Three main hydrological phases are distinguished since the Late Glacial: (1) 13.7–7.5 ka cal BP, a dominant dry climate, with a peak at ca. 8 ka cal BP, leading to a lowstand in water level and unusual mineral authigenesis, zeolite then dolomite, constituting up to 60% of the lacustrine sediments; (2) 7.5 to ca. 5.3 ka cal BP, repeated shortduration hydrological alternations that could have been climate-driven: lowstands in water level with up to 60% biochemical minerals versus higher water levels with\10% biochemical minerals; (3) 5.3 ka cal BP to the Middle Ages (i.e. beginning in the 5th century AD), a hydrological trend towards perennial high water level, with mainly detrital sediments, probably linked to climate evolution, except periods of obvious humandriven drying during the last two millennia.
Fichier principal
Vignette du fichier
Fourmont-JPaleolimnology-2009.pdf (716.47 Ko) Télécharger le fichier
Origin : Files produced by the author(s)
Loading...

Dates and versions

insu-00403897 , version 1 (08-09-2009)

Identifiers

Cite

Agathe Fourmont, Jean-Jacques Macaire, Jean-Gabriel Bréhéret. Contrasted Late Glacial and Holocene hydrology of Sarliève paleolake (France) from sediment geometry and detrital versus biochemical composition. Journal of Paleolimnology, 2009, 41 (3), pp.471-490. ⟨10.1007/s10933-008-9238-y⟩. ⟨insu-00403897⟩
119 View
348 Download

Altmetric

Share

Gmail Facebook Twitter LinkedIn More