The University of Arizona

Refining the Sarliève Paleolake (France) Neolithic Chronology by Combining Several Radiocarbon Approaches

Christine Hatté, Jean-Gabriel Bréhéret, Jérémy Jacob, Jacqueline Argant, Jean-Jacques Macaire

Abstract


Dating sedimentary series spanning the past few tens of thousands of years is often problematic due to the quality of radiocarbon data obtained from organic matter (OM), including bulk OM. This problem recently arose when establishing the chronology of a sediment infill at the Sarliève paleolake (French Massif Central). In the studied section of the cores that covers the Neolithic, Ruppia seeds yielded consistent ages for the lower part (7195 ± 75 to 6050 ± 60 yr BP). A reservoir age of 82 ± 42 14C yr was estimated through the comparison of ages derived from charcoal, Ruppia seeds, and charophyte oogonia sampled on a single level. The upper part of the cores lacks macrofossils and bulk OM dating yields unusable data because of a significant contribution of aged OM derived from the Oligocene substratum in the catchment. We therefore performed dating of lipids extracted from the sediments. The age of the lipids was 2880 ± 30 yr BP near the top of the section, i.e. much younger than the age estimated from previous correlations based on pollen assemblages. These new data call into question previous paleoenvironmental interpretations. The combined dating methodology used for the Neolithic series of Sarliève is a rather uncommon approach that may help to refine chronologies of Holocene sedimentary series.

DOI: 10.2458/azu_js_rc.55.16106


Keywords


geochronology; lacustrine record; macroremain; lipid fraction

Full Text:

PDF